The journal of adhesive dentistryOliver Bailey, Frank Pfefferkorn, Thomas Attin, Roland Frankenberger, Bas Loomans, Anne-Katrin Lührs, Nicola Scotti, Diana Wolff, Reinhard Hickel, Niek Opdam
PURPOSE: There is confusion over the indications, techniques, and material choices for placing direct class II composite restorations among general dentists. This paper synthesizes new data on the general frequency of use of materials and techniques by experts, with a previous related paper that explored if and how experts restored specific class II cavities with varying complexities. It aimed to see if consensus on technique and material use when restoring class II cavities with composite could be pursued. These findings are used to inform an overview of various techniques and provide guidance on the management of more complex class II cavities. METHODS: An international expert group (n = 9) developed an e-questionnaire. The first part of the questionnaire, reported here, covered the general frequency of material and technique use during cavity preparation, control of the operating field, soft tissue management, matrix selection, stabilization and peripheral seal, tooth separation, composite materials, application techniques, light curing, finishing, and polishing. It was distributed to 67 international clinicians with expertise in placing direct composite restorations (September 2024). RESULTS: Response rate was 82%, with 95% of responders completing the first part of the survey. There was a wide variation in frequency of use of a broad variety of materials and techniques. CONCLUSIONS: International experts used a wide variety of materials and techniques for restoration of class II cavities with direct composite. Consensus was therefore not pursued. There are many potential techniques which can offer pragmatic solutions to directly restore complex class II cavities that are not beyond general practitioners.
BMC oral healthMohammed Ehab Mohammed Ali Saad, Nahla Hamed Mohamed Hamed, Mohammed Nasser Anwar
OBJECTIVE: To evaluate the effect of different intra‑canal restorative techniques on the fracture resistance of endodontically treated anterior teeth and to assess the influence of marginal ridge loss on their mechanical behavior. MATERIALS AND METHODS: Ninety extracted sound maxillary central and lateral incisors were selected and randomly divided into five groups. Ten teeth were left intact to serve as the control group, while the remaining teeth were endodontically treated, obturated, and randomly allocated into four groups according to different intra‑canal restorative techniques; (1) PS: packable short fiber‑reinforced composite, (2) FP: prefabricated glass fiber posts, (3) FS: flowable short fiber‑reinforced composite, (4) DC: dual‑cure composite core material, each group was further subdivided according to marginal ridge integrity into two subgroups (n = 10), intact marginal ridges (I) and removed marginal ridge (R). All specimens were subjected to thermocycling for 10,000 cycles. Fracture resistance testing was carried out using a universal testing machine with a load applied at 135° to the long axis of the tooth until the fracture occurred. Fracture patterns were examined using a stereomicroscope and classified as favorable and unfavorable fractures. The data were statistically analyzed using two-way ANOVA, followed by Tukey's post hoc test and fracture patterns were analyzed using Fisher's exact test, with the significance level set at α = 0.05. RESULTS: Intra-canal restorative technique and marginal ridge integrity significantly affected fracture resistance (p < 0.05), whereas no significant interaction was observed (p = 0.564). Fiber post restorations demonstrated the highest fracture resistance values. No statistically significant differences were observed among fiber posts, packable short fiber-reinforced composite, and flowable short fiber-reinforced composite under either marginal ridge condition (p > 0.05). Loss of one marginal ridge significantly reduced fracture resistance across all restorative techniques. The fracture pattern was significantly associated with the restorative technique (p = 0.014), with flowable short fiber-reinforced composite showing the highest proportion of favorable fractures. CONCLUSIONS: SFRC intra-canal restorations showed fracture resistance values that were not statistically different from those of fiber post restorations. Marginal ridge loss significantly compromised fracture resistance of endodontically treated anterior teeth. CLINICAL SIGNIFICANCE: SFRC may represent a promising post-free restorative option for endodontically treated anterior teeth when sufficient coronal tooth structure remains, particularly in teeth with preserved marginal ridge integrity. However, long-term clinical studies and fatigue-loading investigations are required before definitive clinical recommendations can be made.
Clinical oral investigationsGulnaz Aydemir, Jale Gorucu, A Ruya Yazici
OBJECTIVES: To compare the 36-month clinical performance of a no-wait universal adhesive in non-carious cervical lesions (NCCLs) according to etching method and application mode. MATERIALS AND METHODS: Forty-one participants with at least five NCCLs received 215 restorations, which were randomly assigned to five groups according to five surface-conditioning and adhesive application protocols: Enamel and dentin etching with phosphoric acid (ED-A), selective enamel etching with phosphoric acid (SEE-A), self-etch (SE; control group), enamel and dentin etching with laser (ED-L), selective enamel etching with laser (SEE-L). Restorations were placed by a single operator using Clearfil Universal Bond Quick and Clearfil Majesty ES-2 and were evaluated at baseline, 6, 12, 18, 24, and 36 months using modified USPHS criteria. Survival was analyzed using Kaplan-Meier survival analysis with the log-rank test, and categorical outcomes were analyzed using Generalized Estimating Equations (GEE) (p < 0.05). RESULTS: The 36-month recall rate was 97.5% (40 participants; 199 restorations). At 36 months, retention loss was greater in the ED-A group than in the SEE-A and SE groups and in the SEE-L group than in the SEE-A and SE groups (p = 0.036 for all comparisons). Marginal discoloration was greater in the SE group than in the ED-A and SEE-A groups (p = 0.022 and p = 0.004, respectively) and in the SEE-L group than in the SEE-A group (p = 0.014). Marginal adaptation was poorer in the SE group than in the ED-A, SEE-A, and ED-L groups (p = 0.001, p = 0.011, and p = 0.013, respectively). Marginal discoloration increased and marginal adaptation deteriorated significantly over time in all groups (p < 0.05). CONCLUSIONS: Phosphoric acid enamel etching provided the most favorable long-term marginal performance, whereas the SE and selective laser etching protocols showed less favorable marginal behavior.
OBJECTIVE: To evaluate the fluorescence compatibility of five resin composite materials in cervical restorations using multiple assessment techniques. MATERIALS AND METHODS: Forty extracted A2 shade human molars were selected, and standardized Class V cavities were prepared on the buccal surfaces. The cavities were restored using five resin composite materials (n = 8). Fluorescence images were obtained using three assessment techniques based on fluorescence illumination: Tech-I (QrayPen C, 405 nm), Tech-II (Valo X with DSLR camera, 395-415 nm), and Tech-III (Ashur device with DSLR camera, 405 nm). Fluorescence differences (ΔE) were calculated using the CIEDE2000 formula. Statistical analyses included one-way ANOVA, Tukey post-hoc test, and Pearson correlation (p < 0.05). RESULTS: Significant differences were observed among composite materials in all techniques (p < 0.001). Filtek Z250XT showed the lowest ΔE values (Tech-I: 3.83 ± 1.39, Tech-II: 3.60 ± 1.11, Tech-III: 3.41 ± 0.69), indicating the best fluorescence compatibility. Conversely, Estelite Asteria exhibited the highest ΔE values (Tech-I: 15.53 ± 3.94, Tech-II: 23.79 ± 2.72, Tech-III: 14.15 ± 2.46). Strong positive correlations were found among the techniques (Tech-I vs. Tech-II: r = 0.707; Tech-I vs. Tech-III: r = 0.774; Tech-II vs. Tech-III: r = 0.880; p < 0.001). CONCLUSION: The fluorescence compatibility of resin composite materials varies significantly depending on the material type. The Filtek Z250XT demonstrated the closest fluorescence compatibility to natural tooth structure. The assessment techniques showed strong agreement under standardized conditions. CLINICAL SIGNIFICANCE: Understanding the fluorescence behavior of composite materials may guide clinicians in selecting appropriate materials for improved esthetic outcomes and clinical performance.
OBJECTIVES: This study evaluated the load-bearing capacity and reliability of different zirconia materials used for inlay-retained fixed dental prostheses (IRFDPs), considering the influence of substrate type (tooth substrate or resin composite) and thermo-mechanical aging. MATERIALS AND METHODS: IRFDPs (N = 160) were fabricated using four zirconia materials: IPS e.max ZirCAD LT (3Y-TZP), Katana YML (3Y-5Y graded zirconia), Katana HTML Plus, and Katana STML (n = 40 each). Restorations were adhesively cemented onto tooth or resin composite substrates and tested either under dry conditions or after thermo-mechanical aging (1,200,000 cycles, 50 N, 5-55 °C). Fracture load was determined using monotonic load-to-fracture testing. Data were analyzed using two-way ANOVA and Tukey's test (α = 0.05). Reliability of durability was assessed using Weibull analysis. RESULTS: Under dry conditions, material (p = 0.0047), substrate (p = 0.0237), and their interaction (p = 0.0004) significantly influenced fracture load. YML-composite (1406 ± 386 N) and HTML-composite (1142 ± 249 N) showed higher values than STML-composite (553 ± 246 N). No significant differences were observed on tooth. substrate After aging, material and interaction effects remained significant (p < 0.05). HTML-tooth showed the highest fracture load (1727 ± 351 N), while STML-composite showed the lowest (718 ± 292 N). Weibull analysis indicated comparable reliability after aging. CONCLUSIONS: Zirconia type and substrate significantly influenced mechanical performance of IRFDPs. High-translucent and graded zirconia showed substrate-dependent behavior, whereas 3Y zirconia was more stable. CLINICAL RELEVANCE: Zirconia selection and bonding substrate influence fracture resistance of IRFDPs. High-translucent zirconia requires careful substrate selection, while 3Y zirconia provides more consistent performance in posterior applications.
OBJECTIVES: This study aimed to compare the 60-month clinical performance of glass hybrid (GH) and short fiber-reinforced composite (SFRC)-supported microhybrid composite restorations placed in MIH-affected first permanent molars following selective caries removal (SCR). MATERIALS AND METHODS: Thirty-one children (18 girls, 13 boys; 6-12 years) with MIH and at least two fully erupted first permanent molars exhibiting moderate-to-severe lesions (MIH-TNI scores 2 and 4) were enrolled. Following SCR, 62 molars were restored using a randomized split-mouth design. In each participant, one molar received a GH restoration (Equia Forte® HT), whereas the other selected molar was restored with an SFRC material (EverX Flow™) covered with a microhybrid composite resin (G-Aenial® Posterior). Clinical evaluations were performed at baseline and 6, 12, 24, 36, and 60 months using modified United States Public Health Service (USPHS) criteria. RESULTS: Clinical performance deteriorated significantly over time for both materials (p < 0.001). GEE analysis showed no significant independent effect of material type on any modified USPHS criterion (p > 0.05), while time significantly affected retention, marginal adaptation, postoperative sensitivity, and secondary caries (p < 0.001). Kaplan-Meier analysis demonstrated significantly higher survival rates for SFRC-supported microhybrid composite than for GH restorations at 60-month (75.5% vs. 59.2%; p = 0.002). CONCLUSIONS: Both GH and SFRC-supported microhybrid composite restorations provided clinically acceptable long-term outcomes in MIH-affected molars after SCR. Although clinical performance per modified USPHS criteria was comparable, SFRC-supported microhybrid composite restorations demonstrated superior long-term survival. CLINICAL RELEVANCE: When long-term durability is a primary consideration, SFRC-supported microhybrid composite restorations may be preferred for the restorative management of MIH-affected molars. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT07733804.
BACKGROUND: STELA is a newly introduced auto-cured bulk-fill composite proposed as an alternative to amalgam. It does not require light activation and provides an unlimited depth of cure, in addition to acceptable esthetic and mechanical properties. OBJECTIVES: To evaluate cuspal displacement, marginal adaptation, and nanoleakage in mesio-occluso-distal (MOD) Class II preparations of maxillary premolars restored with an auto-cured bulk-fill composite compared with a light-cured bulk-fill composite. MATERIALS AND METHODS: Sixty maxillary human premolars extracted for orthodontic purposes were randomly assigned to two groups (n = 30) according to the bulk-fill composite used. Standardized MOD Class II preparations were made and restored using either Group 1: STELA Capsule (SDI, Australia) or Group 2: Tetric N-Ceram Bulk Fill (Ivoclar Vivadent, Liechtenstein). Each group was subdivided into three subgroups (n = 10) based on the test performed. In Subgroup 1, cuspal displacement was recorded after post-cavity preparation and at (5 min, 24 h) post-restoration using a digital microscope. The remaining restored specimens underwent thermocycling and mechanical loading. Subsequently, marginal adaptation (Subgroup 2) was examined using scanning electron microscopy. Nanoleakage (Subgroup 3) was evaluated using silver nitrate tracing. Statistical analysis was performed using the independent-samples t-test and Fisher's exact test (P ≤ 0.05). RESULTS: STELA Capsule demonstrated significantly lower cuspal displacement at both 5 min and 24 h post-restoration compared with Tetric N-Ceram Bulk Fill (P < 0.001). Following thermocycling and mechanical loading, STELA Capsule also exhibited better marginal adaptation (P = 0.033) and reduced nanoleakage (P < 0.001) compared with the Tetric N-Ceram Bulk Fill. CONCLUSIONS: The STELA composite with its dedicated primer showed favorable laboratory outcomes compared with Tetric N-Ceram Bulk Fill used with Tetric N-Bond. This restorative protocol can serve as a viable clinical alternative to light-cured bulk-fill composites, particularly for restoring MOD Class II preparations in maxillary premolars. CLINICAL RELEVANCE: The novel auto-cured bulk-fill composite with its dedicated primer demonstrated excellent performance in reinforcing weakened premolars. It exhibited superior results in reducing cuspal displacement, improving marginal adaptation, and minimizing nanoleakage compared to a light-cured bulk-fill composite, indicating its potential for clinical use.
Lasers in medical scienceDaniele das Graças Silva, Nayra Kamylle Araujo Fernandes Carvalho, Diêgo de Oliveira Camargos, Arthur Henrique Vieira de Almeida, Valder Ferreira da Silva Filh…
This systematic review aimed to evaluate the effectiveness of high-power lasers in the removal of esthetic restorations compared with conventional methods. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and registered in PROSPERO (registration number: CRD420251055736). A comprehensive electronic search was performed in MEDLINE, Scopus, Embase, Web of Science, and the Cochrane Library. Study selection, data extraction, and methodological quality assessment were independently performed by four reviewers using QUIN tool for in vitro studies. A total of 2.384 records were identified, of which 19 in vitro studies conducted on extracted human permanent teeth met the eligibility criteria and were included in the qualitative synthesis. The included studies evaluated different high-power laser systems, predominantly Er: YAG and Er, Cr: YSGG lasers, as well as CO₂ lasers. Five studies were classified as high quality, whereas the remaining fourteen studies were classified as moderate quality. Available laboratory evidence suggests that laser-assisted techniques may represent a potential alternative approach for removing esthetic restorations, with advantages including conservative tissue removal, reduced damage to underlying tooth structures, and intrapulpal temperature increases within acceptable limits. The Er: YAG laser was the most frequently investigated system, with power settings ranging from 1.5 to 5.9 W, showing particularly favorable laboratorial performance in the removal of lithium disilicate restorations, especially in thinner substrates. Within the limitations of the available evidence, high-power lasers appear to be a promising and minimally invasive alternative to conventional methods for the removal of esthetic restorations. However, the predominance of in vitro studies highlights the need for well-designed clinical trials to confirm these findings and support their clinical application.
OBJECTIVES: This study evaluated the reinforcing effect of various core and overlay materials used in bi-layered restorations on the fracture resistance of compromised endodontically treated maxillary premolars with mesio-occluso-distal (MOD) cavities. METHODS: Three core materials were assessed: a packable short fiber-reinforced composite (everX Posterior (EXP)), its flowable counterpart (everX Flow (EXF)), and a dual-cure core material (GRADIA CORE (GC)). Each core material was combined with one of three overlay restorations: an indirect overlay (ID) using CERASMART 270, a direct overlay (D), or a semi-direct overlay (SD) using Gænial A'CHORD. A total of 110 sound maxillary premolars were allocated to 11 groups (n = 10), including a positive (sound teeth) and a negative (endodontically treated teeth restored with direct composite, without cusp reduction) control groups. Standardized endodontic treatment and MOD cavity preparation were performed with 2 mm buccal and palatal cusp reduction. Fracture resistance was assessed using a universal testing machine at a crosshead speed of 1 mm/min. Failure modes were analyzed using Firth's logistic regression model, while fracture resistance was evaluated using two-way ANOVA followed by post hoc tests. The control groups were compared using an independent t-test. Statistical significance was set at p < 0.05. RESULTS: The overlay restoration, Core material, and their interactions significantly influenced fracture resistance (p = 0.043, p < 0.001, and p < 0.001, respectively). Within the direct overlay group, EXP exhibited the highest fracture resistance (1124.61 ± 213.32 N), significantly higher than EXF but not significantly different from GC. EXP also demonstrated relatively high fracture resistance across the tested overlay restorations. EXF exhibited the lowest fracture resistance in the direct overlay group (596.14 ± 171.40); however, in the indirect overlay group, both EXF and GC showed significantly higher values than EXP. No significant differences among core materials were observed in the semi-direct overlay group. Unfavorable failure mode predominated, with no significant differences observed among the experimental groups. CONCLUSIONS: The fracture resistance of bi-layered restorations was significantly influenced by both the core and overlay materials and their interaction. EXP maintained high fracture resistance across various bi-layered restorations, whereas EXF demonstrated technique-dependent performance. The indirect overlay group achieved high fracture resistance, but was not superior to all direct overlay restorations. CLINICAL RELEVANCE: Packable short fiber-reinforced composite, particularly everX Posterior, demonstrated a promising synergistic effect with direct overlay restorations, resulting in fracture resistance comparable to that achieved with high-performance indirect overlay restorations.
BMC oral healthAhmed Adel Naguib Khater, Ahmad Khaled Abo El Fadl, Ingy Nouh
BACKGROUND: Restoration of endodontically treated teeth (ETT) with significant coronal loss poses a challenge in clinical dentistry. Advances in CAD/CAM technology and biomimetic materials have introduced minimally invasive approaches, such as endocrowns and overlays, which can replace traditional post-core and crown approach. AIM: The aim of this in-vitro study was to comparatively assess the mechanical behaviour of two restorative designs (endocrowns and overlays) fabricated from two CAD/CAM materials in endodontically treated mandibular molars. MATERIALS AND METHODS: Thirty-six endodontically treated lower molars (n = 36) were split into two main groups based on restoration type (n = 18): endocrowns and overlays. Each group was further subdivided into two subgroups based on the CAD/CAM material (n = 9): lithium disilicate (Tessera) and indirect composite (Crios). Restorations were fabricated and bonded to their respective specimens following a strict bonding protocol with an adhesive resin cement (Bisco self-adhesive). Thermo-mechanical aging (Chewing Simulator CS-4, SD Mechatronic) was conducted to simulate oral conditions, followed by a universal testing machine's evaluation of fracture resistance. The test was stopped after fracture. Fractured parts were analysed to determine mode of failure. Data were analyzed using two-way ANOVA followed by Tukey's honestly significant difference (HSD) test for pairwise comparisons (α = 0.05). RESULTS: All specimens survived the 5,000 chewing cycles, simulating early intraoral service. Fracture resistance test showed significantly higher fracture resistance for overlays (2048.46 ± 664.63 N) than endocrowns (1234.54 ± 338.50 N) (p = 0.002). Crios overlays exhibited the highest fracture resistance (2384.60 ± 631.10 N), significantly outperforming Tessera overlays (1712.33 ± 559.59 N) (p = 0.043) and endocrowns (1354.20 ± 346.88 N) (p = 0.004). No substantial material change was seen in endocrown restorations (p = 0.445). CONCLUSION: Overlay restorations and indirect composite material (Crios) provide superior resistance to fracture compared to lithium disilicate overlays and endocrowns and may represent a reliable restorative option for endodontically treated molars.
International dental journalFereshteh Shafiei, Zahra Jowkar, Samaneh Sarrafi, Mahshid Mohammadi-Bassir
AIM: This in vitro study evaluated the effects of immediate dentin sealing (IDS) versus delayed dentin sealing (DDS), dentin pretreatment with quercetin (Qu), and their combination on the fracture strength (FS) of diabetic and non-diabetic premolars restored with ceramic inlays after thermomechanical aging. METHODS: Forty-eight extracted premolars from diabetic individuals and forty-eight from non-diabetic individuals were collected and prepared for standardized MOD lithium disilicate ceramic inlays. Each category of teeth was divided into four groups according to the cementation technique (IDS or DDS) and the presence or absence of Qu pretreatment during inlay cementation. For IDS, the same adhesive was applied in combination with a flowable composite. All restored premolars underwent thermomechanical aging followed by FS testing under axial compression. Data were analyzed using three-way ANOVA and t-tests (P = .05). RESULTS: Technique, Qu treatment, diabetes mellitus (DM), and the interactions between DM and Qu (P = .004) and between DM and technique (P = .021) were significant. The interaction among all three factors and the interaction between technique and Qu were not significant. In all groups except DDS/Qu, diabetic premolars exhibited lower FS than non-diabetic premolars (P < .001). IDS resulted in significantly higher FS in both tooth types (P < .001). The positive effect of Qu pretreatment was observed only in diabetic premolars (P < .001). CONCLUSION: In diabetic premolars, IDS and Qu pretreatment substantially enhanced the FS of teeth restored with ceramic inlays, with the greatest improvement observed when both were combined. In non-diabetic premolars, a significant improvement was observed only with IDS. CLINICAL RELEVANCE: Diabetes-related changes in dentin may compromise the performance of adhesive restorations. Understanding the effects of dentin sealing techniques and the potential benefits of Qu may help improve the durability of indirect restorations in patients with diabetes.
Clinical oral investigationsSensen Chen, Yao Chen, Sifan Chen, Changan Chen, Jie Lin
OBJECTIVE: To investigate the effects of onlay materials and resin core thickness on stress distribution in partial coverage restorations under static and thermal loading using finite element analysis (FEA). METHODS: A 3D mandibular first molar model was created from CBCT data. Four materials (zirconia, lithium disilicate [LD], polymer-infiltrated ceramic network [PICN], gold alloy [GA]) and five resin core thicknesses (1 mm to 4 mm, plus full crown control) were tested. A total of 20 models were loaded with 100 N occlusal force and thermal stresses (5-37 °C and 37-55 °C). The distribution characteristics of the maximum principal stress (MPS) were analyzed for different combinations of variables. RESULTS: Under mechanical loading, thin resin cores (1-2 mm) performed best. Increasing thickness to 3 mm sharply raised enamel stress (zirconia: 77.35-80.72 MPa); at 4 mm, restoration stress peaked (zirconia: 150.12 MPa). Zirconia showed highest restoration stress (54.01-150.12 MPa) but lowest dentin stress (5.02-7.70 MPa); PICN had low and most stable restoration stress (55-91 MPa) but highest dentin stress (8-13 MPa). Under high-temperature thermal stress, enamel stress jumped sharply at ≥ 3 mm resin thickness, markedly higher than under low-temperature stress. GA with an extremely thin resin core (1R4O) caused abnormally high dentin stress (50.83 MPa) at low temperature. CONCLUSION: A thin resin core (1-2 mm) offered better overall mechanical performance. Material type markedly influenced stress distribution. High-temperature thermal stress posed a greater threat to tooth structure than low-temperature stress. Thermal stress barely affected periapical/periodontal tissues. CLINICAL RELEVANCE: For extensive MOD restorations, a 2 mm resin core is recommended as the safe threshold. Material selection should balance the protection of the restoration itself and the stress transfer to the tooth structure.
The Journal of forensic odonto-stomatologyThomas Corfield, Denice Higgins
BACKGROUND: The increasing sophistication of restorative materials in replicating natural tooth fluorescence poses a challenge for both antemortem and postmortem dental charting. This study evaluated the efficacy of various discrete excitation wavelengths, including those from common forensic torches, in differentiating modern restorative materials from tooth. METHODS: Conducted within the Institute for Photonics and Advanced Sensing (IPAS) laboratory framework, six extracted human molars and five contemporary A3-shade restorative materials were examined via spectrophotometry across five excitation wavelengths: 266, 300, 365, 395 and 426nm. Canonical Discriminant Analysis (CDA) was applied to Peak Intensity and Peak Emission Wavelength data to quantify the multivariate statistical separation between groups. RESULTS: UV-A wavelengths of 365nm and 395nm produced the most robust group separation. While 365nm excitation produced the highest absolute emission intensities for visual detection, 395nm excitation elicited unique spectral red-shifts in composite resins, providing the highest mathematical discrimination. Visible violet excitation at 426nm was the least reliable differentiator. CONCLUSION: For forensic practitioners, UV-A torches (365-395 nm) remain effective for detecting the tooth-coloured restorations tested here. While 365nm is optimal for rapid visual screening 395nm provides a more distinctive spectral fingerprints for formal characterisation. Despite improved fluorescence matching under visible light, the modern restorative materials tested here retain unique spectral signatures under UV-A illumination, though variable fluorescence intensity influenced detectability and may limit generalisation to other restorations or teeth.
BACKGROUND: Surgical extraction of impacted mandibular third molars is commonly associated with postoperative pain, swelling, and trismus. Conventional rotatory osteotomy, though widely used, may cause thermal and mechanical trauma. Piezosurgery has emerged as a minimally invasive alternative that may improve clinical outcomes and reduce physiological stress, which can be objectively assessed using salivary biomarkers. PURPOSE: To compare acute stress response and clinical efficacy between piezosurgery and conventional rotatory technique in transalveolar extraction of impacted mandibular third molars. STUDY DESIGN, SETTING, SAMPLE: A prospective randomized controlled clinical trial was conducted on 60 patients (aged 19-40 years) requiring transalveolar extraction. Participants were randomly allocated into piezosurgery (n = 30) and conventional rotatory groups (n = 30). PREDICTOR/EXPOSURE: Type of osteotomy technique (piezosurgery vs conventional rotatory). MAIN OUTCOME MEASURES: Primary outcomes were salivary cortisol and salivary alpha-amylase levels. Secondary outcomes included postoperative pain (VAS), facial swelling, mouth opening, duration of surgery, and patient comfort. COVARIATES: Age, gender, impaction difficulty (Pederson's difficulty index), type of impaction, and duration of surgery. ANALYSES: Data were analyzed using an independent t-test with a significance level of p < 0.05. RESULTS: Postoperative pain showed no significant difference between groups (p > 0.05). The piezosurgery group demonstrated significantly reduced postoperative swelling with a mean difference of approximately 2.07 mm (95% CI: -3.21 to -0.93, p = 0.001) and reduced trismus with improved mouth opening (mean difference: 0.31-0.70 cm across time points, 95% CI: approximately 0.19 to 0.88, p < 0.001). Additionally, higher patient comfort scores (mean difference: 0.87, 95% CI: 0.59 to 1.14, p < 0.001) and lower postoperative salivary cortisol and alpha-amylase levels (p < 0.001) were observed in the piezosurgery group. However, surgical duration was significantly longer in the piezosurgery group. CONCLUSIONS AND RELEVANCE: Piezosurgery offers improved postoperative outcomes and reduced physiological stress compared to conventional techniques, despite longer operative time, making it a valuable alternative in third molar surgery.
The American journal of case reportsYaqiong Jiang, Zhikeng Deng, Bo Yao, Xiaohua Liang, Zhaojun Qin
BACKGROUND Treacher Collins syndrome (TCS) is a congenital disorder resulting from maldevelopment of the first and second pharyngeal arches. A major high-risk comorbidity is obstructive sleep apnea (OSA), characterized by recurrent upper airway collapse during sleep, leading to intermittent hypoxia and sleep fragmentation. This condition requires a tailored anesthetic strategy due to an anticipated difficult airway during intubation and increased vulnerability to postoperative respiratory failure. CASE REPORT A 28-year-old man with TCS and polysomnography-confirmed mild OSA underwent orthognathic surgery. Preoperative evaluation included cone-beam computed tomography (CBCT), which objectively quantified retrolingual airway stenosis. After a multidisciplinary briefing, anesthesia was induced with intravenous remimazolam, propofol, sufentanil, and cisatracurium; the airway was secured through videolaryngoscopy-guided nasotracheal intubation. This technique optimized glottic visualization, and controlled induction was feasible because mask ventilation difficulty was not anticipated. The surgical procedure (Le Fort I osteotomy, bilateral sagittal split osteotomy, and genioplasty) was performed to expand the upper airway and correct skeletal deformities. Comparisons of preoperative and postoperative CBCT images and lateral cephalometric radiographs demonstrated clear upper airway expansion and improvement in airway obstruction. Postoperative anesthetic management prioritized a strict opioid-sparing analgesic protocol and monitored extubation, resulting in an uneventful recovery. CONCLUSIONS Management of patients with TCS and OSA during orthognathic surgery relies on a proactive, imaging-informed approach. Key elements include the use of advanced imaging for precise anatomic risk stratification, selection of an intubation technique that provides definitive airway visualization, and implementation of a structured multidisciplinary plan with vigilant postoperative monitoring to mitigate delayed respiratory complications.
Oral health & preventive dentistryCosmin Dima, Raluca Cosgarea
PURPOSE: This paper describes a novel surgical technique (Sinus-Plate Augmentation Method [SPAM]) using autologous sinus plate bone for posterior lateral maxillary augmentation during sinus lifting and dental implant insertion. MATERIALS AND METHODS: Eight partially edentulous patients aged 52-71 years old (7 females, 2 smokers) with severe horizontal alveolar bone resorption in the maxillary posterior areas, were surgically treated as follows: lateral bone augmentation was performed by harvesting the vestibular bone wall of the sinus window and using a xenogeneic bone graft, followed by external sinus lifting and implant insertion. Seven patients were followed-up for 12-18 months, while one patient was followed-up for 36 months. RESULTS: A total of 24 implants were inserted simultaneously with SPAM and sinus lifting. Post-operative healing was uneventful in all cases. Horizontal alveolar bone gain ranged between 9.28±1.2 mm post-operatively and 8.37±1.5 mm at the 19.5-month follow-up. A statistically significant gain in alveolar bone width of 2.55±1.47 mm was present at the follow-up. CONCLUSION: SPAM seems to be a feasible surgical technique for the horizontal reconstruction of moderate to severely resorbed posterior maxillae, concomitant to external sinus lifting and implant insertion.
BMC oral healthJonathan Bertram, Henry Leonhardt, Fred Podmelle, Thomas Teltzrow, Adrian Franke
BACKGROUND: This retrospective cohort study, adhering to STROBE guidelines, compared the accuracy of maxillary positioning achieved with a patient-specific implant (PSI)-based hybrid workflow, which utilised a temporary intermediate splint to identify and remove posterior bony interferences before definitive splintless PSI fixation, to conventional splint-based positioning using stock titanium osteosynthesis plates in orthognathic surgery. Translational and rotational movement deviations from the virtual surgical plan were assessed. METHODS: Twenty-six patients who underwent non-segmental Le Fort I osteotomy between January 2020 and June 2023 were included. Eleven patients received the PSI-based hybrid workflow, while 15 patients underwent conventional splint-based positioning. Group allocation was based on the logistical feasibility of PSI planning and manufacturing rather than randomisation. Pre- and postoperative 3D images were superimposed using IPS® Case Designer software (KLS Martin) to quantify deviations in three translational and three rotational axes. Between-group comparisons were conducted using unpaired t-tests and two-way ANOVA, and correlations were assessed using Pearson's coefficient. RESULTS: The mean translational deviation was significantly lower in the PSI group compared to the control group (0.46 ± 0.33 mm vs 0.79 ± 0.58 mm; p = .0044), as was the mean rotational deviation (0.82° ± 0.91° vs 1.24° ± 0.85°; p = .0397). Significant differences were identified for vertical translation (p = .0162) and yaw rotation (p = .0205). Operating time did not differ significantly between groups (p = . 1739). In the PSI group, greater planned displacement showed a weak correlation with larger deviations, a relationship not observed in the control group. CONCLUSIONS: The PSI-based hybrid workflow resulted in statistically greater positioning accuracy compared to conventional splint-based fixation. However, the absolute improvements (approximately 0.3 mm and 0.5°) were small, likely of limited clinical relevance, and were not associated with reduced operating times. Due to the retrospective, non-randomised design, small sample size, and use of a PSI-based hybrid protocol, these findings should be considered hypothesis-generating. Larger prospective studies evaluating fully splintless PSI workflows and patient-centred outcomes are recommended. CLINICAL TRIAL NUMBER: Not applicable.
OBJECTIVES: This study evaluated the stain susceptibility and color recovery of Giomer and highly filled injectable composite compared with a nano-filled packable composite, using one-step and multi-step polishing systems. METHODS: Ninety composite specimens were prepared from Filtek Z350, Beautifil Flow Plus, and G-ænial Injectable and divided into three polishing subgroups (n = 10): Mylar strip, OneGloss, and Enamel Plus Shiny. After baseline color measurement (T0), the specimens were immersed in coffee at 37 °C for 30 days. Color changes were measured using a Vita EasyshadeV spectrophotometer after brushing using a soft toothbrush (ΔE_brushing; T₁-T₀) and after repolishing using AL203 paste (ΔE_repolishing; T₂-T₀). Data were analyzed using a linear mixed model with Yeo-Johnson transformation and Holm's correction (α = 0.05). RESULTS: A significant interaction was observed among material type, polishing system, and color change (p = 0.020). G-ænial Injectable showed the lowest stain susceptibility (ΔE_brushing = 2.84; ΔE_repolishing = 1.88). Multi-step polishing significantly improved stain resistance for all tested materials. Repolishing significantly reduced discoloration in all groups (p < 0.001) by increasing L* values and reducing shifts in a* and b* coordinates. Among all materials, only the multi-step-polished G-ænial Injectable achieved color change values that approached the acceptability threshold (ΔE₀₀ ≤ 1.8). CONCLUSION: Highly filled injectable composites and multi-step polishing improved stain resistance and color recovery of resin composites, whereas S-PRG fillers and matrix-set surfaces increased stain susceptibility. CLINICAL RELEVANCE: Multi-step polishing enhances esthetics, while repolishing improves restoration longevity.
Brazilian oral researchFrancieli Regina Bortoli, Filipe Colombo Vitali, Marcio Correa, Roberto Rocha, Fabrício Augusto Menegon, Leticia Fernanda Haas, Lucas da Fonseca Roberti Garcia…
This study evaluated the accuracy of digital panoramic radiography, digital periapical radiography, and cone-beam computed tomography (CBCT) in diagnosing apical root resorption (ARR) using 85 extracted teeth from dry human skulls and mandibles. Four ARR levels were simulated: mild, moderate, severe, and extreme. CBCT scans, panoramic radiographs, and periapical radiographs were obtained before and after ARR simulation. Three examiners independently evaluated all images to determine ARR and, when present, to classify its severity level. Inter- and intra-observer agreement was calculated using Cohen's kappa, and sensitivity, specificity, and accuracy were determined for each method. Receiver operating characteristic (ROC) curve analysis was performed to obtain the area under the curve (AUC). AUCs were compared using the DeLong test. All imaging methods showed substantial inter- and intra-examiner agreement (κ > 0.60). CBCT demonstrated the highest sensitivity, specificity, and accuracy, followed by periapical and panoramic radiography. CBCT was significantly superior (p < 0.01) in detecting mild (AUC = 0.939) and moderate (AUC = 0.947) ARR compared with the other methods (AUC < 0.877). For severe ARR, CBCT (AUC = 0.953) and periapical radiography (AUC = 0.921) performed similarly (p > 0.05) and were superior (p=0.03) to panoramic radiography (AUC = 0.874). For extreme ARR, no significant difference was observed among the methods. In conclusion, CBCT showed high accuracy in detecting ARR, particularly at milder levels (< 2 mm). Periapical radiography was comparable to CBCT for severe resorption (one-third of the root), while all methods performed similarly for extreme resorption (half of the root). Thus, CBCT appears most suitable for early ARR detection, whereas periapical and panoramic radiography are adequate for diagnosing advanced stages.
Brazilian dental journalLaryssa Silva da Cunha, Airin Karelys Avendaño Rondon, Maryuri Del Carmen Macias Bautista, Ianca Daniele Oliveira de Jesus, Guilherme Mendonça Benoni, Gisele R…
This observational field study aimed to evaluate the radiant power (mW), emission spectra (mW/cm²/nm), irradiance (mW/cm²), and the light tip integrity of 40 light-curing units (LCUs) used in 16 public oral health service units in the city of Uberlândia, Minas Gerais, Brazil. The radiant power and emission spectrum were measured using a spectrometer attached to an integrating sphere. Irradiance profiles were obtained using a Beam Profiler. The tips were photographed and classified in 4 categories: A. undamaged, B. contaminated by resin residue, C. damaged, and D. contaminated and damaged. Data were analyzed by one-way ANOVA (α = 0.05), and the emission spectra and beam profiles were analyzed descriptively. The LCUs tested were single-peak light-emitting diode units, and 85% of the LCUs had damaged light tips. The radiant power values were significantly different between the LCUs (P < 0.001) and ranged between 94.2 and 588.2 mW. The irradiance ranged from 255.8 to 1597.8 mW/cm². The LCU tip diameter ranged from 6.1 to 8.3 mm. Two-dimensional beam profiles show that the light distribution was not homogeneous across the tips, and an irradiance peak was often observed at the center of the LCUs with smaller tips. Only 15% of the LCU were undamaged, reflecting substantial variability in radiant power and irradiance delivered. Although no statistically significant differences were observed among tip condition categories, these conditions showed a trend toward reduced and inhomogeneous light output.
Brazilian oral researchAline de Almeida Neves, Lourdes Santos-Pinto, Daniela Rios, Vera Mendes Soviero
Clinical management of patients with molar incisor hypomineralization (MIH) requires a comprehensive and multidimensional assessment that integrates clinical, behavioral, radiographic, functional, and psychosocial parameters. This article discusses key aspects of MIH management, including diagnosis and severity grading; non-invasive strategies aimed at preventing enamel breakdown; restorative management of severely affected molars, including the role of timed extractions; esthetic treatment to mask opacities in anterior teeth; and desensitizing approaches for the management of hypersensitivity. The literature for this narrative review was identified through targeted searches in PubMed for classic and recent publications on the clinical management of MIH. Reference lists of relevant articles were also hand-searched to identify additional relevant studies. Finally, future perspectives and emerging directions in MIH management are discussed.
Brazilian oral researchIgor Paulino Mendes Soares, Maria Luiza Barucci Araújo Pires, Juliana Rios de Oliveira, Lídia de Oliveira Fernandes, Carlos Alberto de Souza Costa, Marco Cícer…
The concept of bioactivity in restorative dentistry has evolved beyond the traditional expectation of inert materials designed solely to replace lost tooth structure. Contemporary restorative systems are increasingly engineered to interact with the dentin-pulp complex by modulating mineral dynamics, matrix stability, and cellular responses. However, misconceptions remain regarding what restorative "bioactivity" can realistically achieve in clinical practice. This review critically discusses the biological basis and clinical relevance of bioactive materials in restorative dentistry, emphasizing dentin-pulp preservation and the distinction between validated bioactivity and laboratory observations. Bioactivity may arise through physicochemical mechanisms, such as ion release, pH modulation, and mineral precipitation, which may contribute to mineral recovery and dentin-pulp preservation, although many proposed effects remain insufficiently validated clinically. In parallel, biological mechanisms involve modulation of odontogenic signaling, pulp cell differentiation, and extracellular matrix dynamics. Strategies targeting collagen stability, including cross-linking, protease inhibition, and intrafibrillar mineralization, may also improve hybrid-layer durability and interfacial longevity. Beyond dentin-focused interventions, pulp-directed bioactivity includes clinically established vital pulp therapy materials and emerging scaffold-based regenerative systems that remain largely investigational. However, important translational questions remain regarding the clinical functionality of current materials. Clinically relevant restorative bioactivity should not be defined by ion release or surface mineral deposition alone, but by the ability of materials to preserve dentin-pulp homeostasis and long-term restorative stability. Moving beyond the "bioactive" label requires evidence-based strategies that sustain dentin-pulp homeostasis rather than merely replacing lost structure.
Brazilian oral researchAdriana da Fonte Porto Carreiro, Anne Kaline Claudino Ribeiro, Gülce Çakmak, Walter Yu Hang Lam, Wei-Shao Lin, Ji-Man Park, Murali Srinivasan, Manabu Kanazawa,…
This scoping review mapped the evidence on the clinical applicability and implications of digital workflows for fixed and removable full-arch rehabilitation in completely edentulous patients, focusing on workflow-related operational parameters and clinician-reported outcomes. This review was conducted in accordance with the PRISMA-ScR and was registered on the Open Science Framework. The research question was "What is the current evidence on digital workflows for full-arch rehabilitations and their implications for clinical practice?". A search was conducted in PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library, and Embase, supplemented by grey literature and reference screening. The inclusion criteria were clinical studies and reviews focusing on the clinical implications of workflow-related performance indicators and the clinician's perceptions, considering the digital workflow. A descriptive analysis was conducted in terms of clinical application and key findings regarding accuracy, time-efficiency, cost-effectiveness, and clinician satisfaction. A total of 40 studies were included. The implant-level impressions demonstrated values for 3D linear deviations within clinically acceptable thresholds (up to 200 μm) and traditional methods remained feasible for tissue impressions due to the highest discrepancies found in the peripheral regions. The digital workflow was time- and cost-saving, ranging from 27.17% to 75.10% and 9.21% to 39.49%, respectively. The digital workflow was accurate for implant-level impressions. Evidence suggests limitations in peripheral and movable mucosa capture; however, certain protocols may improve reliability, and conventional methods remain important in specific clinical contexts. Moreover, it's time- and cost-efficient for interventions in completely edentulous patients, but the evidence remains scarce and inconclusive for clinician satisfaction.
The journal of adhesive dentistryPhattarasinee Phuntusuntorn, Kulapatch Engkatanachai, Weerachai Singhatanadgit, Yanee Tantilertanant
PURPOSE: To evaluate the marginal integrity of cervical margin relocation (CMR) or deep margin elevation (DME) restorations using a universal adhesive in etch-and-rinse and self-etch modes, compared to gold-standard systems after 6-month water aging. METHODS AND MATERIALS: Standardized mesial and distal Class II cavities were prepared in 32 human maxillary premolars. Specimens were assigned to four groups according to adhesive systems and modes: OFL (OptiBond FL), CSE (Clearfil SE Bond), UER (Single Bond Universal; etch-and-rinse), and USE (Single Bond Universal; self-etch) (n = 16 per group). After DME/CMR and final restoration, specimens were stored in 37°C distilled water for 6 months. Marginal integrity was assessed qualitatively via micro-CT by two calibrated observers and quantitatively via 0.5% methylene blue dye. Data were analyzed using weighted kappa coefficient, Wilcoxon signed-rank test, two-way repeated measures analysis of variance (ANOVA), and one-way ANOVA with Games-Howell post-hoc tests (α = 0.05). RESULTS: Micro-CT showed high inter-examiner reliability (κ = 0.84) and stable interfacial adaptation across groups post-aging. However, dye penetration revealed that adhesive mode significantly affected microleakage (p 0.05), while proximal box concavity geometry had no significant effect (p > 0.05). The USE group exhibited the lowest mean microleakage (0.94 ± 0.62 mm), showing no significant differences from OFL and CSE. The UER group showed the highest mean microleakage (1.48 ± 0.09 mm), which was significantly higher than the USE group (p 0.05). CONCLUSION: Within the limitations of this study, the self-etch application of universal adhesives provided superior durability of marginal seals for DME compared to the etch-and-rinse mode. Optimizing matrix application also minimized the influence of concavity geometry.
Sensors (Basel, Switzerland)Riccardo Rosati, Dolaji Henin, Gaia Pellegrini, Maria Francesca Sfondrini, Andrea Scribante, Daniela Carmagnola, Claudia Dellavia
Dental-periodontal afferents contribute to modulating masticatory muscle recruitment. This modulation affects, in turn, load distribution within the stomatognathic apparatus. Standardized surface electromyography (ssEMG) has been proposed to quantify dental occlusion effects on muscle coordination. This study aimed to estimate the applicability of a research measurement protocol evaluating the repeatability and reproducibility of ssEMG-based indices acquired by non-expert clinicians. Sixty-five asymptomatic adults underwent ssEMG recordings of the masseter and anterior temporalis muscles, and 20 standardized indices were computed. Data were collected by non-expert operators during two sessions one week apart. Methodological reliability was assessed through intra- and inter-session ssEMG index comparisons, computing the coefficient of variation (CV%) and minimal detectable change (MDC). Differences in variability were also analyzed between subjects with typical and atypical functional indices. Overall, 15 out of 20 indices were considered clinically reliable. A statistically significant reduction in CV% was observed for five out of six clenching indices in subjects with typical values compared with those showing atypical patterns. ssEMG provides a reliable method for evaluating the functional effects of dental occlusion on masticatory muscle coordination by non-expert operators in routine clinical settings rather than research labs. These findings support the integration of functional, measurement-based approaches into evidence-based research and clinical gnathology.
Clinical oral investigationsBingbing Bai, Xin Zhu, Yanfei Diao, Xinyao Han, Haoran Wang, Yan Zhou, Yan Wang, Peng Zhu, Chao Chen
OBJECTIVES: Accurate radiographic identification of dental implant systems is essential for effective clinical management; however, manual assessment remains time-consuming and susceptible to diagnostic error. Furthermore, conventional computational approaches are constrained by their dependency on manually annotated regions of interest. To overcome these limitations, this study introduces DentalImplantNet, an end-to-end automated deep learning architecture engineered for robust, high-precision implant classification across heterogeneous and radiographically noisy clinical settings. MATERIALS AND METHODS: A multi-modal dataset was constructed from 2,714 panoramic and periapical radiographs alongside high-resolution Bruker micro-CT scans of 64 standalone implant fixtures. An automated pipeline utilizing RT-DETR for real-time localization and ROI extraction was implemented to eliminate manual intervention. To enhance robustness, a Causal-Informed Generalization Framework based on Backdoor Adjustment was utilized to dissociate invariant morphological features from non-causal radiographic noise. Model performance was benchmarked against ResNet-50, EfficientNet-B2, and 12 dental professionals who were divided into three levels of expertise. RESULTS: DentalImplantNet achieved an overall accuracy of 95.29% and a micro-average AUC of 99.6%, significantly outperforming ResNet-50 and EfficientNet-B2, which recorded accuracies of 92.4% and 88.2%, respectively. The model demonstrated high diagnostic stability with an overall F1-score of 94.2% and achieved perfect precision for the Straumann and Osstem categories. In clinical validation, the artificial intelligence (AI) performance substantially surpassed senior implant specialists whose overall and specifically for periapical radiographs did not exceed average numbers of 58% and 53%, respectively. Grad-CAM visualization confirmed that the model prioritized sub-millimeter morphological signatures over transient radiographic artifacts, ensuring high interpretability. CONCLUSIONS: The integration of causal data synthesis with automated deep learning architectures provided a scalable and robust solution for implant identification, effectively minimizing human error in clinical practice. CLINICAL RELEVANCE: Automated deep learning models have demonstrated significant potential in assisting dentists with the precise identification of dental implant brands on panoramic and periapical radiographs, thereby facilitating more effective, efficient, and safer clinical management.
OBJECTIVE: Manual interpretation of dental panoramic radiographs is labor intensive and prone to diagnostic fatigue, particularly in high-volume settings. While artificial intelligence offers potential solutions, existing automated detection models often suffer from limited generalization due to small-scale, inconsistent datasets and scale mismatches between generic algorithms and dental structures. This study aimed to develop a deep learning framework trained on a clinically annotated retrospective dataset to improve the multiclass detection accuracy of dental restorations and appliances. MATERIAL AND METHOD: A retrospective dataset comprising 2,434 anonymized panoramic X-ray images was curated and annotated by trained dental professionals for six categories: crowns, root canal filling, fillings, bridges, implants, and braces. The baseline dataset used for contextual comparison had a different annotation scope and class composition from the enhanced dataset; therefore, it was used only as a descriptive reference rather than as a directly matched comparator. A faster Region based Convolutional Neural Network (R-CNN) model with a ResNet-50 Feature Pyramid Network backbone was trained using domain-specific optimizations, including customized anchor resizing (16-256 pixels) and adaptive data augmentation. FINDINGS: The enhanced dataset setting achieved an mAP@0.5 of 0.75, which was numerically higher than the baseline setting but should not be interpreted as a directly controlled improvement because the datasets differed in source and annotation scope. The system demonstrated significant gains in detecting small targets, with average recall increasing from 0.59 to 0.81. Performance varied by category; implants achieved the highest precision at 0.93, while braces exhibited lower precision at 0.32 due to overlapping artifacts. The average processing time was under 1.2 s per image on the tested laptop workstation. CONCLUSION: These findings suggest that clinically curated data and domain-adaptive design may improve detection performance in panoramic radiography. The framework may have potential as a decision-support tool, but further external and multicenter validation is needed before clinical deployment.
Background and Objectives: The aim of this study was to evaluate the volume of dental tissue removed during conventional versus microscope-assisted coronal access cavity preparation by an undergraduate student in extracted mandibular incisors, and to compare the volumetric assessment capabilities of cone beam computed tomography (CBCT) and intraoral scanner (IOS) for this application. Materials and Methods: Thirty extracted mandibular incisors were randomly allocated to two equal groups: Group 1 (G1), access cavity preparation without magnification; and Group 2 (G2), access cavity preparation with the aid of an operating microscope. Volumetric analysis was performed using CBCT (RAYSCAN® Alpha Plus 130) and an intraoral scanner (3Shape TRIOS® 3) before and after access cavity preparation. Volume loss was calculated for each group. Differences in groups were assessed using the independent-samples Student's t-test for CBCT data and the Mann-Whitney U test for IOS data. Reproducibility between methods was evaluated using the intraclass correlation coefficient (ICC). Results: The CBCT analysis revealed significantly greater tissue loss in G1 (mean 14.93 mm3, SD 4.42) than in G2 (mean 7.64 mm3, SD 2.72) (mean difference 7.29 mm3, 95% CI, 4.54-10.04; p < 0.001; Cohen's d = 1.99, 95% CI, 1.10-2.88). The IOS analysis did not detect a statistically significant between-group difference (G1: mean 5.37 mm3 vs. G2: mean 4.55 mm3; p = 0.436). The ICC for volume loss between methods was 0.011 (95% CI: -0.150 to 0.237), below the threshold conventionally used to indicate acceptable reliability; because CBCT and IOS did not sample identical anatomical extents, this should be interpreted as limited agreement specific to the present protocols rather than general evidence of poor concordance between the two imaging methods. Conclusions: Within the limitations of this exploratory, single-operator in vitro study, microscope-assisted access cavity preparation resulted in significantly less CBCT-measured volumetric tissue loss than conventional access in mandibular incisors.
The international journal of esthetic dentistryAgnė Mališauskienė, Michaela Jarešová, Marcus B Blatz
OBJECTIVE: This article presents the incisal first technique (IFT) as a systematic and conservative approach to restoring larger anterior diastemas using direct composite resin. It is the second part of a two-part series published in IJED; the first part being 'Efficient diastema closure, Part 1: The modified Mylar pull technique for small diastema closure.' The present article emphasizes precise incisal edge placement as the initial step in guiding tooth proportion, contact point positioning, and the emergence profile. CLINICAL CONSIDERATIONS: Conventional techniques for larger diastema closure may rely on wax-ups, mock-ups, or full-surface composite veneering, which can complicate workflow and compromise natural esthetics. The IFT simplifies the process by establishing the incisal edge and final tooth width from the outset, using this reference to guide proportion, contact point positioning, and the emergence profile. The technique builds composite sequentially-starting from the incisal edge and progressing palatally and buccally-while preserving gingival health and tooth anatomy. The modified Mylar pull technique (MMPT) is performed from both palatal and buccal directions to achieve seamless, void-free proximal contact and controlled line angle placement. The IFT allows clinicians to restore complex spaces conservatively, without altering the buccal surface too much or requiring additional preparatory and finishing steps. CONCLUSIONS: The IFT offers a conservative and predictable method that focuses on incisal edge positioning and maintaining biologic and optical parameters. It simplifies tooth proportion control and contact formation and enhances workflow efficiency while maintaining esthetic and biologic integrity. Anatomically correct, void-free larger diastema closure with highly predictable esthetic outcomes can be achieved with a simplified clinical execution while preserving tissue health and structural integrity.
Acta odontologica ScandinavicaVegard B Vårum, Vaska Vandevska-Radunovic, Helen Pullisaar
OBJECTIVE: This retrospective study aimed to investigate the frequency, causes, and temporal distribution of orthodontic emergencies at the Department of Orthodontics, University of Oslo. METHODS: All appointments coded as emergencies from 2015 to 2022 were reviewed and manually screened. Emergencies were classified into three categories: (1) during active treatment, (2) during retention, and (3) miscellaneous. A negative binomial generalized linear regression model was used to assess annual and monthly variations. Chi-square tests for independence were applied to analyze relationships between age group and year, gender and year, and reason for emergency. The significance level was set at p < 0.05. RESULTS: Out of 7206 records screened, 3592 met the inclusion criteria, involving 1657 patients - 685 males (41.3%) and 972 females (58.7%). The mean number of emergencies per patient was 2.2, with no significant year-to-year variation in gender distribution. The most common age groups were 10-14 years and over 20 years. Annual emergency numbers ranged from 313 in 2015 to 638 in 2022, with statistically significant variation. Monthly variation was also significant, with July consistently having the fewest emergencies (p < 0.001). Most emergencies occurred during active treatment (n = 2021), followed by the retention phase (n = 1353), and miscellaneous reasons (n = 218). The most frequent causes were issues related to full fixed appliances and fixed retainers. CONCLUSIONS: No consistent pattern of orthodontic emergencies was observed, indicating that operator experience, the stage of postgraduate training, and seasonal fluctuations are likely the key influencing factors.
BMC oral healthTulin Tasdemir, Sultan Uzun, Melek Tassoker
BACKGROUND: To investigate whether taurodontism is associated with localized alterations in the surrounding trabecular bone microenvironment using quantitative radiomic analysis of panoramic radiographs in children. METHODS: Panoramic radiographs of 24 children (6 taurodontism cases; 18 age-matched controls) were retrospectively evaluated. Due to incomplete root development, severity was qualitatively assessed via Shaw's criteria. Trabecular bone was analyzed across four topographic regions (interradicular epicenter, mesial apex, distal apex, and gonial angle) using Image Biomarker Standardisation Initiative (IBSI)-compliant 3D Slicer. Diagnostic performance was preliminarily evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: Radiomic alterations demonstrated a distinct spatial gradient, with the most pronounced differences localized to the interradicular region and progressively diminishing toward the mesial, distal, and gonial regions. Four higher-order radiomic features showed significant discriminatory performance in the interradicular regions of interest (ROI) (all p < 0.05). GLSZM_ZoneVariance achieved the highest diagnostic accuracy (AUC = 0.824; 95% CI: 0.617-0.948), with 100.0% sensitivity and 72.2% specificity, followed by GLSZM_ZoneEntropy (AUC = 0.815). CONCLUSION: This proof-of-concept study provides preliminary evidence that taurodontism is associated with localized radiomic alterations in the surrounding trabecular bone microenvironment, particularly within the interradicular region. These findings suggest that quantitative radiomic analysis of routinely acquired panoramic radiographs may provide complementary imaging features for investigating developmental dental phenotypes. Further prospective multicenter studies with external validation are required to confirm the biological and clinical significance of these observations.
BMC oral healthRania Abd Elsattar Mangood Ramadan, Sawsan Maged Fadl, Shaimaa Mohamed Abu El Sadat Ali, Rami Maher Ghali
BACKGROUND: Conventional removable partial dentures (RPDs) involve a process that is often susceptible to errors and demands a significant investment of time. The introduction of computer-aided design and computer-aided manufacturing (CAD/CAM) technology and materials witnessed significant advancements in recent years to produce accurate removable partial dentures. This study evaluated the retention and wear of PolyEtherKetoneKetone (PEKK) compared to Cobalt-Chromium (CoCr) in digitally fabricated double crown removable partial dentures for lower Kennedy Class I cases. METHODS: The study was performed on 3D digital models of mandibular Kennedy Class I with prepared premolars bilaterally. The double crown RPDs were designed and fabricated digitally to get 14 copies of RPDs. Two groups were defined (n = 7); the first group were milled from Co-Cr discs, and the other's from PEKK blanks. Initial retention was measured using a universal testing machine. RPDs were then subjected to dynamic loading in a chewing simulator over 100,000 cycles followed by 540 manual insertion and removal cycles and were remounted on the testing machine to measure final retention simulating six months. Wear was assessed using Geomagic Control X software, where negative deviations highlighted areas of degradation. Data was collected and analyzed for statistical analysis. Two Sample t-test was used to compare between the two groups and Paired t test to study the changes within each group. The significance level was set at P ≤ 0.05. RESULTS: PEKK group showed a statistically significantly higher final retentive values after 6 months (11.6 N) than Co-Cr (2 N). Moreover, results showed higher retention loss in Co-Cr group (16.9 N) compared to PEKK (3.7 N). Additionally, wear assessment of primary copings indicated a higher deviation in the Co-Cr group (-0.25 mm) compared to PEKK (-0.096 mm), with a notable correlation (0.651, P-value = 0.011) between retention loss and wear. CONCLUSIONS: Within the limitation of this study, it could be concluded that PEKK provided digitally fabricated double crown RPDs with higher retention values and less wear than Co-Cr after simulation of 6 months of RPD use.
OBJECTIVES: This prospective, randomized, split-mouth clinical study aimed to compare the clinical performance and survival rates of CAD/CAM-fabricated nanohybrid composite overlays (NCOs) and hybrid ceramic overlays (HCOs) produced using a digital workflow in first permanent molars (FPMs) affected by molar-incisor hypomineralisation (MIH). Clinical performance was assessed using the modified USPHS criteria, while tooth hypersensitivity was evaluated as a secondary outcome using the Schiff cold air sensitivity scale. MATERIALS AND METHODS: Twenty children (40 MIH-affected FPMs) aged 8-13 years with MIH-TNI scores of 2b, 2c, 4b, or 4c were included. Using a randomized split-mouth design, one molar received an NCO (Grandio blocs, VOCO, Cuxhaven, Germany) and the contralateral molar an HCO (ENAMIC, VITA Zahnfabrik, Essen, Germany). All restorations were fabricated through digital impressions, CAD/CAM design and milling, and adhesively cemented using a universal dual-cure resin cement. Clinical performance was evaluated by two blinded examiners according to the modified United States Public Health Service (USPHS) criteria at baseline and at the 6-month, 12-month, and preliminary 18-month follow-ups. Tooth hypersensitivity was assessed using the Schiff cold air sensitivity test. Statistical analyses were performed using Mann-Whitney U, Fisher's Exact, Fisher-Freeman-Halton, Wilcoxon signed-rank, and Stuart-Maxwell tests (IBM SPSS v31; p < 0.05). RESULTS: Baseline demographic characteristics and MIH-TNI distributions were comparable between the groups (p > 0.05). Most modified USPHS parameters demonstrated clinically acceptable outcomes in both groups throughout the follow-up. No significant differences were observed between groups at baseline or at the 6-month follow-up regarding surface/marginal staining and postoperative hypersensitivity/tooth vitality according to the modified USPHS criteria (p > 0.05). At the 12-month follow-up, one HCO restoration was rated as Score 2 (Explorer catches slightly, without a visible gap) for marginal adaptation, and no statistically significant difference was observed between the groups for postoperative hypersensitivity (p = 0.050). All restorations were available for evaluation at the 6-month and 12-month follow-ups. Both materials demonstrated favorable short-term clinical outcomes according to the modified USPHS criteria. Preliminary 18-month data were available for 7 patients, among whom one restoration fracture was observed in the HCO group. Tooth hypersensitivity scores significantly decreased in both groups by the 6-month follow-up (p ≤ 0.001), and all treated teeth reached a Schiff score of 0 at the 12-month follow-up (p < 0.001). CONCLUSIONS: CAD/CAM-fabricated NCOs and HCOs showed favorable short-term clinical performance in selected MIH-affected FPMs up to the 12-month follow-up. Preliminary 18-month findings should be interpreted with caution, and longer-term follow-up of the complete cohort is required to determine comparative durability. CLINICAL RELEVANCE: Both materials may represent clinically feasible restorative options for selected pediatric patients; however, longer-term clinical follow-up is required. CLINICAL TRIALS: Clinical trial registration number: NCT06987448.
Journal of visualized experiments : JoVEFang Yu, Hangjie Ren
This retrospective study aimed to compare the clinical efficacy and long-term outcomes of fiber post-and-core crown restoration and all-ceramic onlay restoration for posterior teeth with defects following root canal treatment. A total of 100 patients treated between January 2020 and December 2022 were allocated to two groups (n = 50 each): a fiber post-and-core crown group and an all-ceramic onlay group. Restoration integrity, tooth integrity, marginal adaptation, interproximal contacts, periodontal parameters (periodontal pocket depth, gingival index, and plaque index), masticatory function (bite force and chewing efficiency), and oral health-related quality of life (OHIP-14 scores) were evaluated before treatment and at 3 months and 2 years after restoration. No significant differences were observed between the groups in restoration integrity, tooth integrity, marginal adaptation, or interproximal contacts at either follow-up. However, the all-ceramic onlay group demonstrated significantly lower periodontal pocket depth, gingival index, and plaque index at both follow-up time points. Bite force and chewing efficiency were significantly greater in the onlay group, and OHIP-14 scores indicated better oral health-related quality of life. At the 2-year follow-up, two restoration failures occurred in the fiber post-and-core crown group, whereas no failures were observed in the all-ceramic onlay group. These findings suggest that all-ceramic onlay restorations provide superior clinical outcomes for posterior teeth after root canal treatment, particularly with respect to periodontal health, masticatory function, and patient-reported quality of life, and may represent a promising alternative to conventional fiber post-and-core crown restorations.
BMC oral healthGulnaz Aydemir, Jale Gorucu, A Ruya Yazici
BACKGROUND: Smoking has a great impact on oral health status of the patients. As universal adhesives have become a routine dental adhesive choice, understanding the potential impact of smoking on their clinical performance is crucial. This study aimed to determine the 18-month clinical performance of a universal adhesive used with different application modes in non-carious cervical lesions(NCCLs) of smokers and non-smokers. METHODS: This double-blind, randomized, split-mouth superiority clinical trial included 47 participants(24 non-smokers and 23 smokers) presenting with at least three NCCLs. A total of 228 NCCLs were categorized in line with the smoking status of the participants and universal adhesive(G-Premio BOND) application modes (Etch&Rinse[ER], Selective-Etch[SLE] or Self-Etch[SE]). Randomization was performed at the lesion level, such that within each participant, each non-carious cervical lesion was randomly assigned to one of the three adhesive application modes. Restorations were evaluated at baseline, 6, 12 and 18-months using modified USPHS criteria and patient-reported hypersensitivity was assessed using a 0-10 visual analog scale(VAS) by two calibrated examiners blinded to group allocation. The primary outcome was retention. Secondary outcomes included marginal adaptation, marginal discoloration, color match, postoperative sensitivity and patient-reported postoperative hypersensitivity(VAS). Data were analyzed using Cochran's Q, chi-square, Mann-Whitney-U and Kaplan-Meier tests(p < 0.05). RESULTS: Among the non-smokers, one restoration from the SE and one from the ER group were lost, creating no significant difference regarding retention(p > 0.05). At 18-months, no difference was detected among the application modes within each group for all USPHS criteria(p > 0.05). Kaplan-Meier survival analysis revealed no significant difference in 18-month retention between smokers and non-smokers (p = 0.59). Overall restoration success at 18 months was 100% in smokers and 99.1% in non-smokers (ER 97.5%, SLE 100%, SE 97.5%) Statistically significant differences between smokers and non-smokers were detected only for marginal discoloration at 6 months in the ER group and at 12 and 18 months in the SE group(p < 0.05). Both marginal discoloration and adaptation exhibited significant changes over time in both groups(p < 0.05). VAS scores for postoperative sensitivity were significantly higher in smokers than in non-smokers at all follow-ups(p < 0.05), except for the SE group(p > 0.05). CONCLUSION: The 18-month clinical performance of restorations was found to be similar regardless of the universal adhesive application mode. Smoking status primarily influenced marginal discoloration and patient-reported postoperative hypersensitivity. CLINICAL TRIAL REGISTRATION: The study was registered with clinicaltrials.gov retrospectively registered (protocol number NCT04807465) on 03.13.2021.
Shanghai kou qiang yi xue = Shanghai journal of stomatologyYanhui Feng, Rui Zhu
PURPOSE: To evaluate the efficacy of Ceramage polymeric porcelain inlay and bulk block resin in the restoration of pulpless molars. METHODS: Sixty-eight patients with pulpeless molars admitted to the First Hospital of Yulin from March 2022 to December 2023 were selected, with 68 affected teeth. The patients were divided into the experimental group and the control group by the odd-even number method, with 34 cases in each group. The control group was repaired with bulk block resin, while the experimental group was repaired with Ceramage polymeric porcelain inlay. After 12 months of follow-up, the restoration effect and periodontal health indexes of the two groups were compared. RESULTS: Six months after restoration, there was no significant difference between the two groups in terms of the color of restorations, marginal adaptation, marginal staining, restoration wear, restoration retention, secondary caries degree, proximal contact, gingival index(GI), plaque index(PI), tooth mobility and alveolar bone resorption(P＞0.05). At 12 months after restoration, there were no significant differences in the color, edge fit, edge coloration, restoration retention and proximity relationship between the two groups (P＞0.05). The wear of the prosthesis, the degree of secondary caries, PI and the degree of alveolar bone resorption in the experimental group were significantly lower than those in the control group (P＜0.05), and the load of tooth fracture resistance was significantly higher than that in the control group (P＜0.05). CONCLUSIONS: The dental restoration effect of Ceramage polymeric porcelain inlay for pulpless molars is good, long-lasting and stable.
American journal of dentistryBettina G F D Amaral, Leonardo S Barros, Milagros F Aguilar, Flávio H B Aguiar, Cecilia P Turssi, Roberta T Basting, Waldemir F Vieira-Junior
PURPOSE: This study evaluated the cross-sectional Knoop microhardness (KHN) of enamel and dentin adjacent to restorations made with bioactive materials, and their surface degradation after pH cycling. METHODS: Molar blocks (n=10) were restored with conventional resin composite (RC; Z350XT), resin-modified glass-ionomer cement (R-GIC; Vitremer), flowable compomer (FC; Twinky), resin composite with S-PRG filler (RC-S-PRG; Beautifil II), or self-curing bioactive composite (RC-SP; Cention N). After pH cycling, KHN was measured at 100, 200, and 300 µm from the restoration margins and at depths of 20, 40, and 60 µm from the surface. Surfaces were evaluated using scanning electron microscopy (SEM). Data were analyzed via split-plot ANOVA and Tukey's test (α=0.05). RESULTS: Regardless of material, enamel KHN was lower at 20 µm than at 60 µm depth (100 µm distance), at 40 µm than at 60 µm depth (300 µm distance), and dentin KHN was also lower at 20 µm. RC and R-GIC showed reduced dentin KHN at 20 µm compared to 60 µm. SEM analysis revealed surface degradation in all materials (RC<R-GIC<FC<RC-S-PRG<RC-SP). CLINICAL SIGNIFICANCE: The ion-releasing bioactive materials did not provide superior protection of microhardness compared with the conventional composite. Moreover, bioactive materials exhibited greater surface degradation after acidic challenge, which may compromise their long-term stability in the oral environment.
OBJECTIVES: This research investigated the effect of different applications of Universal bonding on the fracture resistance (FR) of maxillary premolars restored with mesio-occluso-distal resin composite. MATERIALS AND METHODS: One-hundred and eight extracted maxillary premolars were randomly assigned into nine groups (n = 12): (1) ST, sound teeth; (2) nonrestored teeth; (3) SEE, selective enamel etching; (4) E&R, etch-and-rinse; (5) SDE, selective dentin etching; (6) SEE+resin layer; (7) E&R+resin layer; (8) SDE+resin layer/precuring; (9) SDE+resin layer/co-curing. Following restoration, mechanical loading (100,000 cycles, 50 N), 6-month water storage, and thermocycling (1000 cycles), FR was tested. Failure mode was evaluated. Data were analyzed using one-way ANOVA and Tukey test (α = 0.05). RESULTS: SDE+resin layer/precuring showed the highest mean fracture load (1222.0 ± 58.7 N), with a significant difference with all groups (p < 0.001), except SDE+resin layer/co-curing (1166.5 ± 50.3 N). FR of SEE with the lowest value (894.50 ± 70.41 N) was lower than SDE (p < 0.001) but comparable with E&R. Resin layer significantly improved FR in all etching conditions, except the E&R group (p = 0.272). The highest number of restorable fractures was in two SDE with resin layer groups. CONCLUSION: Adhesive application protocols affected FR. Combining short-time dentin etching with a HEMA-free hydrophobic resin may be suggested to increase the stable reinforcement potential of universal adhesive-resin composite restorations in premolars and preserve teeth under high loading. CLINICAL RELEVANCE: The adhesive application protocol considerably affected the fracture resistance of MOD resin composite-restored premolars. A short time dentin etching using an ultra-mild universal adhesive, along with increasing hydrophobicity of the adhesive interface, may enhance the mechanical reinforcement of resin composite-restored premolars during simulated thermal-mechanical intraoral conditions. This approach also possibly prevents the risk of catastrophic failure under unexpectedly high loads.
Clinical oral investigationsJan Rygol, Stefan Raith, Stefan Wolfart, Karin Groß, Oliver Hartkamp, Christoph Mautsch, Anne Rittich, Caroline Streichfuss, Stephanie Metelmann, Sven Reich
OBJECTIVES: The aim of the study was to evaluate antagonist enamel wear caused by posterior monolithic zirconia crowns, and the wear of contralateral enamel/enamel tooth pairs over a 36-month observation period. MATERIALS AND METHODS: Out of thirty-two patients, each provided with one 5 mol% yttria-stabilized zirconia crown on a natural tooth, ten met the inclusion criteria. The surfaces were captured with an intraoral scanner at baseline and after 36 months. The datasets were superimposed, and the mean maximum vertical height losses of the wear facets of the zirconia crowns, the control teeth, and the antagonist teeth of the crowns and the control teeth were determined. The null hypothesis stated was that there was no significant difference between the wear ratio zirconia crowns/enamel antagonists and the wear ratio control teeth/antagonists. RESULTS: The mean maximum vertical loss for the antagonist teeth to the zirconia crowns was 216 µm (SD ± 113 µm). For the contralateral antagonist pair, a mean vertical loss of 151 µm (SD ± 59 µm) and of 113 µm (SD ± 57 µm) was measured, respectively. The zirconia crowns exhibited 38 µm (SD ± 14 µm). The wear ratios of zirconia crowns/antagonists and control teeth/antagonists differed significantly exhibiting 0.25 (SD ± 0.19) and 1.55 (SD ± 0.79), respectively. CONCLUSION: The monolithic zirconia crowns induced approximately twice the amount of wear on opposing enamel compared with natural tooth contacts. CLINICAL RELEVANCE: After three years, the monolithic zirconia crowns caused significantly greater antagonist enamel wear than natural enamel contacts, yet the wear was comparable to that observed for other dental ceramic materials.
OBJECTIVES: To evaluate the effects of cusp reduction and different quartz fiber-ribbon placement strategies on the fracture resistance of endodontically treated maxillary first premolars with mesio-occlusal (MO) cavities. MATERIALS AND METHODS: Flexural strength was measured in composite resin and fiber-reinforced composite resin blocks. Finite element analysis (FEA) was performed to compare five restorative designs (EC, FC, CEC, CBFC, and CCFC) in the endodontically treated first premolar. Fracture strength of the repaired extracted teeth were also conducted, fracture loads and failure modes were recorded. One-way ANOVA and Chi-square tests were used (α = 0.05). RESULTS: Quartz fiber reinforcement significantly increased flexural strength compared with composite resin alone (P < 0.05). FEA showed that the cusp-reduced restoration with coronal fiber placement generated the lowest cervical stress concentration, whereas the composite-only design showed the highest. In fracture testing, the cusp-reduced restoration with coronal fiber placement exhibited the highest fracture load and was significantly stronger than all other groups (P < 0.05). More non-repairable fractures were observed in the cusp-reduced composite-only and basal-fiber groups. CONCLUSIONS: Cusp reduction combined with coronal quartz fiber-ribbon placement provided the most favorable biomechanical behavior and the highest fracture resistance. CLINICAL RELEVANCE: Premolars with single-wall defects are at relatively high risk of fracture with direct restorations. Coronal fiber-reinforced cusp-coverage direct restoration may be a conservative option for restoring structurally compromised endodontically treated premolars.