Faculty Bibliography

OBJECTIVES/OBJECTIVE:This study evaluated the effects of resin-based materials on crack occurrence in ceramic laminate veneers (CLVs) after adhesive cementation. Additionally, the polymerization shrinkage stress (PSS) and maximum polymerization rate (MPR) of the resin-based materials were determined. MATERIALS AND METHODS/METHODS:Four resin-based materials were used as luting agents: Variolink Esthetic LC (Ivoclar), SDR Plus (Dentsply), heated Z100 (69°C, Solventum), and heated VisCalor Bulk (65°C, Voco). Twenty-eight prepared premolars received CLVs (n = 7). CLV integrity was assessed by transillumination and scanning electron microscopy. PSS was measured in a universal testing machine and MPR by FTIR spectroscopy (n = 5). Data were analyzed by one-way ANOVA and Tukey's test (α = 0.05). RESULTS:No CLV cracks were detected. VisCalor Bulk showed the lowest PSS (74.2 ± 15.3 MPa) and Variolink Esthetic LC the highest (135.4 ± 8.4 MPa) and the highest MPR (15.5%/s ± 2.3%/s). SDR Plus presented the lowest (10.0%/s ± 1.2%/s). CONCLUSIONS:The type of luting agent did not influence crack formation in CLVs. The PSS and MPR varied among materials.

STATEMENT OF PROBLEM/BACKGROUND:The fatigue behavior under clinically relevant loading conditions of implant-supported screw-retained crowns cemented to titanium bases fabricated from different restorative materials remains insufficiently understood. PURPOSE/OBJECTIVE:The purpose of this study was to evaluate the failure modes, fatigue reliability, and survival probabilities of metal-ceramic (MC), monolithic zirconia (3Y-TZP), and lithium disilicate (LD) single premolar implant-supported screw-retained crowns cemented to titanium bases using step-stress accelerated life testing (SSALT). MATERIAL AND METHODS/METHODS:Sixty crowns were bonded to titanium bases (UNP RH 4 mm, GH 2 mm; Adin Dental Implant Systems Ltd), connected to internal hexagon implants (4.2-mm platform diameter, 10-mm length; Touareg S, Adin Dental Implant Systems Ltd), embedded in acrylic resin blocks, and subjected to single-load-to-failure testing (n=6) to determine stress profiles for SSALT (n=54). Use-level probability Weibull curves were calculated to estimate reliability for a mission of 100 000 cycles at 200 and 300 N. Failed specimens underwent polarized light stereomicroscopy and scanning electron microscopy (SEM) for fractographic analysis. RESULTS:All specimens failed during SSALT loading profiles. Beta (β) values derived from use-level probability Weibull curves were greater than 1 for all groups, indicating fatigue-driven failure behavior. 3Y-TZP crowns demonstrated the highest fatigue reliability, with survival probabilities up to 98% at tested load levels (200 and 300 N). LD showed intermediate performance (93% at 200 N and 88% at 300 N), whereas MC crowns showed the lowest survival probabilities (86% at 200 N and 82% at 300 N). At 200 N, no statistically significant differences were observed among groups. At 300 N, 3Y-TZP crowns showed significantly higher survival probability than MC crowns (P=.038), while LD showed intermediate values and was not significantly different from either group. Fractographic analysis revealed material-specific fracture origins and crack propagation patterns. CONCLUSIONS:All crown types demonstrated high survival probabilities. 3Y-TZP crowns showed higher fatigue reliability than MC crowns, while LD crowns demonstrated intermediate performance.

OBJECTIVE:To describe a fully digital restorative protocol that combines a 3D-printed stamp guide relined with transparent silicone, a controlled cut-back, and internal resin staining to enhance the esthetic integration of direct anterior composite restorations. CLINICAL CONSIDERATIONS/METHODS:This approach enables enhanced esthetic characterization of direct anterior restorations while maintaining the predictability and minimally invasive nature of guided digital techniques. CONCLUSION/CONCLUSIONS:The double-stamp technique integrates digital planning and guided anatomy transfer with controlled cut-back and internal staining, enabling polychromatic, natural-appearing anterior direct restorations without sacrificing the efficiency and predictability of stamp-based workflows. CLINICAL SIGNIFICANCE/CONCLUSIONS:By combining a silicone-relined 3D-printed stamp guide with internal optical characterization and a second stamping step, this technique addresses common limitations of guided injectable/stamp restorations-guide-to-composite sticking and monochromatic outcomes-while maintaining a minimally invasive, reproducible approach for highly-esthetic anterior cases.

A straightforward technique for a complete mouth rehabilitation under complete isolation using the resin stamp technique and planned and executed using a digital workflow is described. A preoperative scan was recorded under dental dam isolation, ensuring a controlled environment identical to that of the actual procedure and using the same isolation procedures. A virtual diagnostic waxing was designed, followed by the manufacturing of printed clear index guides relined with transparent silicone. For the restorative steps, packable and flowable composite resins were inserted into the relined guide and light polymerized. This technique enabled dental dam isolation, reduced silicone index deformation, and prevented adhesion issues between the printed indices and composite resin material.

BACKGROUND:This clinical study aimed to analyze occlusal tooth wear progression in a group of participants over a 25-year follow-up period. METHODS:Thirty-three participants were assessed in this observational retrospective study. Impressions were taken, and casts from three phases were scanned to generate digital models: Phase I in 1996, Phase II in 1999, and Phase III in 2021. These casts were then analyzed using a 3-dimensional (3D) software program (Geomagic Control; 3D Systems) to establish digital comparisons of tooth wear. The Basic Erosive Wear Examination (BEWE) index was used for qualitative 3D analysis, while superimposed image analysis was utilised for quantitative 3D evaluation of tooth wear. A standardised questionnaire assessed behavioural and clinical factors. Statistical analysis was performed using the Friedman test on occlusal wear (p = 0.05). RESULTS:Occlusal tooth wear increased significantly over time, with median wear affecting 42.9% of teeth in Phase I, 60.7% in Phase II, and 85.7% in Phase III (p < 0.05). Lower first molars were the most affected teeth. BEWE scores also showed a significant increase across phases, indicating moderate tooth wear and a need for treatment. Nonparametric analysis identified behavioural and clinical factors associated with higher BEWE scores, revealing a statistically significant difference between the three phases (p < 0.05). CONCLUSION/CONCLUSIONS:Over 25 years, occlusal tooth wear significantly progressed, especially in lower first molars, with contributing factors including lifestyle and health conditions; 3D digital analysis proved to be a precise and reliable method for long-term assessment.

OBJECTIVES/OBJECTIVE:To quantitatively evaluate the progression of non-carious cervical lesions (NCCLs), gingival recession (GR), and occlusal tooth wear (OTW) over 25 years. METHODS:This observational, retrospective study involved 33 dental students who completed a questionnaire regarding their oral habits, diet, and health information. Impressions from the baseline and the 25-year follow-up were used to create digital casts, which were analyzed with 3D software (Geomagic Control; 3D Systems) to measure the progression of NCCLs, GR, and OTW. Occlusal analysis from Phase I, using the T-Scan system (Tekscan), was also included to evaluate occlusal interferences. RESULTS:NCCL dimensions (area, height, and width) showed moderate associations with GR and only weak correlations with OTW. Multivariate regression analyses identified significant factors associated with NCCL progression. For NCCLs, visible plaque, vigorous toothbrushing, occlusal interferences, dentin hypersensitivity, alcohol consumption, smoking, and frequent exposure to acidic or cariogenic diets were associated with increased NCCL progression. For GR, was significantly associated with occlusal contact, dentin hypersensitivity, alcohol consumption, and smoking. For OTW, unilateral mastication, long-term orthodontic treatment, and smoking were positively correlated with wear progression. CONCLUSIONS:Mechanical and behavioral factors-particularly vigorous toothbrushing, occlusal interferences, and lifestyle habits such as smoking and alcohol consumption-significantly influenced the long-term progression of NCCLs, GR, and OTW. Mandibular molars and premolars were the most frequently affected teeth. CLINICAL SIGNIFICANCE/CONCLUSIONS:The use of digital three-dimensional analysis allows accurate monitoring of NCCLs, GR, and OTW. Preventive measures should prioritize controllable risk factors, including brushing habits, smoking, alcohol consumption, and occlusal imbalances.

Molar-incisor hypomineralization (MIH) is a qualitative developmental defect of the enamel that affects one or more permanent first molars, with or without incisor involvement. This condition often requires esthetic treatment, and therapeutic approaches may vary considerably. This case report describes a step-by-step clinical protocol for a 20-year-old woman who presented with dissatisfaction regarding the appearance of her smile due to hypomineralized spots on the maxillary and mandibular anterior teeth. After anamnesis and clinical examination, the diagnosis of MIH was established. Treatment consisted of in-office bleaching followed by resin infiltration for the maxillary teeth, and microabrasion combined with resin infiltration for the mandibular teeth. This sequence of minimally invasive techniques effectively resolved the esthetic alterations caused by MIH, showing satisfactory results that remained stable over 1 year.

To evaluate the effect of silanized filler particles and blue light-sensitive photoinitiator system on the internal and marginal fit of 3D printed resin crowns as well as the volume of provisional cement space. This study evaluated three commercially available 3D-printing resins (Smart Print Temp/SP, Resilab 3D Temp/RL, and Cosmos Temp/CT). The experimental groups consisted of the addition of 30% by weight (30 wt%) of silanized filler particles and a blue light-sensitive Ternary Photoinitiator System (TPS). Samples were printed for each group (n = 10) and evaluated for internal and marginal fit and volume of cement space using a micro-computed tomography (μCT). The obtained data were analyzed by Generalized Linear Models (α = 0.05). The incorporation of TPS and filler particles to the 3D printing resins altered the internal fit and the marginal fit, increasing the cement space at the occlusal face and decreasing the cement space of the axial walls for all tested materials. The volume was significantly affected too, especially for RL and CT. Internal misfit was significantly higher with the addition of TPS, and marginal misfit with the addition of filler particles. In general, the incorporation of TPS and 30 wt% of filler particles promoted an increase in the volume of cement space, as well as an increase in occlusal space and marginal space and a decrease in the axial walls' spaces.

UNLABELLED:, long polyethylene fiber. It is particularly effective in absorbing and redistributing masticatory forces in teeth with substantial dentin loss. This review aims to analyze the literature on the biomimetic restorative technique using long polyethylene fiber and assess its benefits and indications relative to traditional cusp coverage restorations. METHODS:A search was conducted in the PubMed database until March 2024. The authors selected in vitro studies that studied long polyethylene fiber as a dentin reinforcement. RESULTS:From 247 potentially relevant articles, eighteen studies were included in the review. A detailed analysis of the reviewed literature was summarized into three principal sections involving the use of long polyethylene fiber in restorative dentistry. CONCLUSIONS:Long polyethylene fibers improve fracture resistance and promote favorable fracture modes, helping to mitigate the shrinkage forces in composite restorations. However, their clinical significance over traditional cusp coverage is unclear.