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Abstract Trial design This is a randomized, controlled, superiority, double-blinded, parallel-group, two-arms trial with an allocation ratio of 1:1. This study aimed to assess whether the cavity design could affect the clinical performance of the CAD/CAM generated indirect resin composite restoration in endodontically treated teeth (ETT) evaluated using the Modified USPHS criteria after a two-year follow up. Methods A total of 30 participants who underwent endodontic treatment for MOD cavities in permanent molars were divided randomly into two parallel groups (n = 30 restorations) according to the performed cavity design to group 1 in which there was no cuspal reduction (inlay) and group 2 in which cuspal reduction was performed (overlay). All pulp chambers were filled with bulk fill flowable composite, and the cavities were prepared following the criteria of the cavities for indirect restorations and restored using nano-hybrid composite resin blocks (Brilliant, Coltene, Switzerland). The restorations were evaluated using the modified USPHS criteria at baseline, six months, one-year and two years follow-up visits. For qualitative data, frequencies (n) and percentages (%) were used to display the data, while mean and standard deviation (SD) were used for quantitative data. The normality of the data was evaluated using the Shapiro-Wilk and Kolmogorov-Smirnov tests. For every test, P ≤ 0.05 was used as the significance threshold. Results Twenty-six individuals completed the follow-up period after receiving the assigned intervention.The inter-group comparison showed that, at the 6- months and 12- months observation points, the overlay design had significantly better marginal adaptation, less incidence of discoloration or tooth/restoration fracture, and similar marginal integrity and caries incidence to the inlay design. After 24- months, the overlay design still had better marginal adaptation, less incidence of discoloration or tooth/restoration fracture and less caries incidence in comparison to the inlay design, while there was no difference in the marginal integrity between either design. Conclusions and clinical relevance Cuspal reduction in endodontically treated teeth showed better clinical performance than the cusp preservation thus, the former is more reliable.

Trial design: This is a randomized, controlled, superiority, double-blinded, parallel-group, two-arms trial with an allocation ratio of 1:1. This study aimed to assess whether the cavity design could affect the clinical performance of the CAD/CAM generated indirect resin composite restoration in endodontically treated teeth (ETT) evaluated using the Modified USPHS criteria after a two-year follow up. Methods: A total of 30 participants who underwent endodontic treatment for MOD cavities in permanent molars were divided randomly into two parallel groups (n = 30 restorations) according to the performed cavity design to group 1 in which there was no cuspal reduction (inlay) and group 2 in which cuspal reduction was performed (overlay). All pulp chambers were filled with bulk fill flowable composite, and the cavities were prepared following the criteria of the cavities for indirect restorations and restored using nano-hybrid composite resin blocks (Brilliant, Coltene, Switzerland). The restorations were evaluated using the modified USPHS criteria at baseline, six months, one-year and two years follow-up visits. For qualitative data, frequencies (n) and percentages (%) were used to display the data, while mean and standard deviation (SD) were used for quantitative data. The normality of the data was evaluated using the Shapiro-Wilk and Kolmogorov-Smirnov tests. For every test, P ≤ 0.05 was used as the significance threshold. Results: Twenty-six individuals completed the follow-up period after receiving the assigned intervention.The inter-group comparison showed that, at the 6- months and 12- months observation points, the overlay design had significantly better marginal adaptation, less incidence of discoloration or tooth/restoration fracture, and similar marginal integrity and caries incidence to the inlay design. After 24- months, the overlay design still had better marginal adaptation, less incidence of discoloration or tooth/restoration fracture and less caries incidence in comparison to the inlay design, while there was no difference in the marginal integrity between either design. Conclusions and clinical relevance: Cuspal reduction in endodontically treated teeth showed better clinical performance than the cusp preservation thus, the former is more reliable. [ABSTRACT FROM AUTHOR]

Objective Overview Conclusions Clinical Significance This article puts forward consensus recommendations from PROSEC North America regarding single indirect restorations made from ceramic and nonmetallic biomaterials in posterior teeth.The consensus process involved a multidisciplinary panel and three consensus workshops. A systematic literature review was conducted across five databases to gather evidence. The recommendations, informed by findings from systematic reviews and formulated based on a two‐phase e‐Delphi survey, emphasize a comprehensive treatment strategy that includes noninvasive measures alongside restorative interventions for managing dental caries and tooth wear. The recommendations advocate for selecting between direct and indirect restorations on a case‐by‐case basis, favoring inlays and onlays over crowns to align with minimally invasive dentistry principles. The recommendations highlight the critical role of selecting restorative biomaterials based on clinical performance, esthetic properties, and adherence to manufacturer guidelines. They emphasize the importance of precision in restorative procedures, including tooth preparation, impression taking, contamination control, and luting. Regular follow‐up and maintenance tailored to individual patient needs are crucial for the longevity of ceramic and nonmetallic restorations.These PROSEC recommendations provide a framework for dental practitioners to deliver high‐quality restorative care, advocating for personalized treatment planning and minimally invasive approaches to optimize oral health outcomes.The PROSEC North America recommendations highlight the importance of minimally invasive techniques in posterior tooth restorations using ceramic and non‐metallic biomaterials. These principles prioritize tooth structure conservation and personalized treatment planning, essential for enhancing clinical outcomes and long‐term oral health. [ABSTRACT FROM AUTHOR]

In recent years, CAD/CAM technology has allowed indirect ceramic restorations to become a part of everyday chairside clinical practice. Therefore, the impact of different cavity-preparation designs on the fracture resistance of CAD/CAM fabricated ceramics was assessed in this study. Three designs of cuspal covering (none, palatal, and entire) and two widths of the occlusal isthmus (75% and 100% of the intercuspal distance) were used for the preparation of inlays and onlays to form six groups (n = 10/group). Moreover, thermomechanical cyclic loading was applied to every tooth under a chewing simulator. A universal testing machine was used to measure each group's fracture resistance. The tested specimens were inspected for any signs of fractures and cracks to categorize failure patterns. Thereby, the values of fracture strength showed that there were statistically nonsignificant differences between the tested groups (p < 0.05). However, a significant difference (p = 0.01) was found between group 1 (inlays) (1950 ± 405) and group 6 (onlays) (3900 ± 770). Type III or type IV fracture modes were seen in the majority of the specimens. In conclusion, inlays and onlays made of zirconia using CAD/CAM technology were deemed reliable for restoring premolars, irrespective of the cavity-preparation design, except for inlays with a 75% intercuspal distance. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate the marginal fit of inlays fabricated using conventional and digital impression techniques through stereomicroscopic analysis. Methods: A total of 50 inlays were fabricated, with 25 in each group: conventional impression and digital impression. Marginal fit was assessed using a stereomicroscope at 20x magnification. Mean marginal gap measurements were recorded at predetermined locations (mesial, distal, buccal, and lingual), and statistical analysis was performed to compare the marginal fit between the two groups. Results: The digital impression group exhibited significantly smaller mean marginal gap measurements compared to the conventional impression group at all measured locations (p < 0.001). The mean marginal gap measurements ranged from 52.6 to 58.9 microns in the digital impression group and from 64.2 to 72.1 microns in the conventional impression group. Conclusion: In conclusion, digital impression techniques demonstrated superior marginal fit accuracy compared to conventional impression methods in the fabrication of inlays. These findings highlight the potential of digital technologies to enhance the precision and accuracy of dental restorations, ultimately improving clinical outcomes and patient satisfaction. [ABSTRACT FROM AUTHOR]

Abstract Trial design This is a randomized, controlled, superiority, double-blinded, parallel-group, two-arms trial with an allocation ratio of 1:1. The aim of this trial was to compare the two-year clinical performance of partial indirect restorations fabricated from CAD/CAM nano-hybrid composite and ceramic lithium disilicate blocks using the modified USPHS criteria. Methods In two parallel groups (n = 50 restorations), fifty participants having mutilated vital teeth with a minimum of two remaining walls were randomly enrolled in this trial and received indirect restorations of either nano-hybrid composite resin blocks (Brilliant, Coltene, Switzerland) or Lithium Disilicate (IPS Emax CAD). The restorations were assessed using modified USPHS criteria by two independent blinded assessors at baseline, six months, one-year and two years follow-up visits. Categorical and ordinal data were presented as frequencies and percentages. Categorical data were analyzed using the chi-square test. Ordinal data were analyzed using the Mann-Whitney U test for intergroup comparisons and Freidman’s test followed by the Nemenyi post hoc test for intragroup comparisons. Numerical data were presented as mean and standard deviation values. They were analyzed for normality using the Shapiro-Wilk test. Data were found to be normally distributed and were analyzed using the independent t-test. The significance level was set at p ≤ 0.05 within all tests. Results Forty-eight participants received the allocated intervention and completed the follow-up periods. There was a statistically significant difference between both tested materials for all USPHS criteria regarding Marginal integrity and Marginal discoloration at six-months Follow-up, but with no statistically significant difference at one- and two-year follow-up. Conclusions Both materials showed an acceptable, successful clinical performance along the two-years follow-up period. Clinical relevance The CAD/CAM nano-hybrid composite blocks are as reliable as Lithium disilicate for restoring mutilated vital teeth.

Purpose: Indirect restorations can be performed using different impression techniques (conventional, laboratory, or intraoral scanners). Their accuracy determined their longevity. This study compares the marginal and internal adaptation of milled CAD/CAM composite inlays fabricated by conventional, hybrid, and digital methods. Material and methods: Thirty human premolars were prepared for MOD composite inlays(CI). They were divided into three equal groups depending on the process of fabrication: Group 1 (conventional group)— impression and laboratory-fabricated CI, Group 2 (hybrid group)— impression, laboratory scanner and milled CAD/CAM CI, and Group 3(digital group)— digital impression (intraoral scanner) and milled CAD/CAM CI. The marginal gap (MG), absolute marginal discrepancy (AMD), and internal gap (IG) were measured at 120 different points per CI using X‐ray microtomography. The data were analyzed using Kolmogorov–Smirnov and Mann–Whitney U tests. Results: The conventional and digital composite inlays present significantly smaller marginal and internal gaps than the CAD/CAM group manufactured by hybrid methods. Conclusions: Within the limitations of this in vitro study, we concluded that the CAD-CAM composite inlays fabricated by digital method exhibited statistically better marginal and internal adaptation results than composite CAD-CAM inlays by hybrid methods. The composite CAD-CAM inlays made by digital methods are an alternative to those made by a conventional methodology.

The aim of this study was to assess the fracture behavior of molar teeth restored with MOD inlays made of experimental short fiber-reinforced CAD/CAM composite block (SFRC CAD) before and after cyclic fatigue aging. Standardized MOD cavities were prepared on 60 intact mandibular molars. Three groups of CAD/CAM made inlay restorations (Cerasmart 270, Enamic, and SFRC CAD) were fabricated (n = 20/group). All restorations were luted with self-adhesive dual-cure resin cement (G-Cem One). Half of restored teeth per each group (n = 10) were quasi-statically loaded until fracture without aging. The other half underwent cyclic fatigue aging for 500,000 cycles (Fmax = 150 N) before being loaded quasi-statically until fracture. Then, the fracture type was visually inspected. The microstructure and elemental content of CAD/CAM materials were assessed using SEM and EDS. Two-way analysis of variance (ANOVA) was used to statistically examine the data, and it was followed by the Tukey HSD test (α = 0.05). ANOVA demonstrated that both material type and aging had a significant effect (p < 0.05) on the load-bearing capacity values of the restorations. Teeth restored with SFRC CAD showed significantly the highest (p < 0.05) load-bearing capacity (2535 ± 830 N) after fatigue aging among all groups. SEM images showed the ability of short fibers in SFRC CAD composite to redirect and hinder crack propagation. With regard to fracture mode, Enamic group revealed 85% of catastrophic failure (vs. 45% and 10% for Cerasmart 270 and SFRC CAD, respectively). Large MOD cavities on molar teeth were most favorably restored with SFRC CAD inlays, yielding the highest load-bearing capacity and more restorable failures. [ABSTRACT FROM AUTHOR]

This study evaluated the resistance to fracture of endodontically treated premolars (ETPs) with mesio-occluso-distal (MOD) cavities filled with nanohybrid composite (NHC), fiber-reinforced composite (FRC), horizontal glass fiber posts (HFP), and ceramic inlays (CI). Eighty-four intact maxillary premolars were taken, and endodontic treatment was performed followed by MOD cavity preparations (except in the control group). They were distributed into 7 groups based on type of restoration: intact teeth (control group), ETP + MOD (not restored), NHC, FRC + NHC, HFP + NHC, FRC + HFP + NHC, and CI groups. Samples were subjected to universal testing machine until the fracture occurred and failure mode was visually inspected. Mean and standard deviation of fracture resistance of the 7 groups ranged from 265.6 ± 68.0 N to 1023.7 ± 76.5 N. The highest reading was noted for intact teeth followed by FRC + HFP + NHC group and then the CI group, with no significant difference among the 3 groups. The lowest reading was noted for the ETP + MOD group. Maximum unrepairable fractures were seen in the ETP + MOD and CI groups. FRC + HFP + NHC combination and CIs increased the resistance to fracture of ETPs significantly. [ABSTRACT FROM AUTHOR]

In recent years, CAD/CAM technology has allowed indirect ceramic restorations to become a part of everyday chairside clinical practice. Therefore, the impact of different cavity-preparation designs on the fracture resistance of CAD/CAM fabricated ceramics was assessed in this study. Three designs of cuspal covering (none, palatal, and entire) and two widths of the occlusal isthmus (75% and 100% of the intercuspal distance) were used for the preparation of inlays and onlays to form six groups (n = 10/group). Moreover, thermomechanical cyclic loading was applied to every tooth under a chewing simulator. A universal testing machine was used to measure each group’s fracture resistance. The tested specimens were inspected for any signs of fractures and cracks to categorize failure patterns. Thereby, the values of fracture strength showed that there were statistically nonsignificant differences between the tested groups (p < 0.05). However, a significant difference (p = 0.01) was found between group 1 (inlays) (1950 ± 405) and group 6 (onlays) (3900 ± 770). Type III or type IV fracture modes were seen in the majority of the specimens. In conclusion, inlays and onlays made of zirconia using CAD/CAM technology were deemed reliable for restoring premolars, irrespective of the cavity-preparation design, except for inlays with a 75% intercuspal distance.

Aim: The present study evaluated the effect of different cavity configurations on stresses generated in maxillary first premolars restored with ceramic inlays and onlays using a finite element analysis (FEA). Materials and Methods: An extracted maxillary first premolar was used to generate a 3D FEA model from which three FEA models were designed for inlay designated as Group A and two FEA models for onlay designated as Group B. Further, based on the cavity design, they were subdivided into A1-mesio-occlusal, A2-disto-occlusal cavity, A3-mesio-occlusal distal cavity, and B1-conventional onlay preparation, B2-conservative onlay preparation. Leucite and lithium disilicate ceramics were the materials tested. An axial load of 200N was applied vertically on the Occlusal surface. A static FEA was performed to analyze the stresses generated. Outputs of minimal principal stresses (MPS-compressive) on enamel, maximum von Misses stress values in MPa in dentin, and restoration were recorded and tabulated. Results: MPS recorded in enamel were in the order GrA3 > GrA2 > Gr B1 > GrB2 >GrA1. The von Mises stresses generated in dentin were highest for GrA2 (65.4MPa), followed by Groups A3, A1, B2, and B1 (24.5MPa). The ceramic materials evaluated did not significantly influence the stresses. Conclusion: None of the cavity designs or the materials tested resulted in deleterious stresses leading to failure. Inlays and onlays prove to be reinforcing restorations in maxillary first premolars, with onlays having an embracing effect on the remaining sound tooth structure. [ABSTRACT FROM AUTHOR]

Abstract Background Evaluating the effect of different surface treatment methods on the micro-tensile bond strength (µTBS) of two different resin-matrix computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics (RMCs). Methods A standardized inlay preparations were performed on 100 intact maxillary premolars. According to the type of the restorative material, the teeth were randomly divided into two equally sized groups (n = 50): (polymer-infiltrated ceramic (Vita Enamic) and resin-based composites (Lava Ultimate)). The inlays were fabricated using CAD/CAM technology. In each group, the specimens were randomly assigned to five subgroups (n = 10) according to the surface treatment method: group 1 used was the control group (no surface treatment); group 2, was treated with air abrasion with 50 μm Al2O3 (A) and universal adhesive (UA); group 3, was treated with air abrasion with 50 μm Al2O3 (A) and silane coupling agent (S); group 4, was treated with hydrofluoric acid (HF) and universal adhesive (UA) and group 5, was treated with Hydrofluoric acid (HF) + silane coupling agent (S). The inlays were then cemented to their respective preparations using dual-cure self-adhesive resin cement (RelyX U200, 3 M ESPE) according to the manufacturer’s instructions. The µTBS test was conducted in all groups, and stereomicroscope and scanning electron microscope were used to inspect the failure mode. The data were statistically analyzed using a two-way analysis of variance (ANOVA) and Tukey’s post-hoc multiple comparison tests at a significance level of p

Copyright of Mersin University School of Medicine Lokman Hekim Journal of History of Medicine & Folk Medicine is the property of Mersin University School of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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ABSTRACT The CAD/CAM technology arose from the need to develop materials with better mechanical and optical properties that could be used for making monolithic restorations. Several materials have been used for milling indirect restorations in prefabricated blocks. Among them, lithium silicate reinforced with zirconia. Due to its recent introduction in the market, this case report aimed to present a detailed clinical protocol for the execution of a ceramic onlay of this material using CAD/CAM technology. A 57-year-old female patient sought care with extensive restoration in composite resin (BOMD) of tooth 15 maintained for almost two years. However, due to bruxism, constant dental tightening, the extension of the direct restoration and the need for improved esthetics, it was proposed to replace it with an indirect ceramic onlay restoration. Prophylaxis and choice of the color of the patient’s dental substrate were performed. Afterwards, the dental preparation was made and polished. Subsequently, the molding was made with addition silicone and the provisional restoration confectioned. Once the stone model was obtained, it was scanned and the ceramic onlay restoration was milled using CAD/CAM technology. Finally, the restoration was stained and cemented over the preparation. After 2 years, the restoration remained stable, with no evidence of color mismatch, marginal discoloration, marginal cleft, caries or fracture, proving the effectiveness of the treatment in this time interval. The correct indication of the ceramic material combined with the use of CAD/CAM technology facilitated the restorative process, restoring function and the esthetics desired by the patient.

Copyright of RGO: Revista Gaúcha de Odontologia is the property of RGO: Revista Gaucha de Odontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Evaluating the effect of different surface treatment methods on the micro-tensile bond strength (µTBS) of two different resin-matrix computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics (RMCs). Methods: A standardized inlay preparations were performed on 100 intact maxillary premolars. According to the type of the restorative material, the teeth were randomly divided into two equally sized groups (n = 50): (polymer-infiltrated ceramic (Vita Enamic) and resin-based composites (Lava Ultimate)). The inlays were fabricated using CAD/CAM technology. In each group, the specimens were randomly assigned to five subgroups (n = 10) according to the surface treatment method: group 1 used was the control group (no surface treatment); group 2, was treated with air abrasion with 50 μm Al2O3 (A) and universal adhesive (UA); group 3, was treated with air abrasion with 50 μm Al2O3 (A) and silane coupling agent (S); group 4, was treated with hydrofluoric acid (HF) and universal adhesive (UA) and group 5, was treated with Hydrofluoric acid (HF) + silane coupling agent (S). The inlays were then cemented to their respective preparations using dual-cure self-adhesive resin cement (RelyX U200, 3 M ESPE) according to the manufacturer's instructions. The µTBS test was conducted in all groups, and stereomicroscope and scanning electron microscope were used to inspect the failure mode. The data were statistically analyzed using a two-way analysis of variance (ANOVA) and Tukey's post-hoc multiple comparison tests at a significance level of p < 0.05. Results: Surface treatments significantly increased the µTBS of the materials compared to the control group (p < 0.05). For CAD/CAM RBCs, the µTBS value highest in group 2 whereas, for PICN, the µTBS value was highest in group 3. Cohesive failure of CAD/CAM restorative material was the most predominant mode of failure in all treated groups, whereas adhesive failure at restoration-cement interface was the most predominant failure mode in the control group. Conclusion: Surface treatments increase the µTBS of resin-matrix CAD/CAM ceramics to tooth structure. Air abrasion followed by universal adhesive and hydrofluoric acid followed by silane application appears to be the best strategies for optimizing the bond strength of CAD/CAM RBCs and PICN respectively. [ABSTRACT FROM AUTHOR]

Designing and fabricating dental restorations via the indirect method emerged as a strategic response to the loss of tooth coronal structure that prompted the need for different treatment options depending on the extent of the damage (eg, partial-coverage restorations such as inlays/onlays and laminate veneers, or full-coverage restorations such as crowns). The complexities of the oral environment and patient management in the dental chair also factored into the development of indirect restorations. Indirect restorations involve manufacturing them away from the oral cavity, avoiding some of the difficulties of direct techniques, such as polymerization contraction and marginal adaptation, as polymerization shrinkage stresses only affect the cement layer, reducing the impact on the cavity walls.

Aims To assess and compare how UK general dental practitioners (GDPs) restore endodontically treated molars and what tooth-related factors they consider relevant to their management.Method An online cross-sectional vignette survey was sent out to UK dentists via email and the use of social media platforms. Three clinical cases were designed.Results In total, 394 participants completed the survey. GDPs showed a preference towards restoring the endodontically treated molars with indirect restorations, such as crowns and onlays. Material selection varied, with a notable inclination towards gold and lithium disilicate. This was influenced by factors such as the number of remaining tooth walls, thickness of walls and the presence of parafunction.Conclusion Clinicians generally agreed on whether to place a direct or indirect restoration but there was greater disagreement when deciding on the type of restoration and material. Further evidence and education are required to help UK dentists decide more objectively whether to place an onlay or a crown, what material to select and what prognostic factors are most pertinent to the case., (© 2024. The Author(s).)

Statement of Problem: Current designs of fiber-reinforced composite (FRC) resin-bonded fixed dental prostheses (RBFDPs) have a limited lifespan, failing mainly through veneer-fiber delamination, debonding, and fracture., Purpose: The purpose of this in vitro study was to validate a new inlay-retained 2-unit cantilevered RBFDP with an optimized cavity and fiber layout proposed in a previous study by using simulated occlusal loading., Material and Methods: Two groups of specimens (n=20), 1 with and 1 without glass fibers, were used to test the influence of the cavity design and that of the fiber layout on their load capacity, respectively. The specimens without fibers were directly cut from a resin-ceramic block by using a computer-aided manufacturing system, while those with fibers were manually fabricated with unidirectional glass fibers and composite resin in a silicone mold. The specimens with and without fibers were attached to abutments made of the same resin-ceramic with a cyanoacrylate-based adhesive and a resin-based dental cement, respectively. An increasing compressive load was applied on the mesial fossa of the premolar pontic until failure. Cracking in the specimens during loading was monitored with a 2-channel acoustic emission (AE) system., Results: All the specimens without fiber reinforcement debonded from the abutments. Those using the optimized shovel-shaped cavity design had a mean ±standard deviation failure load (50.0 ±17.3 N) that was 193% higher than that of those with the conventional step-box design (17.1 ±6.2 N; P<.001). No significant difference was found between the groups for the mean number of AE events per specimen (step-box: 49 ±34 versus shovel-shaped: 63 ±34; P=.427), the mean amplitude of each event (58.4 ±1.3 dB versus 59.5 ±2.4 dB; P=.299), or the mean time to failure (283.2 ±122.3 seconds versus 297.5 ±66.7 seconds; P=.798). Between the groups of specimens with reinforcing fibers, the mean failure load of the conventional design was approximately half that of the optimized one. Again, no significant difference was found for the mean number of AE events per specimen (conventional: 28 ±18 versus optimized: 52 ±53; P=.248) or the mean amplitude for each AE event (64.9 ±4.2 dB versus 61.7 ±5.2 dB; P=.187). The connectors of 8 fiber-reinforced specimens with the conventional design fractured; the other 2 debonded from the abutments. Half of the shape-optimized fiber-reinforced specimens had fractured abutments, but the cantilevers remained intact, 4 specimens fractured at the connector, and only 1 debonded from its abutment., Conclusions: The shape-optimized 2-unit cantilevered FRC RBFDP had a higher load capacity than the conventional design., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Objectives: This prospective clinical trial evaluated the clinical performance of ceramic partial coverage indirect adhesive restorations (PCIARs) in posterior teeth luted with a light-cured composite resin., Methods: From April 2016 to January 2017, a total of 60 patients (27 males, 33 females; mean age: 42.2 ± 10.86 years old) received 83 glass-ceramic PCIARs (26 onlay, 57 overlay) made of IPS Emax CAD (Ivoclar Vivadent). All restorations were luted with a light-cured composite resin (Filtek Z250, 3 M ESPE) by two operators. Two independent calibrated examiners blinded to the operators performing the treatment evaluated the restorations at baseline, 1-year, and 5-year following FDI World Dental Federation criteria including esthetic, functional, and biological properties. Data were analyzed with the Friedman test and the Wilcoxon sign test (p < 0.05)., Results: None of the restorations failed due to fracture or retention loss. One restoration was clinically unsatisfactory because of secondary caries. Marginal staining (p:0.000), marginal adaptation (p:0.018) showed significant differences between 1-year and 5-year recall., Conclusions: The PCIARs demonstrated excellent clinical performance at 1-year period. The degradation parameters appeared as minor staining and minor irregularities after 5-year, without any affect on the clinical performance., Clinical Significance: Our findings provide evidence that the clinical performance of PCIARs luted with a light-cured composite resin was clinically acceptable after a five-year evaluation period. Due to secondary caries, only one restoration was considered clinically unsatisfactory., Clinicaltrials Registration Number: NCT04838483., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: To evaluate inlay and onlay marginal adaptation of two different ceramic materials using two intracoronal preparation designs., Materials and Methods: An examination of the marginal adaptation of two materials-lithium disilicate (LD; IPS e.max CAD) and polymer infiltrated ceramic network material (PICN; Vita Enamic)-and two preparation designs, where D1 represents MOD inlay preparation with no cusp reduction and for D2, in addition to the basic MOD preparation, the buccal cusps (functional cusps) were reduced by 1.5 mm. Four sub-groups (LD-D1, LD-D2, PICN-D1, PICN-D2) were conducted. In total, 40 (n &#61; 40) mandibular molars were used. A stereomicroscope was used to assess the marginal gap before, after cementation and after thermocycling. Values were calculated for the mean, median, SD, minimum, maximum, and 95% CI. Pairwise comparisons using Tukey post-hoc test were performed following an ANOVA significance of P ≤ .05., Results: The results revealed that lithium disilicate showed statistically significantly higher mean gap distance than PICN material (61 μm to 99 μm). Pairwise comparisons showed that D2 design has statistically significant higher mean gap values than D1., Conclusions: Both LD and PICN material provided marginal adaptation within clinical accepted range. PICN material restorations provided better fit than lithium disilicate restorations. Cusp coverage has a greater marginal gap compared to conventional preparation.

Background: Partial coverage concepts have met the main goal of conservative dentistry. Vonlays, which combine features of veneers and onlays, are a recent alternative to full coverage designs and overlay partial coverage restorations. This in vitro study was conducted to compare the fracture resistance of the newly introduced pressable zirconia-reinforced lithium silicate with pressable lithium disilicate ceramic and to determine the optimal preparation design for partial coverage on upper premolars., Methods: Fifty-two duplicated epoxy resin dies were prepared following vonlay and overlay preparation guidelines. For each preparation (n = 26), the specimens were divided into two subgroups to be restored with lithium disilicate (IPS e.max Press) or zirconia-reinforced lithium silicate (Vita Ambria) (n = 13 each). Ceramic vonlays and overlays were bonded using dual cure resin cement, subjected to thermomechanical fatigue, and the load to fracture was tested by using a universal testing machine. The specimens were fractographically analyzed via scanning electron microscopy (SEM). The normality of the fracture resistance data was checked using the Shapiro‒Wilk test and Q‒Q plots, and two-way ANOVA was used to assess the effect of the type of preparation and ceramic material on the fracture resistance., Results: The group of overlays restored with zirconia-reinforced lithium silicate showed the highest mean fracture load (1218.69 N), while the group of vonlays restored with lithium disilicate had the lowest mean fracture resistance (967.15 N). The effect of preparation design and material type on fracture resistance was significant for both factors, p = 0.003 and p < 0.0001, respectively. Different features of the fracture surfaces, such as arrest lines, hackles, and directions of crack propagation, were observed., Conclusions: Zirconia-reinforced lithium silicate exhibited greater resistance to fracture compared to lithium disilicate, making it a potential substitute for partial coverage restorations. Additionally, the overlay showed superior fracture resistance when compared to the vonlay preparation design., (© 2024. The Author(s).)

Background: The accuracy of intraoral scanning is critical for computer-aided design/computer-aided manufacturing workflows in dentistry. However, data regarding the scanning accuracy of various adjacent restorative materials and intraoral scanners are lacking. This in vitro study aimed to evaluate the effect of adjacent restorative material type and CEREC's intraoral scanners on the accuracy of intraoral digital impressions for inlay cavities., Methods: The artificial tooth was prepared with an occlusal cavity depth of 2 mm, a proximal box width at the gingival floor of 1.5 mm, and an equi-gingival margin extended disto-occlusally at the transition line angle on both the lingual and buccal sides for an inlay restoration. The adjacent teeth were veneered with crowns made of gold and zirconia, and an artificial tooth (resin) was utilized as the control group. The inlay cavity and adjacent teeth (Gold, Zirconia, and resin) were scanned 10 times using Chairside Economical Restoration of Esthetic Ceramics (CEREC) Primescan (PS), Omnicam (OC), and Bluecam (BC). A reference scan was obtained using a laboratory scanner (3-shape E3). Scanning was performed according to the manufacturer's instructions, including powder application for the BC group. Standard tesselation language files were analyzed using a three-dimensional analysis software program. Experimental data were analyzed using a two-way analysis of variance and the Tukey's post-hoc comparison test., Results: The restorative materials of the adjacent teeth significantly affected the accuracy of the intraoral digital impressions (p < .05). The zirconia group exhibited the highest trueness deviation, followed by the resin and gold groups, with each demonstrating a statistically significant difference (p < .05). The resin group demonstrated the highest maximum positive deviation and deviation in precision. Gold exhibited the lowest average deviation value for trueness compared with those of the other adjacent restorative materials. Intraoral scanner type significantly influenced the trueness and precision of the scan data (p < .05). The average deviation of trueness according to the intraoral scanner type increased in the following order: BC > PS > OC. The average deviation in precision increased in the following order: PS>OC>BC (p < .05)., Conclusion: The restorative materials of the adjacent tooth and the type of intraoral scanner affect the accuracy of the intraoral digital impression. The trueness of the digital images of the BC group, obtained by spraying the powder, was comparable to that of the PS group. Among the adjacent restorative materials, zirconia exhibited the lowest trueness. In contrast, PS demonstrated the highest precision among the intraoral scanners, while resin displayed the lowest precision among the adjacent restorative materials., (© 2024. The Author(s).)

A conservative approach to restoration assists in preserving the remaining tooth structure of extensively destroyed vital teeth. This case report describes a single-appointment chairside technique for placement of ceramic restorations in posterior teeth. A patient presented for treatment of her mandibular right first molar, which had a fractured resin-based composite restoration. Due to the presence of vital pulp, extent of the restoration, and presence of caries in the tooth, the following treatment plan was proposed: placement of a lithium disilicate glass-ceramic onlay fabricated with a computer-aided design/computer-aided manufacturing workflow. After the dentist removed the restoration and performed selective caries removal, structural analysis guided the reduction of the buccal cusps. Immediate dentin sealing was performed with a 2-step self-etching adhesive system, and a 1-mm-thick layer of flowable resin-based composite was placed as a resin coating. A digital impression was obtained, the onlay restoration was designed, and a lithium disilicate block was milled and subsequently crystallized. When the onlay was completed, the tooth preparation was sandblasted, selectively etched, and coated with a universal adhesive. The intaglio surface of the onlay was cleaned and primed, the onlay was bonded with dual-cure resin cement, and occlusal adjustments were completed. Follow-up examinations at 1 and 4 months revealed the clinical success of the case. From start to finish, it takes approximately 2.5 hours to produce a single-appointment chairside restoration. The technique used in this case offers a fast-paced workflow that is comfortable and practical for the patient and provides a predictable clinical outcome without the need for a temporary restoration., Competing Interests: No conflicts of interest reported.

Objectives: To evaluate the fabrication trueness of additively manufactured maxillary definitive casts with various tooth preparations fabricated with different 3-dimensional (3D) printers and print orientations., Methods: A maxillary typodont with tooth preparations for a posterior 3-unit fixed partial denture, lateral incisor crown, central incisor and canine veneers, first premolar and second molar inlays, and a first molar crown was digitized with an industrial scanner. This scan file was used to fabricate definitive casts with a digital light processing (DLP) or stereolithography (SLA) 3D printer in different orientations (0-degree, 30-degree, 45-degree, and 90-degree) (n = 7). All casts were digitized with the same scanner, and the deviations within each preparation site were evaluated. Generalized linear model analysis was used for statistical analysis (α = 0.05)., Results: The interaction between the 3D printer and the print orientation affected measured deviations within all preparations (P ≤ 0.001) except for the lateral incisor crown and canine veneer (P ≥ 0.094), which were affected only by the main factors (P < 0.001). DLP-90 mostly led to the highest and DLP-0 mostly resulted in the lowest deviations within posterior tooth preparations (P ≤ 0.014). DLP-30 led to the lowest deviations within the first premolar inlay and DLP-45 led to the lowest deviations within the central incisor veneer preparation (P ≤ 0.045)., Conclusions: Posterior preparations of tested casts had the highest trueness with DLP-0 or DLP-30, while central incisor veneer preparations had the highest trueness with DLP-45. DLP-90 led to the lowest trueness for most of the tooth preparations., Clinical Significance: Definitive casts with tooth preparations fabricated with the tested DLP 3D printer and the print orientation adjusted on tooth preparation may enable well-fitting restorations. However, 90-degree print orientation should be avoided with this 3D printer, as it led to the lowest fabrication trueness., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Ophthalmology is the branch of medicine that deals with diseases of the eye, the organ responsible for vision, and its attachments. Biomaterials can be made with different types of materials and can replace or improve a function or an organ, specifically the eye in the case of ophthalmic biomaterials. Biomaterials are substances that interact with biological systems for a medical purpose, either as a therapeutic (treat, augment, repair, or replace a tissue function of the body) or a diagnostic agent, and have continued to improve over the years, leading to the creation of new biomaterials. With the arrival of new generations, biomaterials have succeeded in reducing complications and toxicity and improving biocompatibilities associated with older generations. With the aging population, eye problems are becoming more prevalent, and biomaterials have helped in recent years to improve or restore vision, improving the quality of life of many patients. This review focuses on the most clinically used ophthalmic biomaterials, including contact lenses, intraocular lenses, artificial tears, inlays and vitreous replacements. Tissue engineering is presented as a new tool that is able to be treat several ophthalmologic disorders. [ABSTRACT FROM AUTHOR]

Background/Aim: The aim of this study was to evaluate the bond strength of glass ceramic inlay system using 2 antibacterial adhesive luting protocols with 2 cementation techniques to bur-cut dentin.

Objectives: This study evaluated the effect of deep margin elevation (DME) and restorative materials (leucite-reinforced glass–ceramics [C] vs. indirect resin composite [R]) on the fatigue behavior and stress distribution of maxillary molars with 2-mm deep proximal margins restored with MOD inlay. Methods: Fifty-two extracted human third molars were randomly assigned into four groups (n = 13): C; DME + C; R; and DME + R. Inlays were fabricated in CAD-CAM and bonded to all teeth. The fatigue behavior was assessed with the stepwise stress test (10,000 cycles/step; step = 50 N; 20 Hz; initial load = 200 N). Fatigue failure loads and the number of cycles were analyzed with 2-way ANOVA and Tukey's test (p < 0.05) and Kaplan–Meier survival plots. The stress distribution was assessed with finite element analysis. The models were considered isotropic, linear, and homogeneous, and presented bonded contacts. A tripod axial load (400 N) was applied to the occlusal surface. The stress distribution was analyzed with the maximum principal stress criterion. Results: For fatigue, there was no difference for DME factor (p > 0.05). For the material factor, the load and number of cycles for failure were statistically higher in the R groups (p < 0.05). The finite element analysis showed that resin composite inlays concentrated more stress in the tooth structure, while ceramic inlays concentrated more stress in the restoration. Non-reparable failures were more frequent in the resin composite inlays groups. Conclusions: DME was not negative for fatigue and biomechanical behaviors. Resin composite inlays were more resistant to the fatigue test, although the failure mode was more aggressive. Clinical significance: DME does not impair mechanical behavior. Resin composite inlays failed at higher loads but with a more aggressive failure mode. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the occlusal and internal marginal adaptation of inlay restorations made of different materials, using CAD-CAM. Methods: Preparations were made for MOD inlays of one-third intercuspal width and 4 mm depth in 30 third human molars. The teeth were restored using CAD-CAM materials (n=10) of nanoceramic resin (Lava Ultimate), polymer-infiltrated ceramic network (VITA ENAMIC), or lithium disilicate glass-ceramic (IPS e.max CAD). The specimens were cemented with dual resin cement and sectioned at the center of the restoration, after which the two halves were evaluated, and photographed The occlusal and internal discrepancy (µm) was determined at five points: cavosurface angle of the occlusal-facial wall (CA-O); center of the facial wall (FW); faciopulpal angle (FPA); center of the pulpal wall (PW); and center of the lingual wall (LW). The data were submitted to the Kruskal-Wallis and the Dunn tests (a=0.05). Results: No difference was observed among the materials regarding the occlusal discrepancy at the CA-O, FPA, or PW internal points. The e.max CAD measurement at FW showed larger internal discrepancy than that of Lava (p=0.02). The internal discrepancy at LW was greater for e.max CAD than VITA ENAMIC (p=0.02). Conclusion: Lithium disilicate glass-ceramic presented greater internal discrepancy in relation to the surrounding walls of the inlay preparations. [ABSTRACT FROM AUTHOR]

Background/Aim: The purpose of this in-vitro study was to compare the resin-bonded fixed partial dentures (RBFPD) fabricated using two different structural designs and two different antibacterial adhesive lutting protocols in regard to their resistance to debonding.

Context: Marginal fit being the prime concern of indirect restorations. Inlays can be either fabricated by conventional technique or computer-aided design and computer-aided manufacturing (CAD/CAM) techniques. CAD/CAM is the most evolving digital technique with faster, quicker, and precise results. Aims: The aim of this study is to evaluate and compare the marginal fit of MOD inlays fabricated with two different CAD/CAM methods and conventional fabrication methods. Settings and Design: Mesio-occlusal-distal preparation was done on a maxillary premolar typhodont tooth and divided into the following groups. Group A: 30 inlays were fabricated through the conventional impression technique. Group B: Preparation was scanning using an intraoral scanner followed by subtractive milling (Group B1) and subtractive milling of wax patterns (Group B2). Similarly, subgrouping was carried out for Group C except that an extraoral scanner was used. Occlusal and the cervical marginal fit were assessed using the replica technique and stereomicroscope. One-way ANOVA followed by Tukey honestly significant difference post hoc test for determining differences at a 95% level of confidence (P = 0.05). Results: Group A had the highest marginal discrepancy in comparison to Group B and Group C at occlusal and cervical edges, whereas subtractive milling showed comparatively better results than subtractive milling of wax patterns at cervical edges and similar results at occlusal edges. Conclusions: Ceramic inlays fabricated by subtractive milling yielded better results.

The purpose. The features of the restructuring of the lymphoid component of periodontal disease in experimental diabetes mellitus and in the combination with experimental diabetes mellitus with the presence of photopolymer or cement fillings were studied in this research. Materials and methods. The histological, immunohistochemical and lectohistochemical methods were used, the number of antigen-presenting cells, T and B lymphocytes in the periodontium during six weeks was studied. Results. In experimental diabetes mellitus, the number of SBA+-B-lymphocytes doubles than normal. The combination of photopolymer fillings and experimental diabetes mellitus led to an increase in the number of subpopulations of CD4+-, CD8+-lymphocytes by 15–20 %. At the same time, the number of intraepithelial HPA+-lymphocytes increased, which indicates the activation of the cellular immunity unit. In experimental diabetes mellitus, during the entire observation period, there was an increase in the number of subpopulations of CD4+-lymphocytes, compared with the control group. Their number was 4,01 ± 0,01 per conventional unit of area. Conclusions. In animals of the intact group, the periodoid lymphoid component is represented by antigen-presenting cells, CD5+-, CD4+-, CD8+-lymphocytes of the gum epithelium and lymphocytes of the lamina propria. In experimental diabetes mellitus, activation of antigen-presenting cells, cellular and humoral immunity is observed. When comparing the reactivity of the lymphoid component of the gums, the greatest shifts are observed in the presence of a photopolymer filling, in contrast to the cement, especially the humoral immunity. With a combination of experimental diabetes mellitus and the presence of filling material, more pronounced changes in the structure of the lymphoid component are noted in the presence of a photopolymer filling than cement.

Background: The purpose of this in vitro study was to compare and evaluate the stress distribution of maxillary first premolar residual crowns restored with post-core crowns, endocrowns and inlay crowns after deep margin elevation, to explore the fitting restoration for residual crowns using finite element analysis., Methods: A healthy complete right maxillary first premolar from a male adult was scanned by cone beam computed tomography (CBCT). The finite element model of the tooth was established by reverse engineering software such as Mimics, Geomagic and Hypermesh. On this basis, the residual crown model after deep margin elevation was made, and the experimental group models were divided into three groups, those restored with post core crowns, endocrowns and inlay crowns. Vertical and oblique static loads were applied to the experimental models to simulate the force on the tooth during mastication (the loading position was located in the central fossa of the occipital surface, and the load was 100 N) using Abaqus software., Results: The peak value and distribution of von Mises stress in each part of the experimental model were observed. After deep margin elevation, the peak dentin von Mises stresses were lower than the tensile strength of normal dentin in the post-core crown, endocrown, and inlay crown groups; the lowest stress results were found in the post-core crown group for the dentin, restoration, enamel, and deep margin elevation (DME) layers under vertical and oblique loading. In terms of stress distribution clouds, the peak stresses in the dentin tissue were located in the apical 1/3 of the root after postcore crown restorations for both loads, while stress concentrations were evident in the cervical and root areas after endocrown and inlay crown restorations; regardless of the load and restoration method, the corresponding stress concentration areas appeared at the junction of the DME and dentin tissue at the loading site of the restorations; CONCLUSIONS: Post-core crowns, endocrowns and inlay crowns can be used to restore residual crowns after deep margin elevation, and post-core crowns can better protect the residual tooth tissue., (© 2024. The Author(s).)

Statement of Problem: The trueness and precision of intraoral scanners (IOSs) and the effect of intracoronal restorations have been reported. However, studies addressing the accuracy of IOSs in reproducing different complete coverage onlay preparation designs are lacking., Purpose: The purpose of this in vitro study was to evaluate the influence of complete coverage onlay preparation design and intraoral scanning devices on the accuracy of digital scans in terms of trueness and precision., Material and Methods: Three preparation designs on the mandibular first molar were considered: a traditional preparation design with isthmus reduction (IST), a traditional preparation design without isthmus reduction (wIST), and simplified nonretentive preparation (nRET). Digital scans of epoxy resin mandibular arch reference models of the preparations (containing second premolar, first molar, and second molar) were obtained by using 3 IOSs (iTero Element 2 [ELE], TRIOS 3 [TRI], and Primescan [PRI]) (n=10). Trueness (μm) and precision (μm) were analyzed by superimposing the digital scan on the digital reference models obtained with a high-accuracy industrial scanner (ATOS Core 80) in a tridimensional metrology software program. Accuracy was quantified by the absolute deviation (μm). Local and overall mean positive and negative deviations for trueness were also obtained. Data were analyzed by using the Kruskal-Wallis and Dunn tests with a statistical software program (α=.05)., Results: The nonretentive preparation groups obtained higher trueness (3.8 μm) and precision (2.7 μm) than the IST and wIST groups (trueness=7.5 to 6.3 μm, precision=5.5 to 4.6 μm). Trueness values were lower with ELE×IST (16 μm), followed by ELE×wIST (13 μm), and PRI×IST (7.8 μm). In general, no difference was found between PRI and TRI scanners (6.3 to 5.9 μm), with lower performance for ELE (13 μm). Positive deviations were higher on the proximal box of the IST and wIST preparation and on the occlusal box of the IST group. Negative deviation was higher on the ELE×IST occlusal box., Conclusions: Different intraoral scanners and preparation designs influenced the accuracy of digital scans. A more complex preparation such as IST and wIST showed higher deviation. The iTero Element 2 scanner exhibited higher deviation for both trueness and precision., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

This study aimed to evaluate the effects of different resin-coating technique strategies and dual-cure resin luting materials on proximal marginal adaptation and the microtensile bond strengths (μTBSs) of CAD/CAM hybrid ceramic inlays. Extracted human molars were classified into four groups, depending on the coating technique: No coating (None), single coating (1-coating), double coating (2-coating), and flowable resin-coating (Combination). The inlays were bonded with one of the three materials: Panavia V5 (V5), Rely X Ultimate (RXU), and Calibra Ceram (CC). The differences with regard to adaptation were not significant. In the case of μTBS data for V5, no significant differences were observed, whereas for RXU, μTBS values for Combination statistically exceeded those for None and 1-coating. For CC, μTBS values for Combination statistically exceeded those for None, 1-coating, and 2-coating. The coating techniques did not influence the adaptation but influenced the bond strength, and Combination performed the best.

Statement of Problem: More data are needed on the influence of preparation design on the fracture strength, failure type, repairability, and polymerization-induced cracks of molar teeth restored with direct composite resin restorations., Purpose: This in vitro and finite element analysis study investigated the effect of different preparation designs on fracture strength, failure type, repairability, tooth deformation, and the formation of polymerization-induced cracks of compromised molars restored with direct composite resin restorations., Material and Methods: Human molars (n=64) were randomly assigned to 4 different preparation designs: undermined inlay (UI), extended inlay (EI), restricted overlay (RO), and extended overlay (EO). The teeth were restored using direct composite resin and subjected to artificial thermomechanical aging in a mastication simulator, followed by load-to-failure testing. Three-dimensional (3D) finite element analysis was conducted to assess tooth deformation. Polymerization-induced cracks were evaluated using optical microscopy and transillumination. The fracture strength data were analyzed using a Kruskal-Wallis test, while the failure mode, repairability, and polymerization cracks were analyzed using the Fisher exact test (α=.05)., Results: All specimens withstood thermomechanical aging, and no statistically significant difference in fracture strength was observed among the 4 preparation designs (P>.05). The finite element analysis showed differences in tooth deformation, but no correlation was observed with in vitro fracture resistance. The RO and EO groups presented significantly more destructive failures compared with the UI and EI groups (P<.01). The RO group had significantly fewer repairable failures than the UI and EI groups (P=.024). A correlation was found between higher frequencies of repairability and higher tooth deformation. A significant correlation between the increase in microfractures and preparation design was observed (P<.01), with the UI group exhibiting a higher increase in microfracture size compared with the EO group (P<.05)., Conclusions: No influence of preparation design on the fracture strength of compromised molars restored with direct composite resin restorations was evident in this study, but the failure mode of cusp coverage restorations was more destructive and often less repairable. The finite element analysis showed more tooth deformation in inlay preparations, with lower stresses within the root, leading to more reparable fractures. Since cusp coverage direct composite resin restorations fractured in a more destructive manner, this study suggests that even a tooth with undermined cusps should be restored without cusp coverage., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: The aim of this study was to evaluate, in a case control study, the esthetic and functional clinical performance of ceramic inlays used for covering the screw access hole in single monolithic lithium disilicate full-contour crowns bonded on computer-aided design/computer-aided manufacturing (CAD/CAM) prefabricated titanium abutments in order to eliminate the drawbacks of alternative restorative methods. Materials and Methods: Twenty-eight patients with missing teeth in the lateral areas (premolars and molars) received screw-retained implant restorations. In half of the restorations (n = 14), composite fillings were used to seal the access hole (control group), while the other half was sealed with ceramic inlays (test group). To determine the restoration occlusal wear, impressions were obtained after the restorations were finalized, at 1 year, and at 2 years follow-up. The casts were scanned with a 3D Scanner Design System recording the anatomical surfaces of the white model replicates. Wear amounts (µm) were calculated as the maximum loss in height of the occlusal surface. The clinical evaluation was carried out using a kit specifically designed for assessing the FDI criteria. Statistics were performed using analysis of variance (ANOVA). Results: A total of 58 restorations were delivered, and after 2 years of follow-up, the wear values were 228.20 ± 54.68 µm for the control group and 65.20 ± 7.24 µm for the ceramic inlay group. One-way ANOVA showed significant differences among the vertical loss between these two groups (P < .001). Clinical outcomes according to the FDI score for assessing dental restorations revealed substantial deterioration within 2 years of follow-up. Conclusion: The use of ceramic inlays appears to be a predictable, esthetic, and successful method of sealing the screw holes of the screw-retained implant restorations. [ABSTRACT FROM AUTHOR]

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Introduction: The extensively damaged teeth can be treated with the inlay and onlay. The ceramic inlays and onlays can be prescribed for the esthetic needs of the patient. Hence in our study, we aim to evaluate clinically the outcomes of the ceramic inlays and onlays for the posterior teeth. Materials and Methods: We piloted a retrospective analytical study from the departmental records. We included 70 patients who had a total of 160 ceramic inlays and onlays prepared between the years 2010-2020. The survival and the failure rates were noted and compared using the "Kruskal-Wallis H statistics and the Chi-square tests" deliberating P < 0.05 as significant. Results: The mean survival was 6.1 ± 1.8 years. The success rate was 92.21% and the failure was 7.6%. Significant variation was seen with the survival rate between the vital and nonvital teeth and between the molars and premolars. Conclusions: The ceramic inlays and onlays were performed successfully in the posterior teeth with a high survival rate and very low failure. [ABSTRACT FROM AUTHOR]

Ophthalmology is the branch of medicine that deals with diseases of the eye, the organ responsible for vision, and its attachments. Biomaterials can be made with different types of materials and can replace or improve a function or an organ, specifically the eye in the case of ophthalmic biomaterials. Biomaterials are substances that interact with biological systems for a medical purpose, either as a therapeutic (treat, augment, repair, or replace a tissue function of the body) or a diagnostic agent, and have continued to improve over the years, leading to the creation of new biomaterials. With the arrival of new generations, biomaterials have succeeded in reducing complications and toxicity and improving biocompatibilities associated with older generations. With the aging population, eye problems are becoming more prevalent, and biomaterials have helped in recent years to improve or restore vision, improving the quality of life of many patients. This review focuses on the most clinically used ophthalmic biomaterials, including contact lenses, intraocular lenses, artificial tears, inlays and vitreous replacements. Tissue engineering is presented as a new tool that is able to be treat several ophthalmologic disorders.

A clinical and functional examination of the maxillofacial area was performed in 280 patients with the defects of the lateral teeth being replaced with ceramic crown inlays or light-cured composites three years ago. Computer methods were used to assess the articulation, occlusion and tone of the masticatory muscles on the T-Scan III and Bio EMG III devices. In a third of the lateral teeth, an unreasonable increase in indications to composite fillings has been established when more than 50.0% of the occlusal surface is destroyed. Indicators of dental status are significantly better when using ceram- ic inlays compared with fillings made of composite material in the long term after treatment of multiple caries. Ceramic crown inlays prevent occlusal-articulatory disorders and dysfunction of the masticatory apparatus, characteristic in long-term periods for patients with multiple caries when replacement of lateral teeth defects with fillings made of composite.

Inlay-retained dental bridges can be a viable minimally invasive alternative when patients reject the idea of implant therapy or conventional retained full-coverage fixed dental prostheses, which require more tooth preparation. Inlay-retained dental bridges are indicated in patients with good oral hygiene, low susceptibility to caries, and a minimum coronal tooth height of 5 mm. The present study aims to evaluate, through the finite element method (FEM), the stability of these types of dental bridges and the stresses on the supporting teeth, under the action of masticatory forces. The analysis revealed the distribution of the load on the bridge elements and on the retainers, highlighting the areas of maximum pressure. The results of our study demonstrate that the stress determined by the loading force cannot cause damage to the prosthetic device or to abutment teeth. Thus, it can be considered an optimal economical solution for treating class III Kennedy edentation in young patients or as a provisional pre-implant rehabilitation option. However, special attention must be paid to its design, especially in the connection area between the bridge elements, because the connectors and the retainers represent the weakest parts. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of the cementation strategy and mechanical cycling (MC) on the microtensile bond strength (MTBS) of feldspathic inlays cemented to premolars. Materials and Methods: Forty-eight human premolars were prepared and porcelain inlays were produced. Specimens were allocated into 3 groups, based on the cementation strategy: 1) conventional adhesive cementation (RelyX ARC, 3M ESPE): application of etch-and-rinse single bottle adhesive to dentin / ceramic surface treated with hydrofluoric acid (HF) and silane (S) / cementation with resin cement; 2) simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE); 3) modified simplified cementation using a self-adhesive resin cement (RelyX U100, 3M ESPE) with HF+S treatment. Half of the specimens from each group were submitted to MC (2x106 pulses, frequency = 4 Hz, load = 100 N). Each specimen was serially sliced for MTBS and the failures were classified. The stress distribution analysis using FEA was verified. Results: All of the bar-samples from G2 were lost during cutting of the specimens. Mechanical-cycling had no significant effect on bond strength, whereas cementation strategy significant affected MTBS results. The most common type of failure was cohesive of cement. FEA showed that stresses were concentrated mainly at the loading region going up to the root fixation. Conclusion: Porcelain inlays cemented with conventional resin cement or self-adhesive resin cement should be associated with ceramic surface treatment. FEA showed the most critical zone for failure is located in the cement region close to the marginal crest. [ABSTRACT FROM AUTHOR]

Objectives: To assess the long-term clinical performance of ceramic in-/onlays (CIOs) and cast gold partial crowns (CGPCs) in posterior teeth in terms of success, survival, complications (biological, technical) and quality., Material and Methods: In a retrospective study, a total of 325 patients were recorded after up to 24.8 years (mean 13.9 ± 3.8 years) having (pre-)molars restored with CIO (Empress I, Ivoclar Vivadent, n = 161) and CGPC (Degunorm, DeguDent, n = 164) by supervised undergraduate students. A total of 296 restorations were assessed clinically and radiologically in healthy and endodontically treated teeth using modified United States Public Health Service (USPHS) criteria. Cumulative success and survival rates of the restorations were calculated using Kaplan-Meier estimates. Biological and technical complications were recorded. Status of oral health comprising caries risk and localized periodontitis were assessed., Results: The cumulative success rates of CIOs were 92.1% and of CGPCs 84.2% after mean service times of 14.5 years. The annual failure rates of total service times were 0.5% in teeth restored with CIO (n = 155) and 0.7% in teeth restored with CGPC (n = 163). The cumulative survival rates of CIOs were 93.9% after a mean service time of 15.2 years and decreased to 91.7% after 23.5 years. The cumulative survival rates of CGPCs were 92.6% after a mean service time of 14.9 years and 91.8% after 23.5 years. Complications in CIOs (n = 149) were ceramic fracture (6.7%), secondary caries (4.7%), endodontic complication (2.7%) and tooth fracture (1.3%) compared to CGPCs (n = 147) with endodontic complication (8.8%), secondary caries (4.8%) and decementation (2.0%). Endodontically treated teeth restored with CIO or CGPC revealed significantly less often success compared with corresponding vital teeth (p = .02). CIOs and CGPCs revealed clinically and radiographically good and excellent qualities with 71.8% (107/149) and 68% (100/147) without any significant differences regarding type of restoration., Conclusions: Both CIOs and CGPCs achieved high survival rates up to 24.8 years when performed by supervised undergraduate students. The longevity of the restorations may benefit from the intraoral repair of accessible defects and, in case of pulp infection or necrosis, an adequate endodontic management., Clinical Relevance: CIOs and CGPCs made by supervised undergraduate students are proper restoration types in posterior teeth in the long-term. An adequate preparation design, meticulous care in the inserting technique and constant biofilm removal due to proper oral hygiene combined with professional maintenance care are substantial. The clinical long-term performance was mostly limited by ceramic fractures in CIOs and endodontic complications in CGPCs., (© 2024. The Author(s).)

Introduction: Accurate inlay preparation is extremely important in pre-clinical training. However, there is a lack of tools to guide students to efficiently practise inlay preparation. Therefore, a 3D-printed coloured tooth model for inlay preparation was designed to guide beginners to practise inlay preparation by themselves according to different colour prompts. This study aimed to evaluate the benefits of using a 3D-printed coloured tooth model in the pre-clinical training on inlay preparation., Materials and Methods: Twenty-eight students in their fourth-year undergraduate dental program participated in this study. The participants were randomly assigned to two groups for the inlay preparation. Group 1 prepared a plain tooth model for the first and fourth attempts and a 3D-printed coloured tooth model for the second and third attempts (n = 14). Group 2 prepared four plain tooth models (n = 14). The first and fourth tooth models prepared by both groups were scored using an evaluation system (Fair Grade 2000, NISSIN). Next, questionnaires answered by students were used to evaluate the benefits of using a 3D-printed coloured tooth model and self-evaluate hands-on ability using a grading system (1 = strongly agree, 2 = agree, 3 = neutral, 4 = disagree, and 5 = strongly disagree). The scores were evaluated statistically using the Mann-Whitney U test, and the given grades are displayed as percentages and mean values., Results: There was an overall increase in the clinical confidence of all students after repeated attempts to prepare an inlay; however, students from group 1, who had used the 3D-printed coloured tooth model, had more positive experiences and comments. The 3D-printed coloured tooth model for inlay preparation has been widely praised by participants. Comparing the average score of the first and fourth preparations, the average score of group 1 increased by 12% (Ø 54.46 ± 8.33, Ø 61.11 ± 7.13, p = .090), while that of group 2 increased by 0.72% (Ø 56.39 ± 9.59, Ø 56.80 ± 8.46, p = .925)., Conclusion: Students favoured the use of the 3D-printed coloured tooth model, and this improved the average score for inlay preparation. The 3D-printed coloured tooth model for inlay preparation is expected to play an important role in dental education in the future., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: To compare the volumetric loss of clinical crown structure in commonly encountered clinical situations for monolithic ceramic crowns, occlusal overlays, and partial-coverage onlays., Materials and Methods: Typodont teeth made with preexisting mesio-occlusodistal (MOD) preparations for mandibular first molars and maxillary first premolars were prepared with three different preparations: a full-contour monolithic zirconia crown, a lithium disilicate occlusal overlay, and mesio-occlusodistobuccal/mesio-occlusodistolingual (MODB/MODL) lithium disilicate onlays for premolars and molars. 3D-metrologic software was used to evaluate the volumetric loss of clinical crown structure for each preparation type. Subsequently, the mesiolingual cusps of mandibular molars and buccal cusps of maxillary premolars were excluded for a separate analysis to simulate patient presentation with an existing restoration and sheared-off cusp., Results: Full-coverage monolithic zirconia crowns removed 45.37 to 219.53 mm3 of the remaining clinical tooth structure, depending on the clinical scenario and tooth position, while lithium disilicate overlays removed 27.48 to 105.13 mm3 and MODB/MODL lithium disilicate onlays removed 5.48 to 47.45 mm3. In each scenario tested, MODB/MODL onlays removed significantly less clinical crown structure than overlays (P < .001); both MODB/MODL onlays and overlays removed significantly less structure than full-coverage crowns (P < .001)., Conclusions: Monolithic zirconia crown restorations require significantly more removal of remaining tooth structure than lithium disilicate occlusal overlays and partial-coverage onlays for commonly occurring clinical situations requiring indirect restorations.

Purpose: To evaluate the marginal integrity of three inlay-retained fixed dental prosthesis (IRFDP) designs fabricated using monolithic zirconia., Materials and Methods: In total, 30 IRFDPs were fabricated using 4-YTZP monolithic zirconia and randomly divided into three groups according to the cavity design. Groups ID2 and ID1.5 received an inlay cavity preparation, which includes a proximal box and an occlusal extension with a depth of 2 mm or 1.5 mm, respectively. Group PB received a proximal box cavity preparation without an occlusal extension. The restorations were fabricated and cemented using a dual-cure resin cement (Panavia V5) and subjected to an equivalent of 5 years of aging. The specimens were evaluated under an SEM to measure marginal continuity before and after the aging process., Results: During the whole 5-year aging process, no specimens showed signs of cracking, fracture, or loss of retention in any restorations. In the SEM analysis, most marginal defects observed in the restorations were areas of microgaps at the tooth/cement interface (TC) or zirconia/cement interface (ZC), resulting in loss of adaptation. There was a significant difference between the groups after the aging process at both the TC (F = 4.762, P < .05) and ZC (F = 6.975, P < .05), with Group ID2 presenting the best performance. There was a significant difference between TC and ZC in all groups (P < .05), with ZC presenting more gaps in all groups., Conclusions: Inlay cavity designs including a proximal box and an occlusal extension exhibited better marginal stability than a proximal box without occlusal extension.