Two-year performance of CAD/CAM fabricated resin composite inlay restorations: A randomized controlled clinical trial

Clinical performance comparison between lithium disilicate and hybrid resin nano-ceramic CAD/CAM onlay restorations: a two-year randomized clinical split-mouth study

A total of 20 lithium disilicate glass-ceramics (IPS e.max CAD, Ivoclar Vivadent) and 20 resin nano-ceramic (Voco Grandio Blocks) onlay restorations were performed in 20 patients using a split-mouth design to compare the two-year clinical performance of lithium disilicate and resin nano-ceramic onlay restorations. Both restorations were evaluated at baseline, one-year, and two-year clinical follow-ups based on the modified United States Public Health Service (USPHS) criteria. Chi-square and Fisher's exact tests showed no statistically significant difference between Voco Grandio and IPS e.max ceramic restorations for all evaluated parameters during the different follow-up periods (p > 0.05). Cochrane's and MC-Nemar's tests indicated statistically significant differences regarding color match within the Voco Grandio group. They also indicated statistically significant differences in marginal discoloration, marginal adaptation, surface texture, and postoperative hypersensitivity within both ceramic material groups (p < 0.05). Kaplan-Meier curve indicated that the survival rate of both ceramic materials was 90%. After two years of clinical service, IPS e.max CAD and Voco Grandio onlay restorations exhibited similar clinical performance.

Two‑year clinical performance of indirect restorations fabricated from CAD/CAM nano hybrid composite versus lithium disilicate in mutilated vital teeth. A randomized controlled trial

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.

The Effect of Laser Irradiation to Surfaces of Computer-Aided Design/Computer-Aided Fabrication Resin Blocks Coated with a Silane Coupling Agent on Bond Strength between the Resin Blocks and Composite Resin

The aim of this study was to investigate the effect of laser irradiation to computer-aided design/computer-aided fabrication (CAD/CAM) resin blocks coated with a silane coupling agent on the bond strength between resin blocks and composite resin. The CAD/CAM resin blocks used in this study were Cerasmart 300 (GC) and Vita Enamic (Vita); they were cut into plates and then subjected to a series of treatments. After processing with a silane coupling agent, treatment with a semiconductor laser was performed at 3.0, 5.0, and 7.0 W, followed by bonding procedures. The control group included those exposed to silane and bonded without laser application. After bonding, a mold with a simulated cavity was formed on the specimen and filled with flowable composite resin, and they were stored for 24 h or stressed by thermal cycling for subsequent testing that assessed the shear bond strength (n = 10). The results revealed that the bond strength was significantly enhanced by laser irradiation after applying a silane coupling agent (p < 0.03), whereas significant increase was not detected between the materials (p > 0.05). Particularly, 7 W laser irradiation had a significant increase on the bond strength between the composite resin and Cerasmart block after thermal cycling (p = 0.009). The SBS of the composite resin to CAD/CAM resin blocks was significantly enhanced by laser irradiation after silane coupling agent application.

Clinical longevity of direct and indirect posterior resin composite restorations: An updated systematic review and meta-analysis

OBJECTIVES

To answer the PICO(S) question: Is there a difference in clinical longevity between direct and indirect resin composite restorations placed on permanent posterior teeth?

DATA

Randomized controlled clinical trials (RCTs) investigating direct and indirect resin composite restorations in posterior permanent teeth were considered.

SOURCES

Several electronic databases were searched, with no language or date restrictions. The revised Cochrane Collaboration's tool for assessing risk of bias (RoB-2) was used to analyze the studies; meta-analyses were run and the certainty of evidence was assessed by the GRADE tool. A subgroup meta-analysis was performed for resin composite restorations placed on posterior worn dentition.

STUDY SELECTION

Twenty-three articles were included in qualitative synthesis, while 8 studies were used for meta-analyses. According to the RoB-2 tool, 5 studies were ranked as "low risk", 7 had "some concerns", while 11 papers were rated as "high risk" of bias. There were no statistically significant differences in short-term (p = 0.27; RR=1.54, 95% CI [0.72, 3.33]), medium-term (p = 0.27; RR=1.87, 95% CI [0.61, 5.72]) and long-term longevity (p = 0.86; RR=0.95, 95% CI [0.57, 1.59]). The choice of restorative technique had no influence on short-term survival of resin composite restorations placed on worn dentition (p = 0.13; RR=0.46, 95% CI [0.17, 1.25]). The certainty of evidence was rated as "very low".

CONCLUSIONS

Direct and indirect resin composite restorations may show similar clinical longevity in posterior region, regardless of the observation period or substrate (wear-affected and non-affected dentition). The very low quality of evidence suggests that more long-term RCTs are needed to confirm our results.

Clinical evaluation of lithium disilicate versus indirect resin composite partial posterior restorations - A 7.8-year retrospective study

OBJECTIVE

To evaluate retrospectively the longevity of lithium disilicate ceramic (LidiSi) vs. laboratory-processed resin-based composite (RBC) inlay/onlay/overlay restorations and risk factors associated with restoration deficiencies and failures.

METHODS

Patients (n = 91) receiving LidiSi (73.1%) and RBC (36.9%) inlays/onlays/overlays between 2007 and 2017 were selected. The restorations were evaluated using the modified U.S. Public Health Service criteria. The survival of the restorations was analyzed using the Kaplan-Meier method and log rank test. Factors affecting the occurrence of deficiencies were examined by logistic regression analysis. This was performed with the use of the Generalized Estimating Equation model including Repeated measurements (GEER), with the consideration that the same patient had several teeth in the sample. Risk estimation was conducted for each evaluated criterion (p < 0.05).

RESULTS

The survival of LidiSi and RBC restorations were 96.8% and 84.9%, respectively after a mean observation period of 7.8 ± 3.3 years. The annual failure rate was 0.2% for LidiSi and 1.0% for RBC. The probability of survival was above 98% for both restorations in the first 6 years, however, it dropped to 60% for RBC by the end of the 15th year. For both materials the reasons for failure included secondary caries, restoration fracture, and endodontic complication. In addition, LidiSi also failed due to tooth fracture, while RBC due to marginal gap formation and loss of retention. Among the evaluated risk factors, material of restoration (OR=6.8, CI95%:3.1-14.9), oral hygiene (OR=8.0, CI95%: 2.9-22.1], and bruxism (OR=1.9, CI95%: 1.1-3.3) showed a significant impact on the evaluated criteria.

SIGNIFICANCE

LidiSi and RBC restorations showed similarly excellent 6-year survival, however, in the long term significantly more failures should be expected for RBCs.

Mechanical Properties of Three-Dimensional Printed Provisional Resin Materials for Crown and Fixed Dental Prosthesis: A Systematic Review

The emergence of digital dentistry has led to the introduction of various three-dimensional (3D) printing materials in the market, specifically for provisional fixed restoration. This study aimed to undertake a systematic review of the published literature on the Mechanical Properties of 3D- Printed Provisional Resin Materials for crown and fixed dental prosthesis (FDP). The electronic database on PubMed/Medline was searched for relevant studies. The search retrieved articles that were published from January 2011 to March 2023. The established focus question was: "Do provisional 3D-printed materials have better mechanical properties than conventional or milled provisional materials?". The systematically extracted data included the researcher's name(s), publication year, evaluation method, number of samples, types of materials, and study outcome. A total of 19 studies were included in this systematic review. These studies examined different aspects of the mechanical properties of 3D-printed provisional materials. Flexural Strength and Microhardness were the frequently used mechanical testing. Furthermore, 3D-printed provisional restorations showed higher hardness, smoother surfaces, less wear volume loss, and higher wear resistance compared to either milled or conventional, or both. 3D-printed provisional resin materials appear to be a promising option for fabricating provisional crowns and FDPs.

Current treatment approaches of newly graduated, intern dentists and dentists in doctoral and specialty training to teeth with excessive substance loss (cross-sectional study)

Aim: New treatment options have been developed as alternative post-retaining restorations and crowns that preserve remaining tooth tissue in endodontically treated teeth with excessive substance loss. This study, current treatment approaches newly graduated, intern and doctoral or specialist dentists in teeth excessive coronal destruction were evaluated. Material and Method: This cross-sectional study, online questionnaire consisting of 22 questions, 3 parts was applied. First part consists of demographic information participants, second part consists of questions measuring awareness about preferred indirect restorations, last part consists of current treatment approaches newly graduated, intern and doctoral or specialist dentists. Total 234 voluntary participants questionnaires were evaluated. Obtained data were analyzed with IBM SPSS V23. Results: In restoration of endodontically treated buccal mesial walls (least 2 mm thick) molars, participants all 3 groups preferred posterior adhesive indirect restorations according to their titles. Considering level of awareness, participants high group preferred posterior adhesive indirect restorations more in restorations endodontically treated buccal lingual walled molar teeth. Participants all 3 groups preferred use fiber under composite strengthen teeth in the restoration of teeth with excessive substance loss. Conclusion: According to the results, it was determined that awareness and knowledge level of dentists who received specialty or doctoral training about new current treatments was higher than other newly graduated and intern dentists. It was observed that participants group with high level awareness mostly preferred posterior region indirect adhesive restorations such as endocrown and onlay.

Contemporary Evidence of CAD-CAM in Dentistry: A Systematic Review

In this systematic review, we compare the quality and accuracy of computer-aided design (CAD)/computer-aided manufacturing (CAM) techniques currently employed in dentistry with those of traditional materials. Published literature on the study topic was searched in the online MEDLINE, PsycINFO, PubMed, and Cochrane library databases and the database of Indian Council of Medical Research. For this systematic review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework was applied for the assessment of studies fit for investigation. Of the total 103 papers searched, 54 underwent in-depth evaluation. Using criteria for what to include and what to leave out, we chose research that was relevant to our review and narrowed it down to 14 papers that met the review's guidelines. According to our findings and the analysis of the chosen articles, the prospects and current advances of CAD/CAM technology are fascinating and are revolutionizing the field of dentistry. Even though researchers are excited, it is important to make sure that different materials have been tested and looked at well enough before making firm claims and choices to replace materials that have been made in the past. Based on previous research, it has been determined that the CAD/CAM methodology used in the dental field is the most popular method at the moment since it is quick, simple, and efficient. Since there are different kinds of CAD/CAM systems, it is very important to choose the right one and come up with a good plan for treating a patient.

Optical Property Stability of Light-Cured versus Precured CAD-CAM Composites

Objective. The aim of this study was to evaluate the optical property changes after staining of precured (PC) and light-cured (LC) composites. Materials and Methods. Specimens were prepared using different LC composites (GrandioSO—Voco, Filtek Z350-3M/ESPE, Opallis—FGM, and Kalore—GC) and four PC blocks (Grandio Blocs—Voco, Lava Ultimate—3M ESPE, Brava Block—FGM, and Cerasmart—GC) from the same manufacturers (n = 20). Baseline color, gloss, translucency, and fluorescence were evaluated. The staining protocol was performed for 15 days, and the final optical properties were reevaluated. Results. The changes in each property were calculated (ΔGloss, ΔTranslucency, ΔFluorescency, ΔE  $\ast$  00). Data were analyzed by ANOVA and Tukey’s test (α = 5%). Changes in all properties were observed after staining for all materials, with darkening and reduction of gloss, fluorescence, and translucency. Nonsignificant differences were observed between the light-cured and precured materials of the same manufacturer for ΔG and ΔT, but significant differences existed for ΔF and ΔE  $\ast$  00. For ΔF, the only significant differences were observed between Brava Block and Opallis (smaller). For ΔE  $\ast$  00, only the light-cured composites GrandioSO and Z350 showed significantly less change than the corresponding blocks. Precured composites were affected the same way as light-cured ones by the staining in relation to the reduction of gloss and translucency. Conclusion. A higher reduction in fluorescence was observed for only one brand of block and was similar for the others. The two brands of light-cured materials showed less staining, while for the others, the staining was similar. The effects of staining vary according to the composite formulation.

Clinical performance of resin-matrix ceramic partial coverage restorations: a systematic review

OBJECTIVE

To evaluate clinical performance of the new CAD/CAM resin-matrix ceramics and compare it with ceramic partial coverage restorations.

MATERIALS AND METHODS

An electronic search of 3 databases (The National Library of Medicine (MEDLINE/PubMed), Scopus, and the Cochrane Central Register of Controlled Trials) was conducted. English clinical studies published between 2005 and September 2020 that evaluated the clinical performance of CAD/CAM resin-matrix ceramics inlays, onlays, or overlays were selected. The primary clinical question was applied according to PICOS strategy (Population, Intervention, Comparison, Outcome, Study design). The included studies were individually evaluated for risk of bias according to the modified Cochrane Collaboration tool criteria.

RESULTS

A total of 7 studies were included according to the established inclusion and exclusion criteria. From the included studies, 6 were randomized clinical trials while one study was longitudinal observational study without control group. According to the results of the included studies, the success rate of CAD/CAM resin-based composite ranged from 85.7 to 100% whereas the success rate reported for ceramic partial coverage restorations ranged from 93.3 to 100%. Fractures and debondings are found to be the most common cause of restorations failure.

CONCLUSION

CAD/CAM resin-based composite can be considered a reliable material for partial coverage restorations with clinical performance similar to glass ceramic restorations. However, this result needs to be confirmed in long-term evaluations.

CLINICAL RELEVANCE

CAD/CAM resin-based composites provide a potential alternative to ceramic indirect restorations. However, clinicians must be aware of the lake of knowledge regarding long-term outcome.

Effect of thickness on color appearance of multilayer CAD/CAM composite resin blocks

The aim of this study was to evaluate the effect of thickness on the color appearance and translucency parameter (TP) of multilayer CAD/CAM composite resin blocks. Four brands of A3-shade multilayer CAD/CAM composite resin blocks were examined (Katana Avencia, CERASMART Multi, KZR-CAD HR Block 4 E-va, and Block HC Hard AN). Six specimens of five thicknesses were prepared for each brand, yielding 120 specimens in total. CIEL*a*b* values were determined using a spectrophotometer against black and white backgrounds, and the TP was calculated. The color differences (ΔE₀₀) between layers (cervical/middle/incisal) and brands for each thickness against the black background were calculated using the CIEDE2000 system. As a result, on the black background, L* of the incisal layer was greater while a* and b* were smaller than those of the cervical layer for all brands. The ΔE₀₀ values between the cervical and middle layers (1.23-3.27) were smaller than those between the cervical and incisal layers (3.98-5.67) and those between the middle and incisal layers (3.14-5.92). TP decreased with increasing block thickness. Some TP differences between layers were significant, but they were less than 2.75. In conclusion, the color appearance of CAD/CAM blocks was significantly influenced by both the thickness and layer. L*a*b* decreased with thickness, and a negative exponential relationship between TP and thickness was observed for all layers and brands.

Clinical Longevity of Indirect Composite Resin Inlays and Onlays: An Up to 9-Year Prospective Study

Objective This clinical study evaluated the clinical performance of composite resin inlays and onlays over 9 years.

Materials and Methods Sixty composite resin inlays and onlays were placed in 32 patients, aged 20 to 60 years, by a single operator using the same clinical procedure. The restorations were examined for fracture rate; esthetics; and patient acceptance and marginal integrity, including caries, marginal discoloration, tooth integrity, and surface texture. All restorations were evaluated at the time of placement and 3, 6, and 9 years after placement by using the modified U.S. Public Health Service criteria.

Results At the 3-year follow-up, an Alpha score was given to 88.4% of restorations, while a Bravo score was given to the remaining 11.6%. There was not any failure. At the 6-year follow-up, the success rate of the restorations was 100% without failure. None of the restorations was scored with Delta (D). An Alpha score was given to 60% of the restorations, a Bravo score was assigned to 35%, and a Charlie score was 5% of the restorations. Overall, the success rate of the restorations at 9-year follow-up was 85% and the failure rate was 15%. An Alpha score was given to 15% of the restorations, a Bravo score was given to 50%, a Charlie score was assigned to 20%, and a D score was given to 15% of the restorations.

Conclusion Indirect resin composite inlays and onlays showed acceptable long-term clinical results. The success rate of the restorations at 9-year follow-up was 85% and the failure rate was 15%.

Clinical Longevity of Indirect Composite Resin Inlays and Onlays: An Up to 9-Year Prospective Study

OBJECTIVE

 This clinical study evaluated the clinical performance of composite resin inlays and onlays over 9 years.

MATERIALS AND METHODS

 Sixty composite resin inlays and onlays were placed in 32 patients, aged 20 to 60 years, by a single operator using the same clinical procedure. The restorations were examined for fracture rate; esthetics; and patient acceptance and marginal integrity, including caries, marginal discoloration, tooth integrity, and surface texture. All restorations were evaluated at the time of placement and 3, 6, and 9 years after placement by using the modified U.S. Public Health Service criteria.

RESULTS

 At the 3-year follow-up, an Alpha score was given to 88.4% of restorations, while a Bravo score was given to the remaining 11.6%. There was not any failure. At the 6-year follow-up, the success rate of the restorations was 100% without failure. None of the restorations was scored with Delta (D). An Alpha score was given to 60% of the restorations, a Bravo score was assigned to 35%, and a Charlie score was 5% of the restorations. Overall, the success rate of the restorations at 9-year follow-up was 85% and the failure rate was 15%. An Alpha score was given to 15% of the restorations, a Bravo score was given to 50%, a Charlie score was assigned to 20%, and a D score was given to 15% of the restorations.

CONCLUSION

 Indirect resin composite inlays and onlays showed acceptable long-term clinical results. The success rate of the restorations at 9-year follow-up was 85% and the failure rate was 15%.

Computer-aided design and computer-aided manufacturing indirect versus direct composite restorations: A randomized clinical trial

OBJECTIVE

This study compared the clinical performance of large indirect restorations (IRs) versus direct restorations (DRs) in posterior teeth.

METHODS

Thirty subjects received two class II restorations (n = 60), one fabricated from a precured composite block (Grandio Blocs, VOCO) for the indirect technique (IT) and the other with light-cured composite (GrandioSO, VOCO) for the direct technique (DT). For IT, the restoration was created using the computer-aided design and computer-aided manufacturer (CAD/CAM) system. For DT, the material was applied light-cured by using a layering technique. All restorations were evaluated by using the World Dental Federation criteria.

RESULTS

Twenty-three subjects attended the 2-year recall, and 46 restorations were evaluated. No significant differences were detected between the techniques for most parameters analyzed (p > 0.05). For "color match" at 7 days and 6 months, better results were observed for the DT. In relation to the overall scores, all restorations were esthetically acceptable after 2 years, while 93.3% of DT and 90% of IT showed acceptable function. For biological scores, 96.67% of DRs and 100% of IRs was acceptable after 24 months. Considering all properties, the success rates were 93.3% for DRs and 90% for IRs.

CONCLUSIONS

After 2 years, both restorations presented similar and good clinical behavior for all the properties analyzed.

CLINICAL SIGNIFICANCE

Light-cured direct posterior composite restorations may perform similarly to indirect composite restorations made with precured CAD/CAM composite blocks up to 2 years.

Clinical Evaluation of Resin Composite CAD/CAM Restorations Placed by Undergraduate Students

To evaluate the clinical outcomes of resin composite CAD/CAM restorations in a prospective cohort study, and to assess patient and operator satisfaction after restoration placement, 59 indirect resin composite were placed by supervised undergraduate students, of which 43 restorations were followed over a mean period of 28 months (14–44 months) and evaluated using USPHS criteria. Patient and operator satisfaction levels were assessed using a visual analogue scale (VAS) after restoration placement. A total of 37 patients and 47 restorations were included for further study. Four teeth were extracted—three due to extensive drug-induced secondary caries in the same patient, and one tooth due to large periapical periodontitis after 44 months of service. The overall survival rate was 91.4%, and success rate was 87.2%. Differences between baseline and endpoint scores were significant for marginal discoloration (p < 0.05) and adaptation (p < 0.001). Color match (p < 0.05) and surface texture (p < 0.001) differed significantly, affecting all restoration types. VAS scores for patient and operator satisfaction showed a significant rank correlation (p < 0.01), and pairwise comparison showed significant differences for mean overall patient and operator VAS scores (p < 0.001). Lava Ultimate CAD/CAM may be considered a suitable material for overlays and endocrown restorations when combined with IDS, air abrasion, and MDP-containing adhesive systems. Marginal disintegration may present in inlays and onlays over time.

Effect of Direct and Indirect Materials on Stress Distribution in Class II MOD Restorations: A 3D-Finite Element Analysis Study

The aim of this study is to investigate the stress distributions of different restoration options for class II mesio-occluso-distal (MOD) cavities. A class II MOD cavity with proximal box gingival floor 1 mm below cementoenamel junction was designed in a mandibular first molar tooth model. 3D finite-element analysis (FEA) and 3D-CAD modelling were used to examine the occlusal stresses distributed to the remaining buccal enamel (RBE), remaining lingual enamel (RLE), adhesive surfaces, and restorative materials by direct and indirect materials resulting from a 600 N of static occlusal load stimulating foodstuff. von Mises (VM) and maximum principal (Pmax) stresses were evaluated for two CAD/CAM materials and three direct materials. CAD/CAM materials exerted less stress than the direct restorative materials. Significant von Mises and Pmax stress value differences were seen among all restoration models on RBE. Reducing RLE and including it into the cavity would be a more effective option for this model in this scenario. As VM and Pmax stresses of PIHC CAD/CAM material for RBE and dentin were significantly lower than other tested materials, it may be the choice of material for indirect MOD restorations.

Computer-aided indirect bonding versus traditional direct bonding of orthodontic brackets: bonding time, immediate bonding failures, and cost-minimization. A randomized controlled trial

INTRODUCTION

The primary aim of this randomized controlled trial was to compare the time for bracket bonding using either direct or computer-aided indirect bonding; a secondary aim was to assess immediate bracket debondings and cost minimization.

METHODS

Consecutive patients were randomly allocated to two groups (blocks of four, online-generated sequence) using a split-mouth design with a direct and a computer-aided indirect bonding method: group 1 (upper right and lower left quadrants: indirect bonding; upper left and lower right quadrants: direct bonding) or group 2 (opposite situation). The primary outcome was difference in time spent for bonding brackets. The secondary outcome was immediate bracket debondings (at the bonding appointment). Time for indirect bonding was recorded in two steps: digital bracket placement and clinical bonding procedure. Outcome assessment was blinded. Friedman's ANOVA test was used to assess differences in bonding time. Chi-square test was used to compare immediate debondings. A cost-minimization analysis was undertaken.

RESULTS

Thirty-seven patients were randomized to group 1 or 2. Ten patients were excluded: 15 patients were analyzed in group 1 and 12 in group 2. Clinical chair time for bonding half a mouth was significantly shorter for computer-aided indirect bonding (12 minutes 52 seconds) than for direct bonding (16 minutes 47 seconds) (P < 0.001). When adding the time for digital bracket placement, the total bonding time (28 minutes 14 seconds) was longer for indirect bonding than for direct bonding (P < 0.001). There was no single immediate debonding with the direct bonding method, while 14 brackets were lost with the indirect bonding method (5.1 per cent) (P = 0.0001). Cost-minimization analysis showed that computer-aided indirect bonding was more expensive than direct bonding.

CONCLUSIONS

The clinical chair time was significantly shorter for computer-aided indirect bonding than for direct bonding. However, the total bonding time for computer-aided indirect, including digital bracket placement, was longer than for direct bonding. There were significantly more immediate debondings with computer-aided indirect bonding than with direct bonding. Under these conditions, computer-aided indirect bonding was more expensive than direct bonding.

REGISTRATION

This trial was retrospectively registered on ClinicalTrials.gov (University of Aarhus Protocol Record 10101).

PROTOCOL

The protocol was not published before trial commencement.

Review on Polymer, Ceramic and Composite Materials for CAD/CAM Indirect Restorations in Dentistry-Application, Mechanical Characteristics and Comparison

The aim of this review article is to present various material groups, including ceramics, composites and hybrid materials, currently utilized in the field of CAD/CAM. The described technology is amongst the most important in modern prosthetics. Materials that are applicable in this technique are constantly tested, evaluated and improved. Nowadays, research on dental materials is carried out in order to meet the increasing demand on highly aesthetic and functional indirect restorations. Recent studies present the long-term clinical success of restorations made with the help of both ceramic and composite materials in the CAD/CAM method. However, new materials are developed and introduced that do not have long-term in vivo observations. We can outline a monolithic polymer-infiltrated ceramic network and zirconia teeth support that show promising results to date but require further assessment. The materials will be compared with regard to their mechanical and clinical properties, purpose, advantages and limitations.

Which surface treatment promotes higher bond strength for the repair of resin nanoceramics and polymer-infiltrated ceramics? A systematic review and meta-analysis

STATEMENT OF PROBLEM

Which surface treatment provides the optimal bond strength (BS) for the repair of resin nanoceramics (RNCs) and polymer-infiltrated ceramics (PICs) is unclear.

PURPOSE

The purpose of this systematic review and meta-analysis of in vitro studies was to determine the best surface treatment protocols for the repair of PICs and RNCs.

MATERIAL AND METHODS

The PubMed, Scopus, and Web of Science electronic databases were searched to select in vitro studies in English up to March 2020. Studies with fewer than 5 specimens, those that did not evaluate the BS of PICs or RNCs, and those with aging for fewer than 30 days and 5000 cycles were excluded. Data sets were extracted, and the mean differences were analyzed by using a systematic review software program.

RESULTS

Among 284 potentially eligible studies, 21 were selected for full-text analysis, and 9 were included in the systematic review, of which 6 were used in the meta-analysis. The meta-analyses were performed for each treatment surface versus their respective control group and their combinations according to material: RNCs and PICs. For RNCs, airborne-particle abrasion with aluminum oxide (Al₂O₃) treatment was statistically higher than tribochemical silica airborne-particle abrasion (CoJet) (P=.02, I²=90%) and that in the hydrofluoric acid (HF) (P<.001, I²=0%) groups and was statistically similar to diamond rotary instrument grinding (P=.40, I²=54%). For PICs, the treatment with hydrofluoric acid (HF) was statistically significantly higher than with CoJet (P=.03, I²=62%) and airborne-particle abrasion with Al₂O₃ (P<.001, I²=98%).

CONCLUSIONS

The best surface treatment protocol for repair varied according to the restorative material. HF followed by silanization is suggested for PICs, and airborne-particle abrasion with Al₂O₃ or preparation with a diamond rotary instrument for RNCs.

Aging behavior of high-translucent CAD/CAM resin-based composite blocks

OBJECTIVE

The aim of this study was to investigate the influence of artificial aging on the mechanical properties and fracture patterns of novel CAD/CAM resin-based composite blocks (RCB).

METHODS

Flexural strength and modulus of RCBs from seven manufacturers (Voco, Grandio Blocs, GB; Ivoclar Vivadent, Tetric®CAD, TC; DMG, Luxacam Composite, LC; Shofu Block HC, SF; 3M, Lava™ Ultimate, LU; GC, Cerasmart®, CS; Coltene, BRILLIANT Crios, CB) were assessed in a three-point-bending test after an aging process consisting of three sequential steps (14 days storage in artificial saliva, 10,000 thermo-cycles in distilled water between 5/55 °C, 48 h storage in ethanol 75%). Fracture origins were determined in a fractographic examination using reflected light stereomicroscopy combined with transillumination and scanning electron microscopy. Effects of aging were statistically analysed using one-way ANOVA with Tukey's HSD post hoc test (α = 0.05) and Weibull statistics. Correlations regarding filler amount were analysed using linear regression analysis.

RESULTS

The strongest influence on the flexural modulus and strength was exerted based on the parameter material (p < 0.001, ɳ_P² = 0.957; ɳ_P² = 0.770), but the influence of in vitro aging was also significant (p < 0.001, ɳ_P² = 0.623; ɳ_P² = 0.407). Storage in artificial saliva decreased the flexural modulus and flexural strength of all materials, apart from CS, significantly (p < 0.05). The Weibull moduli varied from 5.8 to 22.4. Filler amount correlated significantly with flexural modulus (p < 0.001; R² = 0.739). Fractography revealed four different fracture patterns with fracture origins from the corner, edge or sub-surface and a smooth fracture surface with non-identifiable fracture origin. Specimens with smooth fracture surface showed the significantly lowest flexural strength (p < 0.001). Pores, agglomerates and inclusions were identified as fracture origins.

CONCLUSIONS

Storage in artificial saliva mainly reduced the mechanical properties significantly while additional thermal aging mostly maintained the results. Aging in ethanol mostly maintained the results for flexural modulus but led to an increase in flexural strength values to the level of the unaged specimens. Fractographic analysis revealed a significant accumulation of sub-surface fracture origins after storage in ethanol arising from inherent flaws.

Dentists’ Self-perception on Teledentistry: The Changing Landscape Driven by Technological Booming in the 21stCentury

Aim:

Teledentistry has gained popularity worldwide because it is cost-effective and increase accessibility to dental healthcare. This study assessed the self-perceptions of teledentistry among dental practitioners in Saudi Arabia and examinedany gender-related differences.

Methods:

This cross-sectional study was conducted between January and December 2017 and recruited a convenience sample of dental practitioners, whose self-perceptions of the practice-related use of teledentistry were assessed viaateledentistry survey (TDS). The TDS consisted off our sections:efficiency in patient care, cost reduction,capabilities forimproving practice, and security and confidentiality.Data analyseswere conducted throughdescriptive statistics,internalreliability tests(Cronbach’s alpha), andchi-squaredtests of the TDS.

Results:

The response rate was 620/800(78%). Most respondents were female (62%), and 58% of themworked in the public sector. The internal reliability of the TDS was 0.85 for the whole sampleand 0.85 and 0.90 for males and females, respectively. Among the entire sample, 51% agreed that teledentistry reduced potential cost, and 65% reported shortened waitlists. More females (42%, p<0.001) than males (22%) agreed that teledentistry could help monitor a patient’s condition.More females (35%) than males (13%, p<0.001) considered that teledentistry would require additional appointments for imaging. More females(29%, p=0.0001) than males (22%) expressed great concern aboutpotential violations of confidentiality.

Conclusion:

These findings suggest thatteledentistry in dental practiceis well perceived by practitioners in Saudi Arabia. Gender differences in perceptions are linked to certain aspects of teledentistry.