Are there universal restorative composites for anterior and posterior teeth?

The mechanical, wear, antibacterial properties and biocompatibility of injectable restorative materials under wet challenge

OBJECTIVES

To evaluate the mechanical, wear, antibacterial properties, and biocompatibility of injectable composite materials.

METHODS

Two injectable composite resins (GU and BI), one flowable composite resin (FS), and one flowable compomer (DF), in A2 shade, were tested. Mechanical properties were tested via three-point bending test immediately after preparation and after 1-day, 7-day, 14-day, and 30-day water storage. Under water-PMMA slurry immersion, specimens were subjected to a 3-body wear test (10,000 cycles) against stainless steel balls, while the roughness, wear depth, and volume loss were recorded. After 1-day and 3-day MC3T3-E1 cell culture, cell viability was evaluated with CCK-8 test kits, while the cell morphology was observed under CLSM and SEM. Antibacterial properties on S. mutans were assessed via CFU counting, CLSM, and SEM observation. SPSS 26.0 was used for statistical analysis (α = 0.05).

RESULTS

The mechanical properties were material-dependent and sensitive to water storage. Flexural strength ranked GU > FS > BI > DF at all testing levels. Three nanocomposites had better wear properties than DF. No significant difference on 1-day cell viability was found, but DF showed significantly lower cell proliferation than nanocomposites on 3-day assessment. GU and FS had more favourable cell adhesion and morphology. CFU counting revealed no significant difference, while FS presented a slightly thicker biofilm and BI showed relatively lower bacteria density.

CONCLUSIONS

Injectable nanocomposites outperformed the compomer regarding mechanical properties, wear resistance, and biocompatibility. The tested materials presented comparable antibacterial behaviours. Flowable resin-based composites' performances are affected by multiple factors, and their compositions can be attributed.

CLINICAL SIGNIFICANCE

A profound understanding of the mechanical, wear, and biological properties of the restorative material is imperative for the clinical success of dental restorations. The current study demonstrated superior properties of highly filled injectable composite resins, which imply their wider indications and better long-term clinical performances.

Clinical evaluation of Giomer and self-etch adhesive compared with nanofilled resin composite and etch-and-rinse adhesive - Results at 8 years

OBJECTIVE

This study aimed to evaluate the long-term clinical performance of Giomer and a self-etch adhesive system compared with a nanofilled resin composite and etch-and-rinse adhesive system in Class I and Class II restorations.

METHOD

The study was designed to be double-blinded with intra-individual control. 48 patients with 54 pairs of cavities (class I or class II) were recruited. Each pair of restorations was placed with either BEAUTIFIL II (BF) and FL-BOND II (FL) or Filtek Z350 (Z350) and Scotchbond Multi-Purpose (SMP). Clinical evaluation was performed at baseline, 6-month, 18-month, 4-year and 8-year after placement according to modified USPHS criteria. Kaplan-Meier survival analysis and log rank tests were performed (SPSS 20.0, IBM Corporation, US) to compare the survival probability of different restorations.A generalized linear mixed model (GLMM) was adopted to assess the performance of the materials. The McNemar test was used to show significant changes for all the evaluation criteria and difference between them.

RESULTS

At the eight-year recall, 32 patients with 67 restorations were present. There were twelve restorations in total recorded as failure due to loss of retention, restoration fracture, secondary caries, tooth fracture or endodontic treatment due to pulp necrosis. The survival probabilities and calculated annual failure rate(AFR) of BF and Z350 restorations at 8-year were 87.2 % vs 87.8 % and 1.6 % vs 1.5 % respectively with no significant difference (p > 0.05)between the two materials. Over the recall time range of eight years, decreased possibility of alpha rating was observed for retention, marginal adaptation, marginal staining and surface roughness for both materials (p < 0.05). Decreased possibility of alpha rating was observed for surface staining and secondary caries for Z350 (p < 0.05) and restoration fracture for BF (p < 0.05), respectively. Comparing the two restorative systems over eight years, no significant difference was seen for linear decline of the possibility of alpha rating for any of the criteria evaluated (p > 0.05).

CONCLUSION

Giomer material and the self-etch adhesive system had comparable clinical performance with nanofilled resin composite and etch-and-rinse adhesive system over the observation period of eight years.

Repairability of aged dimethacrylate-free ORMOCER-based dental composite resins with different surface roughening methods and intermediate materials

STATEMENT OF PROBLEM

The repair of damaged composite resin restorations has been recommended as a conservative treatment option. However, a reliable protocol for repairing ORMOCER-based restorations is lacking.

PURPOSE

The purpose of this in vitro study was to investigate the effect of different surface roughening methods, repair composite resins, and intermediate materials on the repair bond strength of a dimethacrylate-free ORMOCER-based composite resin.

MATERIAL AND METHODS

Cylindrical composite resin specimens (Admira Fusion) were roughened by using hydrofluoric acid (HF) or a diamond rotary instrument. In both groups, 4 types of intermediate materials were used (Monobond-S, Clearfil SE bond [second bottle], Clearfil Universal bond, GC Composite Primer), and then half of the specimens were repaired with a similar composite resin, and the other half with dimethacrylate composite resin (Clearfil-APX). The specimens (n=20) were then subjected to repair bond strength and failure mode evaluation. The data were analyzed by using the Weibull test, 3-way and 1-way ANOVA, and the Tukey honestly significant difference (HSD) test (α=.05).

RESULTS

All variables, including the surface roughening method, intermediate material, and repair composite resin, had a significant effect on repair bond strength (P<.001). The lowest repair bond strength values were obtained in the group roughened with HF, prepared with Monobond-S, and repaired with Admira Fusion, and the highest values were obtained in the group roughened with a rotary instrument, prepared with GC Composite Primer, and repaired with Clearfil APX (P<.05). All experimental groups had a lower bond strength than the cohesive and control groups (P<.05). In all experimental groups, the predominant failure modes were adhesive and mixed.

CONCLUSIONS

The use of a diamond rotary instrument was a more reliable method of creating roughness, and different intermediate materials based on the clinical situation can be used to repair dimethacrylate-free ORMOCER-based composite resin with similar or different composite resins. However, in general, the highest repair bond strengths were achieved with Clearfil APX-repaired specimens.

Application and limitations of configuration factor (C-factor) in stress analysis of dental restorations

OBJECTIVE

The configuration factor (C-factor) is an index used to evaluate the relationship between cavity configuration and the development of polymerization shrinkage stress in dental restorations. Although C-factor has been widely researched, its correlation with stress analysis in dental restorations remains controversial. This review aims to discuss the application and limitations of C-factor and define the restricted conditions under which the C-factor "rule of thumb" is applicable.

METHODS

A thorough literature review was conducted on the application and limitations of C-factor in stress analysis of dental restorations. This was principally based on MEDLINE/PubMed and Web of Science databases and a review of the relevant studies and publications in scientific papers in international peer-reviewed journals for the specific topic of C-factor and polymerization shrinkage.

RESULTS

The C-factor alone cannot provide an accurate prediction of the shrinkage stress of restorations and the mechanical behavior of material-tooth interfaces. C-factor is only applicable under one condition not typically seen in clinical practice: low, near-rigid compliance.

SIGNIFICANCE

Conditions for the application of C-factor have been explicitly defined. A more accurate and precise understanding and utilization of the C-factor is of benefit as it contributes to better understanding of polymerization shrinkage behavior of restorations.

Patients´ satisfaction concerning direct anterior dental restoration

The objective of this study was to observe patients' satisfaction with their in-service direct anterior dental restorations and to compare it with clinical evaluation using FDI (Federation Dental International) criteria. Patients scored their own anterior dental restorations regarding satisfaction (satisfactory /dissatisfactory). If dissatisfaction was mentioned, then, they would be interviewed about the complaint. In the same session, the dental restorations were clinically evaluated by two dentists using FDI criteria (1-5 score) concerning esthetic, functional, and biological domains. Descriptive statistics were used for frequencies of scores attributed by patients and clinicians. In order to compare patients' to clinicians' frequencies, the Chi-square test was applied (p ≤ 0.05). A total of 106 restorations were evaluated by patients and clinicians. Patients reported 52.8% of restorations satisfactory and 47.8% dissatisfactory. Overall, clinicians reported the same restorations as 82,3% satisfactory and 17,6% dissatisfactory. Patients' most frequent complaints referred to color, followed by anatomical form, fracture of material and retention, and approximal anatomical form. Comparing patients' satisfaction and dissatisfaction rates to clinicians' evaluation per criteria, there was no difference regarding esthetics. The frequency of dissatisfactory restorations by clinicians was significantly lower when functional and biological properties were compared with patients' opinions. Direct anterior dental restorations were more frequently reported as satisfactory by patients and clinicians, being the main complaints related to esthetic issues. When clinicians and patients' evaluations were compared, it was observed that the frequencies of satisfactory restoration by patients and clinicians were similar regarding esthetic properties, and significantly different regarding functional and biological properties.

Longevity of composite restorations is definitely not only about materials

OBJECTIVES

This review study provides an overview of factors that influence the longevity of all types of direct resin composite restorations.

METHODS

A systematic search was performed in PubMed, Scopus, and Web of Science databases for articles reporting data from primary longitudinal clinical studies on composite longevity published 2011-2021. Prospective or retrospective studies with restorations in permanent dentition, with follow-up periods of at least 5 years were included.

RESULTS

In total, 33 articles were included with different study designs, practice settings, datasets, countries of origin, and sample sizes. Annual failure rates of restorations ranged from 0.08% to 6.3%. Survival rates varied between 23% and 97.7%, success rates varied between 43.4% and 98.7%. Secondary caries, fractures, and esthetic compromise were main reasons for failures. Risk factors for reduced restoration durability included patient-level factors (e.g., caries risk, parafunctional habits, number of check-ups per year, socioeconomic status), dentist factors (different operators, operator's experience), and tooth/restoration factors (endodontic treatment, type of tooth, number of restored surfaces). Patient gender and the composite used generally did not influence durability.

SIGNIFICANCE

A number of risk factors are involved in the longevity of composite restorations. Differences between composites play a minor role in durability, assuming that materials and techniques are properly applied by dentists. Patient factors play a major role in longevity. The decision-making process implemented by dentists relative to the diagnosis of aging or failed restorations may also affect the longevity of restorations. Clinicians should treat patients comprehensively and promote a healthy lifestyle to ensure longevity.

Development of functional fillers as a self-healing system for dental resin composite

OBJECTIVES

To evaluate the incorporation of repairing capsules containing different monomers and polymerization modulators on the self-healing efficiency of an experimental photopolymerizable resin-based composite.

METHODS

Self-healing capsules containing different monomers and polymerization modulators were prepared by emulsion polymerization: TC_DHEPT (TEGDMA and DHEPT), BTC_DHEPT (Bis-GMA, TEGDMA, and DHEPT), and BTC_BPO (Bis-GMA, TEGDMA, and BPO). The capsules were analyzed through Fourier transform infrared spectroscopy and scanning electron microscopy. The capsules were added into experimental photopolymerizable resin composites establishing the following groups: ER (Control without capsules), ER+BPO, ER+BPO+TC_DHEPT, and ER+BTC_BPO+BTC_DHEPT. Filtek Z350 resin composite (3 M ESPE) was used as a commercial reference. The materials were tested for degree of conversion (DC), flexural strength (σf), elastic modulus (Ef), fracture toughness (virgin K_IC), self-healing efficiency (healed K_IC), and roughness. For statistical analysis, the significance value was established at an a = 0.05 level.

RESULTS

When compared to the control material, the incorporation of repairing capsules did not affect DC, σf, and Ef. Fracture toughness was statistically similar between the experimental groups (p ≤ 0.05). Healed K_IC was statistically different between the groups ER+TC_DHEP and ER+BTC_BPO+BTC_DHEPT; the self-healing efficiency was higher for ER+TC_DHEPT. Surface roughness was statistically similar among all groups.

CONCLUSIONS

The use of self-healing capsules promoted repair of the material. Studies with material aging after the self-healing process are necessary to better demonstrate the effectiveness of this system.

CLINICAL SIGNIFICANCE

The self-healing system seemed to be a promising technology to be used in self-repaired restorative materials, which may prevent restoration fractures.

Resin Composites in Posterior Teeth: Clinical Performance and Direct Restorative Techniques

Resin composites are the most versatile restorative materials used in dentistry and the first choice for restoring posterior teeth. This article reviews aspects that influence the clinical performance of composite restorations and addresses clinically relevant issues regarding different direct techniques for restoring posterior teeth that could be performed in varied clinical situations. The article discusses the results of long-term clinical trials with resin composites and the materials available in the market for posterior restorations. The importance of photoactivation is presented, including aspects concerning the improvement of the efficiency of light-curing procedures. With regard to the restorative techniques, the article addresses key elements and occlusion levels for restoring Class I and Class II cavities, in addition to restorative strategies using different shades/opacities of resin composites in incremental techniques, restorations using bulk-fill composites, and shade-matching composites.

Effect of Different Surface Treatments on the Long-Term Repair Bond Strength of Aged Methacrylate-Based Resin Composite Restorations: A Systematic Review and Network Meta-analysis

This systematic review and network meta-analysis is aimed at investigating the effect of common surface treatments on the long-term repair bond strength of aged resin composite restorations and to rank and compare these surface treatments. In vitro studies evaluating the methacrylate-based resin composites subjected to rigorous aging protocols before and after being repaired with a new composite were included. A frequentist network meta-analysis was carried out using a random effects model. P scores were used to rank the efficacy of the surface treatments. Also, the global and node-split inconsistencies were evaluated. Web of Science, PubMed/Medline, Scopus, and Embase databases were searched until July 07, 2022. Twenty-six studies were included in the meta-analysis. The results showed that the application of silane and a total-etch (shear MD 32.35 MPa, 95% CI: 18.25 to 46.40, P score 0.95; tensile MD 33.25 MPa, 95% CI: 25.07 to 41.44; P score 0.77) or a self-etch (shear MD 38.87 MPa, 95% CI: 21.60 to 56.14, P score 0.99; tensile MD 32.52 MPa, 95% CI: 23.74 to 41.29; P score 0.73) adhesion protocol subsequent to the roughening with diamond bur produced the highest (micro)tensile and (micro)shear bond strengths compared to diamond bur alone as the control group. There was no difference between self- and total-etch adhesive protocols. Mechanical surface treatments yielded greater bond strength when used alongside the chemical adhesive agents. Further, it is possible to achieve acceptable repair bond strength using common dental clinic equipment. Therefore, clinicians could consider repairing old resin composites rather than replacing them.

Longevity of Direct Resin Composite Restorations in Maxillary Anterior Crown Fractures: A 4-year Clinical Evaluation

OBJECTIVES

To investigate the longevity of direct composites for Class IV restorations and the possible reasons of failure.

METHODS AND MATERIALS

The longevity of 168 Class IV restorations in 50 adult patients was evaluated, in terms of modified United States Public Health Service criteria, for 4 years. Restorations were performed using a monochromatic layered microhybrid, resinbased composite (RBC) (Essentia, Universal Shade, GC Corporation, Japan; n=76) and polychromatic layered micro/nanohybrid (MD and LE shades, Essentia, GC Corporation, Japan; n=92) RBCs, by a single operator.

RESULTS

The majority of the teeth (n=156) remained acceptable at the end of 4 years, and the overall survival (OS) rate was considered as 92.86%. Survival rates for the monochromatic layering technique (MLT) and polychromatic layering technique (PLT) were 90.8% and 94.6%, respectively. Mean survival was 46 months for MLT and 47 months for PLT, indicating no significant difference (p=0.343). Fracture of the restoration was the most common reason for failure (4.2% out of 7.1% of general failures) for both the layering techniques.

CONCLUSIONS

Under the conditions of this mid-term clinical study, MLT and PLT as well as microhybrid and nanohybrid resin composite materials, showed similar clinical durability. In terms of simplicity, monochromatic layering can be preferred for Class IV restorations, when the right indication criteria are met.

Laboratory methods to simulate the mechanical degradation of resin composite restorations

OBJECTIVES

This study reviewed the literature to identify in vitro approaches that have been used to simulate the mechanical degradation and fatigue of resin composite restorations.

METHODS

A search for articles was carried out in 4 databases and included studies in which composite restorations were bonded to teeth and subject to cyclic loading. Articles were assessed for eligibility, and the following items were the extracted from the included studies: authors, country, year, materials tested, simulation device and details including load magnitude and frequency, number of cycles, type of antagonist, test medium, and temperature. Data were analyzed descriptively.

RESULTS

The 49 studies included showed a high level of heterogeneity in methods, devices, and test parameters. Nineteen different simulation devices were used, applying loads varying between 30 and 2900 N, and frequencies varying between 0.4 and 12 Hz. The load and frequency used most often were ~ 50 N (63.3%) and 1.5-1.7 Hz (32.7%). The number of cycles varied between 10 K and 2.4 M, 1.2 M was the most prevalent (40.8%). The majority of studies combined cyclic loading with at least one additional aging method: static liquid storage, thermo-mechanical cycling applied simultaneously, and thermal cycling as a discrete aging step were the three most frequent methods. The overall evidence indicated reporting problems, and suggested a lack of clinical validation of the research methods used.

SIGNIFICANCE

Validation studies, underlying clinical supporting data, and better reporting practices are needed for further improving research on the topic. Specific suggestions for future studies are provided.

Comparison of mechanical and optical properties of a newly marketed universal composite resin with contemporary universal composite resins: An in vitro study

The purpose of this study was to evaluate the surface roughness, microhardness, color change, and translucency of a newly marketed universal nanohybrid composite resin (CR) (G-aenial A'CHORD) comparing with four contemporary universal CRs including two nanofilled (Filtek and Estelite Asteria) and two nanohybrid CRs (Charisma Dimond and Neo Spectra ST HV in vitro). Sixty-five specimens (8.0 mm × 2.0 mm) were fabricated (n = 13, per group). After finishing and polishing, specimens were subjected to surface roughness and microhardness tests. Color and translucency of the specimens were evaluated at baseline and after darkening with coffee solution at day 1 and day 7. A representative specimen from each group was investigated under scanning electron microscopy (SEM). Data was analyzed statistically (p < .05). There were significant differences among the groups in terms of surface roughness, microhardness, color, and translucency. The surface roughness was recorded as: Charisma Diamond > Neo Spectra ST HV, Filtek > Estelite Asteria, G-aenial A'CHORD, whereas Vickers Hardness number was as: Filtek, Charisma Diamond > Neo Spectra ST HV > G-aenial A'CHORD, Estelite Asteria. Color change was as: Charisma Diamond > Neo Spectra ST HV, Filtek, G-aenial A'CHORD > Estelite Asteria and the translucency was as: Neo Spectra ST HV > G-aenial A'CHORD, Filtek > Estelite Asteria, Charisma Diamond. SEM examinations revealed smooth surfaces for G-aenial A'CHORD, Neo Spectra ST HV and Estelite Asteria. Mechanical and optical properties of universal composite resins with different compositions show variations.

Rheological and Mechanical Properties of Resin-Based Materials Applied in Dental Restorations

Resin-based materials have been prevalent for dental restorations over the past few decades and have been widely used for a variety of direct and indirect procedures. Typically, resin-based dental materials are required to be flowable or moldable before setting and can provide adequate mechanical strength after setting. The setting method may include, but is not limited to, light-curing, self-curing or heating. In this review, based on different indications of resin-based dental materials (e.g., dental filling composite, dental bonding agent, resin luting cement), their rheological and mechanical properties were reviewed. Viscous and flexible properties were focused on for materials before setting, while elastic properties and mechanical strength were focused on for materials after setting. At the same time, the factors that may affect their rheological and mechanical properties were discussed. It is anticipated that the insightful information and prospections of this study will be useful to the future development and fabrication of resin-based dental restorative materials.

The "Pre-Finishing" Approach in Direct Anterior Restorations. A Case Series

In esthetic restorations of anterior teeth the clinician has to manage several aspects in order to have a predictable outcome. A deep knowledge of the anatomy as well as the adhesive procedures and the optical properties of resin-based composites are mandatory to achieve esthetic results. Contemporary restorative materials present either several shades and different translucency properties and therefore they are able to mimic teeth’s optical behavior thus providing a natural aspect to anterior restorations. The wrong thickness of different composite layers may provide unpleasant results such as low value (grayish) restorations that often requires reintervention. A precise step-by-step procedure is therefore mandatory to provide the proper shade at the correct place. There is therefore the need of some corrections and adjustments during the layer procedure in order to avoid errors in shade positioning that could affect final result. The authors present a case series (six clinical cases) treated with the proposed technique with up to five years follow-up.

Could different direct restoration techniques affect interfacial gap and fracture resistance of endodontically treated anterior teeth?

Objectives

To evaluate different direct restoration techniques on various cavity designs in anterior endodontically treated teeth (ETT).

Materials and methods

Ninety upper central incisors (n = 90) were selected, endodontically treated, and divided into three groups (n = 30) accordingly to the cavity design: minimal endodontic cavity access (group A), endodontic access + mesial class III cavity (group B), and endodontic access + two class III cavities (group C). Three subgroups (n = 10) were then created accordingly to the restoration technique: nano hybrid composite restoration (subgroup a), glass fiber post + dual-cure luting cement (subgroup b), and bundled glass fiber + dual-cure luting cement (subgroup c). Samples underwent micro-CT scan, chewing simulation, and a second micro-CT scan. 3D quantification (mm³) of interfacial gap progression was performed; then, samples underwent fracture resistance test. Data were statistically analyzed setting significance at p < 0.05.

Results

Groups A and B showed significantly lower interfacial gap progression compared with group C. Subgroup b performed significantly better compared with subgroups a and c. Improved fracture strength was reported for group C compared with group A, while both subgroups b and c performed better than subgroup a.

Conclusions

Cavity design significantly influenced interfacial gap progression and fracture resistance. Fiber posts significantly lowered gap progression and improved fracture resistance while bundled fibers only increased fracture resistance. A significant reduction of non-repairable fractures was recorded when fibers were applied.

Clinical relevance

A minimally invasive approach, conserving marginal crests, should be applied whenever possible. Inserting a fiber post is indicated when restoring anterior ETT, in order to reduce gap progression, improve fracture resistance, and avoid catastrophic failures.

Clinical study on resin composite and glass ionomer materials in II class restorations in permanent teeth

Background

Glass ionomer cements (GIC) used for restoration of missing dental structures have high biocompatibility and remineralization potential. However, low mechanical resistance excludes their use for long-term restorations of extensive lesions, particularly on approximal surfaces in permanent dentition. GIC with increased viscosity have much better physical properties, which involves better bonding and wear resistance, so they can be considered as an alternative to composite resin materials. The aim of this study was to perform a clinical and radiological assessment of restorations in permanent teeth, made with an increased viscosity GIC - Equia Fil (Ivoclar Vivadent) with Equia Coat (Ivoclar Vivadent) and composite material - Tetric EvoCeram (Ivoclar Vivadent) in young patients.

Material and Methods

A total of 100 cavities on approximal surfaces were filled with the composite material or GIC in 49 patients aged from 12.08 to 19.58 years. During control examinations, the condition of each restoration was assessed with criteria acc. to Hickel et al. Bitewing radiographs had been taken before fillings were placed and after 12 and 24 months.

Results

After two years of observations, two GIC restorations were replaced due to loss of retention and staining. The other 96 restorations were given a satisfactory grade. The clinical efficacy of Equia Fil after 24 months was assessed at 95.83%, the Tetric EvoCeram at 100%. The difference was not statistically significant (P=0.145). When GIC was used, there was a higher risk of marginal adaptation deterioration and the occurrence of staining and erosion. Radiographic efficacy of the Equia Fil material for cavity restoration after 24 months was assessed at 93.75%, for the Tetric EvoCeram material at 100%. Differences were not significant statistically (P=0.073).

Conclusions

Tetric EvoCeram and Equia Fil used for the restoration of approximal lesions in premolars and permanent molars have similar efficacy in a 2-year period of observation. Key words:Dental restoration, permanent, composite resins, glass ionomer cements, clinical study.

Color matching ability of resin composites incorporating supra-nano spherical filler producing structural color

OBJECTIVE

The aim of this study was to evaluate the optical properties of supra-nano spherical fillers with different diameters and the color matching ability of resin composites (RC) incorporating these fillers.

METHODS

Two types of SiO₂-ZrO₂ nano fillers with different diameters (150nm and 260nm) were used. The size distribution of each filler was measured and filler morphology was observed. The colors and spectral reflection spectra were measured by a spectral reflectometer. Experimental RCs incorporating ϕ150-nm/ϕ260-nm filler (D150RC/D260RC) were prepared. For the base dentin part, disc specimens (Estelite Astelia: A1B, A2B, A3B, A3.5B, or A4B) were prepared with a cylindrical cavity. Estelite Astelia with NE shade was layered on top as the enamel layer. Disk specimens with different cavity depths were prepared using A3B shade. Experimental RC was used to fill the cavity, and spectral reflection spectrums were obtained and analyzed. Filtek Supreme Ultra (FSU) with A3B shade was used (n=10) as a control.

RESULTS

Both ϕ150-nm and ϕ260-nm nano fillers showed uniform spherical shape and exhibited no aggregation. The maximum peaks of the spectral reflection spectra of the ϕ150-nm and ϕ260-nm nano fillers were 380nm and 580nm, producing structural colors close to blue and yellow, respectively. The spectral reflection spectrum of FSU had a broad peak at 540nm, and D150RC had a significant peak at 420nm. The D260RC specimen had a broad peak at 680nm. The peaks of D150RC and D260RC significantly decreased in accordance with the shift in base RC shade from A1B to A4B. There was no significant difference in the peak of the reflection spectral spectra among different cavity depths of D260RC. These results suggest that the experimental RC could reflect base RC colors via the matrix resin, and the amount of transmitted light from the base RC was not much different with cavity depth.

SIGNIFICANCE

D260RC producing structural color demonstrated a broad spectrum and reduction in brightness and chromatic value by adapting to surrounding restorative materials, suggesting its ability to enhance the chameleon (blending) effects to improve color matching. D260RC showed better color matching ability than resin composite containing uniformly sized ϕ150-nm SiO₂-ZrO₂ supra-nano spherical filler.

Effect of different placement techniques on color stability and surface roughness of resin composites

Abstract Introduction Longevity and clinical success of dental restorations can be influenced by many factors during the restorative procedures. Objective This study aimed to evaluate the influence of different placement techniques on color stability and surface roughness of two resin composites. Material and method The groups of specimens (n=10) were divided according to resin composite (FiltekTM Z250 XT and FiltekTM Z350 XT) and placement technique: Mylar strip, spatula, dry brush, modeling liquid, and surface sealant. Color stability and surface roughness were accessed using a spectrophotometer (CIELab color space) and a rugosimeter (standard cutoff of 0.8 mm), respectively, after water storage. Subsequently, the specimens were immersed in coffee for 48 h and final color was measured. The data were analyzed using ANOVA and the Tukey’s post hoc test (α=5%) and the correlation between surface roughness (Ra) and color change (∆Eab) was assessed using the Pearson’s correlation coefficient. Result The different placement techniques influenced Ra and ∆Eab on both resin composites. The groups treated with surface sealant showed greater difference in ∆Eab for both resin composites. The FiltekTM Z250 XT resin showed greater color stability compared with the FiltekTM Z350 XT resin regardless of the placement technique used. Ra of each placement technique was similar among the resin composites except for the FiltekTM Z350 XT modeling liquid group, which presented lower Ra values compared with those of FiltekTM Z250 XT. A correlation between Ra and staining was identified (p=0.268). Conclusion Color stability and Ra are influenced by different placement techniques.

Nanofilled/nanohybrid and hybrid resin-based composite in patients with direct restorations in posterior teeth: A systematic review and meta-analysis

OBJECTIVE

A systematic review and a meta-analysis were performed to answer the following research question: Are there differences in the color match and surface texture of nanofilled/nanohybrid and hybrid composite in patients with direct posterior restorations?

DATA

Randomized clinical trials that compared nanofilled/nanohybrid and hybrid composite in direct restoration in posterior teeth were included. For the analysis of the bias the risk of bias tool (RoB) was used. Meta-analyses of different pairs (nanofilled vs. hybrid and nanohybrid vs. hybrid composite) were conducted for surface texture and color match and other secondary outcomes at different follow-ups, using a random effects model. Heterogeneity was assessed with the Cochran Q test and I² statistics. GRADE was used to assess the quality of the evidence.

SOURCES

A search was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library and SIGLE, without restrictions. IADR abstracts (2001-2019), unpublished and ongoing trials registries, dissertations and theses were also searched.

STUDY SELECTION

28 studies remained. No study was considered to be at low RoB; four studies were judged to have high RoB, and the remaining were judged to have unclear RoB.

RESULTS

For the primary and secondary outcomes variables no significant differences were detected between nanofilled/nanohybrid restorations and hybrid composite restorations in any of the study follow-ups (p > 0.08). The body of evidence for surface texture and color match was classified as moderate or low.

CONCLUSION

No evidence of difference was found between nanofilled/nanohybrid and hybrid composite in any of the clinical parameters evaluated.

Comparison of Shear Bond Strength of Three Commercially Available Esthetic Restorative Composite Materials: An In Vitro Study

Introduction

Dental caries remains to be one of the most prevalent diseases encountered in the field of dentistry. Several restorative materials have been introduced with variable properties and among them, composite restorative materials are most widely used nowadays because of their superior esthetic property as well as minimal hard tissue removal. Shear bond strength of a restorative material plays a key role in deciding the restoration’s longevity. Hence, for a better selection of the composite material, shear bond strength needs to be evaluated.

Aim

The study aim was to analyze the shear bond strength of three commercially available esthetic restorative composite materials—Dentsply Ceram X, 3M ESPE™ Filtek™ Z350 XT, and GC Solare Sculpt to the tooth surface.

Materials and methods

Thirty extracted human mandibular permanent molars that were caries-free were selected and erected in acrylic blocks. The uniform dentinal surface was exposed by cutting with a diamond disk. These were then randomly divided into three groups—groups I, II, and III based on the restorative material which was used, i.e., Ceram X, 3M ESPE™ Filtek™ Z350 XT, and Solare Sculpt, respectively. The restorative materials were applied on the dentinal surface of the prepared tooth specimens with the help of plastic molds, followed up by storing them in distilled water until they were subjected to shear bond strength testing. The collected data were examined by applying a one-way analysis of variance (ANOVA) and Turkey’s post hoc test.

Results

The Ceram X (21.6155 ± 2.20717) and Solare Sculpt (19.8747 ± 3.99732) were comparable in terms of shear bond strength values; however, they depicted significantly higher bond strength compared to 3M ESPE™ Filtek™ Z350 XT (12.8068 ± 3.99732).

Conclusion

Among the three materials compared in this study, Ceram X produced higher shear bond strength to tooth surface when compared to Solare Sculpt and 3M ESPE™ Filtek™ Z350 XT.

Clinical significance

Restoration failure continues to be a major problem taking a toll on the dentists’ time and patient satisfaction. Thus, the demand for restorative materials with better shear bond strength as well as excellent esthetics is on the rise. Thus, this particular study compares the shear bond strength of three commercial esthetic nanocomposites.

How to cite this article

Preethy NA, Jeevanandan G, Govindaraju L, et al. Comparison of Shear Bond Strength of Three Commercially Available Esthetic Restorative Composite Materials : An In Vitro Study. Int J Clin Pediatr Dent 2020;13(6):635–639.

[Color measurements of composite materials for tooth restoration in standardized in vitro conditions]

A national standard GOST R 58165-2018 (ISO/TR 28642:2016) 'Dentistry - Guidance on colour measurement' has been developed based on the international document which establishes standardized conditions for carrying out laboratory methods of measuring color by visual and instrumental methods. In vitro tests of samples of FiltekTM Ultimate, FiltekTMZ250 and Premise on the acoustooptic color analyzer SPEKTRON-M (FGUP 'VNIIOFI', Russia) in accordance with the recommendations of the standard GOST R 58165-2018 (ISO/TR 28642:2016) allowed to determine the effect of the shelf life of paste composite materials on the aesthetic indicators: colour compatibility, colour stability after aging and degree of transparency. The greatest changes in color characteristics in the CIELAB system during the storage of pastes were noted for the Premise Kerr A2 Enamel and A3 dentin composites. The greatest color change after exposure in water at 37 ° C was established for FiltekTMZ250 A4 samples with a long shelf life of the composite resin, ΔE=3.92>2.7 (p=0.001), but the color resistance of samples of the same composite from a new batch after exposure in water corresponds to the requirements of the standard, ΔE=2,18<2,7 (p=0,001).

Direct Pulp Capping: Which is the Most Effective Biomaterial? A Retrospective Clinical Study

(1) Background: Recently, tricalcium silicate cements, such as Biodentine™, have emerged. This biomaterial has a calcium hydroxide base and characteristics like mineral aggregate trioxide cements, but has tightening times that are substantially more suitable for their application and other clinical advantages. (2) Methods: A retrospective clinical study was conducted with 20 patients, which included a clinical evaluation of the presence or absence of pulp inflammation compatible symptoms, radiographic evaluation of the periapical tissues, and structural alterations of the coronary restoration that supports pulp capping therapies with Biodentine™ and WhiteProRoot^®MTA. (3) Results: This clinical study revealed similar success rates between mineral trioxide cement and tricalcium silicates cements at 6 months, with 100% and 95% success rates, respectively. There were no statistically significant differences between both biomaterials and between these and the various clinical circumstances, namely the absolute isolation of the operating field, exposure size, the aetiology of exposure, and even the type of restorative material used. (4) Conclusions: Biodentine™ demonstrated a therapeutic effect on the formation of a dentin bridge accompanied by slight inflammatory signs, with a high clinical success rate, indicating the possibility of its effective and safe use in dental pulp direct capping in humans, similar to the gold standard material.

The differences between three performance measures on dental restorations, clinical success, survival and failure: A matter of perspective

OBJECTIVES

The aim of this retrospective methodology study was to investigate the influence of using different definitions for restoration failure and inclusion criteria on restoration longevity expressed in AFR.

METHODS

EPF from fifteen general dental practices were used for collecting the data for this study. From the EPF, 321,749 composite restorations placed in 52,245 patients by forty-seven GDPs between January 2000 and December 2011 were included. Kaplan-Meier statistics were applied and mean AFRs over 2, 5 and 10 years were calculated. The effect on the AFR of using different levels of failure: based on Claims data (CD), Success (SUC), Survival (SUR) and different inclusion criteria of tooth/restoration variables were reported.

RESULTS

Highest AFRs were found for level CD, in which every intervention was considered as failure, and the lowest AFRs for level SUR in which repairs and an endodontic treatments were not considered as a failure. AFRs increased when the observation period prolonged especially for SUR, followed by SUC and CD. An overview of long-term survival studies showed a wide variation in study design, performed clinical examination (USPHS criteria or GDP), number of restorations included, description of restoration failure and found AFRs for CD, SUC and SUR.

SIGNIFICANCE

Using failure criteria, Success and Survival, in future clinical studies would enable a better comparison of studies as well as demonstrate the impact of more conservative restorative intervention protocols on patient care.

A randomised controlled study on the effects of different surface treatments and adhesive self-etch functional monomers on the immediate repair bond strength and integrity of the repaired resin composite interface

OBJECTIVES

To evaluate the effects of different surface conditioning methods on the immediate repair bond strength and integrity of the repaired composite interface.

METHODS

One hundred and five resin composite blocks made of a nanohybrid resin composite were randomly assigned to one of the following surface conditioning groups (n = 15/group): Group 1: Gluma Self Etch™ adhesive system, Group 2: Tokuyama Bond Force II™ adhesive system, Group 3: non-roughened and non-conditioned surfaces, Group 4: sandblasting and Gluma Self Etch™, Group 5: sandblasting and Tokuyama Bond Force II™, Group 6: sandblasting only. A positive control group was also used. Resin composite identical to the substrate was applied and the repaired specimens were subjected to shear bond strength (SBS) testing. Representative samples from all groups were subjected to scanning electron microscopy and surface profilometry to determine their mode of failure. The data were analysed statistically using Analysis of Variance (ANOVA) and two independent sample t-test (α = 0.05).

RESULTS

The mean SBS of all test groups ranged between 1.92 and 5.40 MPa and varied with the degree of composite surface roughness and the type of adhesive system employed. Significantly highest SBS values (5.40 ± 0.36 MPa) were obtained in Group 5 (p = 0.017) which were comparable to the coherent strength of the resin composite in the positive control group (p > 0.05).

CONCLUSIONS

Under the tested conditions, significantly greater SBS of repaired resin composite was achieved when the substrate surface was conditioned by sandblasting followed by the application of the Tokuyama Bond Force II™ adhesive system.

CLINICAL SIGNIFICANCE

Effecting a repair of a nanohybrid composite restoration with sandblasting and the application of TBF II would seem to enhance the interfacial bond strength and integrity of the repaired resin composite interface. Clinical trials are necessary to determine the usefulness of this technique.

Restoration Repair as a Contemporary Approach to Tooth Preservation: Criteria for Decision Making and Clinical Recommendations

Despite the growing body of evidence-based knowledge, evidence-based restoration repair is not always applied in the clinical setting. This article is intended to give an evidence-based insight into the indications, importance, benefits and long-term success of resin composite restoration repair, together with details of relevant operative techniques aimed at conserving as much sound tooth structure as possible.

Survival, Reasons for Failure and Clinical Characteristics of Anterior/Posterior Composites: 8-Year Findings

This retrospective study aimed to compare the annual failure rate (AFR), reasons for failure and factors influencing survival of posterior and anterior composite restorations placed by undergraduate students. Composite restorations placed by undergraduate students were evaluated. The restorations should be in occlusion, with at least one adjacent tooth; and patients should have been present for check-up, with at least 1 annual recall. The investigation was performed in two separate analysis: 1) dental electronic records of 100 patients (n=333 restorations) were selected to assess factors influencing survival; 2) clinical evaluation of 30 patients by examining restorations (n=123) to assess clinical characteristics and failure type distribution. Data were subjected to Kaplan-Meier method, Log-rank test, Cox regression and Fisher's Exact test (p<0.05). After 8-year period, the AFR was 2.62%. There was difference between anterior and posterior restorations (p=0.005), with anterior showing a higher AFR. The patient caries-risk (p<0.001) and the number of surfaces restored (p=0.010) affected restoration survival. The superficial brightness (p=0.029), fracture (p=0.025) and retention (p=0.011) were clinical criteria with differences between anterior and posterior restorations. Income (p<0.001), caries activity (p<0.001), caries risk (p<0.001) and oclusal risk (p<0.001) also influenced on the restorations survival. After 8-year, the AFR of restorations placed by undergraduate students was acceptable and affected by patient risk factors and the position of the tooth in the arch: anterior restorations failed more than posterior.

Objective criteria for assessment of the quality of dental restorations improve student’s critics towards the treatment assignment: a randomized controlled trial

Abstract Introduction Objective parameters may help the decision of how to manage existing dental restorations in patients. Objective This study tested the following hypotheses: i) teaching objective criteria to dental students enhances their criticism toward the indication for replacement of dental restorations; and ii) a complementary practical approach enhances the proportion of correctly indicated treatments compared with a strictly theoretical approach. Method This block-randomized controlled trial involved dental students from a Brazilian university who were randomized to either a didactic/theoretical class group (A, control) or a didactic/theoretical class followed by practical training (group B); both conditions were applied in a moodle-based environment. The proportion of correctly indicated interventions before and after teaching the criteria was compared with using Mann–Whitney U-test (p<0.05), and a comparison between the approaches was established with Wilcoxon test (p<0.05). Result The baseline proportion of correct assignments significantly increased after interventions for both groups (p=0.02), with no significant difference between the interventions (p=0.871). Conclusion The proposed online training enhanced the proportion of correct assignments to restorations, confirming the first study hypothesis. The second hypothesis was rejected because differences between the strategies had no effect on the proportion of correct answers. Focusing on teaching objective criteria for assessment of the quality of restorations would enhance students’ ability to correctly treat them.

Five-year Clinical Evaluation of a Nanofilled and a Nanohybrid Composite in Class IV Cavities

The purpose of this study was to evaluate a nanofilled and a nanohybrid composite, in combination with manufacturer-recommended etch-and-rinse adhesives, in class IV cavities. Thirty-four patients aged 14-46 years (mean age, 27.1 years) comprised the study group. Twenty-six patients received two class IV restorations and eight patients received four class IV restorations. For each patient, half the number of restorations were performed using a nanohybrid composite (Ceram X duo) and the remaining half used a nanofilled resin composite (Filtek Supreme XT), with two- (XP Bond) and three-step (Scotchbond Multipurpose) etch-and-rinse adhesives, respectively. Two experienced examiners evaluated the restorations for retention, color match, marginal discoloration, wear/loss of anatomic form, caries formation, marginal adaptation, and surface texture to compare the baseline (after placement) and annual recalls over 5 years. The cumulative success rates for the Filtek Supreme XT and Ceram X duo restorations after five years were 86.2% and 89.7%, respectively. Four Filtek Supreme XT and three Ceram X duo restorations failed. There was no statistically significant difference between the nanofilled and nanohybrid composites at any of the evaluation periods for any of the parameters evaluated. Despite the limited number of restorations, all restorations were clinically acceptable regarding retention, color match, marginal discoloration, wear or loss of anatomic form, the formation of caries, marginal adaptation, and surface texture, except the failed restorations. Fracture was the main cause of restoration failure.

Does translucency influence cure efficiency and color stability of resin-based composites?

OBJECTIVE

To determine if material's translucency influences the cure efficiency and color stability of resin-based composites (RBCs).

METHODS

Four commercially-available RBCs indicated for aesthetic restorations were selected in different translucent/opaque shades: IPS Empress Direct (IED) A3 Dentin, A3 Enamel, Trans 20, and Trans 30; Filtek Z350 XT (FZX) A3D, A3B, A3E, and CT; Estelite ∑ Quick (EQ) OA3, A3, and CE; and Opallis (OP) DA3, EA3, and T-Neutral. Color was obtained in the L'C'h' system at three distinct periods: 24h after photoactivation (baseline), after 30d of water storage (WS), and after 30d of coffee storage (CS). The translucency parameter (TP) of each RBC was calculated at baseline. The degree of CC conversion (DC) was obtained by Fourier-transform infrared spectroscopy at 0.05mm (top) and 2mm (bottom) surfaces; the cure efficiency considered the bottom/top ratio. The CIEDE2000 color difference (ΔE₀₀) was calculated considering the WS-baseline and CS-baseline values. Data were submitted to two-way ANOVA and Tukey's post-hoc test (α=0.05). Pearson's tests were used to analyze the correlations between TP and DC, and between TP and ΔE₀₀.

RESULTS

For all RBCs, cure efficiency was not affected by materials' translucency. A positive, significant correlation was observed between TP and DC at the bottom surface for FZX only. For all RBCs, the higher the TP, the higher the ΔE₀₀. The ΔE₀₀ was higher after CS than after WS, except for EQ A3. Positive correlation between TP and ΔE₀₀ were observed for all materials.

CONCLUSION

The translucency did not influence the cure efficiency but affected the color stability for all RBCs.

CLINICAL SIGNIFICANCE

High-translucent RBCs presented lower color stability and should be used carefully.

Should my composite restorations last forever? Why are they failing?

Composites resins have become the first choice for direct anterior and posterior restorations. The great popularity is related to their esthetic appearance and reduced need of sound tissue removal as compared with former treatments. Several studies have demonstrated that composite restorations may last long in clinical service. In this review we discuss the factors playing a role on the long-term longevity. Composite restorations have demonstrated a good clinical performance with annual failure rates varying from 1% to 3% in posterior teeth and 1% to 5% in anterior teeth. Factors related to the patients such as caries risk and occlusal stress risk, in addition to socioeconomic factors, may affect the survival significantly. Characteristics of the clinical operators, particularly their decision making when it comes to observing or approaching an existing restoration, are decisive for longevity. Cavity features such as the number of restored walls, composite volume, and presence of endodontic treatment are of major importance and may dictate the service time of the restorative approach. The choice of restorative composite seems to have a minor effect on longevity provided that appropriate technical procedures are used. The main reasons for failure in posterior teeth are secondary caries and fracture (restoration or tooth/restoration), while in anterior teeth esthetic concerns are the main reasons leading to restoration failures. Composite resin restorations can be considered a reliable treatment as long as both the professional and the patient are aware of the factors involved in restoration failures.

Microhybrid versus nanofill composite in combination with a three step etch and rinse adhesive in occlusal cavities: five year results

Objectives

The aim of the study was to evaluate the 5-year clinical performance of occlusal carious restorations using nanofill and microhybrid composites, in combination with 3-step etch-and-rinse adhesives, in patients who were going to commence orthodontic treatment.

Materials and Methods

A total of 118 restorations for occlusal caries were conducted prior to orthodontic treatment. Occlusal restorations were performed both with Filtek Supreme XT (3M ESPE) and Filtek Z250 (3M ESPE) before beginning orthodontic treatment with fixed orthodontic bands. Restorations were clinically evaluated at baseline and at 1, 2, 3, 4, and 5-year recalls.

Results

None of the microhybrid (Filtek Z250) and nanofill (Filtek Supreme XT) composite restorations was clinically unacceptable with respect to color match, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, or surface texture. A 100% success rate was recorded for both composite materials. There were no statistically significant differences in any of the clinical evaluation criteria between Filtek Z250 and Filtek Supreme XT restorations for each evaluation period.

Conclusions

The composite restorations showed promising clinical results relating to color matching, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, and surface texture at the end of the 5-year evaluation period.

Clinical Performance of Different Solvent-based Dentin Adhesives With Nanofill or Nanohybrid Composites in Class III Restorations: Five Year Results

Purpose:

To evaluate the clinical performance of water, acetone, ethanol, and ethanol-water solvent-based dentin adhesives with nanofill or nanohybrid composites in Class III restorations.

Methods and Materials:

A total of 22 patients aged between 14 and 48 years (mean age: 25.2 years) participated in the study. Each patient received four Class III restorations, which were performed using water (Scotchbond Multipurpose), acetone (Prime&Bond NT), ethanol (XP Bond) and ethanol-water (Xeno V) solvent-based dentin adhesive systems with a nanofill (Filtek Supreme XT) or nanohybrid composite (CeramX Duo). Two experienced examiners evaluated the restorations with regard to retention, color match, marginal discoloration, wear/loss of anatomic form, caries formation, marginal adaptation, and surface texture at baseline and at one-, two-, three-, four-, and five-year recalls.

Results:

The five-year survival rates were 100% for Scotchbond Multipurpose, Prime&Bond NT, and XP Bond and 81.2% for Xeno V–bonded restorations. Only three Xeno V–bonded restorations failed. With the exception of marginal discoloration, there were no statistically significant differences among the four adhesive-bonded restorations in any of the evaluation periods in terms of the evaluation criteria.

Conclusions:

With the exception of marginal discoloration and marginal integrity deterioration of Xeno V–bonded restorations, all four adhesive-bonded restorations exhibited good long-term results. However, adhesion strategy (such as self-etch or etch-and-rinse) is more important than the solvent content of dentin adhesive systems in the success of Class III restorations.

Esthetic smile rehabilitation of anterior teeth by treatment with biomimetic restorative materials: a case report

BACKGROUND

In daily clinical practice, esthetics of anterior teeth is a common presenting complaint of patients.

OBJECTIVE

This case report discusses the management of asymmetric smile associated with unsatisfactory extensive composite restorations and describes a clinical protocol using the direct composite resin for smile enhancement to restore the dental harmony of anterior teeth.

METHODS

The treatment planning was based on a diagnostic wax-up and cosmetic mock-up. After clinical and patient approvals were obtained, the patient was subjected to direct and indirect restorative treatment.

CONCLUSION

Nanocomposites are an effective alternative for anterior teeth restorations. Additionally, good planning enables satisfactory esthetic results, leading to the correction of an inappropriate axial inclination of incisors.

Direct resin composite restorations for fractured maxillary teeth and diastema closure: A 7 years retrospective evaluation of survival and influencing factors

OBJECTIVES

This retrospective study evaluated the survival rate of anterior direct resin based composite (RBC) build-ups in vital teeth made of microhybrid and nanofill RBC materials and the influence of bruxism, beverage consumption and smoking on the long-term performance of restorations.

METHODS

Patients receiving anterior restoration between 2006 and 2011, with the diagnosis of fracture or diastema, were selected. A total of 65 adult patients (mean age: 25.2) with 163 restorations (78 Filtek Supreme XT and 85 Enamel Plus HFO) were evaluated using the USPHS criteria. Data were analyzed with Fisher's Exact Test, Extended Cox-regression analysis and Kaplan-Meier method.

RESULTS

Mean observation period was 7.2 (±1.4) years and the mean annual failure rate for this period was 1.43%. The reasons of failures included restoration fracture and color mismatch. Nanofill restorations had significantly higher rate of color mismatch (p=0.002), microhybrids more frequently failed in fracture of restoration (p=0.034). The overall difference in potential hazard of using Enamel Plus HFO or Filtek Supreme XT was not significant (p=0.704). Chipping or fracture of the restoration was more frequent in the first year after placement (p=0.036), while beverage consumption was significantly correlated with discoloration of the restorations (p=0.005).

SIGNIFICANCE

The application of direct RBC restorations provides an excellent treatment option for fractured teeth and for closing diastemas. The overall survival rate was 88.34% up to 10 years. Microhybrid and nanofill RBC restorations showed similar survival rates, however nanofills discolored at a higher rate, meanwhile chipping of the restoration occurred frequently with microhybrids.

Ten-Year Survival of Class II Restorations Placed by General Practitioners

The aim of this retrospective practice-based study was to investigate the survival of direct class II restorations placed by a group of general dental practitioners (GDPs) and to analyze the effect of practice-, patient-, and tooth/restoration-related factors. Electronic patient files of 24 general dental practices were used for collecting the data for this study. From the patient files, survival rates of 222,836 composites, amalgams, glass ionomers, and compomers placed in 61,121 patients by 67 GDPs between 1999 and 2011 were analyzed by Kaplan-Meier statistics and a multiple Cox regression. The investigated group of GDPs placed restorations with a satisfactory survival (mean AFR₁₀, 4.9%; 95% confidence interval, 2.1 to 7.7), although a wide variation in annual failure rate (AFR) existed between the different operators, varying between 2.6% and 7.0%. Restorations placed in young adults (21-30 y old) survived longest, whereas they showed a shorter survival in children (hazard ratio [HR], 1.553) and the elderly (HR, 1.593). Restorations in molar teeth, restorations placed in endodontically treated teeth, and multisurface restorations are more at risk for reintervention. However, restoration size (included surfaces) has a greater impact on restoration survival in premolar teeth. For the future, improved data collection at the practice/operator, patient, and tooth/restoration level (e.g., risk assessment and diagnoses) will provide the opportunity to evaluate even more extensively the risk factors involved. Knowledge Transfer Statement: The results of this study give insight into the long-term survival of direct dental restorations and the influencing practice-, patient-, and tooth/restoration-related variables.

Restoration Survival: Revisiting Patients' Risk Factors Through a Systematic Literature Review

A literature review was conducted to investigate the influence of patient-related factors on restoration survival in posterior permanent teeth as well as to report the methods used to collect these factors. The selection of articles on longitudinal clinical studies investigating the survival of posterior restorations (except full crowns and temporary fillings) and including patient-related factors was performed by applying predefined criteria. The review was organized into two parts, the first describing how patient factors were assessed in the studies (n=45) and the second presenting the statistical significance (n=27) and size of the effect (n=11) of these factors on restoration survival. Patient-related factors mentioned in the studies included age; gender; caries risk; caries activity/severity; decayed, missing, filled teeth; number of restorations; oral hygiene; and bruxism, among others. Sixteen studies included the patient age or age range in the analysis, which was found to be significant in 47% of the studies. Regarding gender, four of 17 reports found a significant effect on survival, showing more failures for men in three studies. The caries risk profile or related variables were included in the analysis of 15 studies, and a significant effect on survival was reported for high-caries-risk individuals (or related variables) in 67% of these studies. Bruxism was also found to influence restoration survival in three of six studies where this variable was investigated. Some issues were found regarding the reporting of methods used to classify patients according to risk and were thoroughly discussed. In view of the information gathered in this review, the assessment of patient factors along with other variables should become part of clinical studies investigating restoration survival, since several of these factors were shown to influence the failure of restorations, regardless of the material type.

Intraoral Repair of Direct and Indirect Restorations: Procedures and Guidelines

The service life of defective direct or indirect restorations could be prolonged by repair or relayering actions where durable adhesion of resin-based composite materials is established for longevity of repairs. The advances in adhesive technologies have introduced several surface conditioning concepts to adhere resin composites onto different restorative materials. The purpose of this report is to summarize reasons for failure, survival of repaired reconstructions, elaborate upon types and mechanisms of available surface conditioning methods, and present operative dentists with practical guidelines for intraoral repair procedures.

Effect of photoinitiator combinations on hardness, depth of cure, and color of model resin composites

OBJECTIVE

This study aims to determine the influence of photoinitiators' combinations on the hardness, depth of cure, and color of model resin composites.

MATERIALS AND METHODS

The composites were formulated by a mixture of BisGMA and triethyleneglycol dimethacrylate (60:40 mol), with barium-aluminum-silicate glass and silicon dioxide particles as inorganic fillers (60 wt%). Three photoinitiator types were tested: camphorquinone/amine (CQ), monoacylphosphine oxide (TPO), and bysacylphosphine oxide (BAPO). Six experimental groups were formed by differences in photoinitiator systems: CQ, TPO, BAPO, CQ+TPO, CQ+BAPO, and CQ+TPO+BAPO. Hardness was determined by Knoop indentation at the top and bottom surfaces (n = 5). Depth of cure was performed according to ISO 4049 scraping method (n = 5). Color was obtained by the CIELAB method (n = 10), 24 hours after curing (baseline), after 30 days storage in distilled water, and after 30 days storage in coffee solution. CIELAB color difference (ΔE*) was calculated for both periods. Data were submitted to analysis of variance, followed by Student-Newman-Keuls method (α = 0.05).

RESULTS

The photoinitiator system influenced hardness, where CQ presented the lowest top and bottom values. No statistical difference among groups was observed for the bottom/top hardness ratio. Regarding the depth of cure, the CQ and those formulated with CQ associations presented higher values than TPO and BAPO. Regarding color, BAPO and CQ+BAPO presented the highest ΔE* after 30 days in water immersion, whereas CQ+TPO and CQ+TPO+BAPO presented the lowest after 30 days in coffee immersion.

CONCLUSION

The associations CQ+TPO and CQ+TPO+BAPO presented improved color stability and hardness when compared with CQ, and did not influence the depth of cure.

CLINICAL SIGNIFICANCE

The combination of alternative photoinitiators with the traditional camphorquinone/amine system improved the color stability of the model resin composites and maintaining their mechanical properties.

A practice-based research network on the survival of ceramic inlay/onlay restorations

OBJECTIVE

To evaluate prospectively the longevity of ceramic inlay/onlay restorations placed in a web-based practice-based research network and to investigate risk factors associated with restoration failures.

MATERIALS AND METHODS

Data were collected by a practice-based research network called Ceramic Success Analysis (CSA). 5791 inlay/onlay ceramic restorations were placed in 5523 patients by 167 dentists between 1994 and 2014 in their dental practices. For each restoration specific information related to the tooth, procedures and materials used were recorded. Annual failure rates (AFRs) were calculated and variables associated with failure were assessed by a multivariate Cox-regression analysis with shared frailty.

RESULTS

The mean observation time was 3 years (maximum 15 years) of clinical service, and AFRs at 3 and 10 years follow up were calculated as 1.0% and 1.6%. Restorations with cervical outline in dentin showed a 78% higher risk for failure compared to restorations with margins in enamel. The presence of a liner or base of glass-ionomer cement resulted in a risk for failure twice as large as that of restorations without liner or base material. Restorations performed with simplified adhesive systems (2-step etch-and-rinse and 1-step self-etch) presented a risk of failure 142% higher than restorations performed with adhesives with bonding resin as a separate step (3-step etch-and-rinse and 2-step self-etch). 220 failures were recorded and the most predominant reason for failure was fracture of the restoration or tooth (44.5%).

CONCLUSIONS

Ceramic inlay/onlay restorations made from several glass ceramic materials and applied by a large number of dentists showed a good survival. Deep cervical cavity outline, presence of a glass ionomer lining cement, and use of simplified adhesive systems were risk factors for survival.