Clinical performance of glass ionomer cement and composite resin in Class II restorations in primary teeth: A systematic review and meta-analysis.

OBJECTIVES: This study compared the clinical performance of glass ionomer cement (GIC) compared to composite resin (CR) in Class II restorations in primary teeth. DATA: Literature search according to PRISMA guidelines including randomized controlled trials comparing Class II restorations performed with GIC, compared to CR, in primary teeth. SOURCES: PubMeb, Scopus, Web of Science, VHL, Cochrane Library, Clinical Trials and OpenGrey, regardless of date or language. STUDY: Ten studies were included in qualitative synthesis, and 9 in the meta-analyses (MA). Six studies were classified as low risk of bias, and 4 as "unclear". Heterogeneity ranged from null to high (0% to 73%). GIC and CR presented similar failure patterns (risk difference -0.04 [-0.11, 0.03]; p = 0.25, I2 = 51%), and the exclusion of studies with follow-up period <24 months, or grouping according to the type of GIC (conventional or resin-modified), or according to the type of isolation (cotton roll or rubber dam), or according to the evaluation criteria applied did not affect the pattern of the results obtained. GIC exhibited significantly lower values of secondary carious lesions (SCL) than CR (SCL: risk difference 0.06 [0.02, 0.10], p = 0.008, I2 = 0%). The materials presented similar performance (p > 0.05) regarding the overall effect, as well as for marginal discoloration, marginal adaptation and anatomical form. The superiority of GIC was maintained when resin-modified GIC and rubber dam isolation were analyzed separately. CONCLUSIONS: GIC and CR presented similar clinical performance for all criteria analyzed, except for secondary carious lesions, in which GIC presented superior performance, especially for the resin-modified GIC and with rubber dam isolation.

Effectiveness of pre-treatment with chlorhexidine in restoration retention: A 36-month follow-up randomized clinical trial.

OBJECTIVES: This study evaluated the effect of the pre-treatment with 2% chlorhexidine digluconate (CHX) as coadjutant in restoration retention of noncarious cervical lesions (NCCL), after 36 months of follow-up. METHODS: A randomized controlled split-mouth and triple-blind (operators, patients and evaluator) trial was carried out. Patients (n=42) with at least two non-carious cervical lesions were included. The teeth with NCCL were randomly assigned to two treatment groups: application of 2% CHX (experimental group) or a placebo solution (control group) for 60s after acid etching and before the adhesive application. A trained and calibrated examiner evaluated the restorations at baseline (1 week) and at each recall (6, 12, 24 and 36 months) using the FDI criteria. A total of 225 restorations were evaluated after 36-month follow-up. Data were subjected to survival analysis using the Kaplan-Meier method, and the log-rank test was used to evaluate the existence of differences between the survival curves (α=0.05). RESULTS: The restorations survival rate after 36 months of follow-up was 76.1%. There was no difference in the retention and failure rates between the experimental and the control group (p=0.968). There was an increased failure trend when restorations were located subgingival compared to those at the gingival level or supragingival. CONCLUSION: The pre-treatment with 2% chlorhexidine digluconate did not promote further restoration retention of noncarious cervical lesions. CLINICAL SIGNIFICANCE: The cavity pre-treatment with chlorhexidine for inhibition of hybrid layer degradation does not add any beneficial effect to the clinical performance of restorations.

Survival of Adhesive Restorations for Primary Molars: A Systematic Review and Metaanalysis of Clinical Trials.

PURPOSE: The purpose of this study was to assess the scientific evidence regarding the survival and clinical performance of adhesive materials for primary molars, comparing composite resin (CR), conventional glass ionomer cement (GIC), resin-modified glass ionomer (RMGIC), silver-reinforced glass ionomer cement, and compomer. METHODS: Six databases were searched without restrictions regarding language or year of publication. Meta-analysis was conducted; risk ratios (RRs) and 95 percent confidence intervals (95% CI) were calculated. RESULTS: Eleven clinical trials were included. Two studies found that the median survival time (MST) of SRGIC was less than that of GIC and RMGIC (P<0.005), and two studies found that the GIC had a lower MST than both RMGIC and compomer (P<0.05). Meta-analysis for CR, compomer, and RMGIC was conducted. These materials did not differ significantly regarding the number of restorations that survived over 24 months: CR versus RMGIC (RR equals 1.12, 95% CI equals 0.96 to 1.31); CR versus compomer (RR equals 1.04; 95% CI equals 0.96 to 1.13); and compomer versus RMGIC (RR equals 1.03; 95% CI equals 0.84 to 1.27). CONCLUSIONS: Silver-reinforced glass ionomer cement has the worst survival rate among ionomers, and adhesive materials with a resin component have similar survival rates.

In vivo Evaluation of Proximal Resin Composite Restorations performed using Three Different Matrix Systems.

OBJECTIVE: The aim of this in vivo study was to radiographically evaluate the proximal contour of composite resin restorations performed using different matrix systems. MATERIALS AND METHODS: Patients with premolars needing class II type resin composite restorations involving the marginal ridge were selected. Thirty premolars were selected and randomly divided into three groups (n = 10 each) to receive restorations using different matrix systems: group 1: metal matrix coupled to a carrier matrix and wood wedge (G1-MMW); group 2: sectioned and precontoured metal matrix and elastic wedge (G2-SME); and group 3: a polyester strip and reflective wedge (G3-PMR). After the restorative procedure, bitewing radiographs were performed and analyzed by three calibrated professionals. The quality of the proximal contact and marginal adaptation of the proximal surfaces was classified as either correct or incorrect (undercontour/overcontour). RESULTS: The Pearson Chi-square statistical test (α = 5%) revealed a statistically difference between frequencies of correct and incorrect restorations (α(2) = 6.787, p < 0.05). The group G2 SME produced a higher frequency of correct proximal contours (90%), while G1-MMW and G3-PMR had a ratio of 40% correct and 60% incorrect contours respectively. CONCLUSION: None of the matrix systems was able to prevent the formation of incorrect proximal contours; however, the sectioned and precontoured metal matrix/elastic wedge configuration provided better results as compared to the other groups.

Marginal adaptation of class V restorations with current-generation dentin-bonding agents: effect of different dentin surface treatments.

This study sought to assess the use of chlorhexidine with several excipients as a dentin surface treatment and its effect on marginal adaptation of class V restorations with current-generation dentin bonding agents. A total of 120 human third molars were selected and allocated into 12 groups, with standardized buccal class V restorations randomly divided into preconditioned dentin rinsed with: water; water + chlorhexidine; ethanol; or ethanol + chlorhexidine. After rinsing of dentin (previously conditioned with 35% phosphoric acid) with the test solutions, the Adper single bond 2, prime and bond 2.1, and Excite bonding systems were applied randomly. Restorations were performed with Filtek™ Z350 XT composite resin. The resulting specimens were subjected to thermal and mechanical load cycling. Quantitative analysis of marginal adaptation was performed on epoxy replicas by means of scanning electron microscopy. Results were assessed by means of the Kruskal-Wallis test (percentages of continuous margins) and Wilcoxon test (differences between percentages of continuous margins before and after thermal cycling and mechanical loading), at a significance level of p < 0.05. Outcomes in the chlorhexidine-treated groups were not superior to those obtained with other treatments.

Longevity of posterior restorations in primary teeth: results from a paediatric dental clinic.

OBJECTIVES: The aim of this retrospective study was to evaluate the longevity of restorations in the posterior primary teeth of children attending to a public paediatric dental clinic and to test the factors associated with failures. METHODS: Patient records of 329 children (162 boys and 166 girls) were used for collecting and analyzing data. A total of 565 restorations in primary teeth were included in the study. All children enrolled in the study were classified as high caries risk. The longevity of restorations from their placement until failure (up to 4 years of follow-up) was assessed using the Kaplan-Meier survival curves with log-rank test. Multivariate Cox regression analysis with shared frailty (p<0.05) was used to assess the factors associated with failures. RESULTS: Up to 4 years of follow-up, the annual failure rates were 9.5% for composite fillings, 12.2% for light-cured glass ionomer restorations, and 12.9% for conventional glass ionomer restorations with statistical difference between the materials (p=0.014). Glass ionomer restorations had a higher risk of failure over time compared with composites (HR 1.86, 95% CI 1.17-2.97). In crude analysis, Class II restorations showed lower survival rate than Class I restorations (p=0.031) but lost significance after adjustments. CONCLUSIONS: Our findings suggested that the material influenced the survival rate of primary posterior restorations, with composite presenting the best performance. CLINICAL SIGNIFICANCE: Differences were observed between restorative materials with different properties in primary teeth up to 4 years of follow-up. This study provides valuable information regarding the primary teeth posterior restoration longevity in a paediatric population with restorations performed under daily life clinical environment.

Cuspal movement related to different polymerization protocols.

OBJECTIVE: The aim of this study to investigate the effects of different polymerization protocols on the cuspal movement in class II composite restorations. MATERIALS AND METHODS: Human premolar teeth were prepared with class II cavities and then restored with composite and three-step and two-step etch-and-rinse adhesive systems under different curing techniques (n = 10). It was used a light- emitting-diode curing unit and the mode of polymerization were: standard (exposure for 40 seconds at 700 mW/cm(2)), pulse-delay (initial exposure for 6 seconds at 350 mW/cm(2) followed by a resting period of 3 minutes and a final exposure of 37 seconds at 700 mW/cm(2)) and soft-start curing (exposure 10 seconds at 350 mW/cm(2) and 35 seconds at 700 mW/cm(2)). The cuspal distance (µm) was measured before and after the restorative procedure and the difference was recorded as cuspal movement. The data were submitted to two-way ANOVA and Bonferroni test (p < 0.05). RESULTS: The type of adhesive system did not influenced the cuspal movement for all the curing methods. Standard protocol showed the highest values of cuspal movement and was statistically different from the pulse-delay and soft-start curing modes. CONCLUSION: Although the cuspal displacement was not completely avoided, alternative methods of photocuring should be considered to minimize the clinical consequences of composites contraction stress.

The effect of mechanical loading on the cusp defection of premolars restored with direct and indirect techniques.

AIM: This study assessed the effect of fatigue load cycling on human premolars restored with MOD restorations (direct and indirect approaches) on cuspal defection, compared to intact teeth (unprepared) and unrestored teeth with an inlay preparation. MATERIALS AND METHODS: MOD inlay preparations were performed on sixty premolars with their roots embedded in acrylic resin. These teeth were divided into six groups (n = 10): (1) intact teeth; (2) unrestored and prepared teeth; (3) teeth restored with direct composite resin; (4) teeth restored with an indirect composite resin; (5) teeth restored with injected ceramic inlays (IPS Empress 2 (Ivoclar); (6) teeth restored with CAD/CAM inlays made of feldspathic ceramic (Vita Mark II). All of the indirect restorations were adhesively cemented. Strain-gauges were bonded to the buccal and lingual surfaces of the specimens. Compressive axial loading of 100N was applied on the occlusal face of the specimens to measure the cuspal deflection (microstrain) under compressive loading. These measurements were obtained before and after mechanical cycling (1 Hz, 37°C, 100,000x). RESULTS: Comparing the results obtained before and after fatiguing, the cuspal defection increased only in the CAD/CAM approach. The prepared tooth group had the highest cuspal defection, before and after mechanical cycling. CONCLUSION: The evaluated restoring approaches decrease the cuspal defection, consequently appear to improve the cuspal reinforcement.

Influence of flowable composite and restorative technique on microleakage of class II restorations.

AIM: The aim of the present study was to evaluate the microleakage in class II cavities restored with dental composite by varying the thickness of two flowable composite resins and the restorative technique. METHODS: A total of 130 cavities were prepared on proximal surfaces of bovine teeth and randomly divided in 13 groups. Twelve experimental groups were performed using flowable composite resin as the liner, and they were divided according to the type of flowable composite resin (Filtek Z350 Flow-Z350F and SureFil SDR Flow-SUR), the thickness of the flowable composite (0.5, 1, or 2 mm), and the restorative technique (flowable composite applied at the cavosurface angle or amelodentinal junction) (n = 10). A control group was performed without using a flowable composite. Following restorative procedures and thermocycling, the samples were immersed in Methylene Blue for 2 h, and prepared for analysis in an absorbance spectrophotometer. All results were statistically analyzed (α = 0.05). RESULTS: There was no significant difference between the flowable composites (P > 0.05). The restorative techniques influenced microleakage and were flowable composite dependent (P ≤ 0.05). The lower thickness of the flowable composite provided less microleakage (P ≤ 0.05). CONCLUSION: The use a lower thickness of a flowable composite resin provided less microleakage, suggesting a better sealing tooth-restoration interface.

Influence of cone-beam computed tomography image artifacts on the determination of dental arch measurements.

OBJECTIVE: To compare dental plaster model (DPM) and cone-beam computed tomography (CBCT) in the measurement of the dental arches, and investigate whether CBCT image artifacts compromise the reliability of such measurements. MATERIALS AND METHODS: Twenty patients were divided into two groups based on the presence or absence of metallic restorations in the posterior teeth. Both dental arches of the patients were scanned with the CBCT unit i-CAT, and DPMs were obtained. Two examiners obtained eight arch measurements on the CBCT images and DPMs and repeated this procedure 15 days later. The arch measurements of each patient group were compared separately by the Wilcoxon rank sum (Mann-Whitney U) test, with a significance level of 5% (α  =  .05). Intraclass correlation measured the level of intraobserver agreement. RESULTS: Patients with healthy teeth showed no significant difference between all DPM and CBCT arch measurements (P > .05). Patients with metallic restoration showed significant difference between DPM and CBCT for the majority of the arch measurements (P > .05). The two examiners showed excellent intraobserver agreement for both measuring methods with intraclass correlation coefficient higher than 0.95. CONCLUSION: CBCT provided the same accuracy as DPM in the measurement of the dental arches, and was negatively influenced by the presence of image artifacts.

Effect of polymerization mode and time of adhesive system on microleakage in composite resin restorations.

AIM: To quantify the microleakage on restorations carried out with a two-step etch-and-rise adhesive system and nanofilled composite resin after thermal and mechanical loading cycling. METHODS: Ninety cavities were prepared on proximal surfaces of incisive teeth, and were randomly divided according to the photoactivation time (10, 20, or 30 s) and light-curing mode (Quartz Tungsten Halogen (QTH) lamps, 450 mW/cm(2); Light Emitting Diode (LED) second generation, 1100 mW/cm(2); or LED third generation, 700 mW/cm(2)) of an adhesive system (n = 10). Following restorative procedures and thermal and mechanical loading cycling, the samples were immersed in Methylene Blue for 2 h. The samples were ground, and the powder was prepared for analysis in an absorbance spectrophotometer. All results were statistically analyzed by anova and Tukey's test at the 5% level of significance. RESULTS: There were no significant statistical difference in microleakage between the light-curing mode (P = 0.1212) and light-curing time (P = 0.2043). CONCLUSION: Different curing modes and increasing the curing time were not factors that influenced the process of microleakage.

Comparison of microleakage of different margin types around Class V resin restorations in primary teeth.

AIM: This in vitro study compared the effect of a concave with a straight-bevelled cavity margin on the microleakage of Class V composite resin restorations in primary teeth. MATERIALS AND METHODS: Standardised Class V cavity preparations were made in vitro on the buccal (all margins placed in enamel) and on the lingual (margins placed in enamel and cementum) surfaces of 20 sound primary molars. The teeth were randomly assigned to two groups of 10 each: in Group 1, a concave bevel was made with a high-speed No. 04 tungsten carbide bur and in Group 2, a straight bevel was made with a high-speed No. 556 tungsten carbide bur. The teeth were restored incrementally with Adper Single Bond 2 (3M) adhesive and Filtek Z 350 (3M) composite resin. All specimens were subsequently thermocycled and immersed in 50% silver nitrate solution. Microleakage of the restorations was then assessed by silver penetration. A grading scale of 0 to 4 was used as the scoring criterion. RESULTS: At the enamel margins no statistically significant differences were observed between the two groups (p>>0.05). Occlusal walls in enamel, in both groups, exhibited less leakage than the cervical walls in cementum (p<0.01) and Group 1 showed better results than Group 2 in decreasing microleakage at the cementum margins (p <0.05). CONCLUSION: Based on the results, it was concluded that concave-beveled cavity preparations may reduce but did not totally eliminate microleakage at the cementum margins of Class V composite resin restorations in primary teeth.

Are there universal restorative composites for anterior and posterior teeth?

OBJECTIVE: This retrospective, longitudinal clinical study investigated the longevity up to 20 years of posterior restorations placed with 3 universal composites (Charisma, Herculite XR, Z100) and of anterior restorations placed with 2 universal composites (Charisma, Herculite XR). METHODS: Records from 90 patients were retrieved from a private practice (374 posterior, 219 anterior restorations). Clinical evaluation was performed by the FDI criteria. Survival analysis was assessed using Kaplan-Meier method and Log-Rank test, and factors associated with failure by multivariate Cox regression with shared frailty. RESULTS: In the first 10 years, almost 95% of the restorations were satisfactory, showing increased failure thereafter. Charisma showed the most failures in anterior and posterior areas. Annual failure rates varied between 0.3% and 2.5%, with slightly better performance for anterior restorations. Fracture (posterior) and aesthetics (anterior) were the main reasons for failure. CLINICAL SIGNIFICANCE: Differences were observed between restorative materials with different properties, but these became apparent only after more than 10 years of clinical service. The present study provides evidence that in a patient group with low caries risk, anterior and posterior restorations placed with universal composites may have excellent long-term clinical performance.

Compatibility between silorane adhesive and simplified methacrylate-based adhesive systems.

The purpose of this study was to evaluate the impact of replacing P90 primer with simplified adhesive systems (with a conventional, two-step adhesive or a self-etching, one-step adhesive) on bond strength to dentin in Class I restorations. The interfaces were also analyzed using confocal microscopy by adding a fluorophore to the adhesive components and SEM using silver nitrate for nanoleakage investigation. X-ray diffraction (XRD) characterized the chemical interaction of the adhesives. Failure mode and nanoleakage varied among groups. Characteristic micromorphology and higher nanoleakage were noted for silorane combinations. On the other hand, no signs of phase crystallization in the silorane adhesive combinations were noted. Replacing the silorane primer with simplified adhesives proved successful as the modified systems provided bonding to dentin comparable to that of the unmodified silorane systems. However, the dedicated adhesive exhibited signs of degradation immediately after application, which may impact the longevity of restorations in short periods.

Evaluation of bond strength and thickness of adhesive layer according to the techniques of applying adhesives in composite resin restorations.

Adhesive restorations have increasingly been used in dentistry, and the adhesive system application technique may determine the success of the restorative procedure. The aim of this study was to evaluate the influence of the application technique of two adhesive systems (Clearfil SE Bond and Adper Scotchbond MultiPurpose) on the bond strength and adhesive layer of composite resin restorations. Eight human third molars were selected and prepared with Class I occlusal cavities. The teeth were restored with composite using various application techniques for both adhesives, according to the following groups (n = 10): group 1 (control), systems were applied and adhesive was immediately light activated for 20 seconds without removing excesses; group 2, excess adhesive was removed with a gentle jet of air for 5 seconds; group 3, excess was removed with a dry microbrushtype device; and group 4, a gentle jet of air was applied after the microbrush and then light activation was performed. After this, the teeth were submitted to microtensile testing. For the two systems tested, no statistical differences were observed between groups 1 and 2. Groups 3 and 4 presented higher bond strength values compared with the other studied groups, allowing the conclusion that excess adhesive removal with a dry microbrush could improve bond strength in composite restorations. Predominance of adhesive fracture and thicker adhesive layer were observed via scanning electron microscopy (SEM) in groups 1 and 2. For groups 3 and 4, a mixed failure pattern and thinner adhesive layer were verified. Clinicians should be aware that excess adhesive may negatively affect bond strength, whereas a thin, uniform adhesive layer appears to be favorable.

Minimal invasive treatment for defective restorations: five-year results using sealants.

Replacement of dental restorations has been the traditional treatment for restorations that are defective. In this five-year randomized clinical trial, restorations with localized marginal defects were treated with sealants. Thirty-two patients (mean age, 26.8 years) with 126 Class I and Class II restorations with defective margins (amalgam n=69 and resin-based composite n=57) were recruited. Treatment was seal with pit and fissure sealant on localized marginal defects (group A: n=43) and was compared with total restoration replacement (group B: n=40) and untreated restorations (group C: n=43) as negative and positive controls. Restorations were assessed by two examiners using the modified US Public Health Service criteria, observing five clinical parameters: marginal adaptation, roughness, marginal stain, teeth sensitivity, and secondary caries at baseline and at five years after treatment. At the five-year recall examination, 23 patients with 90 restorations (71.4% recall rate) were examined. A significant improvement was observed in the marginal adaptation of the restorations in group A compared with group B. None of the treated group showed trends to downgrade in any parameter. Tooth sensitivity and secondary caries showed a low frequency in all groups. No significant difference in marginal adaptation of the restorations was found between amalgam and resin-based composite restorations (p=0.191). This study demonstrated that marginal sealing of restorations is a minimally invasive treatment that may be used instead of the replacement of restorations with localized marginal defects.

Effects of three restorative techniques in the bond strength and nanoleakage at gingival wall of Class II restorations subjected to simulated aging.

OBJECTIVE: To evaluate the effects of simulated aging in bond strength and nanoleakage of class II restorations using three different restorative techniques. MATERIALS AND METHODS: Class II preparations (n = 12) were restored using: FS - composite resin Filtek Supreme Plus (3M/ESPE); RMGIC + FS - resin-modified glass ionomer cement Vitrebond Plus (3M/ESPE) + FS; and FFS + FS - flowable composite resin Filtek Supreme Plus Flowable (3M ESPE) + FS. The teeth were assigned into two groups: Control and Simulated Aging - Thermal/Mechanical cycling (3,000 cycles, 20-80 °C/500,000 cycles, 50 N). From each tooth, two slabs were assessed to microtensile bond strength test (µTBS) (MPa), and two slabs were prepared for nanoleakage assessment, calculated as penetration along the restoration margin considering the penetration length (%) and as the area of silver nitrate particle deposition (µm(2)). Data were analyzed by two-way analysis of variance (ANOVA) followed by Tukey's post hoc test (p < 0.05). RESULTS: FS presented the highest µTBS to dentin (22.39 ± 7.55 MPa) after simulated aging, while the presence of flowable resin significantly decreased µTBS (14.53 ± 11.65 MPa) when compared to no aging condition. Both control and aging groups of RMGIC + FS presented the highest values of silver nitrate penetration (89.90 ± 16.31 % and 97.14 ± 5.76 %) and deposition area (33.05 ± 12.49 and 28.08 ± 9.76 µm(2)). Nanoleakage was not affected by simulated aging. CONCLUSIONS: FS presented higher bond strength and lower nanoleakage and was not affected by simulated aging. Use of flowable resin compromised the bond strength after simulated aging. CLINICAL RELEVANCE: The use of an intermediate layer did not improve the dentin bond strength neither reduced nanoleakage at the gingival margins of class II restorations under simulated aging conditions.

Two-year clinical performance of self-etching adhesive systems in composite restorations of anterior teeth.

OBJECTIVE: The aim of this study was to evaluate the two-year clinical performance of Class III, IV, and V composite restorations using a two-step etch-and-rinse adhesive system (2-ERA) and three one-step self-etching adhesive systems (1-SEAs). MATERIAL AND METHODS: Two hundred Class III, IV, and V composite restorations were placed into 50 patients. Each patient received four composite restorations (Amaris, Voco), and these restorations were bonded with one of three 1-SEAs (Futurabond M, Voco; Clearfil S3 Bond, Kuraray; and Optibond All-in-One, Kerr) or one 2-ERA (Adper Single Bond 2/3M ESPE). The four adhesive systems were evaluated at baseline and after 24 months using the following criteria: restoration retention, marginal integrity, marginal discoloration, caries occurrence, postoperative sensitivity and preservation of tooth vitality. After two years, 162 restorations were evaluated in 41 patients. Data were analyzed using the χ(2) test (p<0.05). RESULTS: There were no statistically significant differences between the 2-ERA and the 1-SEAs regarding the evaluated parameters (p>0.05). CONCLUSION: The 1-SEAs showed good clinical performance at the end of 24 months.

Clinical evaluation of nanofill and nanohybrid composite in Class I restorations: a 12-month randomized trial.

This randomized trial evaluated the 12-month clinical performance of nanofill, a nanohybrid, and a microhybrid composite in restorations in occlusal cavities of posterior teeth. This study utilized 41 patients, each of whom had three molars affected by primary caries or the need to replace restorations. All restorations were performed in accordance with the manufacturer's recommendations and evaluated in accordance with U.S. Public Health Service-modified criteria. Based on the results of the present study, the material investigated demonstrated acceptable clinical performance after 12 months of clinical service. Long-term re-evaluations are necessary for a more detailed analysis of these composites.