Clinical efficacy of resin-based direct posterior restorations and glass-ionomer restorations - An updated meta-analysis of clinical outcome parameters.

The present review is an update of a systematic review that has been published in 2012. Meanwhile, many new clinical trials on resin composites had been published. New materials such as bulk fill resin composites and new glass-ionomer (GIC) based materials had been introduced. The focus of this review was to evaluate the longevity in relation to the material class and adhesive class, while adjusting for a possible study bias effect. The database PUBMED/SCOPUS were searched for clinical trials on posterior resin composites. The inclusion criteria were: (1) studies published between 2000 and 2019, (2) prospective clinical trial with at least 2 years of observation; (2) minimal number of restorations at last recall = 20; (3) report on drop-out rate; (4) report of operative technique and used materials; (5) utilisation of Ryge, modified Ryge or FDI evaluation criteria. The bias of each study was assessed by two independent reviewers using Cochrane Collaboration's tool for assessing risk of bias in randomised trials. For the statistical analysis, linear mixed models fitted on the individual data recorded along time have been used with random effects to account for study, patients and experiment effects. P-values smaller than 0.05 were considered significant. Of the 423 clinical trials, 62 studies (including 110 experiments) met the inclusion criteria. Material class was divided according to the composite filler in microhybrid (39 experiments/2807 restorations), nanohybrid (24 experiments/1254 restorations), and hybrid (22 experiments/1255 restorations). So-called bulk fill materials were treated as a separate category (9 experiments/506 restorations) as were the GIC (11 experiments/2121 restorations) and the compomer materials (5 experiments/238 restorations). Only one study (1.6%) had low risk of bias, 42 (67.7%) were assessed to have unclear risk of bias and 19 (30.6%) had a high risk of bias. In 52.3% of the studies Class II and Class I restorations had been placed. After 10 years, the survival rate for resin composite restorations dropped to about 85-90% with no significant difference between hybrid, microhybrid and nao-hybrid resin materials. The main reasons for restoration replacement were bulk fractures and wear, which accounted for a about 70% of replacements. Caries at the restorative margins accounted for about 20% of the replacements, and retention loss, inacceptable colour match or marginal integrity, endodontic treatment or cusp fracture for about 10% of the replacements of the resin composite restorations. For compomer and GIC restorations the mean overall survival rate was about 80% after 6 years. For GIC, the main reasons for failure were substantial loss of anatomical contour along with loss of proximal contacts and retention loss. Mainly fractures reduced the longevity of compomers restorations. Also, there was no statistically significant difference between hybrid, micro-hybrid, nano-hybrid and bulk fill resin composites with regard to colour match, surface texture, material fractures, and anatomical form. Posterior resin composite restorations that were placed with the enamel etch technique showed the best overall performance; the longevity was not significantly influenced by the filler type or viscosity of resin composite material. With regard to colour match, surface texture and anatomical form, nanohybrid resins were not significantly superior to hybrid or microhybrid resin composites. Compomer and GIC restorations demonstrated considerable shortcomings and had a significant shorter longevity

Bonding of simplified adhesive systems to caries-affected dentin of primary teeth

Purpose: To evaluate the bonding of simplified adhesive systems to sound and caries-affected dentin of primary teeth with microtensile (µTBS) and nanoleakage (NL) tests. Materials and Methods: Occlusal cavities were prepared in 36 sound second primary molars. Half of the specimens were submitted to pH cycling to simulate caries-affected dentin. Teeth were randomly restored with one of three materials: the etch-and-rinse adhesive system Adper Single Bond 2 (SB), the two-step self-etching adhesive system Adper SE Plus (SE), and the one-step self-etching adhesive system Adper Easy One (EASY). After storage for 24 h, specimens with cross-sectional areas of 0.8 mm2 were prepared for microtensile testing (1 mm/min). One stick from each tooth was immersed in silver nitrate solution (24 h) and allowed to develop for 8 h in order to score the nanoleakage with SEM. The fracture pattern was evaluated using a stereomicroscope (400X). The µTBS means were analyzed by two-way ANOVA and Tukey's post-hoc test. For NL, the Kruskal- Wallis and Mann-Whitney tests were used (α 0.05). For all groups, adhesive/mixed fracture prevailed. Cariesaffected dentin promoted silver nitrate uptake into the adhesive interface; however, with SE, the nanoleakage was more pronounced than in the other adhesive systems, even in sound dentin. Conclusion: Caries-affected dentin negatively influences the bond strength and nanoleakage of the two-step etch-and-rinse and one-step self-etching adhesive systems tested in primary teeth

Effect of 2 years water aging on bond strength stability of adhesive systems to artificial caries-affected primary dentin

Purpose To evaluate the effect of 2 years of water aging on microtensile bond strength (μTBS) of an etch-and-rinse and a self-etch adhesive system to sound (S) and artificial caries-affected primary dentin (CAD). Methods Occlusal cavities were prepared in 24 primary molars. Half of the specimens were submitted to a pH-cycling model to simulate artificial caries-affected dentin. Teeth were randomly restored either with two-step etch-and-rinse adhesive Adper Single Bond 2 (SB) or two-step self-etch system Adper SE Plus (SE). After 24 h of storage, the teeth were sectioned into two halves. One half was sectioned into sticks (0.8 mm2) to be tested immediately under μTBS testing. The same procedure was performed in the other half after storage in distilled water for 2 years (2 y). Data were analyzed by three-way repeated measures ANOVA and Tukey tests (α=0.05). Results The μTBS values of both adhesive systems significantly decreased after 2 years aging (SB: S – 38.4%, CAD – 23.9%; SE: S – 17.1%, CAD – 15.7%) (p<0.001). SE showed lower μTBS values compared with SB, regardless of storage period (p<0.001). Higher μTBS were detected in sound dentin, regardless of adhesive (p<0.001). Conclusion The degradation of the resin-dentin bonds occurred after 2 years of water aging, regardless of the substrate condition or type of adhesive. However, the etch-and-rinse adhesive system is preferable due to the highest μTBS in both periods

22-Year clinical evaluation of the performance of two posterior composites with different filler characteristics

Item does not contain fulltextOBJECTIVES: This retrospective longitudinal study investigated the longevity of posterior restorations placed in a single general practice using 2 different composites in filler characteristics and material properties: P-50 APC (3M ESPE) with 70vol.% inorganic filler loading (midfilled) and Herculite XR (Kerr) with 55vol.% filler loading (minifilled). METHODS: Patient records were used for collecting data. Patients with at least 2 posterior composite restorations placed between 1986 and 1990, and still in the practice for regular check-up visits, were selected. 61 patients (20 male, 41 female, age 31.2-65.1) presenting 362 restorations (121 Class I, 241 Class II) placed using a closed sandwich technique were evaluated by 2 operators using the FDI criteria. Data were analyzed with Fisher's exact test, Kaplan-Meier statistics, and Cox regression analysis (p<0.05). RESULTS: 110 failures were detected. Similar survival rates for both composites were observed considering the full period of observation; better performance for the midfilled was detected considering the last 12 years. There was higher probability of failure in molars and for multi-surface restorations. SIGNIFICANCE: Both evaluated composites showed good clinical performance over 22 years with 1.5% (midfilled) and 2.2% (minifilled) annual failure rate. Superior longevity for the higher filler loaded composite (midfilled) was observed in the second part of the observation period with constant annual failure rate between 10 years and 20 years, whereas the minifilled material showed an increase in annual failure rate between 10 years and 20 years, suggesting that physical properties of the composite may have some impact on restoration longevity

Dentin Cross-linking Effect of Carbodiimide After 5 Years

Carbodiimide (EDC)\u2013based dentin primers preserve hybrid layer (HL) integrity. However, aging &gt;1 y has not been investigated. The present study examined whether the cross-linking effect of EDC was reflected in dentin bond strength, endogenous enzymatic activity, and the chemical profile of the HL after 5-y aging in artificial saliva. Noncarious human third molars (N = 42) were cut to expose middle/deep coronal dentin and treated as follows: group 1, dentin etched with 35% H3PO4, pretreated with a 0.3M aqueous EDC primer for 1 min and restored with XP Bond (Dentsply Sirona); group 2, as in group 1 but without EDC pretreatment; group 3, Clearfil SE Bond (Kuraray-Noritake) primer applied to dentin surface, followed by EDC pretreatment as in group 1 and application of bond; group 4, as in group 3 without EDC pretreatment. After composite buildup, the specimens were cut into sticks or slabs, depending on the experiment. All tests were performed at baseline (T0) and after 5 y of aging (T5) in artificial saliva at 37 \ub0C. Microtensile bond strength (\ub5TBS) was tested at a crosshead speed of 1 mm/min until failure. Endogenous enzymatic activity was investigated with in situ zymography. The chemical profile of HL was determined via Raman spectroscopy. Three-way analysis of variance and post hoc Tukey test were used to analyze \ub5TBS and in situ zymography data (\u3b1 = 0.05). EDC pretreatment and aging significantly influenced \ub5TBS and in situ zymography results (P &lt; 0.05). Higher bond strength and lower gelatinolytic activity were identified in the EDC-treated groups at T5 (P &lt; 0.05), especially in the etch-and-rinse groups. Raman spectra revealed less defined amide III peaks in control specimens at T5. The EDC cross-linking effect persisted in the HL for 5 y in terms of bond strength, collagen structure preservation, and dentinal enzyme silencing

Chlorhexidine preserves the hybrid layer in vitro after 10-years aging

Objective: The present study investigated the ability of a chlorhexidine (CHX)-containing primer (0.2% aqueous solution) to inhibit dentinal enzymes, preserve the hybrid layer (HL) and remain within the HL, after 10 years of aging in artificial saliva at 37 \ub0C. Methods: Non-carious extracted molars were assigned to two groups, cut into slabs exposing middle/deep dentin, etched and bonded with Adper Scotchbond 1XT (SB1XT) with or without 0.2% CHX aqueous solution pretreatment. Composite build-ups were made, and the specimens were cut in 1-mm thick bonded sticks. In situ zymography was performed on freshly prepared specimens (T0) and specimens aged for 10 years (T10-yr) at 37 \ub0C in artificial saliva, to investigate endogenous gelatinolytic activity within the HL. At T10-yr, specimens were also decalcified and embedded in epoxy resin for TEM analysis. Micro-Raman spectroscopy was performed at T0 and T10-yr to evaluate the chemical profiles in intertubular dentin and the HL. Results: In situ zymography showed less pronounced enzymatic activity in the CHX-pretreated group (p &lt; 0.05) regardless of aging, maintaining a similar level of fluorescence at T0 and T10-yr (p &gt; 0.05). TEM results showed that 98% of the HL had been degraded in the control group, while 95% of the HL was intact in the experimental group. Moreover, all the Raman spectra peaks assigned to CHX could be identified only in the CHX-pretreated group (T0 and T10-yr). Significance: In vitro, CHX remains in the HL after 10 years with its inhibitory effect preserved. This may be the underlying factor for HL preservation after this long aging period