Indirect Resin Composite Restorations Research Articles

Fracture Resistance of Direct versus Indirect Restorations on Posterior Teeth: A Systematic Review and Meta-Analysis.

The aim of this systematic review and meta-analysis was to compare static compression forces between direct composite resin restorations and indirect restorations for posterior teeth. All studies comparing mechanical properties of direct versus indirect restorations of posterior teeth were included from 2007 up to February 2024. A meta-analysis was conducted for static compression fracture resistance. Medline, Central, and Embase databases were screened. Twenty-four articles were included in the qualitative synthesis, and sixteen studies were finally included in the quantitative synthesis. There was no difference in terms of fracture resistance between direct and indirect restorations for posterior teeth (p = 0.16 for direct and indirect composite resin restorations and p = 0.87 for direct composite resin restorations and indirect ceramic restorations). Also, sub-group analysis with or without cusp coverage in each group revealed no discernable difference. Based on this study, it can be concluded that the choice between direct and indirect restoration approaches may not significantly impact fracture resistance outcomes. There was no statically significant difference between direct and indirect restorations for posterior teeth in all cases of restorations with or without cusp coverage and no matter the used materials. However, to better evaluate these materials, further studies are warranted.

The Evaluation of the Cervical Marginal Sealing of Direct vs. Indirect Composite Resin Restorations in MOD Cavities.

The aim of this in vitro study was to compare the quality of marginal sealing at the cervical margins of indirect and direct composite resin restorations in mesio-occluso-distal (MOD) cavities. MOD preparations were performed on 30 extracted teeth. The mesial cervical margin of each tooth was relocated using a flow composite resin (Enamel Plus HRi Flow, Micerium, Avegno, GE, Italy), then the samples were divided into three groups. In group A, the cavities were directly restored using a nanohybrid composite resin (Miris 2 Coltène Whaledent, Altstaetten, Switzerland) and a universal adhesive (ScotchBond Universal, 3M ESPE, St. Paul, MN, USA) by the etch-and-rinse strategy, for group B, the restoration procedure was similar but the self-etch strategy was used, and the samples in group C were filled using the inlay technique. Each sample was stored for 48 h in a 2% methylene blue solution, then it was cut in a mesio-distal direction using a Struers Secotom 50 device (Cleveland, OH, USA). The marginal sealing and adhesive interface were assessed for each sample at the cervical margin by optical microscopy (OM) and scanning electron microscopy (SEM). One-way ANOVA and Bonferroni post-hoc tests were used with a significance level of 0.05. Significant differences were recorded within groups A and C, between mesial and distal margins (p = 0.02 in group A and p = 0.043 in group C). The marginal sealing is more effective in MOD inlay restoration compared to direct restorations. Relocation of the cervical margin with flow composite resin and the use of different adhesive strategies do not improve the marginal sealing.

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

ObjectiveTo evaluate retrospectively the longevity of lithium disilicate ceramic (LidiSi) vs. laboratory-processed resin-based composite (RBC) inlay/onlay/overlay restorations and risk factors associated with restoration deficiencies and failures. MethodsPatients (n = 91) receiving LidiSi (73.1%) and RBC (36.9%) inlays/onlays/overlays between 2007 and 2017 were selected. The restorations were evaluated using the modified U.S. Public Health Service criteria. The survival of the restorations was analyzed using the Kaplan-Meier method and log rank test. Factors affecting the occurrence of deficiencies were examined by logistic regression analysis. This was performed with the use of the Generalized Estimating Equation model including Repeated measurements (GEER), with the consideration that the same patient had several teeth in the sample. Risk estimation was conducted for each evaluated criterion (p < 0.05). ResultsThe survival of LidiSi and RBC restorations were 96.8% and 84.9%, respectively after a mean observation period of 7.8 ± 3.3 years. The annual failure rate was 0.2% for LidiSi and 1.0% for RBC. The probability of survival was above 98% for both restorations in the first 6 years, however, it dropped to 60% for RBC by the end of the 15th year. For both materials the reasons for failure included secondary caries, restoration fracture, and endodontic complication. In addition, LidiSi also failed due to tooth fracture, while RBC due to marginal gap formation and loss of retention. Among the evaluated risk factors, material of restoration (OR=6.8, CI95%:3.1–14.9), oral hygiene (OR=8.0, CI95%: 2.9–22.1], and bruxism (OR=1.9, CI95%: 1.1–3.3) showed a significant impact on the evaluated criteria. SignificanceLidiSi and RBC restorations showed similarly excellent 6-year survival, however, in the long term significantly more failures should be expected for RBCs.

Direct or indirect composite for restoring permanent first molars affected by Molar Incisor Hypomineralisation (MIH): a randomized clinical controlled trial

AimThis study was undertaken to compare direct composite resin restorations (DCRR) and indirect composite resin restorations (ICRR) for treating permanent first molars affected by MIH in terms of clinical performance.Materials and methodsThis was a controlled, randomized, clinical split-mouth study. The studied sample consisted of 40 asymptomatic first permanent hypomineralised mandibular molars in 20 children aged between 7–11 years, these cases were divided randomly into two groups: Group 1 (experimental): 20 first permanent mandibular molars were restored with ICRR, and Group 2 (control): 20 first permanent mandibular molars that were restored with DCRR. The cavity was prepared using a diamond bur on a high-speed handpiece, and the prepared cavity was wiped with cotton moistened with sodium hypochlorite. The composite was applied directly with a total-etch bonding system. In the ICRR group, an impression for the prepared cavity was taken using a silicon-based material, and the restoration was adhesive with self-adhesive resin cement. The child’s satisfaction with each of the two application techniques was assessed through the scale FACES. Restorations were evaluated during follow-up periods (3, 6, and 12 months) according to Modified USHPH criteria.ResultsThe clinical success rate was 90% in the ICRR group versus 85% in the DCRR group after 12 months of follow-up without statistically significant differences (P = 0.218). Children were significantly more satisfied (P = 0.0351) with ICRR than DCRR.ConclusionsBoth DCRR and ICRR can be considered effective restorations with acceptable clinical performance in the restoration of hypomineralised first permanent molars with an advantage of ICRR in terms of child acceptance of the restoration application technique.

Effect of full-step versus simplified resin cement luting strategies on the push-out bond strength of indirect resin composite restorations bonded to dentin

Indirect restorations made of resin composite materials are increasingly used yet there is no consensus in the literature on how different luting strategies influence the bond strength. The aim of this was to study the influence of luting strategy and aging on the adhesion of indirect restorations on dentin. Bovine incisors (N = 120) received conical cavities and filled them with resin composite. The cone sets were divided into 8 groups (n = 15 each) and the cylinders were cemented according to: ‘Luting strategy’ (U200: Self-adhesive cement resin; ULT: Scotchbond Universal + RelyX Ultimate; SB2: Phosphoric Acid + Adper Single Bond 2 + RelyX ARC; SBMP: Phosphoric Acid + Scotchbond Multi-purpose + ARC) and ‘Aging’ (Tc: With thermocycling/10.000 cycles: 5–55 °C; Without thermocycling). The specimens were subjected to a Push-out Bond Strength (σ) (100 kgf; 0.5 mm/min). Stereomicroscope and scanning electron microscopy (SEM) images were made to classify the failures. Data (MPa) were submitted to two-way-ANOVA, Tukey (α = 5%), and Weibull tests. ANOVA revealed that ‘luting strategy’ and ‘aging’ were statistically significant. When the factor ‘TC’ was evaluated separately, the TC groups presented higher bond strength than the unaged groups. As for the non-thermocycling groups, the different luting strategies had no statistical difference, except for the SB2 group, which was lower than ULT. Among all groups, TC, U200_Tc, SBMP_Tc, and ULT_Tc were statistically similar and significantly higher than that of the SB2-Tc group. The Weibull modulus was statistically different among the groups but characteristic strength was significant. Mixed failures were predominantly observed. Self-conditioning strategy promoted higher bond strength than the two-step conventional strategy but after thermocycling, the two-step conventional strategy presented the worst performance among the experimental groups.

Clinical survival and performance of premolars restored with direct or indirect cusp-replacing resin composite restorations with a mean follow-up of 14 years.

The objective is to evaluate the long-term clinical survival and performance of direct and indirect resin composite restorations replacing cusps in vital upper premolars. Between 2001 and 2007, 176 upper premolars in 157 patients were restored with 92 direct and 84 indirect resin composite restorations as part of an RCT. Inclusion criteria were fracture of the buccal or palatal cusp of vital upper premolars along with a class II cavity or restoration in the same tooth. Forty patients having 23 direct and 22 indirect composite restorations respectively, were lost to follow-up (25.6%). The cumulative Kaplan-Meier survival rates were 63.6% (mean observation time: 15.3 years, SE 5.6%) with an AFR of 2.4% for direct restorations and 54.5% (mean observation time: 13.9 years, SE: 6.4%) with an AFR of 3.3% for indirect restorations. The Cox regression analysis revealed a statistically significant influence of the patient's age at placement on the survival of the restoration (HR 1.036, p=0.024), the variables gender, type of upper premolar, type of restoration, and which cusp involved in the restoration had no statistically significant influence. Direct composite restorations failed predominantly due to tooth fracture, indirect restorations primarily by adhesive failure (p<0.05). There was no statistically significant difference in survival rates between direct and indirect composite cusp-replacing restorations. Both direct and indirect resin composite cusp-replacing restorations are suitable options to restore compromised premolars. The longer treatment time and higher costs for the indirect restoration argue in favor of the direct technique.

Effect of Air Abrasion on Delayed Dentin Sealing Post-operative Sensitivity for Indirect Resin Composite Restorations

BACKGROUND: There are several treatment options available to reduce the post-operative sensitivity (POS) of indirect resin composite restorations. AIM: This study was to evaluate the effect of air abrasion on delayed dentin sealing POS for indirect resin composite restorations. MATERIALS AND METHODS: Twenty-eight patients between the ages of 18 and 30 were enrolled and randomly assigned to one of two treatment groups, with 14 teeth (n = 14) in each group. Following the collection of baseline pre- operative data, the diagnosis of caries was made based on the clinical examination and radiographic examination, and all cavities were prepared. Group one (G1) prepared cavities were exposed to airborne particles before the selective etch technique was used without the use of cementation, and the selective etch technique was used. In the second group (G2), air abrasion during cementation. The visual analog scale was used to evaluate POS at baseline, 1 day after cavity preparation (T1), 1 week after indirect composite restoration cementation (T2), 3 months (T3), and 12 months (T4). STATISTICAL ANALYSIS USED: The one-sample Kolmogorov–Smirnov test was used to assess the normality of distribution parameters first, and then, for non-parametric distributions, the Kruskal–Wallis test was used to assess the interaction between different variables. The Mann–Whitney U-test was then used to compare the two groups. RESULTS: Despite air abrasion’s effect, there was no statistically significant change in scores between the G1 and G2 groups. POS was highest at T1, then T2, T3, and T4. Statistically, these differences were significant (p = 0.001). No statistically significant differences (p &gt; 0.05) were found between T2, T3, and T4 with or without air abrasion. CONCLUSION: The delayed dentin sealing POS is unaffected by air abrasion during indirect resin restorations’ cementation.

Effect of Immediate Dentin Sealing with Air Abrasion on Post-operative Sensitivity for Indirect Resin Composite Restorations

Background: Various treatment modalities are available to decrease the postoperative sensitivity of indirect resin composite restorations.&#x0D; Aim: Compare the effectiveness of immediate dentin sealing using universal adhesive and air abrasion versus immediate dentin sealing without air abrasion on postoperative sensitivity in teeth prepared for indirect resin composite restorations.&#x0D; Methods and Materials: Twenty-eight patients between 18 and 30 years of age were recruited and randomized to two treatment protocols with fourteen teeth (n = 14) included in each protocol. After baseline preoperative data collection, the diagnosis of caries was made depending on the clinical examination and radiographic examination. After cavity preparation was done, all cavities in each protocol were managed with immediate dentin sealing, and the single-bond universal adhesive was applied over all the dentinal surfaces according to the manufacturer’s instructions. Protocol One (P1) air abrasion was used for immediate dentin sealing before cementation. In the second protocol (P2), the dentin was sealed without the use of air abrasion. Postoperative sensitivity (POS) was evaluated using the Visual Analog Scale (VAS) at baseline, one day after the cavity preparation (T1), one-week post-cementation of the indirect composite restoration (T2), after 3 months (T3), and after 12 months (T4).&#x0D; Statistical analysis used: The normality of distribution parameters was evaluated by one-sample Kolmogorov-Smirnov first, and then, for nonparametric distribution, the Kruskal-Wallis Test was used to test the interaction between different variables. followed by the Mann-Whitney U test to compare the two groups.&#x0D; Results: Despite air abrasion's effect, there was no statistically significant change in scores between the P1 and P2 groups. Postoperative sensitivity was highest at T1, then T2, T3, and T4. Statistically, these differences were significant (P 0.001). No statistically significant differences (P &gt; 0.05) were found between T2, T3, and T4 with or without air abrasion.&#x0D; Conclusion: Air abrasion during cementation of indirect resin restorations does not affect postoperative sensitivity after immediate dentin sealing.&#x0D; Keywords: Immediate dentin sealing, Air abrasion, surface treatment, Visual Analog Scale (VAS), Postoperative sensitivity.&#x0D; Key Messages: Air abrasion applied to immediate dentin sealing can be used safely without affecting postoperative sensitivity.

The effect of the die material used in the indirect technique on the fracture resistance of a restored molar.

The aim of this study was to evaluate the effect of different die materials used in the indirect resin composite restorative technique on the fracture resistance and failure mode of restored molars and compare it with the direct resin composite restorative technique. Two flexible die silicone materials for dental models (Die Silicone - Voco and Scan die - Yller) and a type IV dental stone material (Fujirock EP - GC) were evaluated. Sixty third molars were selected and divided into four groups: indirect resin composite restoration - Die silicone (IRCR-DS); indirect resin composite restoration - Scan die (IRCR-SD); indirect resin composite restoration - Fujirock EP (IRCR-FR), and direct resin composite restoration (DRCR). Class II MOD cavities were prepared with 5 mm of buccolingual width and depth. The specimens were restored and subjected to an axial compression load until fracture, and the data were analyzed by one-way ANOVA and Tukey's HSD test (α=.05). The fracture mode was classified into restorable and unrestorable fractures. Fracture resistance values were influenced by the die material used for the IRCR fabrication and by the restorative technique (p<.001). Fracture resistance mean values and standard deviation were: IRCR-DS: 1835.5 ± 324.0 A; IRCR-SD: 1732.5 ± 384.1 AB; IRCR-FR: 1419.3 ± 318.8 BC; and DRCR: 1100.6 ± 224.9 C. Restorable fracture was more prevalent. IRCR with flexible die casts promoted higher fracture resistance and lower prevalence of unrestorable fractures.

Polymerization Kinetics, Shrinkage Stress, and Bond Strength to Dentin of Conventional and Self-adhesive Resin Cements.

To evaluate the kinetics of polymerization and shrinkage stress of resin cements, as well as their bond strength to dentin after 24-h or one-year water storage. Three conventional resin cements were evaluated: RelyX Ultimate (RUL), Panavia V5 (PNV), and Multilink N (MLN); and three self-adhesive resin cements: RelyX Unicem 2 (RUN), Panavia SA Cement Plus (PSA), and G-CEM LinkAce (GCL). Degree of conversion (DC), maximum polymerization rate (RPmax) and gel time values were obtained using Fourier-transform infrared spectroscopy (FTIR/ATR). Shrinkage stress values were determined with a tensiometer, using a universal testing machine (n=5). Indirect resin composite restorations (Solidex) were fabricated and cemented to the dentin surface using self-adhesive resin cements, or conventional resin cements with self-etching adhesive (n=5). Bonding performance was evaluated with the microtensile bond strength (µTBS) test after 24 h or one year of water storage. MLN exhibited a higher DC (76.7%), whereas the percentage of other materials differed slightly (ranging from 54% to 58.5%). The RPmax and shrinkage stress values differed significantly between the cements. PSA showed the longest gel time. Significantly higher µTBS were observed for conventional resin cements after 24-h and one-year storage; a decrease in µTBS was observed for MLN only. Self-adhesive resin cements may not perform as well as conventional resin cements. Although both categories of cements presented similar polymerization kinetics and shrinkage values, the self-adhesive resin cements showed lower µTBS compared to those of conventional resin cements. Nevertheless, storage time only affected the bonding performance of MLN.

The Influence of a Flexible Model on the Marginal Adaptation of Inlay Composite Restorations: A MicroCT Analysis.

The aim of this study was to evaluate the influence of flexible models on the marginal adaptation of indirect resin composite restorations. Thirty-six cavity preparations were made for class II restorations in permanent molar teeth. Three groups (n=12) were defined following three impressions/model material combinations: G(STONE), polyvinylsiloxane, and type IV stone model, as a control group; G(IMPRESSIONPVS), alginate and flexible polyvinylsiloxane; G(MODELPVS), alginate and flexible polyvinylsiloxane for models. All restorations were positioned on their respective teeth and evaluated by micro-computed tomography. Absolute marginal discrepancies were measured digitally (ImageJ). The results were compared using one-way ANOVA (p⟨ 0.05). The mean ± SD absolute marginal discrepancy of indirect resin composite restorations made from flexible and rigid stone models was as follows: G(STONE), 206 (±79.95) μm; G(IMPRESSIONPVS), 221.50 (±61.73) μm; G(MODELPVS), 203.25 (±65.93) μm. Absolute marginal discrepancies were not significantly influenced by the flexible and rigid stone models (p=0.78). The flexible or rigid stone model did not influence the marginal adaptation of the indirect resin composite restorations.

Effect of Additional Dry Heat Curing on Microflexural Strength in Three Types of Resin Composite: An In Vitro Study

Aim: Additional dry heat curing is a method that favorably influences the mechanical properties of an indirect resin composite restoration. Microflexural strength is a property currently applied for the evaluation of indirect resin composite restorations. The aim of the present study was to assess the effect of additional dry heat curing on microflexural strength in three types of direct-use resin composites. Materials and Methods: This in vitro study consisted of 70 resin composites samples made with a 6 × 2 × 1 mm metal matrix and divided into seven experimental groups, which included Gr1a: Tetric N-Ceram without additional dry heat curing (n = 10); Gr1b: Tetric N-Ceram with additional dry heat curing (n = 10); Gr 2a: Filtek Z350 XT without additional dry heat curing (n = 10); Gr2b: Filtek Z350 XT with additional dry heat curing (n = 10); Gr3a: Filtek Z250 without additional dry heat curing (n = 10); Gr3b: Filtek Z250 with additional dry heat curing (n = 10); and Gr4: SR Nexco Paste (control) without additional dry heat curing (n = 10). The samples were stored in distilled water at 37 °C for 24 h. A universal testing machine with a 2000 N load cell at a speed of 1 mm/min was used to assess flexural strength. The data were analyzed with a parametric ANOVA test with Tukey’s post hoc intergroup factor (for groups without heat treatment) and a nonparametric Kruskall Wallis test with Bonferroni’s post hoc (for groups with heat treatment). In addition, the comparison of independent groups in each resin composite type with and without heat treatment was performed with a Mann Whitney U test. A significance level of p &lt; 0.05 was considered. Results: The Filtek Z250 resin composite with and without additional dry heat curing presented the highest microflexural strength values with 137.27 ± 24.43 MPa and 121.32 ± 9.74 MPa, respectively, while the SR Nexco Paste (control) resin composite presented the lowest microflexural strength values with 86.06 ± 14.34 MPa compared to all the resin composites with additional dry heat curing. The Filtek Z250 and Filtek Z350XT resin composites with and without additional dry heat curing presented significantly higher microflexural strength versus the SR Nexco (p &lt; 0.05) and Tetric N-Ceram (p &lt; 0.05) resin composites. In addition, the Filtek Z350XT and Tetric N-Ceram resin composites with additional dry heat curing showed significantly higher microflexural strength (p &lt; 0.05) compared to those without additional dry heat curing. Conclusions: The Filtek Z250 and Z350XT resin composites had significantly higher microflexural strength values with and without additional dry heat curing. In addition, the Filtek Z350XT and Tetric N-Ceram resin composites subjected to additional dry heat curing showed significantly higher microflexural strength compared to when they did not receive the same procedure, a situation that did not occur with the Filtek Z250 resin composite.

Impact of Immediate Dentin Sealing Using Universal Adhesive under Simulated Pulp Pressure on Microtensile Bond Strength of Indirect Resin Composite Restorations and Dentin Permeability.

Objective The aim of this study was to investigate the effect of immediate dentin sealing (IDS) technique using universal adhesive under simulated pulp pressure on microtensile bond strength (μTBS) of indirect resin composite restorations and dentin permeability. Materials and Methods Fifty extracted caries-free human third molars were used for specimens' preparation. Each molar's occlusal table was abraded flat and their roots were separated under continuous water cooling. Forty specimens were used for microtensile bond strength test (μTBST) evaluation. The μTBST specimens were randomly assigned to two groups according to the dentin sealing time; Immediate dentin sealing (IDS) and delayed dentin sealing (DDS). Each group was further subdivided into two subgroups according to the adhesive system used for dentin sealing: iBOND self-etch adhesive and GLUMA Bond Universal. All specimens were exposed to simulated pulp pressure for 1 week then restored using computer-aided design/computer-aided manufacturing (CAD/CAM) resin composite blocks. The μTBS was evaluated for all tested subgroups after 24 hours and 6 months of water storage. The remaining 10 teeth were used for the preparation of dentin discs for dentin permeability evaluation. They were divided into two groups according to type of self-etch adhesive used. Fluid filtration rate was evaluated after etching, with smear layer and after adhesive application. Results obtained were statistically analyzed using Shapiro–Wilk test and Weibull analysis. Results Statistically significant difference was recorded between µTBS mean values of both IDS and DDS techniques at 24 hours and after 6 months of water storage. GLUMA Bond Universal adhesive had significantly higher bond strength compared with iBond at both IDS and DDS techniques, but both adhesives showed a significant reduction in the Weibull characteristic strength after 6 months of water storage. Significant reduction in dentin permeability was recorded by both adhesives without any significant difference between them. Conclusions The IDS technique using universal adhesive in self-etch mode is an effective strategy for improving the final bond strength of CAD/CAM resin composite restorations and reducing dentin permeability.

Microleakage and Marginal Integrity of Direct and Indirect Composite Resin Restorations in MOD Cavities After Thermo-Mechanical Loading

Objective: The aim of this in vitro study is to compare the microleakage of mesial-occlusal-distal (MOD) composite resin restorations made by using CAD/CAM block and methacrylate/ormocer-based direct resin composites after thermo-mechanical loading.&#x0D; Methods: Standard 40 noncarious human third mandibular molars were selected for the study. Standardized MOD (3x4x2mm) cavities were prepared on the mesial and distal sides. The gingival margin was placed above the cementoenamel junction (CEJ) on the mesial side and below the CEJ on the distal side. The prepared samples were divided into three experimental groups [indirect group-GrandioBlock (GB), direct-methacrylate group-TetricN-Ceram+TetricN-Flow (T+TF), direct-ormocer group-Admira Fusion+Admira Fusion Flow (A+AF)] and control group [direct-methacrylate group-GrandioSo+GrandioSoFlow (G+GF)] (n=10). After finishing restorations samples were subjected to 50 N to 240.000 thermo-mechanical cycles (5-55°C, for 60 sec) and kept in 0.2% methylene blue. Samples sectioned longitudinally in the mesiodistal direction with a precision cutting device were examined under stereomicroscope at X8 and X25 and microleakage values were scored. In the evaluation of the data, descriptive statistical methods as well as the chi-square test was used for the comparison of qualitative data.&#x0D; Results: No significant difference was found among the coronal and gingival-enamel microleakage distributions of the groups (p&gt;0.05). A statistically significant difference was observed among the gingival-cementum microleakage distributions of the groups (p=0.003). The distribution of gingival-cement microleakage with the no dye penetration score in the T+TF group was found to be statistically significantly lower than the G+GF and GB groups (p = 0.010, p = 0.001).&#x0D; Conclusion: Under the limitation of this in vitro study; restoring MOD cavities using different matrix structures of the composites could not eliminate the leakage at the gingival seat under CEJ.

Indirect Resin Composite Inlays Cemented with a Self-adhesive, Self-etch or a Conventional Resin Cement Luting Agent: A 5 Years Prospective Clinical Evaluation

Objective: The aim of this study was to clinically evaluate the 5-years clinical performance of indirect resin composite inlays luted with three different resin cement strategies in MOD Class II restorations.Materials and Methods: A randomized clinical trial was conducted following CONSORT guidelines. Forty patients with three large cavities indicated for indirect MOD Class II restorations were enrolled in the current study. Then, 120 indirect resin composite inlay restorations (SR Nexco) were placed and luted with three different resin cement strategies (n=40); an etch-and-rinse (Variolink N), self-etch (Panavia F2.0) and self-adhesive (RelyX Unicem). These restorations were evaluated to the periods of 1 week (baseline), 1, 3 and 5 years using modified USPHS criteria. Statistical analyses were performed with Wilcoxon and Friedman tests with level of significance set at 0.05.Results: The outcome of the clinical trial showed that, there was neither loss of restorations nor recurrent caries after 5 years for all luting cements groups. Both self-etch Panavia F2.0 and self-adhesive RelyX Unicem resin cements exhibited significant differences between the evaluation periods regarding to marginal discoloration and marginal adaptation (p=0.03). At baseline, only 8 cases of etch-and-rinse (Variolink N) resin cement group exhibited post-operative sensitivity which were relieved after short time (p=0.04).Conclusion: All the three resin cement strategies tested, showed acceptable clinical performance after 5-years recall period. In time, etch-and-rinse resin cement group showed better clinical performance regarding marginal discoloration and marginal adaptation at 5-years recall period.Clinical Relevance statement:In vitro and in vivo studies reveal contradictory evidence of the clinical performance of indirect resin composite inlays luted with different resin cement strategies. Thus, this study revealed that etch-and-rinse resin cement still has the best prognosis for adhesive luting of indirect resin composite inlays.

Effects of pre-cementation cleaning protocols on bond strength of indirect composite resin restorations contaminated with saliva.

Objective: Compare the effects of different pre-cementing cleaning protocols on adhesive bond strength (MPa) in indirect composite resin restorations contaminated with saliva. Materials and Methods: 110 tests bodies of indirect composite resin, divided into 2 groups: with no contamination (NC); with contamination (WC); distributed in 22 subgroups (n = 5) according to the Ultrasound (U) variables; Cleaning Paste (CP); Ethanol 96 ° (E), Application times: 5-20-30-180s. Five cylinders (1mm high x 0.7 Ø) of cement (Variolink Esthetic LC) per sample made on treated and light-cured surfaces (20s). After 24hrs / 37ºC + distilled water, they were subjected to the RUA test (0.5 mm / min) until fracture point in a universal test machine. Analyzed with one-way ANOVA and post hoc Tukey test (α = 0.05).Results: Contaminated CP30’’ was the protocol with the highest binding resistance (14.57 ± 1.01) (p &lt;0.05). Conclusion: The gold standard technique - corresponding to ultrasonic washing - is unrecommended for cleaning indirect composite resin restoration, seen as there are other more effective protocols to eliminate surface contaminants. Cleaning paste and Ethanol in times of 20’’ or 30’’ are suggested.

Restaurações indiretas em resina composta em cavidades com diferentes profundidades: Relato de caso

Restaurações indiretas em resina composta são comumente usadas em dentes posteriores nas diferentes cavidades, permitindo maior resistência ao desgaste, adaptação marginal, estabelecimento de contatos proximais e maior dureza, uma vez que passam pelo processo de termopolimerização. O objetivo desse estudo é relatar um caso clínico de substituição de restaurações em amálgama por restaurações indiretas em resina composta em cavidades com diferentes profundidades. Paciente, sexo feminino, 34 anos, procurou a clínica odontológica de uma instituição privada, queixando-se de insatisfação estética nas restaurações em amálgama nos dentes 45, 46 e 47. Após exame clínico, devido à extensão das cavidades, foi sugerido a realização de restaurações indiretas em resina composta nos três elementos. Após a remoção do amalgama, com ponta diamantada, avaliou-se as profundidades das cavidades dos dentes. No dente 45, realizou-se tratamento endodôntico e instalação de pino de fibra de vidro. No dente 46 foi realizado um capeamento pulpar indireto e no dente 47 não foi realizado nenhum tratamento de proteção pulpar. Posteriormente, os dentes foram preparados para restaurações indiretas com ponta diamantada #3131, em seguida, foram moldados com silicone de adição, prosseguindo com vazamento do molde com gesso tipo IV. O modelo foi troquelizado pela técnica de duplo vazamento e as restaurações em resina composta foram confeccionadas sobre o modelo. Na sessão seguinte, as restaurações foram cimentadas com cimento resinoso dual autoadesivo. Por fim, foi realizado o ajuste oclusal, seguido do acabamento e polimento. As terapêuticas empregadas foram eficazes para recuperar a forma anatômica e estética dos elementos dentários envolvidos.

Structural reliability and bonding performance of resin luting agents to dentin and enamel

This study evaluated the bonding performance and structural reliability of indirect resin composite restorations luted to dentin and enamel. Four resin luting agents were tested in the study, namely three total-etch materials (Allcem; Allcem Core; and RelyX ARC) and one self-adhesive material (RelyX U200). The materials were characterized with degree of conversion (DC) and pH analyses, and used to lute resin composite restorations to dentin or enamel (n = 6). The restorations were prepared for microtensile bond strength (μTBS) testing (DL500). Data were analyzed with ANOVA or Kruskal-Wallis and Tukey/SNK (α = 0.05). Weibull analysis was used to verify the structural reliability and characteristic strength of dental bonds. While RelyX ARC exhibited greater DC, RelyX U200 was the most acidic material of the study. Allcem and RelyX U200 demonstrated greater and lower μTBS, respectively, at both dentin and enamel. Comparing μTBS of dentin and enamel, RelyX ARC and RelyX U200 produced higher bonds in dentin. RelyX U200 showed ~100% of adhesive failures, differing from other groups. Structural reliability was higher for Allcem Core in dentin and for RelyX U200 in enamel; the characteristic strength was higher for Allcem and lower for RelyX U200. Conventional resin luting agents performed better than the self-adhesive material, at both dentin and enamel. Among the conventional materials, Allcem demonstrated an overall greater bonding ability and lower probability to failure. DC and pH of resin luting agents did not influence on their bonding performance.

Clinical performance of a direct submicron hybrid and indirect zirconium reinforced composite restorations: A 2-year assessment

Objective: To evaluate the clinical efficacy of direct and indirect composite resin restorations placed in posterior teeth after 2 years. Materials and Methods: A total of 60 teeth were restored with a direct composite resin (BRILLIANT EverGlowTM– Coltene) and an indirect composite resin (CeramageTM– Shofu). All restorations were assessed using the Modified United States Public Health Service criteria at baseline, 3 months, 6 months, 12 months, 18 months, and 24 months after placement. Statistical analysis was performed with Chi-Square test and Cochran's Q test. Results: At the 2-year evaluation, all restorations were retained, with Alpha ratings at 100%. Only two teeth (in the direct restoration group) required endodontic intervention after 18 months due to secondary caries. Surface texture, marginal discoloration, and marginal integrity were predominantly scored as Alpha after 2 years for both groups. Color match was scored as Alpha in 65.4% of direct restorations and 84.4% of indirect restorations. Conclusion: Within the limitations of this study it can be concluded that the clinical performance of the indirect restorations was much improved than that of direct restorations.

Effect of simplified and full-step surface treatments of indirect resin composite on dentin bonding stability and nanoleakage

The study evaluated the effect of the application of simplified or full-step surface treatments and aging times on dentin bonding stability and nanoleakage of indirect resin composite restorations. This is an in vitro study with one hundred and sixty indirect resin composite restorations (4.8 x 2.8 x 4.0 mm) produced to fill dentin preparations in bovine dentin. The specimens were divided into eight groups according to chemical treatment [No treatment; Silane; Scotchbond™ Universal adhesive (SBU); and Silane + SBU], and aging time in water [24 h and six months]. Push-out bond strength (PBS) was evaluated by a universal testing machine (1.0 mm/min), failure modes by a dissecting microscope, and nanoleakage by scanning electron microscopy. Two-way ANOVA and Tukey posthoc tests (p&lt;0.05) were used to compare PBS among the groups, while failure modes and nanoleakage were analyzed descriptively. The bonding stability of indirect resin composite restorations was influenced by chemical surface treatments and aging times (p &lt;0.05). Significant differences were determined between chemical treatment applied, mainly when SBU was used after aging the samples. The different surface treatments and aging time did not influence the nanoleakage at the cement-resin interface. The study results suggest that the simplified surface treatment using a universal adhesive improved the dentin bonding stability of indirect resin composite restorations.