Glutaraldehyde-based desensitizer does not influence postoperative sensitivity and clinical performance of posterior restorations: A 24-month randomized clinical trial.

OBJECTIVES: To evaluate the influence of a glutaraldehyde-based desensitizer (GL) on postoperative sensitivity (POS) in posterior bulk-fill resin composite restorations using an adhesive applied in the self-etch (SE) and etch-and-rinse (ER) strategies; and to assess the clinical performance of the restorations. METHODS: Posterior resin composite restorations (n = 228) at least 3 mm deep were inserted in 57 subjects using a split-mouth design. The adhesive was applied with/without prior application of a GL. A resin composite was used for all restorations. Spontaneous POS (risk and intensity), as well as POS caused by stimulation with an air blast and assess the response to horizontal and vertical percussion was assessed using two scales in the baseline and after 7, 14, and 30 days. In addition, some parameters were evaluated using FDI criteria up to 24 months of clinical service. RESULTS: No significant POS was observed (p > 0.05). A higher absolute risk and intensity of spontaneous POS was observed within 7 days (35.1%), without statistically significant differences among groups. At 24 months 5 restorations were considered clinically unsatisfactory, and 73 restorations showed minor discrepancies in adaptation, with no significant differences between groups (p > 0.05). SIGNIFICANCE: A GL agent does not influence POS in posterior restorations with bulk-fill resin composite. It may be considered a dispensable clinical step in the restorative protocol.

Influence of the self-adhering strategy on microhardness, sorption, solubility, color stability, and cytotoxicity compared to bulk-fill and conventional resin composites.

OBJECTIVES: To analyze and compare, in vitro, the microhardness, sorption, solubility, color stability, and cytotoxicity of three types of resin composites: self-adhesive (SARC) (Dyad Flow (DF)/Kerr), bulk-fill (Filtek Bulk Fill Flow (FBF)/3 M ESPE), and conventional (Filtek Z350XT Flow (Z350)/3 M ESPE). MATERIALS AND METHODS: Thirty cylindrical specimens were prepared using a split metal mold (15 mm × 1 mm), divided into 3 groups (n = 10) according to the material used. Vickers hardness (VH) was calculated from three indentations (300gf/15 s) per specimen. The sorption and solubility were measured according to the ISO 4049:2009 specification after storing in distilled water for 7 days. The color of each resin composite was measured using a portable digital spectrophotometer according to the CIELAB system. After a 7-day immersion in coffee, the color variation (∆E) was calculated. Following the ISO 10993:2012, the cytotoxicity in Vero cells was evaluated through the MTT assay. The results were analyzed using the Kruskal-Wallis test to compare the studied groups. The Wilcoxon test was used to compare the assessments in each studied group. For cytotoxicity analysis, the data were compared by the ANOVA test (α = 0.05). RESULTS: DF showed the lowest VH (28.67), highest sorption (0.543 µg/mm3) and solubility (1.700 µg/mm3), and higher ∆E after 7 days of coffee immersion (p = 0.008). The resin composites studied were considered non-cytotoxic. CONCLUSIONS: The SARC presented inferior mechanical and physical-chemical properties than bulk-fill and conventional resin composites, with comparable cytotoxicity against Vero cells. CLINICAL RELEVANCE: The simplification of the clinical protocol of SARC can minimize the number of possible failures during the restorative technique. However, considering their inferior physical and mechanical properties, their coverage with materials of higher mechanical properties and physical-chemical stability should be considered.

Influence of occlusal reduction on pain after endodontic treatment: a systematic review and meta-analysis.

The purpose of this systematic review was to analyze the influence of occlusal reduction on the postoperative pain levels after endodontic treatment (instrumentation and obturation of the root canal system). This review followed the PRISMA statement and was registered at PROSPERO (CRD42018107918). Two independent reviewers searched the Lilacs, Cochrane Library, PubMed (Medline), Web of Science, Scopus, Scielo, and ScienceDirect for articles published until April 2021. The research question was, "Does occlusal reduction decrease postoperative pain in endodontically treated teeth?". Only randomized clinical trials were included. The RevMan 5 program was used for meta-analysis, calculating the relative risk (RR) and 95% confidence interval (CI) of the dichotomous outcome (presence or absence of pain). The search strategies retrieved 4114 studies. Twelve studies were included for qualitative analysis and nine for quantitative analysis. The meta-analysis results did not reveal a significant difference in the reduction of postoperative pain levels for endodontic instrumentation at 6, 12, 24, 48 h and for endodontic obturation at 6 or 12 h after occlusal reduction. According to the GRADE tool, the analyzed outcome was classified as having a moderate level of certainty. It is concluded that occlusal reduction does not interfere with postoperative pain levels after endodontic treatment.

Effect of Reciprocating and Rotary Systems on Postoperative Pain: A Systematic Review and Meta-Analysis.

Introduction: Our study aimed to compare the incidence and intensity of postoperative pain after endodontic instrumentation with reciprocating and rotary systems. Methods and Materials: An electronic literature search was performed with MEDLINE via PubMed, Scopus, and Web of Science databases from January 2008 to June 2020. Two high-impact endodontic journals were also hand searched. The selection criteria were: 1) Population; patients requiring endodontic treatment (primary or secondary), 2) Intervention and Comparison; endodontic instrumentation with reciprocating versus rotary systems, and 3) Outcome; postoperative pain. We extrapolated all included research data and reported them as dichotomized ordinal variables to evaluate the incidence of pain and continuous variables to assess pain intensity. Standardized mean difference (SMD) was calculated with Inverse Variance method for pain intensity; the incidence of postoperative pain was calculated using relative risk (RR) with the Mantel-Haenszel method. Random-effects model and 95% confidence interval (CI) were used for all meta-analyses. The I2 statistic was used to evaluate the statistical heterogeneity among studies (P<0.05). Results: Twenty-one articles were selected and 17 of them were included in the meta-analysis for the evaluation of postoperative pain in the first 24 h. The meta-analysis was performed in two steps: a) all studies were included; b) subsequently studies with preoperative pain were excluded. A significant difference was observed in the intensity of postoperative pain; with rotary system having more favorable in both steps [a) SMD: 0.27; 95% CI: 0.13 to 0.41; P=0.0002; b) SMD: 0.37; 95% CI: 0.15 to 0.58; P=0.0010]. There was no significant difference in the incidence of pain, and the incidence of mild, moderate and severe pain (P>0.05). Conclusion: The meta-analysis results revealed that rotary system were the instrument of choice as they had lower intensity of postoperative pain. Further controlled studies are advocated to provide clarification for intensity/incidence of postoperative pain in endodontic treatment with mechanized instruments.

DSDapp use for multidisciplinary esthetic planning.

OBJECTIVES: Digital smile design (DSD) is useful in planning multidisciplinary esthetic treatments. However, DSD requires clinician training and skill to ensure its effective use. The Digital smile design application (DSDapp) was recently developed, to facilitate such planning. The objective of this study was to illustrate the use of the DSDapp for esthetic planning in a clinical case that included periodontal plastic surgery and ceramic laminate veneers. CLINICAL CONSIDERATIONS: An intraoral digital scan was performed, and a photograph was obtained using an iPad (frontal facial full smile). The images were analyzed using the DSDapp. All reference lines were inserted, and dental shapes predetermined by the app were superimposed on the photographs. A digital diagnostic wax-up was performed considering the plan created in the DSDapp. After 3D printing the wax-up, a mock-up transferred the planning to the oral cavity. Following this, the patient was referred to a periodontist for the periodontal plastic surgery. After the healing period, the teeth were prepared for computer-aided design/computer-aided modeling lithium disilicate ceramic laminate veneers. CONCLUSIONS: DSDapp use accelerated the initial planning steps. Smile planning can be performed during the clinical session with the patient's active participation. In addition, the DSDapp facilitated better communication within the multidisciplinary team. CLINICAL SIGNIFICANCE: The DSDapp relies more on intuition than on skill and training to execute the treatment plan. The DSDapp provides immediate feedback to the patient, offering greater predictability and helps monitor the planning through all the clinical stages.

Evaluation of postoperative sensitivity in restorations with self-adhesive resin: a randomized split-mouth design controlled study.

OBJECTIVES: To evaluate the postoperative sensitivity of restorations with self-adhesive resin composite (SAC) (Vertise Flow (VER)/Kerr) compared with conventional resin composite with self-etching adhesive (Filtek Z250 (Z250)/3M ESPE; Clearfil SE Bond (CSEB)/Kuraray). MATERIALS AND METHODS: A randomized, controlled, double-blind, split-mouth, two-arm clinical trial was conducted. Twenty-seven volunteers with third molars indicated for extraction received two deep class I restorations, one with each material. Postoperative sensitivity was measured at 24 h and 15 or 30 days after the restorative procedures using a visual analog scale (VAS). When present, information on the characteristics of the pain was also collected. The data were submitted to the McNemar test (α = 0.05). RESULTS: Regardless of the time intervals, the postoperative sensitivity was observed in 52% and 48% of the CSEB and VERT groups, respectively (p = 1.000). When the evaluation periods were analyzed, the 15-day evaluation presented the highest occurrence of pain, but of mild intensity, in both groups. All patients with sensitivity reported that the pain was localized and of short duration. CONCLUSION: Self-adhesive resin composite Vertise Flow and conventional resin composite with a self-etching bonding agent promoted similar response regarding postoperative sensitivity in deep class I cavities. When postoperative sensitivity was present, mild pain was observed, especially after 15 days of the restorative procedure, which decreased over time. CLINICAL RELEVANCE: Postoperative sensitivity to self-adhesive resin composite (SAC) restorations in deep cavities was comparable with that of conventional restorations with a self-etching bonding agent.

Multidisciplinary Approach to Smile Restoration: Gingivoplasty, Tooth Bleaching, and Dental Re-anatomization.

This article reports on the case of a patient who underwent a multidisciplinary treatment in smile design that entailed dental cosmetic techniques involving esthetic periodontal surgery, teeth bleaching, and re-anatomization of the upper incisors. The male patient presented with a chief complaint of an excessive gingival display while smiling, as well as small, darkened teeth with spaces between them. After diagnosis and patient consent, therapy began in the following stages: periodontal plastic surgery with probing, bleeding points delimitation, beveled incision, removal of the gingival band with periodontal curettes, and finishing with an electric scalpel. After 21 days following surgery, dental bleaching using a combined technique that included two sessions of in-office bleaching (35% hydrogen peroxide) and 2 weeks of at-home bleaching (carbamide peroxide 16% for 4 hours per day) was carried out, followed by dental re-anatomization using resin composite. Diagnostic waxing, mock-up, fabrication of a palatal silicone index, incremental sculpturing, and structuring the restoration of the palatal shell to the vestibular surfaces was then completed, followed by occlusal adjustment, finishing, and polishing. The multidisciplinary intervention was fundamental for the accomplishment of the proposed treatment that combined biological, functional, and esthetic concepts.

Influence of Temperature on the Cyclic Fatigue of Nickel-Titanium Instruments with Different Heat Treatments on Severely Curved Canals.

AIM: This study aims to investigate the influence of temperatures of 20 °C and 37 °C on the resistance to cyclic fatigue of NiTi instruments with different heat treatments, as tested in severely curved simulated canals. MATERIALS AND METHODS: Seventy-two instruments were distributed according to the temperature used (20 °C and 37 °C): XP-endo Shaper (30/0.01), ProDesign Logic (30/0.05), and iRaCe (30/0.04). The instruments were rotated freely until the occurrence of fracture inside an artificial severely curved stainless steel canal, which had a 90° angle of curvature and a curvature radius of 5 mm. Kolmogorov-Smirnov, Wilcoxon, ANOVA, and Kruskal-Wallis tests were performed. A p value of <0.05 was considered statistically significant. RESULTS: XP-endo Shaper instruments presented higher NCF values and time to failure compared with ProDesign Logic and iRaCe instruments at 20 °C and 37 °C (p < 0.001). CONCLUSION: Within the limitations of this study, the results show that the body temperature (37 °C) significantly lowers the resistance to cyclic fatigue of all instruments compared with 20 °C. CLINICAL SIGNIFICANCE: Body temperature is an important factor in the results of cyclic fatigue tests.

Clinical performance of bulk-fill and conventional resin composite restorations in posterior teeth: a systematic review and meta-analysis.

OBJECTIVES: The purpose of this systematic review was to compare the clinical performance of bulk-fill resin composites with conventional resin composites used for direct restorations of posterior teeth. METHODS: This review followed the PRISMA statement. This review was registered at PROSPERO (registration number CRD42016053436). A search of the scientific literature was performed by two independent reviewers using the PubMed/MEDLINE, Embase, The Cochrane Library, and Web of Science databases from commencement until January 2018. The research question was "Do bulk-fill resin composites have a clinical performance comparable to conventional resin composites in posterior restorations?" Only studies evaluating class I and II direct restorations in permanent teeth with a follow-up period of at least 1 year were included. The RevMan 5 program was used for meta-analysis, calculating the relative risk (RR) and 95% confidence interval (CI) of the dichotomous outcome (restoration failure or success). RESULTS: Ten articles were selected, comprising 941 analyzed restorations. The mean follow-up period was 33.6 months (12-72 months). No statistically significant differences in the failure rate were observed between conventional and base/flowable bulk-fill resin composites (p = 0.31; RR 1.49; 95% CI 0.69-3.25) or full-body/sculptable bulk-fill resin composites (p = 0.12; RR 1.89; 95% CI 0.84-4.24). CONCLUSIONS: The present systematic review and meta-analysis indicate similar clinical performances of bulk-fill and conventional resin composites over a follow-up period of 12 to 72 months. CLINICAL SIGNIFICANCE: Based on the results of this study, the bulk-fill resin composites could be an alternative for direct restorations in posterior teeth. However, clinical trials of longer duration are required.

Cyclic Fatigue Resistance of Mtwo Rotary Instruments with two Different Instrumentation Techniques.

INTRODUCTION: The objective of this in vitro study was to evaluate whether cervical preparation with Mtwo files in a crown-down technique influences instrumentation time and the cyclic fatigue resistance of these instruments. METHODS AND MATERIALS: Two instrumentation techniques were evaluated (manufacturer and crown-down). Each group consisted of 10 kits containing four Mtwo instruments (10/0.04, 15/0.05, 20/0.06, and 25/0.06), which were used to prepare three standard simulated curved resin canals. The mean instrumentation time and the corresponding number of cycles for each instrumentation (NCI) were recorded. The instruments were rotated at a constant speed of 300 rpm in a stainless-steel canal (diameter of 1.5 mm) at a 90° angle of curvature and 5-mm radius. The center of the curvature was 5 mm from the tip of the instrument. The cyclic fatigue resistance of the files was determined by counting the number of cycles to failure (NCF). Data were analyzed by the Mann-Whitney test. RESULTS: The mean instrumentation time and NCI of files 10/0.04 and 15/0.05 were significantly lower (P<0.05) when the crown-down technique was used compared to the manufacturer's method for the same tip size/taper file. There was no significant difference in the mean NCF between the two techniques. CONCLUSION: The crown-down technique did not interfere with resistance to cyclic fatigue. However, the shorter instrumentation time of files 10/0.04 and 15/0.05 could reduce the fracture risk in the case of reuse of these instruments.

Cyclic Fatigue Resistance of WaveOne Gold, ProDesign R and ProDesign Logic Files in Curved Canals In Vitro.

INTRODUCTION: Endodontic instruments are developed to provide a better cleaning of the root canal system and reduce its risk of fracture. The aim of this study was to evaluate the instrumentation time and cyclic fatigue resistance of WaveOne Gold, ProDesign R and ProDesign Logic files. METHODS AND MATERIALS: Thirty Nickel-titanium (NiTi) rotary instruments were divided into 3 groups (n=10). ProDesign Logic file 25/0.06 was used in continuous rotation after glide path preparation. WaveOne Gold 25/0.07 and ProDesign R 25/0.06 files were used in reciprocating motion. Every file instrumented 3 standardized artificial canals. The average time, the number of cycles (NCI) and cyclic fatigue resistance of each file were determined through the number of cycles to failure (NCF) in a stainless-steel device. The total amount of cycles to fracture was also calculated (NCI+NCF). Data was analyzed using the Kruskal-Wallis and Mann-Whitney tests. RESULTS: The instrumentation time of the ProDesign Logic file was significantly lower when compared to the other files (P=0.019). The longest times to failure were presented by ProDesign Logic (182.07 sec) and ProDesign R (152.38 sec) files. The same differences were observed for the NCF (910.37 and 761.93). The WaveOne Gold group presented a lower NCF as well as a smaller sum of NCI+NCF (748.33) that was statistically significant when compared to the other groups (P<0.05) respectively. CONCLUSION: The use of continuous rotational motion in canals with a glide path in the ProDesign Logic group led to shorter instrumentation time. The cyclic fatigue resistance of ProDesign R and Logic instruments was superior to WaveOne Gold. The thermal treatment of the instrument's alloy, its cross section and the glide path seems to influence the cyclic fatigue resistance.

Marginal and internal analysis of preheated dental fissure-sealing materials using optical coherence tomography.

OBJECTIVES: This study aimed to evaluate the influence of pre-photoactivation temperature on the marginal and internal integrity (occurrence of voids) of fissure-sealing materials on occlusal fissures using optical coherence tomography (OCT). METHODS: Occlusal fissures of 40 human third molars were sealed using a resin-based fissure sealant (Fluroshield) and a flowable composite (Permaflo) photoactivated at 68 °C (preheated) or at room temperature (25 °C) (n=10). After sealing, the teeth were subjected to thermocycling (500 cycles, 5-55 °C) and 14 days of pH cycling (demineralisation for 6 hours/day and remineralisation for 18 hours/day). The occlusal surfaces were scanned in a buccolingual direction, and 20 tomographic images parallel to the long axis of each tooth were obtained. Images presenting marginal gaps and internal voids were counted and statistically analysed using analysis of variance and Tukey's test (P<0.05). RESULTS: There were statistically significant differences between materials and temperatures (P<0.01). The flowable composite had a lower percentage of gaps and internal voids than the resin-based sealant. Preheated materials had a lower percentage of gaps and internal voids than the materials at room temperature. CONCLUSION: Therefore, preheated flowable composite provided the best marginal sealing of fissures, and internal homogeneity of the material.

Alternative methods for determining shrinkage in restorative resin composites.

OBJECTIVES: The purpose of this study was to evaluate polymerization shrinkage of resin composites using a coordinate measuring machine, optical coherence tomography and a more widely known method, such as Archimedes Principle. Two null hypothesis were tested: (1) there are no differences between the materials tested; (2) there are no differences between the methods used for polymerization shrinkage measurements. METHODS: Polymerization shrinkage of seven resin-based dental composites (Filtek Z250™, Filtek Z350™, Filtek P90™/3M ESPE, Esthet-X™, TPH Spectrum™/Dentsply 4 Seasons™, Tetric Ceram™/Ivoclar-Vivadent) was measured. For coordinate measuring machine measurements, composites were applied to a cylindrical Teflon mold (7 mm × 2 mm), polymerized and removed from the mold. The difference between the volume of the mold and the volume of the specimen was calculated as a percentage. Optical coherence tomography was also used for linear shrinkage evaluations. The thickness of the specimens was measured before and after photoactivation. Polymerization shrinkage was also measured using Archimedes Principle of buoyancy (n=5). Statistical analysis of the data was performed with ANOVA and the Games-Howell test. RESULTS: The results show that polymerization shrinkage values vary with the method used. Despite numerical differences the ranking of the resins was very similar with Filtek P90 presenting the lowest shrinkage values. SIGNIFICANCE: Because of the variations in the results, reported values could only be used to compare materials within the same method. However, it is possible rank composites for polymerization shrinkage and to relate these data from different test methods. Independently of the method used, reduced polymerization shrinkage was found for silorane resin-based composite.