Clinical Efficiency of Two Sequences of Orthodontic Wires to Correct Crowding of the Lower Anterior Teeth.

This study compared time to correction of mandibular anterior crowding using two arch wire sequences, one with conventional nickel-titanium (NiTi) arch wires and the other with conventional and NiTi heat-activated arch wires. Twenty-two boys and girls (mean age: 16.68 ± 2.66) with moderate crowding (3-6 mm) were assigned randomly to one of two groups and followed up for five months (six assessments) when arch wires were changed. Time to crowding correction was analyzed statistically using the Kaplan-Meier method. Data were collected during the five-month follow-up, and time to correction was compared between groups using the log rank test. At the end of follow-up, mandibular crowding was corrected in 100% of the cases in the group treated with the sequence that included NiTi heat-activated arch wires, whereas about 30% of those treated with NiTi arch wires were not completely corrected. There was a significant difference in time to complete treatment between groups (log rank = 5.996; p < 0.05). In the group treated with the sequence that included heat-activated wires, alignment and leveling of mandibular anterior teeth were completed earlier than in the group treated only with conventional NiTi arch wires. Clinical trial registration is found at RBR-7g5zng.

Correlation between the Rotation of the First Molars and the Severity of Class II Division 1 Malocclusion.

This study aimed to evaluate the potential correlation between the severity of Class II division 1 malocclusion and the magnitude of mesiopalatal rotation of the maxillary first molars. Scanned images of 104 cast models were grouped according to the severity of Class II malocclusion as follows: Group 1, 1/4 Class II malocclusion; Group 2, 1/2 Class II malocclusion; Group 3, 3/4 Class II malocclusion; and Group 4, complete Class II malocclusion. The rotation was measured using parameters described by Henry, Friel, and Ricketts, referred to as indicators 1, 2, and 3, respectively. The correlation was evaluated using the Spearman's correlation coefficient. The rotational indicators were compared using one-way analysis of variance. For all statistical analyses used p < 0.05, a positive correlation was observed between the severity of Class II malocclusion and the mesiopalatal rotation of the maxillary first molar. This correlation was statistically significant for indicator 1 between Groups 1 and 3 and for indicator 2 between Groups 1 and 4, which include cases of extreme malocclusion. In conclusion, there is a positive correlation between the severity of Class II division 1 malocclusion and the magnitude of mesiopalatal rotation in the maxillary first molars.

Shaping Ability of Reciproc, UnicOne, and Protaper Universal in Simulated Root Canals.

The study aimed to compare the shaping effects, preservation of the original curvature, and transportation of the apical foramen of Reciproc (VDW, Munich, Germany), UnicOne (Medin, Nové Mesto na Morave, Czech Republic), and Protaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) in simulated root canals. Thirty resin blocks with simulated curved root canals were distributed into three groups (n = 10), and prepared using Reciproc (RCp), UnicOne (UnO) and the Protaper Universal (PTu). Standardized photographs were taken before and after the instrumentation, after which they were superimposed. Measurements were taken of the quantity of resin removed from the inner and outer walls of the curvature at 6 levels, the curvature angles before and after instrumentation, and the transportation of the apical foramen. RCp obtained the highest values for amount of resin removed from the inner wall while UnO demonstrated similar shaping on both the inner and outer walls. PTu produced the greatest transportation of foramen when compared to the reciprocating instruments. There was no significant difference between the groups in terms of the change in angle (P > 0.05). All the instruments were capable of maintaining the original curvature of the root canal; however, the UnO, which used reciprocating movement, produced more conservative shapes with lower foramen transportation.

Effectiveness of Oral Antiseptics on Tooth Biofilm: A Study in vivo.

AIM: To evaluate the effectiveness of five different mouthwashes through measurement of the plaque index. MATERIALS AND METHODS: Fifty subjects took part in this blind study, randomized into blocks of five groups according to the active ingredient of the mouthwash: CHX group (0.12% chlorhexidine gluconate), essential oils (EO) group, cetylpyridinium chloride (CPC) group, Tri group (triclosan) and Hamamelis virginiana (HV) group. All subjects were evaluated for a reduction in the bacterial plaque index at 7, 14 and 21 days. RESULTS: There was a significant reduction in the mean plaque index during the period of evaluation (p < 0.01), and the reduction during the period of evaluation was different between mouthwashes (p < 0.01). The reduction in the plaque index at the end of 21 days was, in decreasing order, CHX > EO > CPC > Tri > HV. CONCLUSION: The reduction in the plaque index during the period of evaluation was different between the types of mouth-wash. The mouthwash containing the active ingredient chlorhexidine was the most effective, followed by the essential oil, cetylpyridinium chloride, triclosan and H. virginiana.

Deflection Evaluation of Thermoactivated Nickel-Titanium Archwires after Heat Treatment on their Distal Ends.

OBJECTIVE: This study evaluated in vitro the mechanical changes of 0.018" (0.45 mm) and 0.016 × 0.022" (0.40 × 0.55 mm) thermoactivated nickel-titanium archwires subjected to heat treatment on their distal ends. MATERIALS AND METHODS: Ten archwires in diameters 0.018" and 0.016 × 0.022" by different manufacturers Ormco, Morelli, Orthometric and Unitek were tested. Each tested archwire had an experimental side, submitted to heat treatment, and an annealing-free control. Tests for load/deflection were performed using a universal testing machine, with temperature control in the austenitic transformation phase through tempe rature-controlled chamber. The variables showed normal distribution (Kolmogorov-Smirnov), the t-student test was applied in order to observe the difference between the experi mental and control groups. Statistical significance was set at p < 0.05. RESULTS: There were no statistically significant differences between the groups. CONCLUSION: Heat treatment carried out in the region corresponding to the first molar distal region on thermoactivated nickel-titanium archwires did not influence the load/deflection values in adjacent portion.

The Effect of Self-adhesive and Self-etching Resin Cements on the Bond Strength of Nonmetallic Posts in Different Root Thirds.

PURPOSE: The purpose of this study was to evaluate the effect of self-adhesive and self-etching resin cements on the bond strength of nonmetallic posts in different root regions. MATERIALS AND METHODS: Sixty single-rooted human teeth were decoronated, endodontically treated, post-space prepared, and divided into six groups. Glass-fiber (GF) posts (Exacto, Angelus) and fiber-reinforced composite (FRC) posts (EverStick, StickTeck) were cemented with self-adhesive resin cement (Breeze) (SA) (Pentral Clinical) and self-etching resin cement (Panavia-F) (SE) (Kuraray). Six 1-mm-thick rods were obtained from the cervical (C), middle (M), and apical (A) regions of the roots. The specimens were then subjected to microtensile testing in a special machine (BISCO; Schaumburg, IL, USA) at a crosshead speed of 0.5 mm/min. Microtensile bond strength data were analyzed with two-way ANOVA and Tukey's tests. RESULTS: Means (and SD) of the MPa were: GF/SA/C: 14.32 (2.84), GF/SA/M: 10.69 (2.72), GF/SA/A: 6.77 (2.17), GF/SE/C: 11.56 (4.13), GF/SE/M: 6.49 (2.54), GF/SE/A: 3.60 (1.29), FRC/SA/C: 16.89 (2.66), FRC/SA/M: 13.18 (2.19), FRC/SA/A: 8.45 (1.77), FRC/SE/C: 13.69 (3.26), FRC/SE/M: 9.58 (2.23), FRC/SE/A: 5.62 (2.12). The difference among the regions was statistically significant for all groups (p < 0.05). The self-adhesive resin cement showed better results than the self-etching resin cement when compared to each post (p < 0.05). No statistically significant differences in bond strengths of the resin cements when comparable to each post (p > 0.05). CONCLUSION: The bond strength values were significantly affected by the resin cement and the highest values were found for self-adhesive resin cement.

Can Whitening Strips interfere with the Bond Strength of Composite Resins?

AIM: The aim of this study was to investigate in vitro the bond strength of composite resins on enamel previously treated with whitening strips. MATERIALS AND METHODS: A total of 48 bovine incisors were allocated to four experimental groups (n = 12 each): G1 (WSC)- treated with 9.5% hydrogen peroxide whitening strips (3D White Whitestrips® Advanced Vivid/CREST); G2 (WSO)-treated with 10% hydrogen peroxide whitening strips (3D WhiteTM/Oral B); G3 (WG)-treated with 7.5% hydrogen peroxide gel with fluorine, calcium and potassium nitrate (White Class®/FGM); and G4 (C)-control not subjected to bleaching treatment. The specimens were subjected to bleaching over 2 weeks following the manufacturers' instructions. Following the elaboration of the composite resin test specimens, the samples were stored in artificial saliva and subsequently subjected to the micro-shear test using the universal testing machine (EMIC®). The bond strength values were analyzed by one-way ANOVA and Tukey's statistical test (5%). RESULTS: Significant differences were observed among the investigated groups (p < 0.05). The G3-WG exhibited greater values compared with the control group and the groups treated with strips, G1-WSC and G2-WSO. Analysis of the bond interface revealed that a large fraction of the failures occurred at the enamel-resin interface. CONCLUSION: The bond strength decreased following 14 days of treatment with bleaching strips, whereas the whitening gel with 7.5% hydrogen peroxide, calcium and fluorine increased the bond strength.

Overlays or ceramic fragments for tooth restoration: an analysis of fracture resistance.

PURPOSE: The aim of this study was to evaluate the mode of fracture and resistance of partial ceramic restorations of posterior teeth. MATERIALS AND METHODS: Thirty healthy upper premolars were selected and divided into three groups (n = 10): Group 1- control, healthy unrestored teeth, group 2-teeth restored with ceramic fragments; and group 3-teeth restored with ceramic overlays. The restorations were manufactured with feldspathic ceramic and cemented with RelyX ARC resin cement. After being stored in distilled water for 7 days, the teeth were subjected to axial compression mechanical testing with a universal testing machine. Force was applied to the long axis of the tooth at a speed of 0.5 mm/min until fracture. The data were analyzed with one-way ANOVA and Tukey's test (5%). The mode of fracture was scored according to the degree of involvement of the tooth structure and the type of restoration. RESULTS: A significant difference (p < 0.05) was showed between groups 2 (1155 N) and 3 (846.6 N), but there was no significant difference between group 1 and the other groups (1046 N), More extensive fractures were prevalent in the healthy teeth group (Group 1), which had no occlusal coverage; less severe fractures were found in groups 2 and 3. CONCLUSION: We conclude that teeth restored with ceramic fragments may offer greater resistance to fractures compared to teeth that have overlay restorations.

Atraumatic extraction, implant placement and immediate provisionalization.

Front tooth extraction typically results in significant loss of hard and soft tissue volume, both in the vestibular-lingual and mesiodistal directions. As these changes can compromise the esthetic results of prosthetic rehabilitation, extraction techniques that cause minimal trauma to the remnant tissues are applied in combination with immediate implant placement to minimize such alterations. The case reported in the present article illustrates a therapeutic plan consisting of atraumatic extraction followed by immediate implant placement and provisionalization. When carefully indicated and planned, our results indicate that this technique may provide promising immediate results relative to the maintenance and stability of the peri-implanted tissues.

The prestretching effect on the force decay of orthodontic elastic chain.

This in vitro study evaluated the Influence of prestretching, in the force decay of orthodontic elastic chains, at three time intervals: 2, 7 and 30 days with the brands Morelli, Orthometric and American Orthodontics. In the experimental group, prestretching was performed, stretching the elastics to increase them by 50% of their original length three times in a quick and sequential mode. All of the elastic chains were kept stretched and stored in artificial saliva at 37°C until the time of force measurement. For comparisons between the control and experimental groups, the Mann-Whitney test was used. For comparisons between time points and brands, the Kruskal-Wallis test was used, and for multiple comparisons, Miller's post-hoc test was used. The results showed statistically significant differences among the different commercial brands tested at the initial time point. The mean force at the initial time point ranged from 2.57 to 3.17 N. By day 2, the force values were between 0.97 and 1.49 N; by day 7, the values were 0.56 and 0.94 N. By day 30, the force values ranged between 0.27 and 0.66 N. We concluded that performing and duration of prestretching and the brand all Influenced the force decay of orthodontic elastic chains. Time had a greater Influence on the decay of the elastics than brand or prestretching.

Antimicrobial action of ozonated water and photodynamic therapy with sonic activation in root canals infected with Enterococcus faecalis.

Background: New protocols are constantly being tested in the search for complete disinfection of root canals without the undesirable effects of sodium hypochlorite. This study evaluated the antimicrobial effect of ozonated water and photodynamic therapy (PDT) with sonic activation in root canals infected with Enterococcus faecalis. Material and Methods: Seventy single-rooted canals of human teeth were prepared and contaminated with E. faecalis for 21 days. The teeth were divided into six experimental groups (n=10): ozonized water without (O + S-) and with sonic activation (O + S +); PDT without (PDT + S-) and with sonic activation (PDT + S +); PDT + ozonized water without (PDT + O + S-) and with sonic activation (PDT + O + S +); and two control groups, one positive (n = 5) and one negative (n = 5). Microbial collections were performed before and shortly after treatment, counted in the log of colony-forming units and tested for significant difference between these counts, if any (Student's t-test). The ANOVA two-way test was applied to evaluate whether the Treatment factor (Ozone, PDT and Ozone + PDT) and the Sonic factor (With and without sonic activation) had any effect on microbial reduction. Results: In all protocols, there was a significant microbial reduction (p=0.025), whereas in the groups in which sonic activation was used, the microbial reduction was significantly greater (p=0.001). Conclusions: The treatments significantly reduced the number of microorganisms in the root canals. Sonic activation helped to increase the microbial reduction in infected root canals. Key words:Endodontics, ozone, photodynamic therapy, enterococcus faecalis.

Braden scale has low reliability in different patients under care in intensive care unit.

OBJECTIVE: The aim of this study was to assess the inter-reliability of the Braden scale and its subscales for different patients assisted in the intensive care unit. We hypothesized that the Braden scale has low reliability in different populations. METHODS: This reliability study involved the Braden scale in intensive care unit of a hospital. A total of 200 patients were admitted to the intensive care unit in four different groups: neurological patients, sepsis, elderly, and adults affected by trauma. The Braden scale is a tool composed of six subscales for patient assessment: sensory perception, humidity, activity, mobility, nutrition, and friction. The total score was also calculated. The Braden scale was applied by two different nurses with an interval of 20-30 min between applications. RESULTS: For all populations, kappa values considered unsuitable were observed for most categories of the Braden scale, ranging from 0.06-0.25. Only for the total Braden scale score was moderate reliability identified in all groups evaluated, with intraclass correlation coefficient values ranging from 0.48-0.75. CONCLUSIONS: Braden scale is not a reliable tool to be used in the intensive care unit, and we do not recommend the use of this scale to assess the risk of developing pressure injury.

The Baecke Habitual Physical Activity Questionnaire (BHPAQ): a valid internal structure of the instrument to assess healthy Brazilian adults.

OBJECTIVE: This study aimed to validate the internal structure of the Brazilian version of the Baecke Habitual Physical Activity Questionnaire. METHODS: A cross-sectional study was conducted with individuals over 18 years old of both sexes, with Brazilian Portuguese as their native language. The structure of the Baecke Habitual Physical Activity Questionnaire was tested by confirmatory factor analysis. The model fit was evaluated by the following indices: root mean square error of approximation, comparative fit index, Tucker-Lewis index, standardized root mean square residual, and χ²/degrees of freedom. We used the Akaike information criterion and Bayesian information criterion to compare different structures of the Baecke Habitual Physical Activity Questionnaire. RESULTS: A total of 241 individuals participated in this study. The original structure of the Baecke Habitual Physical Activity Questionnaire with 16 items and 3 domains was compared to a structure with 14 items and 3 domains. The internal structure of the Baecke Habitual Physical Activity Questionnaire with 14 items showed better fit indices and lower Akaike information criterion and Bayesian information criterion values. CONCLUSION: The best internal structure of the Brazilian version of the Baecke Habitual Physical Activity Questionnaire in adults presents 3 domains and 14 items.

Intra- and Interrater Reliability of Short-Term Measurement of Heart Rate Variability on Rest in Individuals Post-COVID-19.

Individuals affected by COVID-19 have an alteration in autonomic balance, associated with impaired cardiac parasympathetic modulation and, consequently, a decrease in heart rate variability (HRV). This study examines the inter- and intrarater reliability of HRV) parameters derived from short-term recordings in individuals post-COVID. Sixty-nine participants of both genders post-COVID were included. The RR interval, the time elapsed between two successive R-waves of the QRS signal on the electrocardiogram (RRi), were recorded during a 10 min period in a supine position using a portable heart rate monitor (Polar® V800 model). The data were transferred into Kubios® HRV standard analysis software and analyzed within the stable sessions containing 256 sequential RRi. The intraclass correlation coefficient (ICC) ranged from 0.920 to 1.000 according to the intrarater analysis by Researcher 01 and 0.959 to 0.999 according to the intrarater by Researcher 02. The interrater ICC ranged from 0.912 to 0.998. The coefficient of variation was up to 9.23 for Researcher 01 intrarater analysis, 6.96 for Researcher 02 intrarater analysis and 8.83 for interrater analysis. The measurement of HRV in post-COVID-19 individuals is reliable and presents a small amount of error inherent to the method, supporting its use in the clinical environment and in scientific research.

Clinical effects of the exposure to red wine during at-home bleaching.

OBJECTIVES: This clinical trial evaluated the effects of red wine exposure on the effectiveness of at-home bleaching with 10% carbamide peroxide, degree of tooth sensitivity, and levels of periodontal inflammatory markers. METHOD AND MATERIALS: Eighty participants were assigned to two groups, namely, those who drank red wine (experimental group), and those who did not drink red wine (control group). The experimental group participants rinsed their mouths with 25 mL of red wine four times a day during the bleaching period. Shade evaluation was assessed visually by using the Vita Classical and Vita Easyshade techniques. Tooth sensitivity was evaluated by the numeric and visual analog scales, and the salivary and gingival crevicular fluids were collected for assessment of nitric oxide (NO) levels, a marker of inflammation. Differences in color change were analyzed by one-way analysis of variance (ANOVA). The absolute risks of tooth sensitivity were compared by the Fisher exact test. Tooth sensitivity intensity data sets for both the visual analog scale and the numeric rating scale were compared using the Wilcoxon signed rank test (α = .05). Repeated measures and two-way ANOVA followed by the Bonferroni test were used to assess time-course and differences between groups in NO production. RESULTS: The bleaching technique was effective regardless of wine consumption (P > .05). Tooth sensitivity was classified as mild, with no differences between groups (P > .05). Red wine reduced both the gingival crevicular fluid and salivary levels of NO (P < .05). CONCLUSION: Red wine does not interfere with the effectiveness and sensitivity of at-home teeth bleaching with 10% carbamide peroxide and protects against bleaching-induced inflammation.

Evaluation of the Bond Strength of Densely Sintered Ceramics Subjected to Extended Firing.

INTRODUCTION: Critical failures in ceramic materials can be caused by the processing mode, which includes all steps taken in the manufacture of a ceramic part, from molding to firing. PURPOSE: To evaluate the effect of extended firing on bond strength in densely sintered ceramics of the zirconium reinforced lithium silicate, lithium disilicate, and feldspathic ceramic. MATERIALS AND METHODS: Three types of ceramics were evaluated: zirconium reinforced lithium silicate, lithium disilicate, feldspathic ceramic. A total of 6 ceramic blocks, two for each material were used in the study. Each block was cut into four square sections. A total of 24 ceramic surfaces were randomly distributed into 6 groups (n = 4 surfaces per group) divided according to the variables: heat treatment: conventional firing or extended firing; test time: immediate (24 hours after cementation) or longevity (after 1000 cycles of thermocycling). The bond strength tests were performed in a semi-universal test machine for microshear bond strength. For data analysis, the Shapiro-Wilk test was performed to evaluate the normality between the groups measured, and regarding homoscedasticity (homogeneity of variances) by the Bartlett test. The comparisons between the groups were made using the nonparametric Kruskal-Wallis test. RESULTS: There was no statistically significant difference of the resistance values in relation to the thermal treatment methods (conventional firing and extended firing) in any ceramic group (p <0.05). Among the times (immediate and long), there was a statistically significant difference (p <0.05), with higher resistance values for immediate time. CONCLUSION: Extended firing did not influence the micro-shear bond strength of zirconium reinforced lithium silicate, lithium disilicate, feldspathic ceramic.

Assessment of the aesthetic impact and quality of life of home dental bleaching in adult patients.

BACKGROUND: This study aimed to evaluate the impact of home bleaching with 10% carbamide peroxide on the quality of life and aesthetic perception of patients. MATERIAL AND METHODS: A total of 107 patients between 18 and 38 years of age with good oral and general health and at least one anterior tooth in color A2 or darker were selected. Patients who previously underwent any type of bleaching procedures were excluded. All patients received a home bleaching treatment with 10% carbamide peroxide. Before beginning the bleaching treatment, the selected patients responded a form with the Oral Health Impact Profile short form (OHIP-14) and Oral Aesthetic Subjective Impact Scale (OASIS) questionnaire. One month after the bleaching treatment, the patients answered the same questionnaires again. The mean ΔE after bleaching was obtained for the canines and lateral and central incisors. The OHIP-14 and OASIS data were measured for the total sample before and after bleaching using the Wilcoxon signed-rank test with a 5% significance level. RESULTS: The effectiveness of whitening by significant color variation was observed in all groups of teeth with less variation in ΔE for central incisors. Comparing before and after bleaching, there was no significant difference in impact for any of the seven domains and total OHIP-14 scores, although a decrease was observed in the discomfort and psychological disability domains. As for the self-perception of dental aesthetics, measured by the OASIS, there was also no significant difference for all the items evaluated; however, it was possible to observe an increase in "concern with dental appearance" after bleaching. CONCLUSIONS: Home bleaching with 10% carbamide peroxide did not have a significant impact on patients' quality of life and aesthetic perception, although there was a decrease in the domain of psychological discomfort and an increase in concerns about dental appearance. Key words:Tooth Bleaching, quality of life, self-perception, dental aesthetics.

Translation, cross-cultural adaptation, and validation of the Canadian Diabetes Risk Questionnaire for the Brazilian population.

OBJECTIVE: The aim of this study was to translate, cross-culturally adapt, and validate the Canadian Diabetes Risk Questionnaire for use in Brazilian Portuguese. METHODS: This is a Questionnaire validity study conducted at a private university. The Brazilian version of the Canadian Diabetes Risk Questionnaire was developed by means of the processes of translation, back-translation, committee review, and pretesting. Test-retest reliability was measured using the intraclass correlation coefficient and kappa coefficient. Internal consistency was measured using Cronbach's alpha. For construct validity, the total score of the Canadian Diabetes Risk Questionnaire was correlated with the Diabetes Knowledge Scale and the Diabetes Mellitus Risk Questionnaire. Ceiling and floor effects were also evaluated in the present study. RESULTS: For construct validity and floor and ceiling effect measurements, a total sample of 100 participants was used. For reliability, a subsample of 34 participants out of the total sample was used. We identified adequate values for reliability (kappa between 0.46-1.00 and ICC 0.96) and internal consistency (Cronbach's alpha 0.80). There were significant correlations between the Canadian Diabetes Risk Questionnaire and the Diabetes Mellitus Risk Questionnaire (rs=0.370, p<0.001), but not the Diabetes Knowledge Scale (rs= -0.162). No ceiling or floor effects were found. CONCLUSION: We concluded that in accordance with the best international recommendations, the Brazilian version of the Canadian Diabetes Risk Questionnaire has adequate psychometric properties.

Interaction effect of Nd:YAG laser and universal adhesive system for dentin sealing.

BACKGROUND: To evaluate the influence of the association of the universal adhesive system to different energy densities of the Nd:YAG laser on the hydraulic conductance of dentin. MATERIAL AND METHODS: Fifty bovine dentin discs were made. The samples were stratified into four groups (n = 10) according to the treatment performed; SBU- Adper Single Bond Universal (3M ESPE), SBU_60 - SBU associated with the Nd:YAG laser (60mJ, 10Hz, 0.6W - 47.77 J / cm²), SBU_80 - SBU associated with the Nd:YAG laser (80mJ, 10Hz, 0.8 W - 63.69 J / cm2) and C - dentin without treatment (smear layer). Hydraulic conductance measurements were taken 24 hours after the treatments (HC1) and after erosive challenge (HC2). Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) helped to visualize the dentin after the different treatments. Scheffe and Games-Howell statistical tests were used to analyze hydraulic conductance (α = 0.05). RESULTS: The treated dentin (SBU, SBU_60, and SBU_80) reduced HC1 when compared to dentin with smear layer (C) (p< 0.001). The erosive challenge has increased HC2 in SBU_60 and C (p< 0.001), and did not promote a significant difference in SBU_80 and SBU. The SEM / EDX analyzes showed an irregular and semi-permeable barrier on the surfaces of the treated dentin. CONCLUSIONS: The association of universal adhesive with Nd:YAG can be an effective alternative for the occlusion of dentinal tubules, whereas higher energy per pulse Nd:YAG (SBU_80) can increase the resistance to permeability when exposed to the erosive challenge. Key words:Dentin, permeability of dentin, Nd:YAG Laser, adhesives.

Could sonic delivery of bulk-fill resins improve the bond strength and cure depth in extended size class I cavities?

BACKGROUND: The implementation of restorative procedures that guarantee success and optimize clinical time is the target of investigations in Restorative Dentistry. This study aimed to analyze the influence of sonic insertion of bulk-fill (BF) and conventional (C) resin composites on the microtensile bond-strength (µ-TBS) and cure depth (CD) of large and deep class I restorations. MATERIAL AND METHODS: Fifty-six healthy human premolars were selected and occlusal cavities (4 x 4 x 3 mm; factor C = 5) were prepared. TC - Tetric N-Ceram (BF), SF - SonicFill (BF), and Z350 - Filtek Z350 XT (C) composite resins were used to restore the cavities, using sonic (S) and non-sonic (NS) insertion techniques. A group restored with conventional incremental insertion (I) using Z350 XT resin was performed serving as a control. Teeth were prepared for microtensile bond-strength test (µ-TBS). And also, restoration depths of 1 and 4 mm were measured with an automatic microhardness indenter (50 g -15 s) to determine the CD. Results were evaluated using ANOVA, Scheffe, and Games-Howel posthoc test (α = 0.05). RESULTS: Types of resins and insertion techniques present statistical differences for µ-TBS and CD (p ≤ 0.001). The µ-TBS was higher respectively for the groups SF > TC > Z350; however, the sonic insertion for SF and Z350 (I) did not present significant differences in µ-TBS. Higher microhardness values were observed on the surface (1mm). At a depth of 4 mm Z350 (I)> SF(S)> SF(NS)> TC(S/NS)> Z350(S/NS) (p< 0.001). Pearson's Correlation of bond strength and base micro-hardness was significant (p ≤ 0.001), strong, and positive (0.955). CONCLUSIONS: The influence of sonic insertion is material dependent, influenced only the microhardness of the SonicFill resin and did not interfere with the bond strength and cure depth of other bulk fill and conventional resin composite. Key words:Composite resins, dentin, hardness tests, tensile strength, Bulk-fill resins, sonic insertion.