Marcos Oliveira Barceleiro

This is a double-blind, split-mouth, randomized clinical study that aims to evaluate the influence of bulk-fill composite packaging presented in syringes (BSy) and capsules (BCa), and the effect of selective enamel etching (SEE) on the clinical performance of class I and II bulk-fill resin composite restorations after 24 months. A total of 295 class I or class II restorations were performed on 70 patients. One universal adhesive was applied in all restorations. SEE was used in 148 restorations and self-etching mode (SET) in 147 restorations. After the adhesive application, cavities were restored with Filtek Bulk-fill Posterior Restorative in syringes (BSy), Filtek One Bulk-fill in capsules (BCa), or Filtek Supreme Ultra in syringes with the incremental technique (In). All restorations were evaluated using the FDI criteria after one week and after six, 12, and 24 months. Kaplan-Meier survival analysis and Pearson's Chi-square test were used (α=0.05) for statistical analysis. After 24 months, 62 patients were evaluated and four restorations were lost due to fracture (one for SEEBSy, two for SEEIn, and one for SETIn). No significant differences in the fracture and retention rate were found between groups (p>0.05). SEE showed significantly fewer marginal adaptation defects than SET (p<0.05). BCa and BSy groups showed fewer marginal discrepancies compared to In (p<0.05). Restorations performed with BCa showed less color mismatch than BSy or In (p<0.05). Although all restorations exhibited satisfactory clinical performance after 24 months of clinical service, the clinical behavior of class I and II restorations' improved when performed with a bulk-fill composite in capsules, mainly when associated with a universal adhesive applied with SEE.

The objective of this study was to evaluate the alteration of the optical properties of bulk Fill resin-based composites after 2 years of simulated toothbrushing. Three high-viscosity bulk fill resin composites and one conventional sculptable resin composite (control) were analyzed. Five specimens of each resin composite were prepared, and roughness, color, translucency and gloss were evaluated initially and after one and two years of simulated toothbrushing. The specimens were submitted to electric simulated toothbrushing (14600 strokes/100g) using a commercially available toothbrush with soft fibers and toothpaste slurry in a proportion of 1:2 by weight. The brushing scheme was of 40 cycles per day (2 cycles per second / 280 cycles in a week). The optical properties and the roughness data were analyzed by a multifactor analysis of variance (MANOVA) and a Tukey post hoc test. The baseline and final values of Ra and Sa were submitted to linear regression analyses, all of which were performed at a significance level of p=0.05. Gloss and roughness presented statistical differences between the resin-time interactions in all composite resins. The gloss (72.5%) and roughness (89.4%) worsened significantly after brushing, but the authors didn’t find statistically significant differences when evaluating translucency and color. Based in the results, it could be concluded that the simulated brushing degraded the brightness and roughness of the used high-viscosity bulk fill composites.

The objectives of this double-blind randomized clinical trial were to compare (a) the clinical times and (b) the occurrence and severity of postoperative sensitivity, of posterior restoration that used a universal adhesive, in a self-etch or selective enamel-etching technique, along with incremental or bulk-fill composites (presented in syringes or capsules). A total of 295 posterior restorations were placed according to the following groups: SETB – self-etch/bulk-fill in syringe; SETC – self-etch/bulk-fill in capsules; SETI – self-etch/incremental; SEEB – selective enamel-etching/bulk-fill in syringe; SEEC – selective enamel-etching/bulk-fill in capsules; and SEEI – selective enamel-etching/incremental. Clinical time was assessed by a reason (s/mm³) between the total volume of resin inserted and the total time required to perform the restorations. Postoperative sensitivity was evaluated using two scales (Numeric Rating Scale and Visual Analogue Scale). Mean clinical time results, analyzed by Wald’s Chi-square, showed significant statistical differences among all groups (p<0.001), indicating that the restorative strategy affected the time required for the restoration. A generalized estimating equation model statistical analysis, performed to compare postoperative sensitivity, showed that neither the restorative technique, the adhesive strategy nor the presentation mode of the bulk-fill composite affected the overall risk of postoperative sensitivity (4.06 [2.22–6.81]). The use of bulk-fill composite, presented in capsules or syringes, is less time consuming and does not increase the risk or intensity of postoperative sensitivity relative to the traditional incremental technique.

The dental profession is still pursuing the most effective way to treat white-spot lesions in order to produce a sound and esthetically pleasing enamel surface. The aim of the present research was to evaluate in vitro the effects of a dentifrice with nanohydroxyapatite (nano-HAp) on the roughness, color, lightness, and brightness (gloss) of bovine enamel subjected to pH cycling. Twelve enamel discs prepared from bovine incisors were divided into 2 experimental groups: dentifrice with sodium fluoride (Colgate Total 12 Clean Mint) and dentifrice with nanoHAp (Megasonex). For 14 days, the specimens were subjected to 30 cycles of simulated brushing twice a day as well as to a pH cycling model (6 hours of demineralization and 18 hours of remineralization daily). The roughness, color, lightness, and brightness of all specimens were evaluated at baseline (immediately after specimen preparation) and after 7 and 14 days of treatment. A Tukey test demonstrated that there were no statistically significant differences in the effects of the dentifrices on any parameter after 7 days (P > 0.05). After 14 days, however, there was a statistically significant increase in mean roughness in the group brushed with fluoride dentifrice (P < 0.05). Thus, the nanoHAp containing dentifrice promoted less superficial roughness after 14 days, but both dentifrices were similar in relation to color variation, lightness, and brightness.

This study evaluated the effect of the administration of pre-operative dexamethasone on tooth sensitivity stemming from in-office bleaching.

SUMMARY: This study aimed to assess longitudinally the radiopacity of resin composites under the influence of photoactivation and photoaging processes. Ten specimens (1 mm thick and 4 mm in diameter) of three different microhybrid resin composites, Filtek Z250 XT (R1), TPH 3 Spectrum (R2), and Opallis (R3), were prepared for this study. For longitudinal assessment of radiopacity, radiographic images were obtained five times. The first time (T1), the specimens were not photoactivated; the second time (T2), the specimens were photoactivated; and the next three times, photoaging was carried out, with images obtained at 24 hours (T3), 48 hours (T4), and 72 hours (T5) after this process. The photoaging was conducted using LED light (700 lumens, 9 W, 6400 k) under controlled environmental conditions at 37°C (±1°C) and 65% (±5%) relative humidity. The digital system DIGORA Optime was used. The digital images were measured using the histogram function, and then the pixel intensity values were converted into mmAl (the standard unit of radiopacity) using a linear regression function, with minimal adjustment of R2 ≥ 0.9. Data in mmAl were statistically analyzed using an analysis of variance (α=0.05). R2 resin composite showed higher values of radiopacity, R1 resin composite showed intermediate values, and R3 resin composite showed lower values. Only at T1 did the higher radiopacity of R2 composite differ significantly from other groups (p = 0.0000). After application of treatments (photoactivation and photoaging), all radiopacity values were similar (p-values to T2=0.0507, T3=0.0536, T4=0.0502, T5=0.0501) due to consecutive increase of radiopacity of R1 and R3 composites from T2. Photoactivation and photoaging processes influenced the radiopacity, but changes occurring in the degree of radiopacity were dependent on the composition and chemical characteristics of each composite used.