Thiago Isidro Vieira

In vitro enamel erosion and abrasion-inhibiting effect of different fluoride varnishes

OBJECTIVE To investigate the erosion and abrasion inhibiting effect of CPP-ACP/NaF and xylitol/NaF varnishes. METHODS Bovine enamel samples (n=40) were exposed to the following treatments (n=10): NaF varnish (Duraphat®, positive control); CPP-ACP/NaF varnish (MI varnishTM); xylitol/NaF (Profluorid®) or distilled and deionized water (MilliQ®, negative control). The samples were submitted for 3days to 4 cycles/day of erosion (5min in Sprite Zero) and 2 cycles of abrasion/day after the first and last erosive challenge, with a toothbrush machine and slurries of a placebo toothpaste for 15s (50 strokes/s). Among the cycles and after the last daily cycle, the specimens remained in artificial saliva. The change in the enamel surface was evaluated by using 3D non-contact optical profilometry with surface roughness (Ra and Sa values) and tooth structure loss (TSL) measurements. Scanning electron microscopy (SEM) assessed the enamel topographic characteristics. Differences in the Ra, Sa and TSL among treatments were tested using one-way ANOVA followed by the Tukey test. RESULTS All varnishes promoted better results for Ra and Sa values than the negative control (p=0.0001), without difference among them (p>0.05). However, CPP-ACP/NaF varnish stimulated fewer TSL (7.09±0.70μm) compared to NaF varnish (10.33±1.36μm, p=0.002), xylitol/NaF varnish (9.96±0.41μm, p=0.007) and the negative control (18.38±3.32μm, p=0.0001). CONCLUSION A single-application of fluoride topical varnishes was effective in reducing enamel wear. The CPP-ACP/NaF varnish had the best effect against enamel loss from an erosion-abrasion challenge.

Does flavoured dentifrice increase fluoride intake compared with regular toothpaste in children? A systematic review and meta-analysis

BACKGROUND Toothpaste manufacturers encourage through aggressive marketing strategies the overconsumption of fluoridated dentifrices. There are conflicting results regarding fluoride intake from toothpastes in children. AIM The aim of this systematic review and meta-analysis was to determine whether dentifrice flavour increases fluoride ingestion by children. DESIGN We included clinical trials on children that evaluated the use of flavoured dentifrice - FD vs regular dentifrice - RD to identify the fluoride intake. An electronic search was performed in PubMed, Web of Science, Scopus, The Cochrane Library, LILACS/BBO, and grey literature followed by manual search. The methodological quality of the studies was assessed using the Cochrane Collaboration common scheme for bias and ROBINS-I tool. Data were analysed in subgroups such as low (G1) and ordinary (G2) fluoride concentrations of dentifrices. We carried out heterogeneity and sensitive analyses. RESULTS For G1, the fluoride intake from RD was significantly higher than from FD [standardised mean difference = -2.57 (-3.26, -1.89), P < 0.00001]. For G2, the fluoride ingestion from RD was significantly higher than from FD [mean difference = -0.00 (-0.00, -0.00), P = 0.02]. CONCLUSIONS There is evidence to support the null hypothesis that flavouring from dentifrice does not increase fluoride intake in young children.

Cytotoxicity of novel fluoride solutions and their influence on mineral loss from enamel exposed to a Streptococcus mutans biofilm

OBJECTIVE This study evaluated the cytotoxicity, antimicrobial activity and in vitro influence of new fluoridated nanocomplexes on dental demineralization. DESIGN The nanocomplexes hydroxypropyl-β-cyclodextrin with 1% titanium tetrafluoride (TiF4) and γ-cyclodextrin with TiF4 were compared to a positive control (TiF4), a blank control (without treatment) and negative controls (hydroxypropyl-β-cyclodextrin, γ-cyclodextrin, deionized water), following 12- and 72-hour complexation periods. The cytotoxicity was assessed using the neutral red dye uptake assay at T1-15 min, T2-30 min and T3-24 h. A minimum bactericidal concentration (MBC) against Streptococcus mutans (ATCC 25175) was performed. Enamel blocks were exposed to an S. mutans biofilm, and the percentage of surface microhardness loss was obtained. Biocompatibility and microhardness data were analysed using ANOVA/Tukey tests (p < 0.05). RESULTS At T1, the cell viability results of the nanocomplexes were similar to that of the blank control. At T2 and T3, the 72 h nanocomplexes demonstrated cell viability results similar to that of the blank, while the 12 h solutions showed results different from that of the blank (p < 0.05). All fluoridated nanocompounds inhibited S. mutans (MBC = 0.25%), while the MBC of TiF4 alone was 0.13%. All fluoridated compounds presented a percentage of surface microhardness loss lower than that of deionized water (p < 0.05). CONCLUSIONS The new fluoridated nanocomplexes did not induce critical cytotoxic effects during the experimental periods, whilst they did show bactericidal potential against S. mutans and inhibited enamel mineral loss.

Effect of the inclusion nanocomplex formed of titanium tetrafluoride and β-Cyclodextrin on enamel remineralization

Objective: Titanium tetrafluoride (TiF4) is a topical agent used in the control of dental caries; however, it is highly acidic. To minimize this effect, cyclodextrins (CDs) are used. This study evaluated the in vitro potential of TiF4and β-CD on remineralization. Methods: Forty bovine enamel blocks were selected by microhardness and randomly assigned to four groups (n = 10 per group): control (distilled and deionized water), 1% β-CD solution, 1% TiF4solution, and TiF4: β-CD solution. The blocks were subjected to a pH cycling regimen for 8 days. After that, samples were evaluated by cross-sectional microhardness (CSMH), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS). Data were assessed for normality and analyzed using ANOVA and Tukeys tests (α = 0.05). Results: Regarding CSMH, TiF4: β-CD was statistically superior to the control (P = 0.033), β-CD (P = 0.022), and TiF4(P = 0.006). SEM photomicrography revealed the titanium dioxide coating on slabs treated with TiF4and TiF4: β-CD. EDS assessment demonstrated the presence of titanium on the surface of slabs treated with TiF4and TiF4: β-CD. Conclusion: The solution containing the inclusion nanocomplex formed of TiF4and β-CD was able to reharden the enamel subsurface.

Atividade antimicrobiana de produtos naturais frente a bactérias formadoras do biofilme dentário

Resumen pt: Objeti vo: Verifi car, in vitro, o efeito anti microbiano do polen e dos extratos alcoolico e aquoso da propolis em suas formas pura e diluidas sobre cep...

Accuracy of visual and image-based ICDAS criteria compared with a micro-CT gold standard for caries detection on occlusal surfaces

The aim of this study was to check the in vitro accuracy of ICDAS criteria on digital images compared to visual examination for the diagnosis of occlusal caries against a micro-CT gold standard. ICDAS was scored in 40 extracted permanent molars by means of visual inspection and stereomicroscopic images. Visual examinations were performed in duplicate and at a one-week interval by three different calibrated examiners. The analysis of digital images by ICDAS criteria was also performed in duplicate, 1 month after visual examinations. The detection methods were compared by means of sensitivity, specificity, area under the curve, predictive positive and negative values, and accuracy for two different thresholds (1- sound vs. carious teeth; 2- tooth requiring operative vs. non-operative treatment). Sensitivity and accuracy values for threshold 1 in the visual ICDAS and image-based ICDAS methods were high for sensitivity (0.93 and 0.97) and for accuracy (0.83 and 0.85), but low for specificity (0.55 for both methods). Specificity values for threshold 2 were 0.77 and 0.82, while sensitivity was 0.33 and 0.28 for each method. Spearmans rank correlation coefficient was 0.53 and 0.43 (p<0.05) for visual and image-based ICDAS compared to the gold standard scores. Both visual and image-based ICDAS scores were similar to each other in terms of diagnostic accuracy when compared to the micro-CT gold standard. Low specificity for the presence of caries and sensitivity for the detection of caries requiring operative treatment were found.

Social capital and self-perceived need for complete denture use or exchange

Purpose: to analyze self-perceived need for complete denture use or exchange in the population aged 35-44 and 65-74 years, as well as to carry out the association between that self-perception with social capital in the municipalities of Conde and Pedras de Fogo, Paraiba. Methods: a total of 134 adults and 54 elderlies participated in this sectional study. The outcome of interest was self-perceived need for complete denture use or exchange. Data were analyzed descriptively and association between variables was performed by means of statistical tests and regression models (=5%). Results: self-perception regarding the need for complete denture use or exchange was observed for 61.2% (n=82) of adults and 59.2% (n=32) of elderlies, and it was found to be statistically associated with dental prosthesis use (X² test; p-value<0.05). According to logistic regression, scholarity (OR=0.83, IC: 0.74-0.94), poor oral health self-perception (OR=19.22, IC: 1.29-286.45) and global use of dental prosthesis (OR=0.16, IC: 0.07-0.40) were found to be associated to the outcome. Conclusion: that self-perceived need for complete denture use or exchange was more frequent among adults that made use of dental prosthesis comparatively to the elderlies. In addition, individuals with lower scholarity level, unsatisfied with their oral health and users of dental prosthesis were more inclined to report needing for complete denture use or exchange.