Andréa Fonseca-Gonçalves

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.

Lifestyle and oral facial disorders associated with sleep bruxism in children

Objective: The aim of the study was to investigate the routine, sleep history, and orofacial disorders associated with children aged 3–7 years with nocturnal bruxism. Methods: Children (n = 66) were divided into groups of parent reported nocturnal bruxism (n = 34) and those without the disorder (n = 32). Data about the child’s routine during the day, during sleep and awakening, headache frequency, temporomandibular joint (TMJ), and hearing impairments were obtained through interviews with parents/caregivers. Electromyography examination was used to assess the activity of facial muscles. Multiple logistic regression (MLR), chi-square test, and t-test analyses were performed. Results: MLR revealed association of nightmares (p = 0.002; OR = 18.09) and snoring (p = 0.013; OR = 0.14) with bruxism. Variables related to awakening revealed an association with bruxism (p < 0.05). Parents of the main group (children with nocturnal bruxism) reported more complaints of orofacial pain, facial appearance, and headache occurrence (p < 0.05). Auditory and muscle disorders were not significant variables (p > 0.05). Conclusion: Nightmares and snoring are associated with nocturnal bruxism in children. Bruxism in children elicits consequences such as headache, orofacial pain, and pain related to awakening.

Sleep Bruxism and Anxiety Impacts in Quality of Life Related to Oral Health of Brazilian Children and their Families

OBJECTIVE This study aimed to assess the impact of parent reported sleep bruxism, trait anxiety and sociodemographic/socioeconomic features on quality of life related to oral health (OHRQoL) of children and their families. STUDY DESIGN Healthy children aged 3-7 years, with (n=34) and without (n=32) bruxism were select for this study. Data was collected by applying the following instruments: The Early Childhood Oral Health Scale (B-ECOHIS) and Trait-anxiety Scale (TAS). The sociodemographic/socioeconomic characteristics were obtained by interviews with parents. Multiple logistic regression tests were performed to observe the influence of sociodemographic/socioeconomic characteristics, bruxism and trait-anxiety on the childrens OHRQoL. RESULTS No association between sleep bruxism and all evaluated sociodemographic/socioeconomic conditions, with exception of being the only child (p=0.029), were observed. Mean B-ECOHIS and TAS scores were different (p<0.05) between children with (3.41 ± 4.87; 45.09 ± 15.46, respectively) and without (0.63 ± 1.28; 29.53 ± 11.82, respectively) bruxism. Although an association between bruxism and OHRQoL (p=0.015) was observed, it was dropped (p=0.336; OR=1.77) in the logistic regression model. Trait anxiety was the variable responsible for the impact on the OHRQoL of children (p=0.012; OR=1.05). CONCLUSION Our results indicated anxiety as the main factor that interfered in the OHRQoL of children with sleep bruxism.

Knowledge of parents/guardians about nocturnal bruxism in children and adolescents

Background: Bruxism is a repetitive jaw–muscle activity characterized by the clenching or grinding of teeth and/or the bracing or thrusting of the mandible. Objective: This study assessed parents/guardians’ knowledge of nocturnal bruxism in children/adolescents. Method: A cross-sectional study using a validated questionnaire was carried out on 134 Brazilian guardians. Data were analyzed descriptively and through the chi-square test to assess the association if guardians reported bruxism and the causes and consequences of nocturnal bruxism. Results: Mothers (68.7%) were the main contributors; 23.1% said their child had bruxism. Although most participants (73.9%) had no opinion, some believe bruxism is linked to emotional stress (13.4%), mysticism/religiosity (3.7%), health (3.7%) or dental problems (3.0%), and presence of parasites (2.2%). Among the parents/guardians of children without bruxism, 81.9% were unaware of some possible cause versus 18.1% of those with bruxism (p=0.011). There was no association between children with bruxism and the type of sleep (p=0.191) or sleep duration (p=0.377). The majority (90.3%) of guardians whose children have bruxism believe the condition affects their health (p=0.006). Conclusion: Guardians have a widespread ignorance about the causes and consequences of sleep bruxism.

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.

A dual energy micro-CT methodology for visualization and quantification of biofilm formation and dentin demineralization

OBJECTIVE The aim of this study was to induce artificial caries in human sound dentin by means of a microcosm model using human saliva as source of bacteria and to apply a novel dual-energy micro-CT technique to quantify biofilm formation and evaluate its demineralization potential. DESIGN Eight sound third molars had the occlusal enamel removed by cutting with a diamond disk and five cylindrical cavities (±2mm diameter; ±1.5mm depth) were prepared over the dentin surface in each specimen (n=40 cavities). After sterilization, each specimen received the bacterial salivary inoculum obtained from individuals without any systemic diseases presenting dentin caries lesions and were incubated in BHI added of with 5% sucrose for 96h to allow biofilm formation. After that, two consecutive micro-CT scans were acquired from each specimen (40kv and 70kv). Reconstruction of the images was performed using standardized parameters. After alignment, registration, filtering and image calculations, a final stack of images containing the biofilm volume was obtained from each prepared cavity. Dentin demineralization degree was quantified by comparison with sound dentin areas. All data were analyzed using Shapiro-Wilk test and Spearman correlation using α=5%. RESULTS Dual-energy micro-CT technique disclosed biofilm formation in all cavities. Biofilm volume inside each cavity varied from 0.30 to 1.57mm3. A positive correlation between cavity volume and volume of formed biofilm was obtained (0.77, p<0.01). The mineral decrease obtained in dentin was high (±90%) for all cavities and all demineralized areas showed mineral density values lower than a defined threshold for dentin caries (1.2g/cm3). CONCLUSION Dual-energy micro-CT technique was successful in the quantification of a microcosm human bacterial biofilm formation and to quantify its demineralization potential in vitro.

An In Vitro Evaluation of Human Enamel Surfaces Subjected to Erosive Challenge After Bleaching.

OBJECTIVES This study aimed to evaluate whether tooth enamel bleached with hydrogen peroxide (H2 O2 ) is more susceptible to erosion when compared with unbleached tooth enamel; and whether the presence of calcium (Ca) in the bleaching gel influenced this process. MATERIALS AND METHODS Enamel blocks were prepared from human molars, and submitted to surface microhardness analysis (baseline). Blocks were prepared and randomly divided into four treatment groups (n = 20): G1 and G2-bleached with 7.5% H2 O2 , with and without Ca, respectively; G3 and G4-bleached with 35% H2 O2 , with and without Ca, respectively. After bleaching, these groups were submitted to an erosive challenge with 1% citric acid. G5 and G6 (n = 20, each) were the negative (without bleaching) and positive controls (without bleaching, but with erosion), respectively. The percentage of surface hardness loss (%SHL), the 3D non-contact profilometry and Scanning Electron Microscopy (SEM) analyses were performed. RESULTS G2 showed the highest %SHL after bleaching. G1 presented the lowest %SHL in comparison with G2, G3, G4, and G6 after erosion (p < 0.05), which was confirmed only by the SEM analysis. CONCLUSION It is suggested that low concentration of H2 O2 with calcium can be recommended for at-home bleaching agents, which may avoid the mineral loss of bleached enamel after an erosive challenge. CLINICAL SIGNIFICANCE Low concentration of H2 02 with calcium can be recommended for at-home bleaching agents, which may avoid the mineral loss of bleached enamel after an erosive challenge. (J Esthet Restor Dent 29:128-136, 2017).

Influence of the microbiological component of Cariogram® for evaluating the risk of caries in children

Abstract Objective: To compare the risk for caries in children as determined by Cariogram® software (CS; Stockholm, Sweden) with and without its microbiological component and by a form based on Cariogram® (FBC). Methods: Children (n = 28) aged 3–9 years were included. Data were collected clinically and from anamnesis. The salivary levels of Streptococcus mutans (SM) were evaluated. A linear regression model was used to determine which variables were predictive for each type of risk analysis. Caries risk was the dependent variable and the independent variables were caries experience, related disease, plaque amount, diet frequency, salivary levels of SM, fluoride sources and clinical judgment. A paired Student t-test was used for the following comparisons: (a) CS with and without SM; (b) CS without SM and FBC; (c) CS with SM and FBC. Results: The mean dmft/DMFT was 5.56 ± 2.51. There was no difference between the methods (p < .05). Regardless of caries risk, the children presented the same levels of SM (p = .889). Caries experience, plaque amount, diet frequency and fluoride sources were predictors of caries risk in all assessment methods. Clinical judgment was a significant predictor in CS. Conclusions: Caries experience, plaque amount, diet frequency and fluoride sources are valuable predictors of caries risk; microbiological tests are not necessary for evaluating caries risk in children, which can be assessed similarly by CS without SM and FBC.

Treatment of dental biofilm with a tincture of Bauhinia forficata leaves: an ex-vivo study

Abstract The inhibitory activity of a Bauhinia forficata tincture (TBF) was investigated against oral microorganism’s strains and against a mature oral biofilm. The viability of planktonic cells was analyzed by Minimal Inhibitory and Microbicidal concentrations of TBF. Salivary samples from health volunteers were collected and mixed to form a saliva pool. An aliquot from this pool were seeded on membranes, which were incubated to form biofilm (48 h). The biofilm was treated according to the groups: G1-Chlorhexidine 0.12%; G2-TBF at the highest MMC; G3-Ethanol at the TBF highest MMC. G4 was the growth control. Streptococcus spp. (S) and total microorganisms (TM) from biofilm were counted. TBF was microbicidal against all oral pathogens. G2 was able to reduce the counts of S and TM from biofilm compared to G3 and G4, but less than G1 (p < 0.05). TBF is able to reduce the microbial levels from a mature oral biofilm.

Efficacy of sealing occlusal caries with a flowable composite in primary molars: A 2-year randomized controlled clinical trial

OBJECTIVES This randomized controlled clinical trial evaluated the efficacy of sealing carious dentin in controlling the progression of lesions in primary molars for 2-year follow-up. MATERIALS AND METHODS Children (6.79 ± 1.81 years, n = 28) presenting primary molars with occlusal caries in the outer half of dentine were randomized and allocated into 2 groups: test (sealing caries with a flowable resin - SC) and control (partial removal of caries followed by restoration - PRC). The primary outcomes were: the clinical success of restorations evaluated by USPHS criteria and the radiographic analysis of caries progression. The children anxiety was evaluated by a Facial Image Scale; and the time required to perform the treatments was registered. RESULTS In 21 patients evaluated after 2 years, 48 primary molars were analyzed. Clinically, there was no difference between the groups. There was no difference between treatments (p = 0.848) considering lesion progression. The anxiety level did not change after the two interventions (p = 0.650). The treatment time of SC (9.03 ± 1.91 min) was lower (p = 0.002) than the PRC time (17.13 ± 5.26 min). CONCLUSION Sealing carious dentin may be used in dentistry since it did not alter the children anxiety, reduced the chair time and demonstrated clinical success rate and no radiographic difference in relation to the partial caries removal followed by restoration.