Scientific article in vitro evaluation of the influence of air abrasion on detection of occlusal caries lesions in primary teeth

The purpose of this study was to assess the influence of cleaning pits and fissures with an aluminum oxide air abrasion system on the detection of occlusal caries in primary teeth using laser fluorescence (LF) and visual examination. Methods: The sample comprised 65 pit and fissure sites on extracted primary teeth suspected to be carious. The sites were submitted to 2 visual examinations (examiner JAR) and 2 LF readings (examiner TMV). Next, the occlusal surfaces were air-abraded and re-examined thereafter using both methods. The teeth were sectioned, and the histological analysis of the sites with a stereoscopic magnifying lens at X32 magnifi cation was used as the gold standard. Results: Cohen's kappa statistic for LF and visual examination were, respectively, 0.282/0.884 before and 0.896/0.905 after air abrasion. LF showed a sensitivity of 0.28 increasing to 0.49 and a specifi city of 0.50 increasing to 0.92. Visual examination showed sensitivity of 0.78 and specifi city of 0.73. Both increased after air abrasion. Conclusion: The findings suggest that cleaning pits and fissures with aluminum oxide air abrasion increased the accuracy of LF and visual examination for detection of occlusal caries in primary teeth.

Genetic polymorphism of Streptococcus mutans strains associated with incomplete caries removal

Aim: Despite the antibacterial properties of dental materials, the survival of residual bacteria under restorations has been demonstrated after incomplete caries removal. The aim of this study was to evaluate the genetic polymorphism of Streptococcus mutans strains isolated from deep dentinal lesions before and three months after incomplete caries removal. Methods: Samples of carious dentin were collected from 33 primary and/or permanent molars before and after indirect pulp treatment and processed for microbiological isolation of mutans streptococci (MS). After three months of the dental treatment, positive cultures for MS were detected in only ten of these teeth. DNA of MS isolates were obtained and subjected to polymerase chain reaction (PCR) for identification of S mutans. The arbitrary primed-PCR method (primer OPA-13) was used to detect the genetic polymorphism of S. mutans strains. Results: Identical or highly related S. mutans genotypes were observed in each tooth, regardless of the collect. Considering each tooth separately, a maximum of nine genotypic patterns were found in each tooth from all the collects. In addition, at least one genotypic pattern was repeated in the three collects. Genetic diversity was observed among the S. mutans isolates, obtained from different teeth after three months of the dental treatment. Conclusions: The persistence of identical genotypic patterns and the genetic similarity among the isolates, from the same tooth in distinct collects, showed the resistance of some S. mutans strains after incomplete caries removal treatment.

Influence of the ICDAS e-learning program for occlusal caries detection on dental students

The aim of this study was to evaluate the influence of ICDAS training in a group of dental students for occlusal caries detection in permanent teeth. Premolars and molars (N=104) with occlusal surfaces varying from ICDAS scores 0 to 6 were cleaned, one occlusal site per tooth was selected, and a photograph taken to identify the site. Eight senior dental students examined the teeth twice with a one-week interval between examinations during each of two phases: before and after the ICDAS e-learning program. Teeth were histologically assessed for caries extension. Intraclass correlation coefficients for intra- and interexaminer repeatability were high, both before (0.75 and 0.72, respectively) and after e-learning (0.82 and 0.78, respectively). The ICDAS scores decreased significantly from before to after e-learning (p=0.0001). Correlation between ICDAS scores and histology scores was moderate (0.57 before e-learning and 0.61 after). Although the ROC curve shows an improvement in the use of the ICDAS scoring after e-learning, the difference was not significant (p=0.10). Specificity of the ICDAS scores significantly improved after e-learning (77 percent vs. 36 percent), and sensitivity was reduced slightly after e-learning (87 percent vs. 92 percent). The ICDAS e-learning program improved the performance of the diagnostic skills of the investigated students for the detection of occlusal caries lesions.

Dental caries experience in children attending an infant oral health program

Aim: To investigate: a) caries experience in 5 year-old children and its relationship to the caries risk evaluation made before 1 year of age; b) compliance of parents to an infant oral health program as well as the abandonment reasons. Methods: Group A (GA) - 242 children (60-71 months old) who stayed in the program and had been enrolled since their first year of life underwent a clinical examination according to the WHO's criteria; their parents/caregivers were interviewed to ascertain their compliance to the program. Group B (GB) - parents of 60 children, who had dropped out of the program, were interviewed to check the reasons of withdrawing. The caries risk classification was based on the file at the first appointment. Chi-square test was used (α=0.05) for statistical analyses. Results: Most of the children were free of caries (71.1%). Caries risk evaluation showed low sensibility (34.3%, 95% CI = 22.4-46.1) and high specificity (74.4%, 95% CI = 67.6-81.2) to caries experience. Sixty-two mothers (25.6%) reported difficulty to follow the guidelines. The main reason for dropping out was changing to similar health services (40.0%). Conclusions: Caries risk in the first year of life was not efficient to predict dental caries experience at 5 years of age. Educational practice should be improved to increase the compliance of the parents to the program.

Effect of drying on the reproducibility of DIAGNOdent to detect caries-like lesions

The aim of this study was to verify the drying effect on the reproducibility of DIAGNOdent (Dd) devices to detect caries-like lesions. Three areas were created in each of the 34 bovine incisors: sound (S), demineralized (DE) and remineralized (RE). One examiner measured each area with two Dd devices (denominated X and Y), twice under humid, and twice under dry condition. Intra-rater agreement according each device and inter-device agreement were estimated by kappa statistics (κ). Intra-rater agreement for device Y was substantial under humid (κ DE=0.68 and κ RE+S=0.68) and dry condition (κ DE=0.64 and κ RE+S=0.67). For device X, it was substantial under humid condition (κ DE=0.57 and κ RE+S=0.49), and it was almost perfect after air drying (κ DE=1.0 and κRE+S=1.0). Inter-device agreement was slight (κ =0.17) under humid condition, and it was substantial under dry condition (κ =0.62). As reproducibility increased under dry condition, drying is advised to detect caries-like lesions on free smooth surfaces when different devices are used.

Caries experience associated to social and preventive factors in children of a pastoral community from Limeira-SP

Aim: To evaluate caries experience and prevalence associated to social and preventive factors in 3-6-year-old children of a Pastoral Community from Limeira, Brazil. Methods: A cross-sectional study was carried out through an epidemiologic research about the oral conditions of 110 children registered at the Children's Pastoral Community from the city of Limeira, SP, Brazil. Intraoral examination was performed by a trained dentist and the parents/caregivers filled out a questionnaire in order to outline the children's profile with respect to gender, parental education and oral health. Results: Differences related to gender were not detected (p= 0.3404). The most frequent periods of breastfeeding were 0 to 2 months (36.36%) and 2 to 6 months (35.45%), corresponding to 71.81% of the cases. The time bottle feeding pointed to two most frequent categories: 1) more than 12 months (35.45%) and 2) between 2 and 6 months (22.63%). Regarding parental education, the majority of the sample has not completed primary school (38.32%). It was observed a larger number of decayed teeth in male children (63.39%). Caries experience was significantly higher in children who were breastfed for only 2 months of life (41.96%). Children that did not use baby bottle or did not use a baby bottle for more than 1 year presented a smaller dmft, corresponding to 29.17% and 28.33%, respectively. Time of use of bottle and pacifier presented a significant association (p<0.05). Conclusions: The implementation of adequate strategies and actions is needed to reinforce oral health conditions in risk groups.

Mechanisms of action of fluoride for caries control

Fluoride was introduced into dentistry over 70 years ago, and it is now recognized as the main factor responsible for the dramatic decline in caries prevalence that has been observed worldwide. However, excessive fluoride intake during the period of tooth development can cause dental fluorosis. In order that the maximum benefits of fluoride for caries control can be achieved with the minimum risk of side effects, it is necessary to have a profound understanding of the mechanisms by which fluoride promotes caries control. In the 1980s, it was established that fluoride controls caries mainly through its topical effect. Fluoride present in low, sustained concentrations (sub-ppm range) in the oral fluids during an acidic challenge is able to absorb to the surface of the apatite crystals, inhibiting demineralization. When the pH is re-established, traces of fluoride in solution will make it highly supersaturated with respect to fluorhydroxyapatite, which will speed up the process of remineralization. The mineral formed under the nucleating action of the partially dissolved minerals will then preferentially include fluoride and exclude carbonate, rendering the enamel more resistant to future acidic challenges. Topical fluoride can also provide antimicrobial action. Fluoride concentrations as found in dental plaque have biological activity on critical virulence factors of S. mutans in vitro, such as acid production and glucan synthesis, but the in vivo implications of this are still not clear. Evidence also supports fluoride's systemic mechanism of caries inhibition in pit and fissure surfaces of permanent first molars when it is incorporated into these teeth pre-eruptively. © 2011 S. Karger AG, Basel.

Topical use of fluorides for caries control

Since the early findings on the protective effects of fluoride present in drinking water upon caries incidence and prevalence, intensive research has been conducted in order to determine the benefits, safety, as well as the cost-effectiveness of other modalities of fluoride delivery. The present chapter reviews the various forms of topical fluoride use - professionally and self-applied - with special emphasis on clinical efficacy and possible side effects. The most widely used forms of fluoride delivery have been subject of several systematic reviews, providing strong evidence supporting the use of dentifrices, gels, varnishes and mouth rinses for the control of caries progression. Dentifrices with fluoride concentrations of 1,000 ppm and above have been shown to be clinically effective in caries prevention when compared to a placebo treatment, but the evidence regarding formulations with 450-550 ppm is still subject of debate. Therefore, the recommendation for low-fluoride dentifrice use must take into account both risks and benefits. The evidence for the combined use of two modalities of fluoride application in comparison to a single modality is still inconsistent, implying that more studies with adequate methodology are needed to determine the real benefits of each method. Considering the currently available evidence and risk-benefit aspects, it seems justifiable to recommend the use of fluoridated dentifrices to individuals of all ages, and additional fluoride therapy should also be targeted towards individuals at high caries risk. © 2011 S. Karger AG, Basel.

Effect of bleaching on sound enamel and with early artificial caries lesions using confocal laser microscopy

The aim of this study was to evaluate effect of bleaching agents on sound enamel (SE) and enamel with early artificial caries lesions (CL) using confocal laser scanning microscopy (CLSM). Eighty blocks (4 × 5 × 5 mm) of bovine enamel were used and half of them were submitted to a pH cycling model to induce CL. Eight experimental groups were obtained from the treatments and mineralization level of the enamel (SE or CL) (n=10). SE groups: G1 - unbleached (control); G2 - 4% hydrogen peroxide (4 HP); G3 - 4 HP containing 0.05% Ca (Ca); G4 - 7.5% hydrogen peroxide (7.5 HP) containing amorphous calcium phosphate (ACP). CL groups: G5 - unbleached; G6 - 4 HP; G7 - 4 HP containing Ca; G8 - 7.5 HP ACP. G2, G3, G6, G7 were treated with the bleaching agents for 8 h/day during 14 days, while G4 and G8 were exposed to the bleaching agents for 30 min twice a day during 14 days. The enamel blocks were stained with 0.1 mM rhodamine B solution and the demineralization was quantified using fluorescence intensity detected by CLSM. Data were analyzed using ANOVA and Fisher's tests (α=0.05). For the SE groups, the bleaching treatments increased significantly the demineralization area when compared with the unbleached group. In the CL groups, no statistically significant difference was observed (p>0.05). The addition of ACP or Ca in the composition of the whitening products did not overcome the effects caused by bleaching treatments on SE and neither was able to promote remineralization of CL.

Dentistry for babies: Caries experience vs. Assiduity in clinical care

Aim: This study analyzed and compared the experience of dental caries in 300 children aged 0 to 48 months, who were participants and non-participants of a preventive program 'Dentistry for babies', as well as the correlation between assiduity of dental visits and experience of dental caries. Methods: The subjects were randomly selected and divided into two groups: G1 'Non participant children of the Program' (n=100) and G2 'Participant Children of the Program' (n=200). Each group was subdivided in two subgroups: 0-24 months and 25-48 months. The collected data from G2 were analyzed, relating the variation of the dmft index (dmft refers to primary teeth: d = decayed, m = missing/extracted due to caries, f = filled, t = teeth) (C) and dental caries prevalence (P) with the influence of assiduity factor in each subgroup. To collect data, clinical examinations were performed using tactile and visual criteria by a single calibrated examiner. The data were statistically analyzed using the 'paired t-test', 'Mann-Whitney' and 'Chi-Squared' tests (p<0.05). Results: It was found that prevalence and dmft index were statistically significant (P=0.0001) with the greatest values observed in G1 (p=0.0001). The values were: PG1 (73%), PG2 (22%), CG1 (3.45±3.84), CG2 (0.66±1.57). Assiduity was significant in G2 (p=0.0001). The values observed were: P-Assiduous (2%), P-Non-assiduous (42%), C-Assiduous (0.04±0.31), and C-Non-assiduous (1.29±2.01). Conclusions: The participation in the program had a positive influence on the oral health of babies. Complete assiduity to the program resulted in the lowest rates and prevalence of dental caries.

Traditional and novel methods for occlusal caries detection: Performance on primary teeth

This study aimed to assess the performance of International Caries Detection and Assessment System (ICDAS), radiographic examination, and fluorescence-based methods for detecting occlusal caries in primary teeth. One occlusal site on each of 79 primary molars was assessed twice by two examiners using ICDAS, bitewing radiography (BW), DIAGNOdent 2095 (LF), DIAGNOdent 2190 (LFpen), and VistaProof fluorescence camera (FC). The teeth were histologically prepared and assessed for caries extent. Optimal cutoff limits were calculated for LF, LFpen, and FC. At the D 1 threshold (enamel and dentin lesions), ICDAS and FC presented higher sensitivity values (0.75 and 0.73, respectively), while BW showed higher specificity (1.00). At the D 2 threshold (inner enamel and dentin lesions), ICDAS presented higher sensitivity (0.83) and statistically significantly lower specificity (0.70). At the D 3 threshold (dentin lesions), LFpen and FC showed higher sensitivity (1.00 and 0.91, respectively), while higher specificity was presented by FC (0.95), ICDAS (0.94), BW (0.94), and LF (0.92). The area under the receiver operating characteristic (ROC) curve (Az) varied from 0.780 (BW) to 0.941 (LF). Spearman correlation coefficients with histology were 0.72 (ICDAS), 0.64 (BW), 0.71 (LF), 0.65 (LFpen), and 0.74 (FC). Inter- and intraexaminer intraclass correlation values varied from 0.772 to 0.963 and unweighted kappa values ranged from 0.462 to 0.750. In conclusion, ICDAS and FC exhibited better accuracy in detecting enamel and dentin caries lesions, whereas ICDAS, LF, LFpen, and FC were more appropriate for detecting dentin lesions on occlusal surfaces in primary teeth, with no statistically significant difference among them. All methods presented good to excellent reproducibility. © 2012 Springer-Verlag London Ltd.

Dental caries experience and Molar-Incisor Hypomineralization

Objective. This cross-sectional study assessed the prevalence and severity of the enamel defects, known as Molar-Incisor Hypomineralization (MIH) and its relationship to dental caries. Materials and methods. A sample of 1157 schoolchildren (population based), aged 6-12 years, of the Araraquara city-Brazil, was evaluated according to the European Academy of Paediatric Dentistry (EAPD) criteria by two trained examiners. The dental impact caused by MIH was evaluated with the Decayed, Missing and Filled Teeth (DMFT) index (WHO). Data were analyzed using ANOVA and Chi-square tests (p < 0.05). The socioeconomic status was collected using a questionnaire answered by parents. Results. The prevalence of MIH was 12.3%. Mild impairment was the most frequent diagnosis. DMFT of children with MIH was 0.89 (±1.18), which are higher than those of the unaffected group (0.43 ± 1.01). An association was found between dental caries only in the permanent dentition of children with MIH (p = 0.0001). Family income was considered low in 85% of the families of children with MIH in the public system, while in private school it was 18% (p < 0.05). Conclusion. The prevalence of MIH in Araraquara was associated with greater caries experience in the permanent dentition. © 2013 Informa Healthcare.

Comparison of the caries-preventive effect of a glass ionomer sealant and fluoride varnish on newly erupted first permanent molars of children with and without dental caries experience

Purpose: This longitudinal clinic study evaluated the effect of a glass ionomer sealant (GIS) and a fluoride varnish (FV) in the prevention of dental decay on newly erupted permanent molars of children with and without caries experience. Materials and methods: Eighty children, aged 6-8 years, with all four newly erupted first permanent molars, were divided into two groups. Group 1 consisted of 53 children without caries experience and group 2 consisted of 27 children with dental caries experience. Permanent molars of the right side were sealed with GIS and the fluoride varnish was applied on the other two permanent first molars. Evaluation of GIS retention and the effectiveness of both materials in the prevention of dental caries were performed after 6, 12 and 18 months. Results: After 18 months, of the 299 teeth, 271 (91%) showed no caries lesions and 28 presented caries lesions (9%). Teeth sealed with GIS had more carious lesions (15) than teeth with fluoride varnish (13). Most of the teeth (70%) that presented carious lesions were in group 2. Of the 138 sealed teeth, only one showed GIS to be totally present, 95 were partially present and 42 teeth were absent. Conclusion: The caries-preventive effect was very similar between both treatments. The presence of dental caries prevailed in the children with caries experience. © 2013 Informa Healthcare.

Microtensile bond strength of resin cements to caries-affected dentin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)