Accuracy of Two Visual Criteria for the Assessment of Caries around Restorations: A Delayed-Type Cross-Sectional Study.

The aim of this study was to compare the performance of two visual criteria used for the detection of caries around restorations in permanent teeth. In this delayed-type cross-sectional study, the study sample was randomly allocated to one of two visual criteria for the assessment of restorations as follows: (a) International Dental Federation (FDI) criteria, considers marginal staining, marginal adaptation, and caries recurrence and (b) Caries Associated with Restorations or Sealants (CARS) criteria, defined by the International Caries Classification and Management System. A calibrated examiner assessed the restorations using two reference standards as follows: (i) for restorations requiring operative interventions (repair/replacement), the restoration was partially or totally removed and the presence or absence of carious tissue was assessed; and (ii) for restorations requiring nonoperative intervention, follow-up for a period of 1 year was recommended to allow identification of the presence of new lesions not detected at baseline. The sensitivity, specificity, area under receiver operating characteristic curve (Az), and accuracy of the criteria were assessed. The study included 305 restorations. The FDI marginal staining parameter had the lowest Az value (Az = 0.501), while similar sensitivity was observed between the CARS (62.0%), FDI presence of caries (65.0%), and FDI marginal adaptation (74.0%) parameters. CARS exhibited the highest specificity (88.3%) and accuracy (85.6%). The CARS criteria exhibited better specificity and accuracy in detecting caries around restorations, followed by the FDI criteria for caries recurrence and marginal adaptation. Considering marginal staining or combining multiple marginal features to assess secondary caries resulted in an increased risk of false-positive outcomes and overtreatment.

Comparison of two clinical approaches based on visual criteria for secondary caries assessments and treatment decisions in permanent posterior teeth.

BACKGROUND: This cross-sectional study aimed to compare two clinical approaches based on visual criteria for secondary caries assessments and treatment decisions in permanent posterior teeth. METHODS: The two clinical visual criteria tested for the assessments of restored teeth were: FDI criteria-based on the caries presence, marginal adaptation and staining criteria, adapted from the FDI (International Dental Federation) criteria and CARS criteria-"Caries Associated with Restorations or Sealants" (CARS) criteria described by the International Caries Classification and Management System. Adults were randomized according to the criteria. One calibrated examiner assessed the restorations and assigned the treatment according to the criteria. The primary outcome was replacement indication. RESULTS: A total of 185 patients were included, totalling 718 restorations. The strongest correlation founded between the methods was for the presence of caries lesions (Rho = 0.829). A moderate correlation (Rho = 0.420) was founded between the treatment decisions proposed by the CARS and by the FDI criteria. The multilevel regression analysis showed that the FDI criteria indicated five times more replacements when compared to the CARS (< 0.001). Also, using the FDI criteria restorations were 2.7 times more related to caries around restorations (p < 0.001) compared to the other criterion. CONCLUSIONS: The visual criteria used on the restoration's assessment directly influences the treatment decision to intervene or not on the restoration. The use of a minimally invasive based approach for assessing secondary caries may prevent overtreatment.

Influence of biofilm removal from the tooth-restoration interface on the progression of secondary caries lesions: a preliminary in vitro model study.

This study investigated the effects of biofilm removal from the tooth-restoration surface on secondary caries lesion progression. Biofilms were grown for up to 28 days on resin-restored enamel-dentin disks with an interfacial gap with DMM or DMM + 1% sucrose under five different protocols of Visible Biofilm Removal (V-BR; n = 7): (1) without V-BR, (2) with partial V-BR, (3) with total V-BR, (4) with total V-BR and saliva reinoculation, and (5) without V-BR under 9 h of cariogenic challenge. V-BR was performed at 7, 14 and 21 days. ΔS and CFU counts served as outcome variables. Linear regression models showed that ΔS values were higher for outer lesions than wall lesions, and outer lesion progression generally increased over time (p < 0.01). All protocols tested, except total V-BR, increased the lactobacilli count (p < 0.005). V-BR did not influence the progression of caries lesions on the cavity wall in this biofilm model.

Study protocol for a diagnostic randomized clinical trial to evaluate the effect of the use of two clinical criteria in the assessment of caries lesions around restorations in adults: the Caries Cognition and Identification in Adults (CaCIA) trial.

BACKGROUND: The assessment of restored teeth in dentistry remains a challenge, mainly related to the detection of caries around restorations. There is a diversity of clinical criteria available to assess the caries lesions, resulting in differences in the dentists' diagnosis and treatment decisions. In addition, there is a lack of evidence regarding the best criteria to detect caries lesions around the restorations. Thus, the present protocol aims to evaluate the effect of using 2 visual criteria to assess restored teeth on the outcomes related to oral health in adults. METHODS: The design protocol of the Caries Cognition and Identification in Adults trial correspond to a triple-blind randomized, controlled clinical trial with parallel-groups. Two groups will be compared: patients who will receive the diagnosis and treatment decision according to FDI (World Dental Federation) criteria-FDI group; and patients who will receive diagnosis and treatment decision according to the "Caries Associated with Restorations or Sealants" criteria defined by the International Caries Classification and Management System (ICCMS group). The participants will be followed up after 6, 12, 18, 24, and 60 months, and the restoration failure will be the primary outcome. The analysis will be conducted through Cox regression with shared frailty. The impact of oral health on quality of life and the cost-effectiveness of the methods used will be the secondary outcomes. Two-tailed analyzes will be used, considering a level of significance of 5%. DISCUSSION: This is the first clinical trial to assess the effect of using two visual methods to detect caries lesions around restorations on the outcomes related to oral health in adults. The findings of this study will define what is the best diagnostic strategy for the assessment of caries around restorations in permanent teeth. Trial registration NCT03108586 (registered 11 April 2017).

Impact of a diagnostic workshop on undergraduate teaching-learning process for the diagnosis and management of tooth restorations-A randomised controlled study.

OBJECTIVE: The aim of this study was to investigate the impact of a diagnostic workshop on undergraduate teaching-learning process for the diagnosis and management of tooth restorations. METHODS: The first stage of the study was a randomised controlled study with two parallel groups: lecture (L) and lecture coupled with a diagnostic workshop (LW). A pool of cases of tooth restorations including secondary caries and marginal defects was used for training. Theoretical knowledge, perception about the activity and practical abilities were evaluated. The second stage of the study assessed students' theoretical knowledge retention six months following intervention. All students included in the first stage of the study were exposed to LW. Hence, a new control group of students not exposed to LW was selected. One-way analysis of variance, Fisher's exact test, Kruskal-Wallis test and multilevel regression analysis were used as part of statistical analysis. RESULTS: The LW group had greater scores for the assignment of lesion severity and activity, presence of marginal defect and treatment indication than the L group (P < 0.05). Multilevel regression analysis showed a positive impact of the workshop diagnosis in the correct assessment of lesion activity (P = 0.03). There was no statistical difference between the LW and L groups in students' perception of the activity. The LW group showed greater knowledge retention after six months than the L group (P = 0.027). CONCLUSION: Lecture coupled with diagnostic workshop improved students' practical skills of diagnosis restorations and knowledge retention in the six months following intervention.

Influence of the Inoculum Source on the Cariogenicity of in vitro Microcosm Biofilms.

This study investigated the cariogenic potential of biofilms originating from different types of inoculum (saliva and dental plaque) from caries-active and caries-free individuals. Ten volunteers were selected from each caries condition for the paired collection of saliva and dental plaque. Microcosm biofilms were grown in triplicate from each inoculum on enamel specimens in 24-well plates under cariogenic challenge. After 10 days, the biofilms were collected for analysis of outcome variables: percentage of surface hardness change (%SHC) and microbiological composition of biofilms. Statistical analysis was performed using the t test, the linear multivariate analysis model and Pearson's correlation coefficients (α = 0.05). A comparative analysis between microbiological baseline data showed higher counts of mutans streptococci in plaque samples within caries-active individuals; a comparative analysis of colony-forming unit (CFU) counts between individuals with different caries status showed higher counts of acid-tolerant microorganisms and mutans streptococci in dental plaque and of acid-tolerant microorganisms in saliva. After 10 days of biofilm growth, the CFU values for total microorganisms, lactobacilli, mutans streptococci and acid-tolerant bacteria, as well as for SHC, were not statistically significant, considering the type of inoculum and caries condition (p > 0.05). A positive correlation was found for %SHC and CFU counts of acid-tolerant bacteria (r = 0.406) and lactobacilli (r = 0.379). Under the limits of this study, the cariogenic potential of biofilms, formed under identical conditions in vitro, is similar, regardless of baseline differences between the source and type of inoculum.

Influence of caries activity and number of saliva donors: mineral and microbiological responses in a microcosm biofilm model.

OBJECTIVE: this study evaluated the mineral and microbiological response of biofilms originating from different types of saliva inoculum with distinct levels of caries activity. METHODOLOGY: the biofilms grown over enamel specimens originated from saliva collected from a single donor or five donors with two distinct levels of caries activity (caries-active and caries-free) or from pooling saliva from ten donors (five caries-active and five caries-free). The percentage surface hardness change (%SHC) and microbiological counts served as outcome variables. RESULTS: the caries activity of donors did not affect the %SHC values. Inoculum from five donors compared to a single donor showed higher %SHC values (p=0.019). Higher lactobacilli counts were observed when saliva from caries-active donors was used as the inoculum (p=0.017). Pooled saliva from both caries activity levels showed higher mutans streptococci counts (p<0.017). CONCLUSION: Overall, pooled saliva increased the mineral response of the derived biofilms, but all the inoculum conditions formed cariogenic biofilms and caries lesions independently of caries activity.

The effect of two clinical criteria in the assessment of caries lesions around restorations in children (CARDEC-03): study protocol for a diagnostic randomized clinical trial.

Introduction: The detection of caries lesions around restoration can be challenging. Therefore, the use of some criteria has been proposed in order to give more objectivity to the diagnosis process. Two of them are the International Dental Federation (FDI) and the Caries Associated with Restorations and Sealants (CARS) criteria. Both methods have a different approach to caries, and it is not possible to know which one of them is the best to use in clinical practice to assess restorations in children. Thus, the present protocol aims to evaluate the effect of the use of the FDI and CARS criteria in the assessment of caries lesions around restorations in primary teeth on outcomes related to oral health in children and costs resulting from the assessments. Methods and analysis: A total of 626 restorations of children from three to 10 years were randomly assessed and are being treated following the FDI criteria (FDI group) or CARS criteria (CARS group). Participants will be followed-up after six, 12, 18, and 24 months. The primary outcome will be the need for a new intervention in the evaluated restorations. This outcome consists of several components, and each of these events will be analyzed separately as secondary outcomes. The changes in children's oral health-related quality of life and the cost of the restoration dental treatments will also be analyzed as secondary outcomes. The methods will be compared using the Cox regression model with shared frailty. A significance level of 5% will be adopted for all statistical analyses. Discussion: This will be the first randomized clinical study carried out regarding the detection of caries lesions around restorations in primary teeth. Trial registration: The study underwent registration in Clinicaltrials.gov ( NCT03520309) on 9 May 2018.

Impact of individual-risk factors on caries treatment performed by general dental practitioners.

OBJECTIVE: This prospective study investigated how individual patient risk factors impacted non-operative and operative treatment decisions in a dental practice-based research network in The Netherlands. METHODS: Data from were collected from 11 dental practices, whose patients visited the practice at least once during the observation period (January 2015 to September 2017). Descriptive analysis was performed, followed by multiple logistic regression. RESULTS: The records of 39,690 patients were analyzed. Approximately one-half of the population (n = 21,056) underwent a restoration procedure during the observation period, of which 5981 (28.4%) were classified with fair oral hygiene, and 5341 (25.4%) with a high risk for caries. The population without restorative intervention (n = 18,634) consisted mainly of patients with good oral health (n = 5132 [27.5%]) and low risk for caries (n = 7792 [41.8%]). A high risk for caries was associated with a greater chance of preventive instruction (odds ratio [OR] 1.60), applications of topical fluoride (OR 1.20) or sealants (OR 1.39), and restorative interventions (OR 5.72). There was wide variation among practices regarding the treatment provided. CONCLUSION: Of the 11 general dental practices that participated in this study, there was a higher chance of patients with a high risk for caries to receive preventive instructions, and professionally applied topical fluoride and sealants in the majority of practices promoting a personalized treatment approach to patients with caries. CLINICAL SIGNIFICANCE: A more personalized treatment approach for patients with caries was associated with a higher prevalence of high caries risk patients in the majority of practices. More studies, however, are needed to investigate whether general dental practitioners consider the assessment of individual patient risk factors in planning personalized treatment strategies.

Color restoration and stability in two treatments for white spot lesions.

This study evaluated the effectiveness of resin infiltration or enamel microabrasion for restoring color changes caused by incipient carious lesions as well as the color stability achieved by these treatments. Enamel specimens were subjected to cariogenic challenge to produce white spot lesions (WSLs) using a microcosm biofilm model. These lesions were treated with resin infiltration or enamel microabrasion (n = 8), and color changes were measured with a spectrophotometer at baseline and after the treatments. Untreated specimens were used as a control. The treated specimens were then immersed in coffee for 1 week, and tooth color was measured again. Data for ΔL*, Δa*, Δb*, and ΔE were analyzed by two-way repeated measures ANOVA and Tukey's test (α = 0.05). Caries induction resulted in significant color changes, mainly decreased lightness. Neither resin infiltration nor enamel microabrasion were able to restore tooth color. The specimens subjected to resin infiltration and the control specimens were more susceptible to color changes following immersion in coffee. In conclusion, enamel microabrasion and resin infiltration were unable to restore the initial tooth color observed prior to WSL induction. Moreover, resin-infiltrated enamel seems more susceptible to staining solutions than enamel subjected to microabrasion.

The role of human milk and sucrose on cariogenicity of microcosm biofilms.

This study investigated the effect of human milk, alone and associated with sucrose, in the cariogenicity of biofilms in a microcosm biofilm model and compared with the cariogenicity of sucrose and bovine milk. Microcosm biofilms were grown in enamel discs in 24-well plates. Six growth conditions were studied: DMM (chemically defined artificial saliva - negative control), DMM with 1% of sucrose (DMM+s) (positive control), human milk with DMM, human milk with DMM+s, bovine milk with DMM, and bovine milk with DMM+s. After 5 days, the outcome variables surface hardness change (%SHC), microbiological composition of biofilms, and pH of supernatant were analyzed. All groups had significantly lower hardness loss compared to the DMM group with 1% of sucrose. Human and bovine milk associated with sucrose showed higher hardness loss. The supernatant pH values after 6 hours of different treatments were similar for the groups sucrose and human milk associated with sucrose (p>0.05). After 18 hours at rest in pure DMM, an increase in the pH of the supernatant was observed. Higher values of total microorganisms count were found for sucrose and bovine milk groups compared to the group supplemented only by DMM. Bovine milk group showed greater amount of total aciduric microorganisms in comparison to human milk group. Within the limits of this study, it can be infered that both human and cow milks have some cariogenic potential, although differing from sucrose in terms of mineral loss.

Validation of assessment of intraoral digital photography for evaluation of dental restorations in clinical research.

OBJECTIVES: The aim of this study was to investigate the validity of assessment of intraoral digital photography in the evaluation of dental restorations. METHODS: Intraoral photographs of anterior and posterior restorations were classified based on FDI criteria according to the need for intervention: no intervention, repair and replacement. Evaluations were performed by an experienced expert in restorative dentistry (gold standard evaluator) and 3 trained dentists (consensus). The clinical inspection was the reference standard method. The prevalence of failures was explored. Cohen's kappa statistic was used. Validity was accessed by sensitivity, specificity, likelihood ratio and predictives values. RESULTS: Higher prevalence of failed restorations intervention was identified by the intraoral photography (17.7%) in comparison to the clinical evaluation (14.1%). Moderate agreement in the diagnosis of total failures was shown between the methods for the gold standard evaluator (kappa = 0.51) and consensus of evaluators (kappa = 0.53). Gold standard evaluator and consensus showed substantial and moderate agreement for posterior restorations (kappa = 0.61; 0.59), and fair and moderate agreement for anterior restorations (kappa = 0.36; 0.43), respectively. The accuracy was 84.8% in the assessment by intraoral photographs. Sensitivity and specificity values of 87.5% and 89.3% were found. CONCLUSIONS: Under the limits of this study, the assessment of digital photography performed by intraoral camera is an indirect diagnostic method valid for the evaluation of dental restorations, mainly in posterior teeth. This method should be employed taking into account the higher detection of defects provided by the images, which are not always clinically relevant.

Effect of selective carious tissue removal on biomechanical behavior of class II bulk-fill dental composite restorations.

OBJECTIVES: This study aimed to develop a method to induce carious lesions in the pulpal floor dentin of a class II cavity preparation, and to determine the effects of this carious lesion on the biomechanical behavior of the dental composite restoration. METHODS: The pulpal floor dentin of class I cavities in sound third molars were demineralised with acetic acid for 35days followed by a 7-day exposure to pooled human saliva biofilm and demineralization was verified by micro-CT. Subsequently, the proximal walls were removed forming a class II cavity and the caries lesion was left intact or was completely removed prior to restoration with a bulk-fill dental composite (n=10). Cuspal deflection was assessed by strain-gauge and micro-CT imaging. The presence of enamel cracks was assessed by transillumination before and after restoration, and again after 1,200,000 cycles of mechanical fatigue in a chewing simulator. Finally, resistance to fracture by axial compressive loading and failure mode was determined. Data were analyzed by 2-way repeated measures ANOVA, Fisher's exact test, and t-test (α=0.05). RESULTS: The presence of carious lesions had no significant effect upon cuspal deflection, formation of enamel cracks, and fracture strength of the dental composite restorations. The restorative procedure increased the number of enamel cracks, which was not affected by mechanical cycling. SIGNIFICANCE: Maintaining carious lesions does not affect the biomechanical behavior of class II restorations performed with bulk-fill dental composite.

Decision-making of general practitioners on interventions at restorations based on bitewing radiographs.

OBJECTIVE: The aim of this study was to compare decision-making based on bitewing analysis of restored proximal surfaces by general dental practitioners (GDPs) with diagnossis and clinical decisions made by experts in cariology and restorative dentistry. METHODS: This practice-based study used a database of 7 general dental practices. Posterior bitewing radiographs were selected from the electronic patient files of patients, and 770 cases of proximal restored surfaces were selected. Fifty percent of the cases which lead to the restorative decision, and the other half were cases decided for monitoring by the GDPs. Three experts performed radiographic assessment. The outcome variables were agreement of diagnosis and decision of treatment. Cohen's kappa statistic was used. RESULTS: For the experts, moderate to substantial intraexaminer agreement was observed for the diagnostic criteria, and kappa values of 0.77, 0.79, and 0.88 were obtained for each expert regarding the treatment assignment. Agreement between GDPs and the majority of experts for secondary caries varied between 67 and 83%. One hundred seventy-three out of 385 cases that were treated by GDPs were decided for monitoring by the experts, while 8 cases that were decided for monitoring by the GDPs were decided for treatment. The agreement between experts and GDPs was moderate for secondary caries detection, and fair for treatment decision. CONCLUSION: The GDPs tend to have a less conservative approach regarding the decision to intervene or not concerning the reassessment of restorations, showing moderate agreement with the experts for secondary caries detection and fair agreement regarding the treatment decision. CLINICAL SIGNIFICANCE: This study highlights that GDPs tend to have a less conservative approach to the decision to intervene or not in posterior restorations, compared to experts in cariology and restorative dentistry. Efforts should be made to reduce these differences based on minimally invasive dentistry.

Clinical relevance of studies on the visual and radiographic methods for detecting secondary caries lesions - A systematic review.

OBJECTIVE: Accuracy studies should associate the diagnostic criteria and outcomes collected to the treatment decision for patients to be considered clinically relevant. This systematic review performed a critical evaluation of the clinical relevance of accuracy studies on the visual and radiographic methods for secondary caries detection, and other aspects. SOURCE: The search was conducted in PubMed, SCOPUS and ISI Web of knowledge databases. STUDY SELECTION: Accuracy studies assessing clinical and/or radiographic method for evaluation of secondary caries were included. The systematization of the diagnostic criteria, lesion activity assessment and differential diagnosis of secondary caries from factors that can lead to misinterpretations were assessed. Clinical relevance was evaluated by the report of aspects related to: link to treatment decision, evaluation of patient-centered outcomes, establishment of thresholds for non-operative and operative treatment, lesion activity assessment, and reference method. Risk of bias was also assessed. A descriptive analysis was performed. DATA: Following eligibility criteria, 19 articles of the 3089 searched were reviewed. Different diagnostic criteria were reported, mainly for the visual inspection. The use of a standardized diagnostic system, lesion activity assessment and differential diagnosis were described by a limited number of studies. Approximately half of the studies reported association of diagnosis and treatment. Enamel lesions were evaluated radiographically in 28.6% of studies, and visually in 69.2%. Visual diagnosis was more relevant in relation to the operative treatment decision. Patient-centered outcomes were not investigated. CONCLUSION: The majority of studies fails to present clinical relevance and report of patient-centered outcomes.

Influence of caries activity and number of saliva donors: mineral and microbiological responses in a microcosm biofilm model

Abstract Objective this study evaluated the mineral and microbiological response of biofilms originating from different types of saliva inoculum with distinct levels of caries activity. Methodology the biofilms grown over enamel specimens originated from saliva collected from a single donor or five donors with two distinct levels of caries activity (caries-active and caries-free) or from pooling saliva from ten donors (five caries-active and five caries-free). The percentage surface hardness change (%SHC) and microbiological counts served as outcome variables. Results the caries activity of donors did not affect the %SHC values. Inoculum from five donors compared to a single donor showed higher %SHC values (p=0.019). Higher lactobacilli counts were observed when saliva from caries-active donors was used as the inoculum (p=0.017). Pooled saliva from both caries activity levels showed higher mutans streptococci counts (p<0.017). Conclusion Overall, pooled saliva increased the mineral response of the derived biofilms, but all the inoculum conditions formed cariogenic biofilms and caries lesions independently of caries activity.

The role of human milk and sucrose on cariogenicity of microcosm biofilms

Abstract This study investigated the effect of human milk, alone and associated with sucrose, in the cariogenicity of biofilms in a microcosm biofilm model and compared with the cariogenicity of sucrose and bovine milk. Microcosm biofilms were grown in enamel discs in 24-well plates. Six growth conditions were studied: DMM (chemically defined artificial saliva - negative control), DMM with 1% of sucrose (DMM+s) (positive control), human milk with DMM, human milk with DMM+s, bovine milk with DMM, and bovine milk with DMM+s. After 5 days, the outcome variables surface hardness change (%SHC), microbiological composition of biofilms, and pH of supernatant were analyzed. All groups had significantly lower hardness loss compared to the DMM group with 1% of sucrose. Human and bovine milk associated with sucrose showed higher hardness loss. The supernatant pH values after 6 hours of different treatments were similar for the groups sucrose and human milk associated with sucrose (p>0.05). After 18 hours at rest in pure DMM, an increase in the pH of the supernatant was observed. Higher values of total microorganisms count were found for sucrose and bovine milk groups compared to the group supplemented only by DMM. Bovine milk group showed greater amount of total aciduric microorganisms in comparison to human milk group. Within the limits of this study, it can be infered that both human and cow milks have some cariogenic potential, although differing from sucrose in terms of mineral loss.

Desenvolvimento de lesões de cárie em dentina em um modelo de biofilme simplificado in vitro: um estudo piloto / Development of dentin caries lesions in an in vitro simplified biofilm model: a pilot study

Introdução: Modelos laboratoriais de biofilmes vêm sendo desenvolvidos com a finalidade de simular o ambiente bucal e o processo de formação da cárie dental. Objetivo: Estabelecer e padronizar um modelo de biofilme in vitro para o desenvolvimento de lesões de cárie em dentina. Material e método: Doze discos padronizados de dentina bovina foram divididos em três tempos experimentais: 4, 7 e 10 dias. As amostras de cada tempo experimental foram inoculadas com Streptococcus mutans UA 159 em meio de cultura BHI com 1% de sacarose e cultivadas em anaerobiose. As variáveis de resposta foram a perda de dureza integrada (ΔS) dos discos de dentina e dureza do substrato em diferentes profundidades. Os dados de ΔS foram analisados através de ANOVA seguido do teste Tukey, ambos com significância de 5%, e os dados de dureza de profundidade de lesão analisados descritivamente. Resultado: Houve maior perda mineral aos 10 dias de crescimento microbiológico quando comparados aos 4 dias (p = 0,034), no entanto não houve diferença entre 7 e 10 dias (p = 0,853). O grupo de 4 dias mostrou perda de dureza em regiões mais superficiais (10-40µm); e o grupo de 10 dias mostrou desmineralização em áreas mais profundas, até 150 µm. Conclusão: O modelo proposto mostrou-se capaz de desenvolver lesões de cárie artificiais em dentina. Em 7 dias, as lesões subsuperficiais de dentina foram adequadas para estudos de des-remineralização.

Introduction: Oral laboratory biofilm models have been developed to reproduce the oral environment and the process of caries lesion formation in vitro. Objective: To establish and standardize an in vitro biofilm model for the development of caries lesions in dentin. Material and method: Twelve standardized bovine dentin discs were assigned into three experimental times: 4, 7, and 10 days. Samples of each experimental period were inoculated with Streptococcus mutans UA 159 in a BHI culture medium with 1% sucrose, and cultured under anaerobic conditions. The integrated hardness loss (ΔS) of dentin discs and the hardness of the substrate at different depths were considered as response variables. The ΔS data were analysed by ANOVA followed by Tukey's test, both with significance level of 5%, and the data of hardness at different depths were analysed descriptively. Result: There was a higher hardness loss after 10 days of microbial growth when compared to 4 days (p = 0.034), however, there was no difference between 7 and 10 days (p = 0.853). The 4-day group showed loss of hardness of the surface layers (10-40μm) and the 10-day group showed demineralization in the deeper area around 150µm. Conclusion: The proposed model was able to develop artificial caries lesions in dentin. In 7 days, the dentin sub superficial lesions were suitable to des-remineralisation studies.

Reabilitação restauradora em dentes anteriores que sofreram trauma: relato de caso / Restorative rehabilitation in traumatized anterior tooth: case report

Os dentes anterossuperiores são os mais comumente acometidos em casos de fraturas coronárias. Além dos traumatismos dentários acidentais, vários fatores predispõem tais fraturas, como a presença de sobremordida, dentes fragilizados por amplas restaurações, lesões de cárie extensa, além de dentes tratados endodonticamente. Em fraturas sem comprometimento pulpar, sempre que possível, realiza-se a colagem do fragmento, porém, quando ele não estiver presente, a segunda opção é a restauração com resinas compostas de uso direto, que permitem resultados estéticos satisfatórios. O objetivo deste trabalho é descrever um caso clínico de fratura coronária, no qual se optou pela restauração com resina composta do remanescente fraturado.

The anterior teeth are most commonly affected in cases of coronal fractures. In addition to the accident itself, several factors can contribute to this type of fracture such as: the presence of overbite, large restorations, large carious lesions and endodontic treatment. In fractures without pulpal compromising, tooth fragment reattachment is preferable whenever is possible. However, when the fragment is not available, the second option is direct restorations using composite resins, allowing satisfactory esthetic results. The aim of this work is to describe a clinical case of coronal fracture, where was chosen a restoration using composite resin.