Laura Guimarães Primo

Microhardness of dentine underlying ART restorations in primary molars: an in vivo pilot study

Objective To evaluate the microhardness of dentine underlying glass ionomer restorations made with Atraumatic Restorative Treatment.Design An experimental single-centre study.Setting University Department, Brazil, 2001.Materials and Methods Sixteen children were selected showing primary molars containing carious cavities (n=29), which were restored using Fugi IX. Subsequently, some teeth were extracted respecting Nolla stage 7 or 8 of the permanent successor, and categorised according to the post-restoration time in the mouth: G1 (baseline, immediate extraction), G2 (30 days), G3 (90 days) and G4 (180 days). Four teeth were excluded because they were not in time of normal exfoliation. The 25 extracted teeth were resin embedded, sectioned mesiodistally and prepared metallographically. Knoop microhardness analysis (Micromet 2003; 10g for 1.5 sec.) produced identations in three areas of dentine: Zone 1 (just below the restoration), Zone 3 (as close as possible to the pulp) and Zone 2 (intermediate region between 1 and 3). Non-parametric statistical tests were done — at a significance level of 5%.Results Four teeth were excluded. No significant difference was noted among the zones, inside the groups. Zones 1 and 2 showed a considerable increase of microhardness according to the time, except for Group 3 (p>0.05).Conclusion Although microhardness had increased, it was not sufficiently equal to the microhardness of the healthy dentine, regardless of the depth evaluated.

Histopathologic and SEM analysis of primary teeth with pulpectomy failure

OBJECTIVE The objective of this study was to identify the probable factors associated with pulpectomy failure of primary teeth through qualitative analysis by histopathology (HIST) and scanning electron microscopy (SEM). STUDY DESIGN A longitudinal clinical investigation of the efficacy of pulpectomy in primary teeth with irreversible pulp changes was carried out with 133 teeth (66 children) evaluated up to 48 months. The overall success was 86.1% during follow-up. Of the 18 teeth extracted as a result of treatment failure, 8 presented sufficiently undamaged roots to be randomly selected for HIST (n = 4) and SEM (n = 4) analysis. RESULTS Necrotic tissue and chronic inflammatory cells were observed in all specimens submitted to HIST as external radicular resorption associated with Howships lacunae. SEM analysis showed apical and furcation areas heavily infected with microorganisms and Howships lacunae. CONCLUSION These findings suggest that the main factors responsible for pulpectomy failure were technique limitations associated with the morphological irregularities created by external/inflammatory resorption.

Effect of the sodium hypochlorite and citric acid association on smear layer removal of primary molars

This study aimed to assess the capacity of a sodium hypochlorite and citric acid (CA) association (the latter at different concentrations) in removing coronal smear layer (SL) of primary teeth. For this purpose, the pulp chamber roof and floor of 28 primary molars were removed to obtain enamel and dentine disks. SL was produced on the internal walls of the disks using high-speed drills. The disks were irrigated with 1% sodium hypochlorite and citric acid at different concentrations (CA-4%, CA-6%, CA-8% and CA-10%), and with 0.9% sodium chloride. The samples were split and observed under SEM. Scores were attributed to the obtained photomicrographs, according to the amount of SL present. It was noted that all the tested concentrations of citric acid used after the sodium hypochlorite were capable of removing SL. The results were analyzed by the Kruskal-Wallis test, and there was no significant statistical difference among the scores of the groups tested. However, it was observed that CA-8% and CA-10% caused peritubular dentine destruction, and that CA-4% presented a larger number of samples with dense SL. Based on these results, 6.0% citric acid in association with 1% sodium hypochlorite is suggested as auxiliary chemical substances for primary teeth irrigation.

FREQUENCY AND CHARACTERISTICS OF SUPERNUMERARY TEETH IN BRAZILIAN CHILDREN: CONSEQUENCES AND PROPOSED TREATMENTS

The study had the objective of identifying the frequency of supernumerary teeth on patients attended at the Pediatric Dentistry Clinic at the School of Dentistry of the Universidade Federal do Rio de Janeiro (FO-UFRJ), from 1981 to 1990, relating the frequency to the sex and dentition of the patients. Some characteristics relating to and consequential upon the pathology, as well as the proposed treatments, are also part of this work. To achieve the proposed objectives, 1,907 files of patients with full mouth radiographs were examined. Children who had disturbances such as cleft lip or palate, cleidocranial dysostosis or Gardners Syndrome were excluded from the study. The age of the patients who comprised the sample varied from 2 to 14

The influence of smear layer removal on primary tooth pulpectomy outcome: a 24-month, double-blind, randomized, and controlled clinical trial evaluation

BACKGROUND The effect of smear layer (SL) removal on primary tooth pulpectomy outcome has not been well elucidated. AIM To determine the effect of SL removal on primary tooth pulpectomy outcome. METHODS This is a double-blind, randomized, and controlled clinical trial. Forty-eight patients were randomly divided into SL removal (G1 = 40 teeth) or smear layer nonremoval (G2 = 42 teeth) groups. Following the chemomechanical preparation with K-files and 2.5% sodium hypochlorite (NaOCl), teeth were irrigated with either 6% citric acid and 0.9% physiologic solution (G1) or only 0.9% physiologic solution (G2). Camphorated paramonochlorophenol was used as intracanal medication. At the second appointment, 1 week after, root canals were filled with zinc oxide-eugenol paste. Clinical and radiographical baseline criteria were stipulated equally for both groups. RESULTS The success rate (G1 = 91.2%; G2 = 70.0%) was statistically different (P = 0.04) between the groups. In G2, the outcome was affected significantly by pulpal necrosis (P = 0.02), pre-operatory symptoms (P = 0.02), and periapical/inter-radicular radiolucency (P = 0.04). CONCLUSION The pulpectomy outcome was improved by smear layer removal. The outcome for teeth with pulpal necrosis, pre-operatory symptoms, or periapical/inter-radicular radiolucency was significantly improved by removal of the smear layer.

Effects of citric acid on cultured human osteoblastic cells

We investigated the effects of citric acid (CA) on cultured human osteoblastic (HOB) cells by evaluating cell adhesion, proliferation, and cytotoxicity. (3)H-Thymidine-labeled HOB cells were incubated in culture medium supplemented or not with 4%, 6%, 8%, or 10% CA for 1 minute. After incubation, cell morphology was evaluated by Nomarski interferential light microscopy, cell proliferation was accessed by measurements of (3)H-thymidine associated to the cells, and cell lysis was monitored by measuring the amount of (3)H-thymidine released by cells. We observed that most of the CA-treated cells presented numerous atypical vacuoles, and such cells were also highly polymorphic, exhibiting round-shaped cells. Nonetheless, CA at all concentrations assayed did not yield cytotoxicity as measured by (3)H-containing DNA release, although significant decrease in cell proliferation was observed (P > .05). Furthermore, cells which were treated with CA at the lowest concentration assayed (4%) restored normal proliferation rates 3 days after treatment.

Lower dental caries prevalence associated to chronic kidney disease: a systematic review.

BackgroundThe aim of this systematic review was to determine whether there is any evidence in the literature referring to a lower prevalence of dental caries in children and adolescents with chronic kidney disease (CKD) compared to healthy individuals.MethodsA search of the PubMed Medline, Ovid Medline and Cochrane Library databases was performed using the MeSH terms “dental caries” and “chronic renal failure”. To be eligible for entry in our study, controlled observational studies had to present a decayed, missing and filled index for primary teeth (dmft) and/or for permanent teeth (DMFT) in children and adolescents with CKD.ResultsAfter evaluation of title, keywords and abstracts of the articles selected, six articles met the inclusion criteria. Three of these six articles included studies which showed susceptibility to bias and possible confounding factors. A subsequent assessment of the six studies revealed that the mean caries indices in both primary (dmf) and permanent (DMF) teeth were lower in the children and adolescents with CKD compared with healthy individuals.ConclusionData in the literature weakly support a lower prevalence of caries in children and adolescents with CKD than in their healthy counterparts. There is still a lack of well-designed studies that provide better scientific evidence in support of this conclusion.

Dental calculus formation in children and adolescents undergoing hemodialysis

BackgroundThis study aimed to determine whether dental calculus formation is really higher among patients with chronic kidney disease undergoing hemodialysis than among controls. Furthermore, the study evaluated correlations between dental calculus formation and dental plaque, variables that are related to renal disease and/or saliva composition.MethodsThe Renal Group was composed of 30 patients undergoing hemodialysis, whereas the Healthy Group had 30 clinically healthy patients. Stimulated whole saliva and parotid saliva were collected. Salivary flow rate and calcium and phosphate concentrations were determined. In the Renal Group the saliva collection was carried out before and after a hemodialysis session. Patients from both groups received intraoral exams, oral hygiene instructions, and dental scaling. Three months later, the dental calculus was measured by the Volpe–Manhold method to determine the rate of dental calculus formation.ResultsThe Renal Group presented a higher rate of dental calculus formation (p < 0.01). Correlation was observed between rate of dental calculus formation and whole saliva flow rate in the Renal Group after a hemodialysis session (r = 0.44, p < 0.05). The presence of dental calculus was associated with phosphate concentration in whole saliva from the Renal Group (p < 0.05).ConclusionIn conclusion, patients undergoing hemodialysis presented accelerated dental calculus formation, probably due to salivary variables.

Bruxism Control in a Child with Cerebral Palsy

Cerebral palsy (CP) is one of the most severe childhood disabilities due to a lesion in the developing brain. Oral conditions often observed in this pathogenic are a tendency for the delayed eruption of permanent molars, higher percentages of malocclusion and parafunctional habits, including bruxism. The significance of oral conditions observed in CP patients demonstrates the need for intensive home and professional care for these individuals. This paper presents a 7-year-old boy, with cerebral palsy, severe mental retardation, who had high abrasion wear of the primary teeth related to bruxism. Dental care was carried out under oxide-induced sedation, and management of the bruxism was achieved after the use of a resin acrylic protective appliance fixed on both sides of the mandibula. The treatment performed offered efficiency advantages, was clinically viable, and should be a valuable option to practitioners considering appliance therapy to control parafunctional behavior.

Role of saliva in the caries experience and calculus formation of young patients undergoing hemodialysis

ObjectivesThe aims of this study were to investigate the caries experience, periodontal status, oral hygiene habits, and salivary parameters of children and adolescents undergoing hemodialysis (HD) and to compare them with their healthy counterparts.MethodsFifty-two HD patients were matched for age, sex, ethnicity, and social class with 52 healthy subjects for analysis of the number of decayed, missing and filled teeth, plaque and gingival index, dental calculus accumulation, measurements of pocket depth, clinical attachment level, gingival recession, and bleeding on probing. Stimulated saliva samples were collected to assess salivary flow rate, pH and buffer capacity, and salivary concentrations of calcium, phosphate, and urea by colorimetric method.ResultsHD patients had lower dental caries (p = 0.004), greater plaque and calculus accumulation (p = 0.001), and reported flossing less often than the controls (p = 0.013). Regarding salivary analysis, HD patients showed significantly higher values of pH, buffer capacity, and salivary urea concentration when compared to the controls (p = 0.001).ConclusionHD patients had lower caries experience, higher accumulation of dental plaque, and calculus deposition than their healthy counterparts, probably due to the differences found in their salivary biochemical parameters.Clinical significanceA significant number of children and adolescents undergoing hemodialysis are candidates for kidney transplantation and should receive complete pre-transplant dental exams and dental treatment. Our results open the way for the development of an individualized dental protocol for these patients with preventive measures and treatment of the poor oral health in HD patients.