Epidemiological investigation of non-carious cervical lesions and possible etiological factors.

BACKGROUND: Epidemiological studies of non-carious cervical lesions (NCCLs) are being conducted in all geographical regions, which is completely justified, considering the high frequency of these lesions and possible consequences. Data obtained from such studies are of great importance because, beside describing the extent and degree of lesions, they can also point to specific etiological factors. The purpose of this study was to analyze the frequency and distribution of NCCLs among the patients of Faculty of Dentistry in Pancevo, Serbia, and to investigate the impact of certain etiological factors on the frequency of NCCLs. MATERIAL AND METHODS: The study included 394 patients, who were clinically examined for the presence of NCCLs and interviewed about potential etiological factors using specially designed questionnaire. Saliva samples were analyzed for 30 patients with multiple NCCLs (≥3) and 30 patients without signs of cervical lesions and restorations. Subject - level logistic regression was used to analyze the association of potential etiological factors and presence of NCCLs and Wilcoxon test for the quantity and quality of saliva. RESULTS: NCCLs were diagnosed at 68.5% from total number of respondents, 15% from all present teeth were affected. The highest prevalence was recorded on premolars. Presence of lesions significantly increased with age. Frequent consumption of citrus fruit was associated with the presence of NCCLs. Significantly lower frequency of NCCLs was recorded among subjects who frequently chew gums. Significantly lower pH values of unstimulated and stimulated saliva were recorded in the group of patients with multiple NCCLs compared to control group. CONCLUSIONS: This study showed high frequency of NCCLs among subjects of different age. Premolars were the most frequently affected. Age, frequent consumption of citrus fruit and lower salivary pH value were associated with an increased occurrence of NCCLs. Chewing gums habit was associated with an decreased occurrence of NCCLs. Key words:NCCL, abrasion, erosion, abfraction, saliva.

Environmental lead pollution and its possible influence on tooth loss and hard dental tissue lesions.

BACKGROUND/AIM: Environmental lead (Pb) pollution is a global problem. Hard dental tissue is capable of accumulating lead and other hard metals from the environment. The aim of this study was to investigate any correlation between the concentration of lead in teeth extracted from inhabitants of Pancevo and Belgrade, Serbia, belonging to different age groups and occurrence of tooth loss, caries and non-carious lesions. METHODS: A total of 160 volunteers were chosen consecutively from Pancevo (the experimental group) and Belgrade (the control group) and divided into 5 age subgroups of 32 subjects each. Clinical examination consisted of caries and hard dental tissue diagnostics. The Decayed Missing Filled Teeth (DMFT) Index and Significant Caries Index were calculated. Extracted teeth were freed of any organic residue by UV digestion and subjected to voltammetric analysis for the content of lead. RESULTS: The average DMFT scores in Pancevo (20.41) were higher than in Belgrade (16.52); in the patients aged 31-40 and 41-50 years the difference was significant (p < 0.05) and highly significant in the patients aged 51-60 (23.69 vs 18.5, p < 0.01). Non-carious lesions were diagnosed in 71 (44%) patients from Pancevo and 39 (24%) patients from Belgrade. The concentrations of Pb in extracted teeth in all the groups from Pancevo were statistically significantly (p < 0.05) higher than in all the groups from Belgrade. In the patients from Pancevo correlations between Pb concentration in extracted teeth and the number of extracted teeth, the number of carious lesions and the number of non-carious lesions showed a statistical significance (p < 0.001, p < 0.01 andp < 0.001, respectively). CONCLUSION: According to correlations between lead concentration and the number of extracted teeth, number of carious lesions and non-carious lesions found in the patients living in Pancevo, one possible cause of tooth loss and hard dental tissue damage could be a long-term environmental exposure to lead.

[Influence of different bonding agents on marginal sealing quality of amalgam restorations].

INTRODUCTION: Although advanced adhesive systems are in use, marginal microleakage is one of the greatest problems of contemporary restorative dentistry. OBJECTIVE: The aim of this in vitro study was to evaluate the influence of different bonding agents on the marginal sealing quality of class II amalgam restorations. METHODS: Forty freshly extracted human premolar and molar teeth were divided into four groups with 10 teeth in each one. Class II preparations were prepared and different adhesives were applied as follows: group I--Amalgam Liner (Voco); group II--ONE-STEP PLUS (Bisco); group III--PQ 1 (Ultradent). Group IV was used as a control, without any bonding agent. Amalgam (Cavex Non Gamma 2, Cavex) was hand-condensed into each preparation. Specimens were thermocycled 200 times at the following temperatures: 5-7 degrees C, 37 degrees C and 57-59 degrees C, and were then immersed into 1% solution of gentian violet for 72 hours. The teeth were sectioned longitudinally and microleakage was graded in the area of the gingival and occlusal quantity rim using a binocular magnifying glass with 25 times magnification. RESULTS: The highest microleakage was recorded in the Amalgam Liner group; 1526.0 microm at the gingival wall and 694.5 microm at the occlusal cavity wall. The lowest dye penetration was observed in the PQ1 group; 589.5 microm at the gingival wall, and 599.9 microm at the occlusal wall of the restoration. ANOVA test showed that there was a statistically significant difference of dye penetration values at the gingival wall among all examination groups (p < 0.01). No statistically significant differences were found comparing microleakage values at the occlusal wall. CONCLUSION: Results of this study showed that the best marginal sealing was accomplished by using the PQ1 bonding agent.

[Comparative evaluation of sealing ability of different obturation materials].

INTRODUCTION: Root canal filling materials are intended to prevent microleakage and passing of microorganisms and their toxins along the root canal space and into the periradicular tissues. OBJECTIVE: Objective of this in vitro study was to evaluate and compare apical leakage of root canals obturated using a modified warm vertical condensation technique and different materials. METHODS: Sixty-five extracted single-root teeth were prepared according to the crown-down/ step-back technique. Each canal was rinsed with 3% NaOCl during and after the preparation. The teeth were divided into 3 groups. Every group was obturated by the same technique, but with different materials: RealSeal system (SybronEndo), gutta-percha with AH Plus (Dentsply Maillefer) and gutta-percha with Acroseal sealer (Septodont). The remaining 20 teeth were in the control group. The teeth were immersed in 1% methylene blue for 72 hours. After that period, the roots were split longitudinally, and dye penetration was measured using a stereomicroscope. RESULTS: Dye penetration occurred in all groups. The least dye penetration occurred in the RealSeal group (0.33 +/- 0.29 mm), while the highest dye penetration occurred in the Acroseal group (1.11 +/- 0.52 mm). According to the Student's t-test, Acroseal showed significantly more leakage (p < 0.001) than RealSeal and AH Plus materials. The microleakage of RealSeal system was not significantly different (p > 0.05) from that of AH Plus sealer with gutta-percha. CONCLUSION: The results suggested that new material Resilon (RealSeal) and conventional combination AH Plus with guttapercha had the least apical dye penetration and provided the best sealing.