The Microfloral Analysis of Secondary Caries Biofilm around Class I and Class II Composite and Amalgam Fillings

<p>Abstract</p> <p>Background</p> <p>Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. The diversity of the bacterial sources and the different types of filling materials could play a role in secondary caries. The aim of this study was to determine and compare the microbial spectrum of secondary caries biofilms around amalgam and composite resin restorations.</p> <p>Methods</p> <p>Clinical samples were collected from freshly extracted teeth diagnosed with clinical secondary caries. Samples were categorized into four groups according to the types of restoration materials and the classification of the cavity. Biofilms were harvested from the tooth-restoration interface using a dental explorer and after dilution were incubated on special agars. The bacteria were identified using the biochemical appraisal system. Statistical calculations were carried out using SPSS11.5 software to analyze the prevalence of the bacteria involved in secondary caries.</p> <p>Results</p> <p>Samples from a total of four groups were collected: two groups were collected from amalgam restorations, each had 21 samples from both Class I and Class II caries; and the other two groups were from composite resin restorations, each had 13 samples from both class I and class II caries. Our results showed: (1) Anaerobic species were dominant in both restoration materials. (2) In terms of the types of individual bacteria, no significant differences were found among the four groups according to the geometric mean of the detected bacteria (P > 0.05). However, there were significant differences among the detected bacteria within each group (P < 0.05). The composition of each bacterium had no statistical difference among the four groups (P > 0.05), but showed significant differences among the detected bacteria in each group (P < 0.05). (3) Among the four groups, there were no significant differences for the detection rate of each bacterium (P > 0.05), however, the detection rate of each bacterium within each group was statistically different among the detected bacteria (P < 0.05).</p> <p>Conclusions</p> <p>The proportion of obligatory anaerobic species was much greater than the facultative anaerobic species in the biofilm of secondary caries. Statistically, the materials of restoration and the location of secondary caries did not show any significant effects on the composition of the microflora.</p

Preferences over dental restorative materials among young patients and dental professionals.

Knowledge of the patient's view is necessary, as patients' rights are an issue of increasing importance in dental practice. This study aimed to examine how dentists (n = 42), dental assistants (n = 65), and young dental patients (n = 306) in Norway and Denmark valued three attributes of dental restorations, namely, expected longevity, the appearance, and the risk of an adverse reaction. According to the discrete choice method, participants were presented with several scenarios, describing different levels of the attributes, for comparison of two restorations (A and B). The differences among patients, dentists, and dental assistants were examined by logistic regression analyses. The likelihood of a dentist favoring one restoration over another was very sensitive to the difference in the expected longevity of the restorations, and much less to differences in visibility. The patients had considerable sensitivity to differences in visibility and much less to differences in duration. Danish teenagers attach less importance to visibility of the restoration and greater importance to the risk of an adverse reaction than Norwegian teenagers. All differences were statistically significant. Preferences associated with properties of dental restorations differ between teenage patients and dental professionals and this should be addressed in clinical decision-making