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

Abstract

BackgroundSecondary 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.MethodsClinical 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.ResultsSamples 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).ConclusionsThe 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.

Is secondary caries with composites a material-based problem?

“…These results might suggest that composites lead to certain changes in the dental biofilm favoring the outgrowth of more cariogenic species. On the other hand, a study by Mo et al [68] showed that neither the type of restorative material nor the location of the SC lesion have a significant effect on the microbiota under the restoration. However, it should be emphasized that in all reviewed studies, the composition of dental biofilms was determined using traditional microbiological techniques consisting of cultivation of microorganisms on different selective and non-selective agar plates and subsequent identification by physiological, biochemical and serological tests.…”

Evaluation of Streptococcus mutans biofilms formed on fluoride releasing and non fluoride releasing resin composites

“…1,2 However, many tooth-coloured restorations have been replaced because of secondary caries, which is responsible for 60% of all restoration replacements in typical dental practice. 3,4 One of the important causative factors in the development of secondary caries is the accumulation of dental biofilms adjacent to the margins of restorations, which causes dissolution of the adjacent tooth surfaces and finally shortens the serving life of the restorations. 5,6 If dental biofilms are allowed to remain on tooth surfaces or margins of restorations with the frequent consumption of a high carbohydrate diet, Streptococcus mutans, as a constituent of the biofilm community, will continue to synthesize extracellular polysaccharides (EPS) and metabolize the sugars to organic acids.…”

Quaternary ammonium silane-functionalized, methacrylate resin composition with antimicrobial activities and self-repair potential

“…Thus, the antimicrobial activities of polymerized resin disks prepared from comonomer blends with bis-GMA:TEGDMA:QAMS-3 PH mass ratios of 70:30:0, 70:10:20 and 70:0:30 were investigated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) or Candida albicans (ATCC 90028). The first two represent cariogenic oral pathogens that are associated with recurrent decay around tooth fillings [44]. Candida albicans , a common commensal fungus in humans, may be converted to an opportunistic pathogen associated with oral candidiasis in susceptible hosts [45].…”