Influence of microleakage, surface roughness and biofilm control on secondary caries formation around composite resin restorations: an in situ evaluation

Abstract

This study was carried out to evaluate in situ the influence of microleakage, surface roughness and biofilm control on caries formation around composite resin restorations. During 28 days, 12 volunteers wore palatal devices containing bovine enamel slabs restored with composite resin. Restorations were made without leakage, when the adhesive system was applied, or with leakage, when adhesive system was omitted. Half of the restorations in each group were finished and the remaining were finished and polished. In one side of the palatal device, biofilm was left to accumulate over the restored slabs, and in the other side dental slabs were brushed, to allow biofilm removal. There was an extraoral application of 20% sucrose solution (8x/day) over the enamel slabs. The formation of caries lesions (white spots) was evaluated by visual inspection under stereomicroscopy. Additionally, the dental slabs were sectioned and observed under polarized light microscopy. Data were submitted to Kruskal-Wallis test and Spearman's correlation test at 5% significance level. Polishing and bonding were not significant factors regarding white spot formation (p>0.05). Biofilm control (brushing) was associated with reduction of caries formation close to the restorations (p<0.01). Polarized light microscopy confirmed the visual inspection findings. These results suggest that while microleakage and surface roughness did not influence caries lesion formation, biofilm control may prevent the enamel demineralization.

Development of caries adjacent to composite restorations after exposure to dentifrices with different fluoride concentrations

“…The importance of dentifrices containing fluoride in the reduction of caries is incontrovertible, since the daily use of this product provides a concentration of fluoride sufficient to maintain levels that contribute actively to the processes of reduction of demineralization and activation of remineralization 2 . This is mainly in children that have had experience with caries and who continue to have increased risk of developing this disease 10 .…”

“…One of the materials of choice for restorations in primary teeth is the composite; however, when these restorations are not properly prepared, in terms of polishing and finishing, they become areas susceptible to the accumulation of biofilm 10,16,17 . If the caries in the child have not been controlled, it remains susceptible to the development of new caries near the restoration.…”

“…In patients with previous experience of caries and who have restorations, if the carie is not treated, a lesion adjacent to the restoration, called recurrent caries, could occur 2,10 . This type of lesion presents a problem with high personal and social cost and is one of the main reasons for the replacement of restorations 10 .…”

Influence of fluoride-containing adhesives and bleaching agents on enamel bond strength

“…2,3 Therefore, controlling and/or preventing this condition is a concern that has led to the development of adhesives with anticariogenic potential. 5 However, aside from biofilm formation, the interface of ex- isting restorations may be submitted to bleaching treatments, and it is unknown whether the addition of F -to these agents would affect enamel bonding.…”

“…1 The development of secondary caries is similar to that of primary caries but differs according to the location and characteristics of the surface, such as roughness and marginal defects. 2,3 Conventional three-and two-step etch-and-rinse adhesives can effectively seal the enamel interface. 4 To prevent caries around the interface, fluoride has been added to some of these adhesives, thus allowing these agents to work as "fluoride reservoirs" to avoid mineral loss by inhibiting Declaration of Interests: The authors certify that they have no commercial or associative interest that represents a conflict of interest in connection with the manuscript.…”