In situ effects of restorative materials on dental biofilm and enamel demineralisation.
OBJECTIVE
Since secondary caries is one of the main reasons for replacing restorations, this study assessed the effects of different restorative materials on the microbiological composition of dental biofilm and on enamel demineralisation around the restoration.


METHODS
A randomized, double-blind, split-mouth in situ design was conducted in one phase of 14 days, during which, 20 volunteers wore palatal devices containing five human dental enamel slabs. Each slab was randomly restored with one of the following materials: Filtek-Z-250/Single Bond, control group (composite resin), Permite (amalgam), Fuji II (encapsulated resin-modified glass ionomer), Vitremer (resin-modified glass ionomer) and Ketac Molar (conventional glass ionomer). The volunteers used fluoride dentifrice, 3x/day and a 20% sucrose solution was dripped onto the slabs 8x/day. The biofilm formed on the slabs was analyzed to determine the counts of total streptococci, mutans streptococci and lactobacilli. Enamel demineralisation was determined by cross-sectional microhardness (CSMH) at 20 and 70 microm from the margin of the restoration. Kruskal-Wallis and analysis of variance, followed by least mean squares (LMS) test, were used to evaluate microbiota and CSMH among the groups. The significance level used was 5%.


RESULTS
No statistically significant differences were found in the cariogenic microbiota grown on the slabs. At a 20-mum distance, only Fuji II statistically differed from the other groups, showing the lowest demineralisation. At 70 microm, Fuji II significantly inhibited demineralisation when compared to Permite, Filtek-Z-250 and Ketac Molar.


CONCLUSIONS
In the context of fluoride dentifrice and under the cariogenic exposure conditions of this study, only the encapsulated resin-modified glass ionomer material provided additional protection against secondary caries.
Sousa
R P
RP
Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, CE, Brazil.
Zanin
I C J
IC
Lima
J P M
JP
Vasconcelos
S M L C
SM
Melo
M A S
MA
Beltrão
H C P
HC
Rodrigues
L K A
LK
D000328:Adult; D018441:Biofilms / Q000187:drug effects*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000494:pharmacology; D002326:Cariogenic Agents / Q000009:adverse effects; D002327:Cariostatic Agents / Q000627:therapeutic use; D003188:Composite Resins / Q000494:pharmacology; D003723:Dental Amalgam / Q000494:pharmacology; D003743:Dental Enamel / Q000187:drug effects* / Q000382:microbiology; D003764:Dental Materials / Q000494:pharmacology*; D003793:Dental Restoration, Permanent / Q000379:methods*; D003802:Dentifrices / Q000627:therapeutic use; D017220:Dentin-Bonding Agents / Q000494:pharmacology; D004311:Double-Blind Method; D005260:Female; D005459:Fluorides / Q000627:therapeutic use; D005500:Follow-Up Studies; D005899:Glass Ionomer Cements / Q000494:pharmacology; D006244:Hardness; D006801:Humans; D007778:Lactobacillus / Q000187:drug effects; D008297:Male; D013291:Streptococcus / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects; D013395:Sucrose / Q000009:adverse effects; D017001:Tooth Demineralization / Q000382:microbiology / Q000517:prevention & control*; D055815:Young Adult
D002326:Cariogenic Agents; D002327:Cariostatic Agents; D003188:Composite Resins; D003764:Dental Materials; D003802:Dentifrices; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D005899:Glass Ionomer Cements; C084550:Vitremer; C110712:ketac-molar; C115612:single bond; C084541:Fuji glass-ionomer lining cement; D017438:Bisphenol A-Glycidyl Methacrylate; D013395:Sucrose; D003723:Dental Amalgam; C092423:Permite C; D005459:Fluorides