Determination of caries risk at resin composite margins.
OBJECTIVE
To design an artificial mouth in order to evaluate if a new diagnostic tool (Clinpro Cario Diagnosis) can be used for early detection of secondary caries at resin composite margins in vitro.


METHODS
32 intact human third molars received standardized Class-V resin composite restorations (Tetric Ceram bonded with Syntac SC). After storage for 4 weeks at 37 degrees C, teeth were subjected to 5,000 or 10,000 thermocycles (+/- 5 degrees C and +/- 55 degrees C) and polysiloxane impressions were taken. Streptococcus mutans 10449 (SM) was used in a nutrition medium to initiate a secondary caries process. Daily, the teeth were incubated for 2 x 2.5 hours in SM containing nutrition medium followed by 2 x 9.5 hours incubation in artificial saliva. Teeth were investigated after total incubation periods of 4, 6, and 8 weeks. After the different incubation protocols, the restoration margins were evaluated for infection and secondary caries processes in using Clinpro Cario Diagnosis which measures site-specifically the lactic acid production of SM in response to a sucrose challenge. The color signal was read 5 minutes after removal of the diagnostic impression. After thermocycling and biological load cycling, precision polysiloxane impressions were taken and replicas were investigated under a light microscope for gap widths at enamel and dentin margins. Demineralization was evaluated by fluorescence microscopy in using a special FITC filter. The demineralization depths at the cavity margin were calculated with Xpert for Windows using a pixel distance of 5 microm.


RESULTS
After the different thermocycling protocols, no differences in gap widths and demineralization depths were found (P > 0.05). After SM incubation, gap widths and demineralization depths were significantly dependent on SM incubation time and previous number of thermocycles (P < 0.05). Lactic acid formations of SM were detectable by Clinpro Cario Diagnosis at dentin cavosurface margins formed after 6 weeks of incubation with SM (P < 0.05).
Krämer
Norbert
N
Department of Paediatric Dentistry, University of Dresden, Fetcherstrasse 74, D-1307 Dresden, Germany. Norbert.kraemer@uniklinikum-dresden.de
Kunzelmann
Karl-Heinz
KH
García-Godoy
Franklin
F
Häberlein
Ingo
I
Meier
Bettina
B
Frankenberger
Roland
R
D003188:Composite Resins / Q000737:chemistry*; D003731:Dental Caries / Q000382:microbiology / Q000473:pathology; D003733:Dental Caries Susceptibility; D003743:Dental Enamel / Q000648:ultrastructure; D003760:Dental Impression Materials / Q000737:chemistry; D003793:Dental Restoration, Permanent / Q000145:classification; D003804:Dentin / Q000648:ultrastructure; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D006801:Humans; D019344:Lactic Acid / Q000032:analysis; D012008:Recurrence; D019279:Resin Cements / Q000737:chemistry; D018570:Risk Assessment; D012464:Saliva, Artificial / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013295:Streptococcus mutans / Q000302:isolation & purification / Q000378:metabolism; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D017001:Tooth Demineralization / Q000473:pathology
D003188:Composite Resins; D003760:Dental Impression Materials; D005456:Fluorescent Dyes; D019279:Resin Cements; D012464:Saliva, Artificial; D012833:Siloxanes; C078484:Syntac dentine adhesive; C121818:Tetric ceram; D019344:Lactic Acid; D016650:Fluorescein-5-isothiocyanate