In vitro investigation of the wear of human enamel by dental porcelain.
BACKGROUND
Metal ceramic systems are advocated when both esthetics and strength are required. A major drawback to many porcelains is their wear and destruction of opposing natural dentition.


OBJECTIVE
This study evaluated the wear of enamel opposing 1 traditional and 2 recently introduced low-fusing feldspathic dental porcelains.


METHODS
Six blocks of Ceramco II, Finesse, and Omega 900 feldspathic porcelain materials were fabricated and fired according to manufacturer recommendations. Porcelain blocks were polished through 0.25 microm diamond polishing paste. Thirty-six enamel specimens were obtained and milled to a 2 mm (+0.5 mm) diameter. Enamel specimens were attached to an offset cam motor operating at 60 Hz. Enamel specimens were in constant contact with the stationary porcelain blocks under a load of 600 g and traversed a distance of 8 mm. Diameter and height of enamel specimens were measured at times of 0, 6, 12, 24, and 48 hours and subsequent determination of enamel volume loss recorded. Profilometric surface roughness of the ceramic blocks was also measured for the corresponding times.


RESULTS
Statistical analysis revealed that both Finesse and Omega 900 feldspathic porcelains caused significantly less enamel volume loss when compared with Ceramco II porcelain at all time intervals. Surface roughness revealed no consistent significant differences among porcelains.


CONCLUSIONS
Both Finesse and Omega 900 porcelains were not as destructive to human tooth structure as Ceramco II porcelain. These results suggest an advantage of the new, lower-fusing porcelains in conditions where natural dentition wear is a concern.
Baylor College of Dentistry, Texas A & M University System, Dallas, Texas, USA. metzler@ndak.net
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D000538:Aluminum Silicates / Q000737:chemistry; D000704:Analysis of Variance; D003743:Dental Enamel / Q000473:pathology* / Q000648:ultrastructure; D003775:Dental Polishing; D003776:Dental Porcelain / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D017680:Potassium Compounds / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D019217:Tooth Attrition / Q000209:etiology* / Q000473:pathology
D000538:Aluminum Silicates; C096478:Omega Dental Ceramic; D017680:Potassium Compounds; D003776:Dental Porcelain; C016447:feldspar; C058233:Ceramco