Quantitative measurement of tooth and ceramic wear: in vivo study.
OBJECTIVE
The aim of this study was to quantitatively measure tooth and ceramic wear over a 2-year period using a novel superimposition technique. Three ceramic systems--experimental hot-pressed ceramic (EC), Procera AllCeram (PA), and metal-ceramic--were used.


METHODS
A total of 90 posterior crowns in 48 patients were randomized into 3 groups, and impressions were made at baseline and at 6-month intervals for 2 years. Clinical images were taken after using a dye to highlight surface changes. The impressions were digitized and modeled as superimposable 3-dimensional colored surface images. The depth of wear at the occlusal contact areas was quantitatively measured at 6, 12, 18, and 24 months.


RESULTS
The quantitative evaluation showed more wear in Procera AllCeram at the occlusal contact areas, whereas the experimental and metal-ceramic systems showed less wear. There was a significant difference in the amount of enamel worn between all types of restorations (P < .05). There was a statistically significant difference (P < .05) in the mean depth of wear between all systems.


CONCLUSIONS
The metal-ceramic and experimental systems showed less change, indicating improved wear resistance compared with Procera AllCeram. In addition, enamel opposing metal-ceramic and experimental crowns showed less wear compared to enamel opposed by Procera AIICeram crowns.
Etman
Maged K
MK
Division of Prosthodontics, College of Dentistry, University of Saskatchewan, Saskatoon, Canada. maged.etman@usask.ca
Woolford
Mark
M
Dunne
Stephen
S
D000328:Adult; D000537:Aluminum Oxide / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry; D001641:Bicuspid / Q000473:pathology; D003442:Crowns; D003743:Dental Enamel / Q000473:pathology; D003776:Dental Porcelain / Q000737:chemistry*; D019554:Dental Restoration Wear / Q000145:classification*; D005260:Female; D005500:Follow-Up Studies; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008875:Middle Aged; D008963:Molar / Q000473:pathology; D011446:Prospective Studies; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D019217:Tooth Attrition / Q000145:classification* / Q000473:pathology
C105314:AllCeram; D000538:Aluminum Silicates; D006047:Gold Alloys; C075815:IPS-Empress ceramic; D016876:Metal Ceramic Alloys; C438843:Panavia-Fluoro; C077451:Procera; D019279:Resin Cements; C493120:lithia disilicate; D003776:Dental Porcelain; D014025:Titanium; D000537:Aluminum Oxide