الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Caries excavation is the preliminary step for restoration of carious teeth. The ceramic bur (Cera Bur) by Komet, Germany is a new caries excavation bur that is believed to have selective caries excavation properties.
The present study aimed to evaluate the caries excavation efficacy and the time needed for complete caries excavation using ceramic bur on primary teeth compared to conventional tungsten carbide bur.
The present study consisted of two parts, a randomized controlled clinical trial with a split-mouth design and an in-vitro study. The clinical trial included 20 patients, with twenty bilateral maxillary class V carious lesions in primary canines, with age range 4-8 years with mean age 5.9 years. In every patient, one canine served as test while the other side served as control. group I(n=20): caries was excavated using ceramic bur (Cera Bur), group II(n=20): caries was excavated using conventional tungsten carbide bur. The efficacy of caries excavation was evaluated by absence of tug back sensation according to visual-tactile criteria and time needed for complete caries excavation was measured in seconds. The teeth were then restored with light cure composite resin according to the manufacturer’s instructions. The in-vitro study was performed on 10 freshly extracted primary canines that were sectioned to constitute 20 specimens distributed on two groups (n=10). The specimens were examined using SEM to assess the dentin topographic after caries excavation using ceramic bur in comparison to conventional tungsten carbide bur.
The in-vivo study showed complete caries removal when tungsten carbide bur was used for excavation compared to 90% of teeth when the ceramic bur was used. This difference was not statistically significant (P= 0.50). The time taken to excavate caries by the tungsten carbide bur ranged from 23-89 sec., with a mean ±SD of (40.2±18.8) sec. While the time taken by the ceramic bur ranged from 28 to 117 sec., with a mean of (49.75± 26.41)sec. The difference between the two groups was statistically significant (P= 0.03).
The in-vitro study showed that the dentin surface excavated by the ceramic bur demonstrated a variety of features with variable amount of patent dentinal tubules and smear layer deposits in different sections. In specimens excavated by the tungsten carbide bur, the dentinal tubules were exposed with minute remnants of smear layer partially occluding some openings.
Based on the results of the study, it is concluded that the ceramic bur had the same efficacy of caries excavation as the tungsten carbide but with significantly longer excavation time. The ceramic bur also produced a smooth dentin surface with partial removal of the smear and patent dentinal tubules compared to the tungsten carbide bur.