1994-6-3-179-183 - Saudi Dental Journal

ISSN (Print) 1013-9052
EISSN 1658-3558

The Saudi Dental Journal,
P.O. Box 52500,
Riyadh 11563,
Kingdom of Saudi Arabia

Tel.	966-1-467-7328
Fax.	933-1-467-7308 / 966-1-467-7534
Email	saudidj@ksu.edu.sa

Selection Of Burs For Finish Line Crown Preparation

Mohiddin R. Dimashkieh, DDS, MSc
Department of Restorative Dental Sciences, King Saud University College of Oenfetry, P.O. Box 60169, Riyadh 11545, Saudi Arabia

The dentist must determine the gingival location and configuration of finish line during tooth preparation. Rotary instruments are selected to prepare teeth and to develop a well-defined smooth and uniform finish line. Subgingival finish lines damage and traumatize gingival tissues due to the contact with rotary or dental instruments used during preparation. Crown tooth junction enhance plaque accumulation and its harmful effecton the periodontium. Subgingival crown margins are difficult to clean, and the relation between gingival tissue and restoration can never be the same as with natural tooth. Supragingival margins that are fully exposed to cleaning action are easier to prepare and biologically acceptable. The efficacy of conventional diamond cutting instruments when used with high or low speed handpieces as compared to the Mohiddin R. Dimashkieh (MRD) rotary cutting instruments are reviewed. Conventional instruments may produce inaccurate finish lines or may remove more tooth structure than required and traumatize the gingival tissue due to doubtful running handpiece and operator's ill judgement that half of the diameter of the conventional bur is outside the contour of the tooth during preparation. On the other hand the use of MRD instruments, designed by the author, with its depth stop tip and safe end will ensure that only half of the instrument will be embedded in the tooth, giving control of adequate and uniform tooth reduction and gingival safety.

Saudi Dental Journal 1994;6(3):179-183.