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A Quantitative Study of Cementum Removal With Hand Curettes
Author(s) -
Coldiron Nancy B.,
Yukna Raymond A.,
Weir Jim,
Caudill Richard F.
Publication year - 1990
Publication title -
journal of periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.036
H-Index - 156
eISSN - 1943-3670
pISSN - 0022-3492
DOI - 10.1902/jop.1990.61.5.293
Subject(s) - cementum , dentistry , orthodontics , medicine , dentin
A n in vitro study was conducted to quantitatively measure the depth of root surface removal using curettes of standardized sharpness and with definite stroke number. Extracted periodontally healthy teeth from patients 10 to 15, 16 to 25, and 26 to 40 years old had periodontal ligament remnants removed with dry gauze before being secured in a vertical position during root planing. The force applied to the root surface was measured with a tension load cell. The “bright line” test was used to assess curette sharpness. After histologic processing, the thickness of cementum adjacent to the root defect, the cementum (if any) in the root defect, total amount of cementum removed, and depth of root defect were measured by a microscopic ocular grid. Teeth from each age range were evenly distributed into 6 groups of 10 teeth each. In the majority of teeth from the 20 stroke group through the 70 stroke group, complete cementum removal was observed at the site of planing. However, in some sections from each group, fragments of cementum remained on the root surface. A positive relationship (r/s = 1) was found between the number of strokes and the force applied to the root surface and the mean depth of defect ( P < 0.05). However, an inverse relationship existed between mean force per stroke and mean defect depth (r/s = –.99) such that as mean force per stroke increased, the mean defect depth decreased. As the root surface became smoother with an increasing number of strokes, the forces increased and were more consistent. This study showed that for “healthy” root surfaces, total cementum removal was generally achieved with a minimum of 20 strokes at the same exact location on the root surface; however, cemental fragments remained in various sections even in the 70 stroke group. This finding emphasizes the inconsistency of present mechanical therapy and points to the significance of chemical treatment or detoxification in achieving a predictable healing response. The results also suggest that effective root planing in a quadrant would take at least 90 minutes. J Periodontol 1990 ; 61 : 293 – 299 .