Clinical evaluation of the speed and effectiveness of subgingival calculus removal on single-rooted teeth with diamond-coated ultrasonic tips.

Several studies have found incomplete calculus removal during periodontal treatment with traditional hand curets, sonic, and ultrasonic instruments. This study evaluated the speed and effectiveness of subgingival calculus removal with new diamond-coated ultrasonic tips on single-rooted teeth. Single session subgingival scaling and root planing was performed on 80 teeth with 5 to 12 mm probing depths in 15 patients. Each patient provided groups of 4 teeth that were randomly treated with either hand curets (HAND); standard smooth ultrasonic tip (US); or fine grit (FINDIAM) or medium grit (MEDDIAM) diamond-coated ultrasonic tips. The time taken to reach the therapeutic endpoint of a clean, smooth root surface in a defined region on each tooth with each instrument by the 3 therapists with differing experience levels was recorded. The teeth were then atraumatically extracted, stored in a surfactant, photographed at 10X, and the percent of calculus present in the area of the pocket or on a comparable control surface calculated by histometric point counting. ANOVA and paired t tests showed that mean percent remaining calculus on treated versus control surfaces was HAND 4.6 +/- 5.3 versus 57.5 +/- 28.2, US 4.7 +/- 6.4 versus 54.4 +/- 25.9, FINDIAM 4.3 +/- 5.2 versus 37.5 +/- 22.1, and MEDDIAM 3.4 +/- 4.2 versus 50.7 +/- 20.1, respectively (all P < 0.01). The mean time in seconds to reach the clinical endpoint ranged from HAND 289 +/- 193, US 194 +/- 67, FINDIAM 167 +/- 71, to MEDDIAM 147 +/- 92. All powered instruments were significantly faster than HAND (P < 0.05), but did not differ from each other. On a 0 = "smooth" to 3 = "rough" scale, most often HAND resulted in "smooth" surfaces (10/20), the powered tips of all types "slight" surface roughness (10/20 each), and US the most "moderate" roughness (7/20). There were no differences in percent calculus remaining, surface roughness, or time spent among the 3 treating clinicians despite their varying experience levels. The results of this study showed that percent calculus remaining was <5% with all the instruments given time ad libitum on a given root surface. Root roughness was generally slightly greater with all 3 powered tips. All of the powered instruments took significantly less time than the HAND. Both DIAM tips took less time than US. Diamond-coated ultrasonic tips appeared to be much more efficient than HAND or US in removing calculus in moderate-deep probing depths on single-rooted teeth in vivo.

Root surface removal with diamond-coated ultrasonic instruments: an in vitro and SEM study.

Adequate root preparation in periodontal procedures includes the removal of plaque, calculus, and perhaps contaminated cementum and dentin. The purpose of this study was to evaluate and compare the amount of root surface removal and residual surface texture using similarly shaped regular (US) and both fine (FINDIAM) and medium (MEDDIAM) grit diamond-coated ultrasonic inserts. Forty-five (45) premolars extracted for orthodontic reasons were randomly divided into 3 groups of 15 teeth each. They were individually mounted in a jig and instrumented with a standardized 500 gram force while they were moved a precise horizontal distance of 12 mm over a 1.2 second period using specially designed and computer controlled instrumentation. Three measurements were made to the nearest 0.0005" at 3 points along the test area before instrumentation and after 10 and 20 strokes. The mean depth of root structure removed was US 5.8 +/- 6.6 microns, FINDIAM 50.1 +/- 14.2 microns, MEDDIAM 30.8 +/- 12.1 microns, after 10 strokes, and US 12.7 +/- 10.9 microns, FINDIAM 83.3 +/- 20.1 microns, MEDDIAM 58.7 +/- 17.9 microns after 20 strokes, respectively. All 3 instruments were different from each other (P < 0.001) in the 10 stroke group, while in the 20 stroke group FINDIAM and MEDDIAM were different from US (P < 0.001), but not from each other. Only FINDIAM showed a significant difference between 10 and 20 stroke values for depth of root removal. Modified loss of tooth substance index SEM scores indicated increasingly greater root surface roughness from US to FINDIAM to MEDDIAM. Substantially greater root surface removal and greater residual root surface roughness occurred with diamond-coated ultrasonic inserts under standardized in vitro conditions. These results suggest that caution should be used with diamond-coated ultrasonic instruments during periodontal root planing procedures.

Mast cell distribution in oral tissues of germ-free vs. conventional beagle dogs.

Light microscopic examination of the mast cell distribution in various oral tissues in germ-free and conventional beagle dogs revealed no differences between the two animals. Mast cells were observed in all tissues examined, with an increasing order of incidence as follows: cervical lymph node, parotid and submandibular glands, marginal gingivae, buccal mucosa and the middle one-third of the tongue. All four types (round, oval, elongated, and pseudopodial) of mast cells cell shapes previously described in the literature were observed. The marginal gingivae associated with the mandibular, second bicuspids was examined by light microscopy and was classified as to degree of inflammatory involvement. In a comparison of germ-free and conventional animals, the distribution of the degree of inflammation proved to be random. Correlation between mast cell densities and the degree of inflammatory infiltration was not statistically significant. However, mast cells tended to decrease as the inflammation became more severe. Electron microscopic examination of mast cells in the buccal mucosa revealed no difference in morphology of cells from germ-free or conventional animals. Cytoplasmic granules were of two basic types, one exhibited an amorphous matrix of uniform density and the other consisted of laminated coils of various sizes and densities.