Correlation between plaque control and gingival health using short and extended oral hygiene intervals.

OBJECTIVES: To evaluate the correlation between dental plaque formation and gingival health in subjects performing high oral hygiene standards over short or extended intervals. MATERIALS AND METHODS: Fifty-two non-dental students volunteered for this study. The subjects, trained to perform high oral hygiene standards, were randomized to perform oral hygiene at 12-, 24-, 48-, or 72-h interval over 30 days. The plaque index (PlI) and the gingival index (GI) were evaluated at baseline, 15, and 30 days. For the statistical analysis, oral hygiene intervals were collapsed into daily (12 and 24 h; G12/24) and extended (48 and 72 h; G48/72) intervals. Summary statistics (mean ± SD) and Spearman correlations between the PlI and the GI at baseline, 15, and 30 days were estimated. RESULTS: At baseline, correlation coefficients between PlI and GI were positive for both groups (r = 0.29 and r = 0.25). At day 15 and 30, correlation was maintained with similar baseline values for the G48/72 group. GI levels did not increase despite an increase in PlI for the G12/24 group, and the correlation was lower than that observed at baseline (r = 0.13 vs. r = 0.29). CONCLUSIONS: In subjects with high oral hygiene standards, the oral hygiene frequency governs the correlation between dental plaque formation and gingival health. Subjects performing high oral hygiene standards at daily intervals will maintain gingival health in difference to subjects using extended hygiene intervals. CLINICAL RELEVANCE: Subjects performing high oral hygiene standards at daily intervals will maintain gingival health in difference to subjects using extended hygiene intervals.

Effect of bone morphogenetic protein-2, demineralized bone matrix and systemic parathyroid hormone (1-34) on local bone formation in a rat calvaria critical-size defect model.

AIM: To determine the potential of recombinant human bone morphogenetic protein-2 (rhBMP-2) soak-loaded on to an absorbable collagen sponge (ACS) to induce local bone formation compared with the clinical reference demineralized bone matrix (DBM) and to investigate potential additive/synergistic effects of exogenous parathyroid hormone (PTH). METHODS: Critical-size (8 mm), through-through calvaria osteotomy defects in 160 adult male Sprague-Dawley rats were randomized to receive one of eight interventions: rhBMP-2/ACS, DBM, ACS, or serve as controls (empty defects) combined or not with systemic PTH. Ten animals from each group were followed for 4 and 8 wks for radiographic and histometric analysis. Multivariable analysis was used to assess the effect of experimental intervention and healing time on local bone formation. RESULTS: In the multivariable analysis, rhBMP-2/ACS exhibited significantly greater histologic bone formation than control (ß ± SE: 54.76 ± 5.85, p < 0.001) and ACS (ß ± SE: 9.14 ± 3.31, p = 0.007) whereas DBM showed significantly less bone formation than control (ß ± SE: -32.32 ± 8.23, p < 0.001). Overall, PTH did not show a significant effect on bone formation (ß ± SE: 2.72 ± 6.91, p = 0.70). No significant differences in histological defect closure were observed between 4 and 8 wks for all but the control group without PTH. CONCLUSION: rhBMP-2/ACS significantly stimulates local bone formation whereas bone formation appears significantly limited by DBM. Systemic application of PTH provided no discernible additive/synergistic effects on local bone formation.

Growth and differentiation factors for periodontal regeneration: a review on factors with clinical testing.

BACKGROUND AND OBJECTIVE: A large body of evidence implies that growth and differentiation factors, based on their ability to regulate various functions of cells originating in the periodontal tissues, may support periodontal wound healing/regeneration, creating an environment conducive to and/or immediately inducing de novo tissue formation. This study presents a short systematic overview on growth and differentiation factor technologies evaluated in the clinic for their potential to enhance periodontal wound healing/regeneration. MATERIAL AND METHODS: Reports on growth and differentiation factor technologies evaluated in the clinic for their potential to enhance periodontal wound healing/regeneration were selected for review. RESULTS: Growth and differentiation factor technologies intended for periodontal wound healing/regeneration and evaluated clinically included platelet-derived growth factor, insulin-like growth factor-I and -II, basic fibroblast growth factor, bone morphogenetic protein-3 and growth differentiation factor-5; platelet-derived growth factor was the only Food and Drug Administration-approved commercially available growth and differentiation factor technology. In general, enhanced periodontal regeneration was observed in sites receiving growth and differentiation factors compared with control(s). However, improvements of relatively limited clinical magnitude have been shown thus far. CONCLUSION: Although growth and differentiation factors project considerable appeal as candidate technologies in support of periodontal wound healing/regeneration, current candidate and commercially available technologies enhance treatment outcomes only to a limited extent in clinical settings.

Exploratory study on the effect of osteoactivin on bone formation in the rat critical-size calvarial defect model.

BACKGROUND AND OBJECTIVE: Osteoactivin is a novel glycoprotein shown to exhibit an important role in regulating osteoblast differentiation and function. The aim of the present study was to evaluate the potential of osteoactivin to support bone regeneration using an established defect model. MATERIAL AND METHODS: Critical-size, 8-mm-diameter through-and-through calvarial osteotomy defects were created in 60 adult male Sprague-Dawley rats. Test animals received 0.1 mL of osteoactivin in phosphate-buffered saline (50 µg/mL) soak-loaded onto an absorbable collagen sponge. Controls received 0.1 mL of phosphate-buffered saline soak-loaded onto the absorbable collagen sponge or no further intervention (sham-surgery). The animals were euthanized 2 and 4 wk after treatment and histometric analyses were performed. RESULTS: The absorbable collagen sponge control (mean ± standard deviation: 40.9 ± 26.9%) showed borderline significant greater bone fill compared with sham-surgery (22.9 ± 15.8%; p = 0.10) and osteoactivin (20.2 ± 11.8%; p = 0.07) treatments at 2 wk. In contrast, osteoactivin (84.7 ± 15.8%) showed significantly greater bone fill than sham-surgery (28.4 ± 9.6%; p < 0.001) and absorbable collagen sponge (41.8 ± 22.1%; p < 0.001) at 4 wk. No animals receiving sham-surgery or absorbable collagen sponge exhibited complete bone fill at 4 wk while 70% of the animals receiving osteoactivin showed complete bone fill. CONCLUSION: Osteoactivin demonstrates a significant potential to support bone regeneration/formation. Studies using discriminating large animal models are necessary to explore clinical application for periodontal and craniofacial indications.

Bone morphogenetic proteins for periodontal and alveolar indications; biological observations - clinical implications.

Surgical placement of endosseous oral implants is governed by the prosthetic design and by the morphology and quality of the alveolar bone. Nevertheless, often implant placement may be complexed, if at all possible, by alveolar ridge irregularities resulting from periodontal disease, and chronic and acute trauma. In consequence, implant positioning commonly necessitates bone augmentation procedures. One objective of our laboratory is to evaluate the biologic potential of bone morphogenetic proteins (BMP) and other candidate biologics, bone biomaterials, and devices for alveolar ridge augmentation and implant fixation using discriminating large animal models. This focused review illustrates the unique biologic potential, the clinical relevance and perspectives of recombinant human BMP-2 (rhBMP-2) using a variety of carrier technologies to induce local bone formation and implant osseointegration for inlay and onlay indications. Our studies demonstrate a clinically relevant potential of a purpose-designed titanium porous oxide implant surface as stand-alone technology to deliver rhBMP-2 for alveolar augmentation. In perspective, merits and shortcomings of current treatment protocol including bone biomaterials and guided bone regeneration are addressed and explained. We demonstrate that rhBMP-2 has unparalleled potential to augment alveolar bone, and support implant osseointegration and long-term functional loading. Inclusion of rhBMP-2 for alveolar augmentation and osseointegration will not only enhance predictability of existing clinical protocol but also radically change current treatment paradigms.

The interdental gingiva, a visible guide for placement of mini-implants.

OBJECTIVES: To determine whether the tip of the interdental gingiva can serve as a visible guide for placement of mini-implants. SETTING AND SAMPLE POPULATION: Computer tomography (CT) images from 15 males and 15 females (mean age 27 years, range: 23-35 years) were used to evaluate the distance from the tip of the interdental gingiva to the alveolar crest from the central incisor to the 1st molar. The distance from a reference point to the tip of interdental gingiva was recorded from study models using a caliper. The distance between the reference point and the alveolar crest was recorded using CT and added to the model recordings thus providing the distance from the tip of interdental gingiva to the alveolar crest for the various interdental sites. Two-way anova and Student-Newman-Keuls test for multiple comparisons were used for the statistical analysis. RESULTS: There was no significant difference in the distance from the tip of interdental gingiva to the alveolar crest between maxilla and mandible. The distance between the tip of interdental gingiva and the alveolar crest at the central/lateral incisors was the shortest compared with that of other sites. There was also a statistically significant difference between the male and female groups except for the maxillary 2nd premolar/1st molar interradicular site. CONCLUSION: The tip of interdental gingiva appears a reasonable visual guide for the placement of mini-implants for orthodontic anchorage.