The purpose of this study was to compare the effects of scaling and Nd:YAG laser treatments with that of scaling alone on cementum and levels of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, and Treponema denticola. Study samples consisted of 14 patients, age 30 to 75 years, 8 females and 6 males, with a total of 150 periodontally involved sites with probing depth > or = 5 mm. Group A consisted of 100 pockets that were subdivided into 4 equal groups that were treated with conventional scaling and pulsed Nd:YAG laser using an optic fiber of 300 microns and 4 different power levels as follows: Group 1: P = 0.8 W, f = 10 Hz, E = 100 mJ/pulse; Group 2: P = 1.0 W, f = 1.0 Hz, E = 100 mJ/pulse; Group 3: P = 1.2 W, f = 12 Hz, E = 100 mJ/purse; and Group 4: P = 1.5 W, f = 15 Hz, E = 100 mJ/pulse. The time of each treatment was 60 sec per pocket in all 4 groups. Group B consisted of 50 pockets that were treated by conventional scaling alone and served as a control group. Microbiological samples from group A were collected before scaling; after scaling = before laser, just after laser, 2 weeks later, 6 weeks later, and 10 weeks later. Microbiological samples from group B were collected before scaling, after scaling, 6 weeks later, and 10 weeks later. Microbiological analysis of all samples was done by the Institute Für Angewandte Immunologie (IAI) method. The effects of laser on root surfaces were assessed by SEM examination and the sample consisted of 13 teeth from 5 different patients. Four sets of 3 teeth each were treated with Nd:YAG laser using 0.8, 1.0, 1.2, and 1.5 W, respectively. One tooth was just scaled and not treated with laser to serve as a control. Microbiological analysis of Group A samples indicated posttreatment reduction in levels of all 4 bacterial types tested compared to pretreatment levels and Group B controls. SEM examination of the specimens treated with Nd:YAG laser at different levels exhibited different features of root surface alterations.

These studies provide the first evidence that LPA stimulates human GF regenerative responses and that it interacts positively with PDGF-BB to regulate these actions. The results suggest that LPA needs to be further investigated in the oral system as a factor that should be considered for incorporation when designing new periodontal wound-healing therapies using PDGF.

Two separate investigations were undertaken to assess the clinical characteristics and the safety, and to determine whether an absorbable type 1 bovine collagen barrier membrane would result in the improvement of clinical parameters during guided tissue regeneration in humans. The collagen membrane barrier was placed over a total of 21 interdental intrabony periodontal defects in 18 patients. The surgical procedures and postsurgical regimen were similar in both components of the investigation. Sulcular incisions were used and the sites were surgically exposed by reflection of full thickness mucoperiosteal flaps. The intrabony defects were debrided and the root surfaces prepared with automatic scalers and curets. Four 1-minute applications of tetracycline HCl 50 mg/ml were applied to the root surface. The collagen membrane barrier was hydrated in sterile saline until pliable, then trimmed so it covered the osseous defect and extended 2 to 3 mm beyond the defect. In both investigations, the collagen barrier membrane was not sutured, but retained by "pouching" or undermining the flap. Healing occurred without complications. There were no untoward or adverse reactions to the material in either phase of the study. In the initial investigation, 13 intrabony defects with probing depths of > or = 5 mm were treated in 9 patients having a mean age of 50.6 years. No controls defects were treated. Soft and hard tissue measurements were taken at the time of initial surgery and at 2, 4, and 6 months. In the second phase, 9 patients were enrolled with a mean age of 49.7 years. They had similar bilateral interdental intrabony defects with probing depths > or = 6 mm. One defect received the collagen membrane barrier, while the other was treated by flap debridement alone. The collagen membrane had undergone modification since the initial investigation, and was more highly cross-linked to retard absorption. After initial therapy, and prior to the surgical procedure, a series of 3 dermal patch tests were used to determine whether the patient would elicit a reaction to the collagen. Venous blood was drawn at baseline, 7 to 10 days, 18 to 21 days and at 8 weeks for analysis by ELISA for comparison of test and control sites relative to baseline. There were no allergic response to the dermal tests, and the ELISA tests indicated no significant differences between test and control sites. An automated probe was used to record soft and hard tissue measurements. These included the probing depths and clinical attachment levels.(ABSTRACT TRUNCATED AT 400 WORDS)

The data indicated the bioabsorbable collagen and copolymer membranes resulted in comparable results. A larger sample size would be necessary to determine if one membrane was superior to the other.

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