Platelet-rich fibrin and bovine porous bone mineral vs. platelet-rich fibrin in the treatment of intrabony periodontal defects.

BACKGROUND AND OBJECTIVE: Bovine porous bone mineral (BPBM) is a xenograft that has been successfully utilized in periodontal regeneration. Platelet-rich fibrin (PRF) is a leukocyte and platelet preparation that concentrates various polypeptide growth factors and therefore has the potential to be used as regenerative treatment for periodontal defects. The purpose of this study was to examine the suitability of autologous PRF as regenerative treatment for periodontal intrabony defects in humans and to examine the ability of BPBM to augment the regenerative effects exerted by PRF. MATERIAL AND METHODS: Using a split-mouth design, 17 paired intrabony defects were randomly treated either with PRF or with PRF-BPBM combination. Re-entry surgeries were performed at 6 mo. Primary study outcomes were changes in pocket depth, attachment level and defect fill. RESULTS: Preoperative pocket depths, attachment levels and transoperative bone measurements were similar for the PRF and PRF-BPBM groups. Postsurgical measurements revealed a significantly greater reduction in pocket depth in the PRF-BPBM group (4.47±0.78 mm on buccal and 4.29±0.82 mm on lingual sites) when compared with the PRF group (3.35±0.68 mm on buccal and 3.24±0.73 mm on lingual sites). The PRF-BPBM group presented with significantly greater attachment gain (3.82±0.78 mm on buccal and 3.71±0.75 mm on lingual sites) than the PRF group (2.24±0.73 mm on buccal and 2.12±0.68 mm on lingual sites). Defect fill was also greater in the PRF-BPBM group (4.06±0.87 mm on buccal and 3.94±0.73 mm on lingual sites) than in the PRF group (2.21±0.68 mm on buccal and 2.06±0.64 mm on lingual sites). CONCLUSION: The results of this study indicate that PRF can improve clinical parameters associated with human intrabony periodontal defects, and BPBM has the ability to augment the effects of PRF in reducing pocket depth, improving clinical attachment levels and promoting defect fill.

Guided tissue regeneration using calcium phosphate implants together with 4 different membranes. A study on furcations in dogs.

Four different membranes were used in conjunction with porous calcium phosphate granules to treat grade II furcations in lower molars of 6 dogs. Six months later block sections were used to measure the amount of regeneration and inflammation. The 4 membranes (polycarbonate, silicone rubber, polytetrafluoroethylene, and polycaprolactone) all gave similar improvements in bone fill ranging from 1.74 +/- 0.44 mm to 2.02 +/- 0.38 mm while control areas had only 0.34 +/- 0.12 mm. The amount of new attachment ranged from 2.32 +/- 0.62 mm to 2.58 +/- 0.62 mm for the membranes and was 0.26 +/- 0.11 mm for controls. There were increased numbers of chronic inflammatory cells seen with the polycarbonate and polycaprolactone group compared to controls and the other 2 membranes.

The effect of topical application of dextran on the gingiva of the beagle dog.

Dextrans derived from Leuconostoc mesenteroides were placed on clinically healthy gingiva of Beagle dogs once a day for 21 days. Control gingival tissues received saline. Both healthy controls and dextran-treated tissues were brushed daily. Inflamed control tissues were obtained by allowing plaque to accumulate for 21 days. Tissues receiving daily application of dextran solutions developed chronic gingival inflammation but displayed no clinical signs of gingivitis. Healthy control gingival tissues showed no clinical signs of gingivitis and minor histologic inflammatory changes. Tissues exposed to dental plaque showed the typical clinical and histological inflammatory changes of gingivitis. Thus dextran, a substance similar to the extracellular polysaccharide found in dental plaque, was able to penetrate the sulcular epithelium, enter healthy gingival connective tissue and cause chronic inflammation. This connective tissue inflammation occurred without inducing any of the clinical signs of gingivitis. Therefore, it is concluded that dextran produced one component of the gingivitis response, chronic histologic inflammation, independent of another major component of the disease, clinical inflammation.

Evaluation of guided tissue regeneration in Class II furcation defects. A clinical re-entry study.

Twelve patients with two comparable furcation Class II lesions in lower molars were included in this study. After adequate presurgical preparation and pertinent clinical measurements, the areas were treated with full thickness flaps and thorough debridement and scaling and planing of the root surfaces. One of the defects was randomly selected to be covered with Gore-Tex periodontal material, held in place by sling sutures of expanded polytetrafluoroethylene. On both sites the flaps were positioned slightly coronal to their original level and sutured. After 6 months both sites were re-entered surgically and remeasured. The test sites showed a statistically significant reduction in pocket depth and gain in attachment levels while the controls had not changed from preoperative levels. No changes in bone levels were detected in test or control sites. However, because of the large variability in the measurements, and the short period of observation, there may be differences in bony changes between the two therapies. Studies with larger groups, more accurate methods, and longer time intervals are needed to better evaluate the effects of barrier membranes in periodontal healing.

The use of autogenous periosteal grafts as barriers for the treatment of Class II furcation involvements in lower molars.

This study clinically analyzed the efficacy of a connective tissue graft including the periosteum used as a barrier to enhance new attachment and osseous regeneration. Fifteen patients, with no systemic diseases, and adult periodontitis including 2 Class II furcation involvements in lower molars comprised the study group. After completion of the initial phase of therapy, all patients were treated with full-thickness periodontal flaps, using sulcular incisions, and thorough scaling and root planing. One furca, selected at random, had a connective tissue graft, obtained from the palate and including the periosteum, placed over the furca with the flap sutured over the top of this graft. Control furcas received no graft and the flap was sutured in its original position. Both molars were treated in the same session. The following presurgical measurements were made: probing pocket depth, attachment level, gingival recession, sulcular bleeding index, and plaque index. The horizontal and vertical dimensions of the osseous defects were recorded after flap elevation and debridement. Six months later all clinical parameters were again measured and reentry flaps were performed to measure the bony defects. No statistically significant differences were found preoperatively between control and experimental molars with respect to soft tissue and osseous measurements. Six months after surgery, the experimental molars showed, in comparison to the controls, significant reduction in pocket depth and gain in attachment level as well as in vertical and horizontal measurements of the inter-radicular osseous defect.

Treatment of class II furcation defects using porous hydroxylapatite in conjunction with a polytetrafluoroethylene membrane.

The purpose of the present study was to determine whether the use of a porous hydroxylapatite in conjunction with guided tissue regeneration technique influenced the clinical results in the treatment of Class II furcation defects in humans. Fifteen subjects with a mean age of 39.4 +/- 9.3 years were used in this study. All subjects had Class II furcation defects on the buccal surfaces of 2 lower molars. In each subject one furcation defect was filled with granular porous hydroxylapatite and then a barrier of polytetrafluoroethylene periodontal material was positioned over the furcation. The other furca was treated in the same manner except that no hydroxylapatite was used. The flaps were placed coronally to their presurgical level. Before the surgery and 6 months postsurgery all areas were clinically evaluated using the same clinical parameters. Reentry procedures were used to repeat measurements of the osseous defects made during the initial surgery. At 6 months both surgical procedures resulted in statistically significant reduction in pocket depth and gain in probing attachment level with no significant difference between the two surgical procedures. When porous hydroxylapatite was used in conjunction with a polytetrafluoroethylene membrane, however, less gingival recession and more defect fill were obtained. This study suggests that there is a difference in healing of molar furcations when porous hydroxylapatite is used in conjunction with a barrier membrane. The lesions treated with porous hydroxylapatite gain in clinical attachment and horizontal and vertical bone fill, while the lesions treated with membrane only gain probing attachment with less bony fill.

The effect of electrosurgery on alveolar bone.

The facial marginal alveolar bone of dogs was exposed with a full-thickness flap and touched by an activated electrosurgery electrode for periods of 0, 1, 5 and 10 seconds. Microscopic results were evaluated after periods ranging from 0 hours to 28 days. Various electrode exposure times produced similar changes in bone and periodontal ligament. The extent of the destruction was greater than that found in surgical areas not exposed to electrosurgery; healing and remodeling phases were also delayed in the electrosurgical sites.

The effect of metronidazole on human periodontal disease. A clinical and bacteriological study.

Fifteen female subjects undergoing treatment for nonspecific vaginitis with metronidazole 250 mg q.i.d. for 7 days were studied. Clinical and microbiological evaluations were carried out initially and at 2 and 4 weeks. The following parameters were measured in two quadrants: plaque index, sulcular bleeding index, pocket depth, attachment level and amount of gingival fluid. Dark field microscopy was used to quantitate the plaque constituents. One quadrant was subjected to root planing at the initial visit; the other quadrant received no therapy. No oral hygiene instructions were given. All the clinical parameters were significantly reduced in all areas. Gingival fluid, sulcular bleeding index and pocket depth showed greater improvement in the root-planed quadrant compared to the nonroot-planed quadrant. Dark field microscopy showed decreases in fusiforms, curved rods and spirochetes in all areas with a concomitant increase in cocci. The root-planed quadrant showed no significant differences in microbiological aspects when compared to the nonplaned quadrant. Clinically, metronidazole therapy resulted in improvement of periodontal status with some additional but small enhancement due to root planing. Microbiologically, metronidazole dramatically changed the quality of plaque with no supplemental effect when root planing was added.

The effect of cigarette smoking on anaerobiosis in the oral cavity.

Nineteen young adult male smokers were compared to 19 adult male nonsmokers to determine if cigarette smoking resulted in any changes to anaerobic bacteria in dental plaque, to intraoral oxidation-reduction potential (Eh) levels, or to intraoral pH. There was no statistical difference between smokers and nonsmokers in the proportion of anaerobic bacteria found in dental plaque. There were no significant differences between smokers and nonsmokers with respect to the resting Eh in the floor of the mouth nor in the Eh in the region of buccal surface of the upper molars. The smoking of one cigarette resulted in a dramatic fall in Eh in both intraoral regions and this occurred in all subjects, both smokers and nonsmokers. The magnitude of this fall in Eh was similar in both groups. There were also uniform increases in pH, but these pH changes were much smaller in magnitude.

Osteogenesis enhanced by chitosan (poly-N-acetyl glucosaminoglycan) in vitro.

Chitosan, with a chemical structure similar to hyaluronic acid, has been implicated as a wound healing agent. The purpose of this research was to evaluate the effect of chitosan on osteoblast differentiation and bone formation in vitro. Mesenchymal stem cells were harvested from fetal Swiss Webster mice calvariae prior to osteoblast differentiation and calcification (12 to 13 days in utero). Stem cells were seeded into 6-well culture plates at a density of 350,000 cells per well. Using this model, it was possible to quantify the influence of chitosan on osteoprogenitor differentiation and osteogenesis. Experimental wells were pretreated with 200 microliters chitosan (2 mg/ml in 0.2% acetic acid vehicle). Control wells were pretreated with 200 microliters vehicle (0.2% acetic acid) or remained untreated. Cells were allowed to grow under optimal conditions for 14 days. Cell cultures were fixed with glutaraldehyde and stained with Von Kossa stain to identify bone forming colonies. Positive staining colonies were identified and counted under light microscopy. Histologic cross-sections of representative positively stained colonies identified osteoblasts and confirmed bone formation. Examination of control wells revealed 3.6 +/- 0.6 colonies per well while experimental wells revealed a significantly greater average of 6.2 +/- 1.2 colonies per well (P < or = 0.01). Computer-assisted image analysis of the average area of bone formed by control colonies was 0.34 +/- 0.09 (relative units) while that of experimental colonies was 0.39 +/- 0.06 (relative units) per average bone forming colony. The difference in mean size (control versus chitosan bone forming colony) was not statistically significant (P = 0.4691). The results of this in vitro experiment suggest that chitosan potentiates the differentiation of osteoprogenitor cells and may facilitate the formation of bone.

Guided tissue regeneration in Class II furcation involved maxillary molars: a controlled study of 8 split-mouth cases.

The purpose of this study was to clinically evaluate the effectiveness of polytetrafluoroethylene membranes in the healing of interproximal Class II furcation defects in maxillary molars using a surgical treatment technique based on the principles of guided tissue regeneration. Eight subjects with similar bilateral Class II furcation lesions on the mesial aspect of maxillary first molars participated in this study. Patients received initial therapy consisting of oral hygiene instructions, scaling and root planing, and occlusal adjustment if necessary. Clinical parameters evaluated included plaque index, sulcular bleeding index, probing depth, attachment level, gingival recession, and open horizontal and vertical furcation fill. An acrylic occlusal stent was used to assure reproducibility of measurements. Experimental sites received a polytetrafluoroethylene membrane following surgical exposure of the furcation. Control sites were treated in the exact same manner but without a membrane. Membranes were removed at 6 weeks after the first surgery. Reentry surgeries were performed at 9 months. Postsurgical results showed a significant improvement in probing depth, attachment level, and open horizontal furcation fill for both groups when compared to baseline values, with experimental sites performing significantly better than controls. Control sites showed a slight loss in open vertical furcation fill while experimental sites remained unchanged. This study suggests that guided tissue regeneration using polytetrafluoroethylene membranes is of some but limited value in the treatment of maxillary molar interpoximal Class II furcation lesions.

Evaluation of periosteal membranes and coronally positioned flaps in the treatment of Class II furcation defects: a comparative clinical study in humans.

The purpose of this study was to compare the clinical effectiveness of connective tissue grafts including periosteum used as a mechanical barrier for guided periodontal tissue regeneration and coronally positioned flaps in the treatment of Class II furcation defects. A total of 28 furcation defects were treated; 14 received a periosteal barrier and 14 received a coronally positioned flap. Reentry surgeries were performed at 6 months. No statistically significant differences were found preoperatively between the two treatment groups with respect to clinical parameters and osseous measurements. Postsurgically, both treatment modalities resulted in a significant decrease in probing depth and a significant gain in clinical attachment, but the differences observed were not statistically significant. The periosteal barrier group presented with a significantly better gain in vertical components of the alveolar bone (1.93 +/- 0.15 mm and 0.20 +/- 0.26 mm for periosteal barrier and coronally positioned flap groups, respectively; P < or = 0.001) and horizontal components of the alveolar bone (1.60 +/- 0.21 mm and 0.13 +/- 0.90 mm for periosteal barrier and coronally positioned flap groups, respectively; P < or = 0.001). The results of this trial indicate that similar clinical resolution of Class II furcation defects can be obtained with periosteal barriers and coronally positioned flaps. Periosteal barriers, however, are a better treatment alternative in achieving bone fill of the furcation area.

Flap technique for periodontal bone implants. Papilla preservation technique.

A new flap design for placement of implants into osseous defects has been described. The flap design can be used in anterior and posterior areas of human subjects. Photographs of representative cases are presented. Wound healing always occurred by primary intention and without evidence of immediate graft exfoliation. Interdental soft tissue craters did not develop, making it easier for patients to maintain optimal oral hygiene. This type of flap design can also be used without grafts in order to improve postoperative soft tissue contour.

Histologic study of healing of human periodontal defects after placement of porous hydroxylapatite implants.

Two intrabony pockets on teeth that were to be extracted for prosthetic reasons, in two patients, were treated by means of papilla preservation flaps and implantation with porous hydroxylapatite. The teeth, with a portion of their periodontium, were extracted 5 and 6 months after treatment and processed histologically. Both cases showed the implants invaded by connective tissue, which was actively forming bone. There was no inflammatory reaction triggered by the implant material, although there was some recurrence of inflammation in the vicinity of the pocket wall. The junctional epithelium in both cases extended slightly beyond the coronal level of the implant. One of the cases had an abundant new cementum formation with fibrous tissue next to the implant, that appeared to be a rebuilt attachment of collagen fibers. Although some multinucleated giant cells were found in the pores and next to the newly formed bone, the implanted material did not appear to be resorbed in the period of time studied.

The use of a porous hydroxylapatite implant in periodontal defects. II. Treatment of Class II furcation lesions in lower molars.

Twenty-three human subjects with two Class II furcation involvements in lower molars were treated with initial therapy following which presurgical measurements of pocket depth, gingival recession and attachment level were made. Periodontal flaps were used to expose the furcation defects, and one defect was implanted with porous hydroxylapatite while the other served as an unimplanted control. At the time of surgery, bone defects were measured obliquely and horizontally using a specially designed device to ensure reproducible probe angulation. Six months later the presurgical measurements were repeated, and reentry surgical procedures were carried out to measure the changes in the bone defects. Areas implanted with porous hydroxylapatite showed a statistically significant reduction in pocket depth and a statistically significant improvement in attachment level and fill of bone defects when compared with control defects. There was statistically less gingival recession in the implanted areas compared with the control sites. Control sites at six months showed no significant change in pocket depth, an increased loss of attachment and worsening of the bone defects.

Bone formation within porous hydroxylapatite implants in human periodontal defects.

Tissue samples from three subjects who had periodontal defects treated with a porous hydroxylapatite implant were investigated using light microscopy and scanning electron microscopy. The 3-month specimen showed connective tissue infiltration through the pores and a narrow zone of bone formation present along the walls of the pores. At 4 months, continued evidence of bone deposition was present with osteocytes, osteoblasts and organization of collagen fibers apparent throughout the implant. The 6-month implant had further evidence of continued bone formation with lamellar bone being the major component within the pores.

The use of a porous hydroxylapatite implant in periodontal defects. I. Clinical results after six months.

Twenty-five patients with advanced periodontal destruction were used in the study. Following initial therapy, two angular interproximal defects were selected in each patient. During flap surgery a porous hydroxylapatite implant shaped to fit the periodontal defect was placed in one defect, the other defect was used as nonimplanted control. The material used for implantation was a hydroxylapatite replicate of coral from the genus Porites, with a pore size of 190 to 220 micron. Clinical parameters were measured prior to flap surgery for each of the defects. An occlusal acrylic stent was used to give a stable reference point for pocket depth, attachment level and gingival margin height measurements. Also gingival fluid, gingival inflammation, plaque index and tooth mobility were recorded. Periapical radiographs using a standardized positioning device were also taken. At the time of surgery, the depth of the osseous defect and the height of the alveolar crest were recorded. After 6 months the clinical measurements were repeated and a re-entry surgery was carried out in 15 selected sites. Results showed that the porous implant produced statistically significant reduction in pocket depth, in the depth of osseous lesion, and a statistically significant gain in attachment level, as compared to control areas.

Comparative clinical study of porous hydroxyapatite and decalcified freeze-dried bone in human periodontal defects.

Interproximal bony defects were treated with either porous hydroxyapatite (PHA) or decalcified freeze-dried bone allograft (DFDB) implants at two different clinical centers. Twelve paired defects in 12 patients were treated at each center. Six months post-surgically the defects were measured to assess changes from the presurgical status. No statistically significant differences were found between the groups in changes in gingival fluid, bleeding index, plaque index, or tooth mobility. The porous hydroxyapatite implant produced greater reduction in pocket depth (P = 0.03) and more gain in clinical attachment level (P = 0.001) and defect fill (P = 0.001) when compared with DFDB grafted sites. This study indicates that more clinical resolution of interproximal periodontal defects in humans can be obtained with the use of PHA than with the use of DFDB.

Combination use of bovine porous bone mineral, enamel matrix proteins, and a bioabsorbable membrane in intrabony periodontal defects in humans.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of a combination of enamel matrix proteins (EMP), bovine porous bone mineral (BPBM), and a bioabsorbable membrane for guided tissue regeneration (GTR) as regenerative therapy for intrabony defects in humans and compare it to an open flap debridement (OFD) technique. METHODS: Using a split-mouth design, 18 pairs of intrabony defects were treated and surgically reentered 6 months after the initial surgery. Experimental sites were treated with EMP, grafted with BPBM, and received a collagen/polylactic acid membrane for GTR. Control sites were treated with OFD. The primary outcomes evaluated in the study included probing depth resolution, clinical attachment gain, and bony defect fill. RESULTS: Preoperative probing depths, attachment levels, and intraoperative bone measurements were similar for the experimental and control groups. Postsurgical measurements taken at 6 months revealed a significantly greater reduction in probing depth in the experimental group (4.95+/-1.52 mm on buccal sites and 4.74+/-1.47 mm on lingual sites) when compared to the control group (2.83+/-0.83 mm on buccal sites and 2.90+/-0.91 mm on lingual sites). The experimental sites also presented with significantly more attachment gain (3.89+/-1.16 mm on buccal sites and 3.78+/-1.14 mm on lingual sites) than the control sites (1.52+/-0.83 mm on buccal sites and 1.48+/-0.78 mm on lingual sites). Surgical reentry of the treated defects revealed a significantly greater amount of defect fill in favor of the experimental group (4.76+/-1.36 mm on buccal sites and 4.81+/-1.37 mm on lingual sites) as compared to the control group (1.78+/-0.92 mm on buccal sites and 1.67+/-0.90 mm on lingual sites). CONCLUSIONS: The results of this study indicate that a combination technique including BPBM, EMP, and GTR results in better clinical resolution of intrabony defects than treatment with OFD. Differences observed were both statistically and clinically significant. The exact role of each of the 3 technique components in achieving the clinical improvement observed in this study remains to be determined.

A comparison between enamel matrix proteins used alone or in combination with bovine porous bone mineral in the treatment of intrabony periodontal defects in humans.

BACKGROUND: It has been shown that clinical improvement of intrabony periodontal defects can be achieved with the use of enamel matrix proteins (EMPs) or by grafting with bovine porous bone mineral (BPBM). There is no report on the potential synergistic effect of EMPs and BPBM in periodontal regenerative therapy. The purpose of this study was to compare the clinical effectiveness of EMPs used alone or in combination with BPBM in the treatment of periodontal intrabony defects in humans. METHODS: Twenty-one paired intrabony defects were surgically treated using a split-mouth design. Intrabony defects were treated either with enamel matrix proteins (EMP group) or with enamel matrix proteins combined with bovine porous bone mineral (EMP/BPBM group). Re-entry surgeries were performed at 6 months. RESULTS: Preoperative probing depths, attachment levels, and transoperative bone measurements were similar for the EMP and EMP/BPBM groups. Postsurgical measurements taken at 6 months revealed a significantly greater reduction in probing depth in the EMP/BPBM group (3.43 +/- 1.32 mm on buccal sites and 3.36 +/- 1.35 mm on lingual sites) when compared to the EMP group (1.91 +/- 1.42 mm on buccal sites and 1.85 +/- 1.38 mm on lingual sites). The EMP/BPBM group also presented with significantly more attachment gain (3.13 +/- 1.41 mm on buccal sites and 3.11 +/- 1.39 mm on lingual sites) than the EMP group (1.72 +/- 1.33 mm on buccal sites and 1.75 +/- 1.37 mm on lingual sites). Surgical re-entry of the treated defects revealed a significantly greater amount of defect fill in favor of the EMP/BPBM group (3.82 +/- 1.43 mm on buccal sites and 3.74 +/- 1.38 mm on lingual sites) as compared to the EMP group (1.33 +/1.17 mm on buccal sites and 1.41 +/- 1.19 mm on lingual sites). CONCLUSIONS: The results of this study indicate that BPBM has the ability to augment the effects of EMPs in reducing probing depth, improving clinical attachment levels, and promoting defect fill when compared to presurgical levels.