Histometric evaluation of periodontal surgery I. The modified Widman flap procedure

Abstract The present investigation was performed in the Rhesus monkey to determine the effect of the modified Widman flap procedure on the level of the connective tissue attachment and supporting alveolar bone. Two adult male Rhesus monkeys were used. Eighteen contralateral pairs of periodontal pockets were produced in a standardized manner. Surgical treatment of the pockets was performed around experimental teeth and the contra-lateral teeth were used as the unoperated controls. Twelve months following treatment the animals were sacrificed and histological sections obtained. Using the cemento-enamel junction (CEJ) as a fixed reference point, linear measurements along the. root surface were made to the most apical cells of the junctional epithelium (JE), to the crest of the inter-proximal alveolar bone (CR), and to the apical extent of angular bony defects (AAD). These measurements from operated and unoperated pockets were then compared. The data revealed that treatment of periodontal pockets using the modified Widman flap procedure produced no gain in connective tissue attachment and no increase in crestal bone height. In angular bony defects a certain degree “bone fill” was noted. This bone repair was never accompanied by new connective tissue attachment.     

Subperiosteal and intraosseous connective tissue grafts for pocket reduction: a 9- to 13-year retrospective case series report.

BACKGROUND: Recent histological evidence has documented that grafted palatal connective tissue is capable of forming a new attachment to previously exposed roots in the treatment of gingival recession. No clinical studies have tested the ability of connective tissue that has been implanted beneath the periosteum into periodontal osseous defects to reduce probing depth and increase clinical attachment levels. This study reports the long-term clinical effect of subperiosteal and intraosseous connective tissue grafts on deep periodontal pockets. METHODS: Connective tissue (CT) grafts were placed in 32 periodontal pockets on 27 patients. Grafts were classified into 3 groups. Type I grafts had 50% or more vascular surface contact and were < or = 2.5 mm thick. Type II grafts had 50% or more contact but were > 2.5 mm thick, and Type III grafts had less than 50% vascular contact regardless of thickness. Twelve of 14 Type I sites, 9 of 15 Type II sites, and 3 of 3 Type III sites were analyzed 9 to 13 years following treatment. RESULTS: Clinical attachment level change differed significantly between the graft types on survivor teeth (P < 0.05): Type III had 2 mm loss (95% confidence interval [CI]: 0.4 to 3.6), while Type II and Type I grafts had a 2.7 mm gain (95% CI: 2.0 to 3.4) and 4.3 mm gain (95% CI: 3.3 to 5.2), respectively. Similar substantial differences were presented for changes in probing depth and recession. CONCLUSIONS: This long-term (9 to 13 years) retrospective case-series analysis suggests substantial improvements in periodontal clinical measures for Type I CT grafts in deep periodontal pockets. Randomized trials are required to evaluate this promising procedure.     

Effect of porous and dense hydroxyapatite implantation on periodontal tissue regeneration in monkeys

Two different kinds of hydroxyapatite (HA) granules (size: 400-630 microns), 1) porous HA fabricated by the H2O2 bubbling method and 2) dense HA, were placed into the experimentally created, 3-wall, wide periodontal defects in two monkeys to evaluate whether the different structures of hydroxyapatite influence the periodontal response after implantation. Defects without HA implantation served as controls. The HA implant groups showed excellent biocompatibility. Both the porous HA and the dense HA showed a greater amount of "connective tissue attachment or adhesion" than the control group. The amount of the increase by the porous HA group was statistically significant when compared with the control group. However, the three groups showed a similar amount of new cementum formation. These results indicate that the improvement of tissue regeneration by hydroxyapatite implantation was probably due to the prevention of the epithelial downgrowth rather than to the acceleration of the coronal proliferation of the periodontal ligament cells. In the porous HA group, ingrowth of fibrous and osseous tissue in the HA and indefinite tissue-apatite interface were observed. These findings suggest that the porous HA granules formed a firmer attachment to the surrounding periodontal tissue.     

Freeze-dried bone and coralline implants compared in the dog

Partially demineralized, antigen-extracted, freeze-dried cadaver bone and a hydroxyapatite replica of a marine coral skeleton were implanted in 30 surgically created two-wall intrabony pockets in two dogs. Results after 6 and 8 months showed connective tissue encapsulation and some periodontal ligament formation around the cadaver bone. In contrast, the coralline implant was consistently invaded by fibrovascular tissue, showed bone formation on its internal surfaces and had some periodontal ligament formation around it.     

Subperiosteal connective tissue grafts for pocket reduction and preservation of gingival esthetics: a case report

BACKGROUND: Clinical studies and recent histological evidence following mucogingival surgery for the treatment of gingival recession have documented that when closely adapted to a previously exposed root surface, connective tissue is capable of forming a new attachment. Despite these findings, no clinical tests have been conducted to examine the ability of connective tissue to reduce probing depth (PD) and increase clinical attachment levels (CAL) when it is implanted into periodontal osseous defects. The purpose of this paper is to report the clinical results on a patient following 2 subperiosteal connective tissue grafts. METHODS: Subperiosteal connective tissue grafts were placed in 2 sites of periodontal bone loss and deep pocketing in one patient. Following flap reflection and root preparation, a connective tissue graft 1.5 to 2.0 mm in thickness was draped and sutured over each osseous defect and then completely covered by the external flap. RESULTS: Ten months following subperiosteal connective tissue grafting, tooth #7 had 4 mm of CAL gain. Tooth #10 had 3 mm of CAL gain 8 months postoperatively. Both teeth had 1 mm gain in gingival recession. Both teeth probed 3 mm postoperatively. CONCLUSIONS: When connective tissue was grafted into 2 periodontal osseous defects, there were significant reductions in probing depth and gains in CAL. There was minimal postoperative gingival recession. The new clinical attachment gain remained stable for 8 to 10 months following subperiosteal connective tissue grafting.     

Collagen membranes prevent apical migration of epithelium and support new connective tissue attachment during periodontal wound healing in dogs

The capacity of collagen membranes to prevent the apical migration of epithelium and to support new connective tissue attachment was assessed in experimental periodontal defects in dogs. Experimental periodontal defects were produced in 8 mongrel dogs by removing the alveolar bone and the periodontal ligament over the most coronal 5 mm of the labial aspect of the maxillary canines. Experimental defects associated with the right canine and its surrounding bone were covered by collagen membranes prepared by air drying gels of rat type I fibrillar collagen. Flaps were repositioned and sutured. The contralateral control defects were sham-operated without using collagen membranes. Animals were killed, 10 and 30 days after surgery, 4 at each time point. The experimental and control sites were processed for histologic and histomorphometric evaluation. At 10 d, the average distance between the apical margin of the epithelium and the apical level of the defect (EA) sites was 3.20 +/- 0.55 mm for the experimental sites and 0.73 +/- 0.18 mm for the controls. The experimental root surfaces apical to the epithelium and the collagen membranes were covered by connective tissue cells. At 30 d, the EA for experimental and control sites were 2.55 +/- 0.36 mm and 0.47 +/- 0.30 mm, respectively. In the experimental sites healing by long junctional epithelium was observed in the coronal 40% of apico-occlusal dimension of the defect and new connective tissue attachment with inserting fibers in the apical 55% of the defect length. No new bone formation was observed. In the control sites, pocket formation was found in the most coronal one-third of the defect.(ABSTRACT TRUNCATED AT 250 WORDS)     

A controlled re-entry study on the effectiveness of bovine porous bone mineral used in combination with a collagen membrane of porcine origin in the treatment of intrabony defects in humans

AIM: The purpose of this study was to evaluate the clinical effectiveness of a bovine porous bone mineral used in combination with a porcine derived collagen membrane as a barrier in promoting periodontal regeneration in intrabony defects in humans. MATERIAL AND METHODS: The study employed a split-mouth design. 22 paired intrabony defects were treated and surgically re-entered 6 months after treatment. Experimental sites were grafted with bovine porous bone mineral and received a collagen membrane for guided tissue regeneration. Control sites were treated with an open flap debridement. RESULTS: Preoperative pocket depths, attachment levels and trans-operative bone measurements were similar for control and experimental sites. Post surgical measurements revealed a significantly greater reduction in pocket depth (differences of 1.89 +/- 0.31 mm on buccal 0.88 +/- 0.27 mm on lingual measurements) and more gain in clinical attachment (differences of 1.51 +/- 0.33 mm on buccal and 1.50 +/- 0.35 mm on lingual measurements) in experimental sites. Surgical reentry of the treated defects revealed a significantly greater amount of defect fill in favor of experimental sites (differences of 2.67 +/- 0.91 mm on buccal and 2.54 +/- 0.87 mm on lingual measurements). CONCLUSIONS: The results of this study indicate that clinical resolution of intrabony defects can be achieved using a combination of bovine porous bone mineral and an absorbable, porcine derived collagen membrane when employing a technique based on the principles of guided tissue regeneration. The nature of the attachment between the newly regenerated tissue and the root surfaces needs to be evaluated histologically to confirm the presence of new attachment.     

Effect of surgical implantation of recombinant human bone morphogenetic protein-2 in a bioabsorbable collagen sponge or calcium phosphate putty carrier in intrabony periodontal defects in the baboon

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) in a proper carrier has been shown to induce clinically relevant bone formation for several oral/maxillofacial and periodontal indications and to stimulate regeneration of the periodontal attachment. The objective of this study is to evaluate regeneration of alveolar bone, cementum, periodontal ligament, and associated root resorption and ankylosis following surgical implantation of rhBMP-2 in an absorbable collagen sponge (ACS) or a calcium phosphate putty (alphaBSM) carrier in 3-wall intrabony periodontal defects in the baboon. METHODS: rhBMP-2/ACS and rhBMP-2/alphaBSM were implanted in surgically produced, maxillary and mandibular, large size, 3-wall intrabony defects in 4 baboons. Contralateral jaw quadrants were implanted with buffer/ACS, buffer/ alphaBSM, or served as sham-operated surgical controls. Treatments were allocated to left and right, maxillary and mandibular, jaw quadrants following a randomization schedule. Four months following implantation, block biopsies of defect sites were obtained, processed, and subjected to histologic and histometric analysis. RESULTS: Defect sites receiving rhBMP-2/ACS and rhBMP-2/alphaBSM demonstrated significantly greater regeneration than controls. No significant differences were observed between defect sites receiving rhBMP-2/ACS or rhBMP-2/alphaBSM regarding epithelial migration and connective tissue attachment and new bone formation. However, rhBMP-2/ACS supported significantly greater new cementum formation. Ankylosis or root resorption were not observed. CONCLUSIONS: The results of this study support the use of rhBMP-2 to enhance periodontal regeneration of intrabony periodontal defects. While this novel technology holds promise, refinement in carrier systems may provide the key to enhancement of the regenerative potential.     

Observation on implants of porous hydroxyapatite granules in periodontal osseous defects

The purpose of this study was to observe the regeneration of the periodontal tissue using porous hydroxyapatite granules in experimental periodontal lesions. The upper lateral incisors of three Macaca fuscatae were extracted. After a 12-week recovery period, three wall infrabony defects were surgically prepared on the distal surface of the central incisors. In order to accumulate the plaque and cause inflammation, a wire with dental floss was placed inside the defects for a period of four weeks and then removed. Flap operations were performed and porous hydroxyapatite granules were placed into the defects. Twelve weeks after surgery, the samples were taken out and fixed in glutaraldehyde solution. They were embedded in polyester resin and undecalcified sections were prepared. The specimens were stained with toluidine blue and observed under light microscope. Results: 1) The implanted area was divided into three distinctive zones. The first zone was located distally and occupied two-thirds of the total area. A large quantity of osseous tissue was detected. The second zone was situated near the root and presented only a small quantity of osseous tissue; Fibrous connective tissue predominated in the third zone adjacent to the root. 2) Bone apposition and resorption caused by physiologic mobility and movement of the teeth were observed. These results suggest that the elimination of the functional forces is advisable during the healing period whenever hydroxyapatite granules are placed into the periodontal defect.     

New attachment and bone formation in periodontal defects following treatment of submerged roots with guided tissue regeneration

Abstract The purpose of the present study was to examine the effect on periodontal regeneration of preventing bacterial contamination of the membrane material following the guided tissue regeneration procedure (GTR). Periodontal dehiscence defects were surgically produced in 2 monkeys. In each monkey, 8 of these defects were submerged after resection of the crowns of the teeth and a teflon (Gore-Tex Periodontal Material®) or a polyglactin (Vicryl Mesh®) membrane was adjusted to cover the defect and the exposed root surface. 4 defects on non-crown resected teeth were treated with either a teflon or a polyglactin membrane positioned with the coronal border approximately 2 mm below the margin of the covering tissue flap. Following 6 months of healing, the animals were sacrificed. Histological evaluation of the specimens revealed that roots which were kept completely covered during the healing period demonstrated new connective tissue attachment and bone formation corresponding to 67–100% of the length of the initial defect depth, whereas the amount of new connective tissue attachment and bone on non-submerged roots ranged between 30–59% and 11–31%, respectively. It seems reasonable to anticipate that it is bacterial contamination of the membrane material which jeopardizes the formation of new connective tissue attachment but in particular bone formation following the GTR-procedure.     

Tissue response to biphasic calcium phosphate ceramic with different ratios of HA/beta TCP in periodontal osseous defects.

The purpose of this study was to determine the optimal ratio of calcium hydroxyapatite (HA) to beta tricalcium phosphate (beta TCP) in a biphasic porous calcium phosphate (BCP) ceramic for effective repair of periodontal osseous defects. Defects were surgically produced in beagle dogs and made chronic for 4 months to simulate periodontal disease. Mucoperiosteal periodontal flaps were reflected, followed by osseous defect debridement and root planing. Specially prepared ceramic with different HA/beta TCP ratios were implanted into the prepared defects. The sites were allowed to heal for 6 months, animals were euthanized, and site-blocks were removed for histological study. During the follow-up phase, scaling and polishing were done once a month, and standardized probing attachment levels were recorded pre- and 6-months postoperatively. The Duncan's multiple range test showed that all the treatments produced statistically significant higher gain in probing attachment levels than the control group (0HA/0 beta TCP) (P < 0.05). Among the 7 "active" treatment groups, 2 (65/35 and 85/15) had significantly higher gain in probing attachment levels than those in 3 groups (50/50, 100/0, and 0/100) (P < 0.05). Histologically, higher HA ratio (but not 100% HA) showed accelerated new bone formation and new attachment levels. Based on histological results, the 85HA/15 beta TCP ratio appears to demonstrate greater gain in attachment level and bone regeneration in the treatment of periodontal osseous defects.     

The significance of alveolar bone in periodontal disease

The periodontal conditions in 19 patients with unilateral cleft lip, alveolus and palate (CLAP) and in 6 patients with bilateral CLAP, were evaluated in 1979 and re-examined in 1987. During these 8 years, these patients were not subjected to any professionally supervised maintenance care program. Pronounced plaque accumulation and high frequency of gingival units exhibiting bleeding on probing were noted in the majority of the patients both in 1979 and 1987, documenting inadequate oral hygiene standards with resulting inflammatory reactions of the periodontal tissues. Progression of periodontal disease over time was assessed as loss of clinical attachment and loss of alveolar bone height. The periodontal destruction was not found to be more severe at cleft sites with a long connective tissue attachment than at control sites not affected by cleft defects. It was concluded that sites with a long supracrestal connective tissue attachment do not seem to be more prone to periodontal destruction, induced by bacterial infection, than sites with a normal length of the supraalveolar fibrous attachment. The results also show that the alveolar bone height, as visualized in radiographs at sites with alveolar defects, is of limited value for the diagnosis of the degree of periodontal destruction at such sites.     

Regeneration of oxytalan fibres in different types of periodontal defects: a histological study in monkeys

The aim of the present study was to investigate in monkeys the regrowth of oxytalan fibres in different types of acute and chronic periodontal defects following regenerative periodontal treatment. One-wall intrabony and mandibular furcation III-defects were produced surgically in 3 monkeys (Macaca fascicularis). After a 6-wk dental plaque accumulation period the defects were exposed using a full thickness flap procedure. The granulation tissue was removed and the root surfaces were scaled and planed. Additionally, fenestration-type defects were produced at the vestibular surfaces of the maxillary and mandibular canines by surgically removing the vestibular bone plates and the root cementum. Subsequently, the defects were treated with guided tissue regeneration (GTR), enamel matrix proteins (EMP), combination of EMP and GTR or with coronally repositioned flaps. The postoperative care included tooth cleaning once a week during the experiment. After 5 months the animals were sacrificed and and the block sections were embedded in paraffin. Eight μm histological sections were cut and stained with the oxone-aldehyde-fuchsin-Halmi method. The results revealed that in all specimens where a regenerated periodontal ligament could be observed newly formed oxytalan fibers were present. They had a mainly apico-occlusal orientation and were localized closer to the cementum than to the alveolar bone. The regenerated oxytalan fibers had a similar morphological appearance than those observed in the original periodontal ligament regardless of the treatment modality by which regeneration was accomplished. Their presence was related to that of newly formed cementum suggesting a strong relationship between these 2 tissues. The neoformation of oxytalan fibres can thus be observed in some types of periodontal defects where the cementum and the periodontal ligament have been regenerated.     

Healing following surgical treatment and root demineralization in monkeys with periodontal disease

Abstract The aim of the present investigation was to study the potential for new attachment to root surfaces which 1) had become devoid of attachment either by mechanical removal or in conjunction with experimental periodontal tissue breakdown and 2) subsequently had been conditioned with citric acid. Three adult monkeys (Macaca cynomolgus) were used. Periodontal pockets were produced during a 2–6-month period around the maxillary central incisors and first and second premolars and around the mandibular central incisors by the placement of orthodontic elastics. Surgical treatment of the pockets was carried out with the use of a flap procedure. During surgery, the roots of the premolars on the right side of the jaws were first scaled and planed and subsequently treated with citric acid. Citric acid conditioning was not performed on the premolars of the left side. In the front tooth regions the surgical treatment included citric acid conditioning of the mandibular central incisors in two animals and of the maxillary central incisors in one animal. Surgical procedures were also carried out around the mandibular second premolars and first molars which had not been exposed to periodontal tissue breakdown. Folio wing flap elevation, the buccal bone plate was mechanically removed within an area corresponding to that of bone loss produced by the experimental periodontitis model in the maxillary premolars. The cementum layer of the surgically denuded portion of the roots was removed by root planing. In all treated teeth, a notch was prepared in the buccal root surfaces at the level of the alveolar bone crest. Six months following treatment the animals were sacrificed and histologic sections prepared. Linear measurements were made along the root surface from the apical border of the prepared notch to the apical termination of the junctional epithelium and to the crest of the alveolar bone. The results demonstrated that cementum formation and new connective tissue attachment did not occur on root surfaces previously exposed to periodontal pockets and subsequently subjected to scaling and root planing or on root surfaces surgically deprived of their supporting bone and previously “non-exposed” cementum layer. Cementum formation and new connective tissue attachment also failed to occur following citric acid conditioning of root dentin surfaces. In all sections representing all three treatment groups, the attachment between the gingiva and the root was established by epithelium.     

Study on hybrid materials compounded with porous hydroxyapatite and culture cells. 1. Attachment and the invasion of cultured cells to porous hydroxyapatite

The purpose of this study was to investigate the effects of hybrid material compounded with periodontal ligament cells on human teeth and porous hydroxyapatite. As the first step, we tried to produce hybrid materials compounded with periodontal ligament cells and porous hydroxyapatite, and to observe the attachment and invasion of periodontal ligament cells porous hydroxyapatite. Human periodontal ligament cells which had been scraped off the root with a disposable blade were cultured at 37 degrees C in alpha-MEM plus 10% fetal calf serum. The culture cells were attached to the porous hydroxyapatite in vitro. After 3 and 14 days of incubation, the specimens were fixed in gluteraldehyde and examined using SEM. Other specimens were embedded in paraffin and successive specimens were prepared for to remodelling of the attachment and invasion. Many cells attached to the P-HAP granules, and some cells invaded the P-HAP granules. The results suggest that when these hybrid materials are implanted in bone defects, the cells remain in the defect for a certain period, and exhibit the functions and characteristics of itself.     

Periodontal response after tooth movement into intrabony defects

The present study was undertaken since conflicting evidence exists regarding the effect of such tooth movement on levels of connective tissue attachment. Localized intrabony pockets were produced around isolated incisors in four rhesus monkeys. The root surfaces were planned to the level of the bone at the base of the angular bony defects. An oral hygiene regime was begun and continued for the remainder of the study. The experimental teeth were moved orthodontically into, and through, the original area of the intrabony defect. Two months after cessation of active tooth movement, block specimens were removed for histologic analysis. Control specimens comprised those teeth with induced periodontal defects, but without tooth movement. In specimens not subjected to tooth movement, angular bony defects were present and epithelium lined the root surface to the apical extent of instrumentation. The alveolar bone adjacent to the orthodontically moved teeth no longer had angular defect morphology. On the pressure side, epithelium lined the root surface, was interposed between root surface and bone and terminated at the apical limit of root instrumentation. On the tension side, the crest of the bone was located apical to the level of root planing, and epithelium lined the instrumented portion of the root surface. It was concluded that orthodontic tooth movement into intrabony periodontal defects was without effect upon the levels of connective tissue attachment.     

The regenerative potential of oxytalan fibers An experimental study in the monkey

Abstract Although a number of studies have described the oxytalan fibers as being a natural component of the periodontal ligament, little information exists about the regenerative potential of these connective tissue fibers. The aim of the present study was to examine whether oxytalan fibers have the capacity to reform after regenerative periodontal therapy, Intrabony defects were produced surgically at the mesial aspects of teeth 37, 35, 45, 47 and at the distal aspects of teeth 11, 21, 31, 41 in one monkey (Macaca faseicularis).After 3 months, the defects were exposed using a full-thickness flap procedure. The root surfaces were debrided and subsequently PDGF-growth factors were placed in the defects. 4 of the 8 sites were covered with a bioresorbable membrane before closure of the wound. Post-surgically, antibiotics were given systemically for 1 week, and tooth cleaning was carried out 1 × a week during the entire experimental period. After 5 months, the animal was sacrificed and the oral tissues were fixed by perfusion with 10% buffered formalin. Specimens containing the defects and surrounding tissues were dissected free and histological sections were cut in the mesio-distal direction, parallel to the long axes of the teeth. The sections were stained with hematoxylin and eosin or with the oxone-aldehyde-fuchsin-Halmi staining method and subsequently examined in the light and in the electron microscope. The results revealed that new oxytalan fibers oriented mainly in an apico-occlusal direction had developed in the regenerated periodontal ligament. Many of the newly-formed fibers were inserted into the new cementum, thus suggesting a strong relationship between this tissue and the oxytalan fibers. It is concluded that the regenerated periodontal ligament connective tissue formed after surgery contains oxytalan fibers similar to those present in the original tissue. These results demonstrate that oxytalan fibers develop de novo in the newly-formed periodontal ligament.     

New periodontal attachment procedure based on retardation of epithelial migration

Abstract A new attachment procedure based on retardation of epithelial downgrowth was used for the surgical treatment of 88 intrabony periodontal defects. Split flaps were made at the vestibular and oral aspect of the intrabony defect leaving a layer of connective tissue on the bone and corresponding to the missing bony walls. Granulation tissue was removed from the defect and the root surface planed. After transplantation of autogenous cancellous bone grafts from edentulous ridges, the defect was covered with a free palatal graft which was sutured to the adjacent, attached gingiva and underlying periosteum. The grafted area was covered with telfa and Coe pack was applied for 1–2 weeks. This procedure and a modification of it resulted in a markedly greater zone of new attachment when compared with traditional flap surgery. Residual pockets deeper than 3 mm were found in only 10 per cent of the defects treated by the soft tissue grafting technique.     

Comparison of freeze-dried bone allograft and porous hydroxylapatite in human periodontal defects

This study was conducted to clinically compare the efficacy of freeze-dried bone allograft (FDBA) and porous hydroxylapatite granules. Nineteen pairs of intraosseous defects were grafted in seven patients. One defect of each pair was implanted with FDBA, the other with granular porous hydroxylapatite. Matching defects were treated similarly in all other aspects. Evaluations were based on both preoperative and postoperative measurements from a fixed reference point, standardized radiographs, surgical osseous measurements, and histology of degranulated tissues. Grafted sites were reentered 6 to 11 months postsurgery. Results showed a mean osseous fill of 2.1 mm for FDBA versus 1.3 mm for granular porous hydroxylapatite (P = .07). A mean clinical attachment gain of 2.2 mm for FDBA versus 1.3 mm for granular porous hydroxylapatite (P less than .05), and a mean decrease in probing depths of 3.0 mm for FDBA versus 1.4 mm for granular porous hydroxylapatite (P less than 0.5) was found. FDBA was clinically indistinguishable from host bone, whereas porous hydroxylapatite appeared to be separated from host bone by soft tissue. The data and clinical findings suggested that FDBA may have some enhanced reparative potential when compared to granular porous hydroxylapatite in the treatment of periodontal defects in humans.     

Human freeze-dried dura mater allografts as a periodontal biological bandage

Freeze-dried dura mater allografts (FDDMA) were used as a biologic bandage covering periodontal osseous defects which were grafted with autogenous bone particles. Seven consenting adult patients having multiple one-, two-, and wide three-wall periodontal osseous defects participated in the study. Four to 6 weeks following initial preparation, all defects were treated by full thickness flap surgery, debridement of defects, root planing, intramarrow penetration as needed, and autogenous bone grafts that filled the defects. Randomly selected grafted defects in each patient were then covered with FDDMA (experimental) or by the host flap (RF) (control). Periodontal dressing and systemic tetracycline (250 mg q.i.d.) were used for 7 days. Frequent maintenance was performed until reevaluation at 6 months postsurgically. Soft tissue results showed no significant differences in initial probing pocket depths, recession, or gain of probing attachment. There was a significantly greater amount of probing pocket depth reduction and significantly shallower residual pockets when FDDMA was used. Hard tissue findings indicated that there were no significant differences in initial defect depth, amount of crestal resorption, or amount or percent of defect fill with either treatment. There were significant differences in the percent of defect resolution and the depth of the residual defect in favor of the FDDMA treatment. None of the FDDMA sites were felt to need a secondary surgery to correct residual defects or residual pockets. This study suggests that FDDMA may be beneficial as a "biologic bandage" to cover periodontal osseous defects that were filled with autogenous bone grafts. The trends in this study suggest that FDDMA may be very useful in periodontal regeneration procedures.