Histology of a human biopsy section following the placement of a subepithelial connective tissue graft

This case report histologically examines the type of attachment that can occur after root coverage of a long-standing facial recession defect on a maxillary premolar with a subepithelial connective tissue graft. Histologic findings suggest that various types of tissue attachment, including periodontal regeneration, may occur over a recession defect after placement of a subepithelial connective tissue graft. In the present case, it was noteworthy that after 1 year the greatest area of exposed root surface was covered by a connective tissue attachment (adhesion), which had remained intact during orthodontic movement and distal drifting of the tooth.

The treatment of intrabony defects with bone grafts

There is substantial clinical and histological evidence that support the concept that extraoral and intraoral autogenous bone grafts and demineralized freeze-dried bone allografts are effective regenerative materials in the treatment of intrabony defects. Moreover, long-term evaluations currently available suggest that the regenerative gains achieved remain clinically stable. Synthetic grafts may result in improved probing depths and clinical attachment levels but have yet to demonstrate the ability to initiate or enhance the formation of a new attachment apparatus.

Supracrestal bone regeneration: a pilot study

The purpose of this study was to determine the feasibility of regenerating bone in patients with advanced horizontal bone loss. Demineralized freeze-dried bone allografts (DFDBA) in particle, strut, and laminar forms were used in combination with guided tissue regeneration. The cortical struts and strips were processed from long bones and were supplied in different widths and lengths. The strips were prepared in various thicknesses ranging from 100 to 500 microns; the struts ranged from 1 to 3 mm thick. These 2 materials provided structural support for the retention of DFDBA particles supracrestally, and they supported the gingival flap as a space maintainer, preventing the collapse of the tissue onto the roots and existing bone. The results indicated successful supracrestal regeneration of horizontal defects when combining existing techniques and materials. The mean attachment gain for the 7 patients studied ranged from 2.6 to 3.0 mm.

A technique report on the in situ application of Atrisorb as a barrier for combination therapy

This article describes a novel technique in which Atrisorb (Atrix Laboratories) is applied in situ as a barrier over a demineralized freeze-dried bone allograft on roots treated with citric acid. Follow-up reentry at 4.5 months demonstrated the effectiveness of this procedure. A rationale for in situ barrier application is presented.

Regenerative therapy in the treatment of maxillary molar Class II furcations: case reports

This report demonstrates the use of regenerative therapy in the treatment of maxillary molar Class II furcations. The predominant therapy provided was open debridement in combination with DFDBA, e-PTFE membranes, and citric acid root conditioning. Case reports of consecutively treated patients that include radiographs and reentry photographs demonstrate that maxillary molar furcations can be successfully treated with predictability.

Pedicle procedure use in the management of regenerative therapy problems

Regenerating a periodontium that has been lost because of disease has been made possible by the use of demineralized freeze-dried bone allografts (DFDBA), guided tissue regeneration with e-PTFE membranes, and combination therapies involving DFDBA covered by either an e-PTFE membrane or calcium sulfate. During regenerative therapy, problems may arise because of an adverse mucogingival condition, loss of a papilla, or significant exposure of the membrane from soft-tissue recession, slough, or fenestration leading to direct exposure of the site to the oral environment. Pedicle procedures can be used to cover these regenerative sites while providing mucogingival repair.

Modifications of the subpedicle connective tissue graft technique: a predictable procedure for covering exposed roots

This article reviews modifications to Nelson's technique for covering exposed roots using an autogenous connective tissue graft covered by a double papilla pedicle graft. Case reports will illustrate how this technique can be used for both root surfaces pathologically exposed to the oral environment and those previously restored with cosmetic bonding procedures. Enhancements of this procedure over Nelson's original description will be enumerated, and advantages over other root coverage modalities will be presented.

Fate of demineralized freeze-dried bone allografts in human intrabony defects

Demineralized freeze-dried bone (DFDBA) is the most widely used allograft in periodontics. Little information exists, however, on the fate of DFDBA matrix or on the effects of residual particles within grafted defects. The purpose of this study was to histologically examine the fate of DFDBA used for regeneration in intrabony defects. A secondary objective was to compare the amount of new attachment apparatus formation, including component tissues, in relation to the presence or absence of residual graft material. Histologic data were obtained from earlier studies in which intrabony defects grafted with DFDBA were removed at 6 months en bloc and submitted for histologic examination. Histologic sections (1,120) from 12 patients with 32 grafted defects revealed that 72% of the grafted defects exhibited residual DFDBA particles. When present, DFDBA appeared amalgamated within the new viable bone. Data from 5 patients with 14 grafted sites permitted a within-subject comparison of the amount of regeneration in relation to the presence or absence of residual graft material. Defects harboring residual graft particles exhibited significantly greater amounts of new attachment apparatus formation (1.72 mm vs. 0.20 mm), including new bone (2.33 mm vs. 0.23 mm), cementum (1.74 mm vs. 0.23 mm), and associated periodontal ligament than sites without evidence of graft matrix (P < or = 0.05). No apparent differences were seen in the nature of the new attachment apparatus or component tissues, other than in amount of formation. Inflammation and graft containment appear to be important factors influencing the fate of DFDBA and the regenerative response.

Correction of a large periradicular lesion and mucosal defect using combined endodontic and periodontal therapy: a case report

The successful treatment of a large endodontically induced periradicular defect and soft tissue fenestration by combined endodontic and periodontal therapy is described. Endodontics was performed on the mandibular left central incisor, the apex was resected, and a retrograde amalgam was placed. The defect was thoroughly debrided and the exposed root surface was planed with curettes. Demineralized freeze-dried bone allograft and a nonresorbable membrane were placed over the defect and the exposed root surface. The membrane was removed in 6 months and there appeared to be bone regeneration with complete closure of the soft tissue fenestration. Endodontic therapy in combination with guided tissue regeneration and bone grafting may provide another modality of treatment for endodontically related hard and soft tissue defects.

Periodontal regeneration of intrabony defects: an evidence-based treatment approach

A task force of periodontists established clinical and histologic outcomes (goals) for the treatment of intrabony defects and researched the literature for techniques that would most predictably achieve these goals. The group also identified factors that could influence predictability. The treatment outcomes selected by the task force included regeneration of a true attachment apparatus; gain in bone and probing attachment levels; reduction in probing pocket depth; minimal gingival recession; increased patient comfort; esthetic appearance and state of wellness; and maintenance of health, comfort, and function over time. Based on evidence, it was concluded that guided tissue regeneration, guided tissue regeneration combined with the use of decalcified freeze dried bone allografts and freeze-dried bone allografts alone are the most predictable regenerative procedures for achieving selected treatment outcomes. Various factors, such as patient characteristics, the morphology of the defect, and the surgical technique can influence the healing response of intrabony defects. Patient factors, such as plaque control, compliance, and cigarette smoking, can directly affect predictability of periodontal regeneration. Defect selection is critical, and deep and narrow defects are the most predictable response to regenerative procedures. The number of remaining bony walls is important in grafting procedures, but their influence is questionable in guided tissue regeneration. Various technical procedures, such as flap design, defect debridement, and wound protection, may influence the predictability of regeneration.

Regenerating the periodontium in advanced periodontal disease

Current techniques can benefit patients with advanced periodontal disease and oral injuries. Future technology offers even greater promise for regenerating periodontal tissue.

Regenerating bone in clinical periodontics

Bone autografts and allografts, various alloplastic materials, and guided tissue regeneration are used to reconstruct lost periodontal tissues. This paper focuses on controversies related to these therapeutic modalities as well as their role in periodontal regeneration.

The apical location of calculus within the intrabony defect

Although several studies have concluded that calculus removal becomes more difficult as pocket depth increases, few have examined the clinical location of calculus within the intrabony defect. This study evaluated the relationship between apical calculus position and the depth and morphology of the intrabony defect. As part of an on-going study of new attachment procedures in humans, 260 intrabony defects were surgically entered in 39 patients. Using magnifying loops and fiber optics in all defects, the most apical level of calculus was grooved to serve as both a clinical and histologic reference point. Clinical measurements made prior to root debridement included the alveolar crest to base of calculus, and the base of calculus to base of defect. The type of defect was classified by the number of remaining osseous walls. Calculus has not been found apical to the groove in any histologic section. The mean distance measured clinically between the base of the calculus and the base of the defect was found to increase with the depth of the defect. This relationship did not vary with either tooth type or number of remaining osseous walls in the defect. Data analysis of this group of patients (N = 39) showed a positive correlation (r = .83) between increasing depth of intrabony defect and the distance of the most apical calculus from the defect base.

Histologic evaluation of new attachment apparatus formation in humans. Part I

Part I of this three-part human study evaluated the formation of a new attachment apparatus (bone, cementum, and periodontal ligament) on pathologically exposed root surfaces in an open and closed environment. The most apical level of calculus on the root served as a histologic reference point to measure regeneration on root surfaces exposed to the oral environment. Attempts were made to initiate the formation of a new attachment apparatus by flap curettage, root planing, coronectomy, and submersion of vital roots beneath the mucosa. Nonsubmerged defects were treated by the same surgical technique and served as controls. Biopsies were obtained at 6 months and regeneration was evaluated histometrically by two investigators who were unaware of the treatment performed. Data from 9 patients with 25 submerged and 22 nonsubmerged defects were submitted for statistical analysis. Results indicate that a new attachment apparatus did not form in any of the 22 nonsubmerged teeth; a new attachment apparatus did form in a submerged environment (0.75 mm); significantly more new attachment apparatus (P less than 0.05), new cementum (P less than 0.01), new connective tissue (P less than 0.05), and new bone (P less than 0.02) formed in submerged defects; new cementum was cellular in nature and formed equally well on old cementum and dentin. Greater percent positive regeneration of the attachment apparatus and all component tissues occurred in submerged defects and no extensive root resorption, ankylosis, or pulp death was observed on submerged or nonsubmerged roots.

Histologic evaluation of new attachment apparatus formation in humans. Part III

There is still controversy as to the role of bone grafting materials in the formation of a new attachment apparatus and component tissues (bone, cementum, and periodontal ligament). The purpose of this study was to compare the healing of intrabony defects with and without the placement of decalcified freeze-dried bone allograft (DFDBA) in a nonsubmerged environment in humans. The most apical level of calculus on the root served as a histologic reference point to delineate root surfaces exposed to the oral environment and to measure new attachment apparatus and new component tissue formation. Free gingival grafts were placed over grafted and nongrafted defects to retard epithelial migration. Biopsies were obtained at 6 months and regeneration was evaluated histometrically. Data from 12 patients with 32 grafted and 25 nongrafted defects were submitted for statistical analysis. Results indicate that in nongrafted defects, a long junctional epithelium formed along the entire length of exposed root surfaces and often extended apical to the calculus reference notch. Free gingival grafts did not enhance regeneration of a new attachment apparatus, new cementum, new connective tissue, or new bone in nongrafted defects. The formation of a new attachment apparatus was observed when intrabony defects were grafted with DFDBA (x1.21 mm); significantly more new attachment apparatus (P less than .005), new cementum (P less than .005), new connective tissue (P less than .05), and new bone (P less than .0001) formed in intrabony defects grafted with DFDBA than in nongrafted defects. There was a greater chance for regeneration of a new attachment apparatus and component tissues in grafted defects than in nongrafted defects. New cellular cementum formed on old cementum and dentin but more often formed over both in the same defect). The periodontal ligament was more frequently oriented perpendicular to the root; there was greater loss in alveolar crest height in nongrafted than grafted defects (P less than .05); and extensive root resorption, ankylosis, and pulp death were not observed in grafted or nongrafted defects.

Histologic evaluation of new attachment apparatus formation in humans. Part II

There is conflicting evidence regarding the value of graft materials in enhancing the formation of new bone, cementum, and periodontal ligament (new attachment apparatus). Part II of this study compared the healing of intrabony defects with and without the placement of decalcified freeze-dried bone allograft (DFDBA) in a submerged environment. The most apical level of calculus on the root served as a histologic reference point to measure regeneration on root surfaces exposed to the oral environment. Biopsies were obtained at 6-months and evaluated histometrically by two investigators unaware of the treatment performed. Data from 9 patients with 30 grafted defects and 13 nongrafted defects were submitted for statistical analysis. Results indicate that in a submerged environment significantly more new attachment apparatus (P less than .05) and new bone (P less than .05) formed in grafted than nongrafted sites. Significantly greater loss of alveolar crest height occurred in nongrafted than grafted defects (P less than .05); regeneration of new attachment apparatus, new bone, and new cementum occurred more frequently in grafted than nongrafted defects. There was a greater chance for the regeneration of a connective tissue attachment in nongrafted intrabony defects than in grafted defects; new cellular cementum formed equally well on old cementum, dentin, or both old cementum and dentin in the same defect. The periodontal ligament was oriented parallel, perpendicular, or both parallel and perpendicular in the same defect; and, no extensive root resorption, ankylosis, or pulp death was observed in grafted or nongrafted defects.

Histologic observations following the placement of tricalcium phosphate implants in human intrabony defects

Biopsies of soft tissue with visible ceramic particles were removed from the coronal part of grafted sites during reentry surgery. After 1 year there was evidence of osteoid forming alongside and within many of the ceramic particles. Viable fragments of mature bone were also observed separate from the ceramic material.

Histologic evaluation of new attachment in humans. A preliminary report

This study was designed to evaluate the potential for regeneration of a new attachment (alveolar bone, cementum and a functional periodontal ligament) in patients whose attachment apparatus had been destroyed by periodontal disease. In each of the three parts of the investigation, the most apical level of calculus on the root served as a histologic reference point to measure regeneration. In Part I, attempts were made to initiate the formation of a new attachment by surgical debridement, crown removal (coronectomy) and submersion of the vital root below the mucosa. Nonsubmerged, surgically debrided defects served as controls. In Part II, debrided intrabony defects were treated with and without demineralized freeze-dried bone allograft and the associated vital roots were submerged. Part III evaluated potential for regeneration of a new attachment in nonsubmerged roots with and without the use of demineralized freeze-dried bone allograft. Gingival grafts were placed over the experimental and control sites in an attempt to retard epithelial migration. Biopsies were obtained in 6 months and regeneration was evaluated histometrically. Preliminary results in 7 patients and 24 intrabony defects indicate that new attachment is possible on pathologically exposed root surfaces in a submerged environment with and without the incorporation of demineralized freeze-dried bone allografts. New attachment was observed on pathologically exposed root surfaces in a nonsubmerged environment when intrabony defects were grafted with demineralized freeze-dried bone allograft. New attachment was not observed on nongrafted, nonsubmerged, defects with and without the placement of gingival grafts over the defects.

Clinical evaluation of freeze-dried bone allografts in periodontal osseous defects. Part III. Composite freeze-dried bone allografts with and without autogenous bone grafts

Freeze-dried bone allografts (FDBAs) were evaluated alone and in combination with various types of autogenous bone in the treatment of periodontal osseous defects. A total of 381 defects were evaluated by surgical reentry approximately 1 year after grafting. Reentry data were compared with similar data obtained when the grafts were placed. Osseous regeneration and pocket reduction were rated as complete, greater than 50%, less than 50%, or failed. Complete or greater than 50% regeneration was considered successful. When compared with FDBAs, composite freeze-dried bone allografts/autogenous bone grafts (FDBA/ABGs) appear to offer significantly improved results in both osseous regeneration and pocket reduction. Use of composite FDBA/ABGs resulted in significant improvement in the treatment of combination one/two-wall defects and furcation involvements. A trend of improvement was seen with two-wall defects. The surgical data indicated that complete wound closure and the use of antibiotics enhanced graft success. The results also indicated that the presence of endodontically obturated teeth may be a consideration in the success or failure of the graft.

Comparison of bone graft materials. Part I. New bone formation with autografts and allografts determined by Strontium-85

The purpose of this study was to obtain a direct comparison of the bone forming abilities of autogenous osseous coagulum, autogenous bone blend, freeze-dried bone allograft, and decalcified freeze-dried bone allograft. Defects were created in the calvaria of 35 guinea pigs. The graft materials were placed in porous nylon chambers and implanted into the defects. Empty nylon chambers served as the controls. Three days prior to sacrifice, each animal received an injection of 85Sr. The animals were killed in groups of five at 3, 7, 14, 21 28, 35, and 42 days. At sacrifice, a small section of ilium was removed from each animal. The samples were recovered, weighed, and the uptake of 85Sr into new bone determined. An osteogenic index was obtained by dividing cpm/mg for each sample by cpm/mg of ilium. It was concluded that in this model system decalcified freeze-dried bone allograft is a graft material of high osteogenic potential while autogenous bone blend and osseous coagulum were of less potential, and freeze-dried bone allograft even less.

Comparison of bone graft materials. Part II. New bone formation with autografts and allografts: a histological evaluation

The purpose of this study was to make a direct histological comparison of new bone formation evoked by decalcified freeze-dried bone allograft, freeze-dried bone allograft, autogenous osseous coagulum, and autogenous bone blend. Defects were surgically created in the calvaria of 35 guinea pigs. The graft materials were placed in porous nylon chambers and implanted into the defects. Implanted empty nylon chambers served as controls. The animals were sacrificed at 3, 7, 14, 21, 28, 35, and 42 days. New bone formation was determined quantitatively from histologic preparations. It was concluded that, in this model system, decalcified freeze-dried bone allograft is a graft material of high osteogenic potential; autogenous osseous coagulum and bone blend of less potential, and freeze-dried bone allograft even less.

The effect of particle size on the osteogenic activity of composite grafts of allogeneic freeze-dried bone and autogenous marrow

This study was carried out to determine if particle size is a factor to be considered in the evaluation of the osteogenic activity of freeze-dried bone allografts (FDBA) and, if so, whether small particles enhance or inhibit osteogenesis. Small particle FDBA (100-300 microns) plus marrow and large particle FDBA (1000-2000 microns) plus marrow were placed in plexiglass diffusion chambers secured to the femurs of six Rhesus monkeys. Control chambers contained either marrow alone or were left empty. Two animals were given injections of oxytetracycline hydrochloride at 5 and 7 weeks to obtain intravital osseous labeling. All chambers were removed after 8 weeks. Ten chambers were evaluated for new bone formation by fluorescent microscopy. The contents of 15 additional chambers were evaluated by single blind technique for presence or absence of bone resorption and ossification. The results indicated that there was significantly more new bone formation associated with small particle FDBA (100-300 microns) plus autogenous marrow than with large particle FDBA (1000-2000 microns) plus autogenous marrow. In addition, small particle FDBA (100-300 microns) plus autogenous marrow tended to display more resorption than large particle FDBA (1000-2000 microns) plus autogenous marrow. It was concluded that within the parameters of this study, small particles of FDBA enhance osteogenesis. This study also demonstrated that particle size is a variable to be considered when comparing the osteogenic potential of freeze-dried bone allografts.

Clinical evaluation of freeze-dried bone allografts in periodontal osseous defects--part II

Freeze-dried crushed cortical bone allografts were implanted into widemouthed three-wall, two-wall, one-wall, combination, and furcation defects. One hundred eighty-nine sites were reentered in 97 patients and of these 60% had osseous regeneration of greater than 50%. A total of 231 sites were evaluated for pocket elimination, of which 63% demonstrated greater than 50% pocket reduction. This study presented additional evidence indicating that freeze-dried bone allografts have definite potential as grafting material in certain periodontal osseous defects. Information from additional cases is being tabulated as it becomes available and will supplement the current data.

A clinical study of healing in humans following the excisional new attachment procedure

The excisional new attachment procedure was used to treat 75 suprabony pockets on 32 teeth in 9 patients. One-year postoperative measurements demonstrated an overall mean pocket reduction from 4.7 mm to 2.0 mm, of which 2.1 mm (77%) was new attachment and 0.6 mm was recession. Average amount of new attachment and percentage of new attachment were greatest on the midlingual surfaces of the teeth treated in this study. The results of this study showed the excisional new attachment procedure to be a simple, effective, and predictable procedure for achieving pocket elimination by means of a clinical new attachment of the gingival tissues in suprabony pockets.

The effects of facial bone from facial tipping of incisors in monkeys

Four male monkeys were utilized to determine whether alveolar dehiscences of fenestrations could be produced by facial tipping of mandibular incisor teeth. Two experimental teeth and two controls were chosen in each monkey. The experimental incisors were moved facially from 2.1 to 5.0 mm over a period of 36 to 95 days. Following movement, the teeth were placed in retention and the monkeys were sacrificed at 0, 30, 60, and 120 days. Clinical measurements were made prior or orthodontic movement by laying a mucoperiosteal flap and measuring the height of the alveolar crest. Measurements were also taken at the time of sacrifice and experimental and control tooth in each animal was used for histological examination. The results were as follows: 1. There was no significant difference in bone loss between the control and experimental teeth. 2. No dehiscences or fenestrations developed with the facial movement of the experimental teeth.

Clinical evaluation of freeze-dried bone allografts in periodontal osseous defects

Freeze-dried cortical bone allografts of a fine particle size were implanted into wide three-wall, two-wall, one-wall, combination, and furcation defects. Of the 97 defects treated, 23 manifested complete bone regeneration; 39 showed greater than 50%; and 24, less than 50% osseous repair. Twelve defects failed to demonstrate any bony regeneration, of which nine were furcation involvements. From the preliminary data available, there is strong evidence which indicates that freeze-dried bone allografts have definite potential as grafting material in certain periodontal osseous defects. However, final determination must await the outcome of a larger number of cases and also histologic evidence.