Longitudinal evaluation of durapatite ceramic as an alloplastic implant in periodontal osseous defects after 3 years

Biofabricated marine hydrozoan: a bioactive crystalline material promoting ossification of mesenchymal stem cells

This study introduces a novel three-dimensional biomatrix obtained from the marine hydrocoral Millepora dichotoma as a scaffold for hard tissue engineering. Millepora dichotoma was biofabricated under field and laboratory conditions. Three-dimensional biomatrices were made in order to convert mesenchymal stem cells (MSCs) to exemplify osteoblastic phenotype. We investigated the effect of the biomatrices on MSCs proliferation and differentiation at 2, 3, 4, 7, 10, 14, 21, 28, and 42 days. Different analyses were made: light microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), calcium incorporation to newly formed tissue (alizarin red), bone nodule formation (von Kossa), fat aggregate formation (oil red O), collagen type I immunofluorescence, DNA concentrations, alkaline phosphatase (ALP) activity, and osteocalcin concentrations. MSCs seeded on Millepora dichotoma biomatrices showed higher levels of calcium and phosphate incorporation and higher type I collagen levels than did control Porites lutea biomatrices. ALP activity revealed that MSCs seeded on M. dichotoma biomatrices are highly osteogenic compared to those on control biomatrices. The osteocalcin content of MSCs seeded on M. dichotoma remained constant up to 2 weeks before rising to surpass that of seeded P. lutea biomatrices after 28 days. Our study thus showed that M. dichotoma biomatrices enhance the differentiation of MSCs into osteoblast and hence have excellent potential as bioscaffold for hard tissue engineering.

Low level laser irradiation stimulates osteogenic phenotype of mesenchymal stem cells seeded on a three-dimensional biomatrix

Mesenchymal stem cells (MSCs) seeded on three-dimensional (3D) coralline (Porites lutea) biomatrices were irradiated with low-level laser irradiation (LLLI). The consequent phenotype modulation and development of MSCs towards ossified tissue was studied in this combined 3D biomatrix/LLLI system and in a control group, which was similarly grown, but was not treated by LLLI. The irradiated and non irradiated MSC were tested at 1-7, 10, 14, 21, 28 days of culturing via analysis of cellular distribution on matrices (trypan blue), calcium incorporation to newly formed tissue (alizarin red), bone nodule formation (von Kossa), fat aggregates formation (oil red O), alkaline phosphatase (ALP) activity, scanning electron microscopy (SEM) and electron dispersive spectrometry (EDS). The results obtained from the irradiated samples showed enhanced tissue formation, appearance of phosphorous peaks and calcium and phosphate incorporation to newly formed tissue. Moreover, in irradiated samples ALP activity was significantly enhanced in early stages and notably reduced in late stages of culturing. These findings of cell and tissue parameters up to 28 days of culture revealed higher ossification levels in irradiated samples compared with the control group. We suggest that both the surface properties of the 3D crystalline biomatrices and the LLLI have biostimulatory effects on the conversion of MSCs into bone-forming cells and on the induction of ex-vivo ossification.

Autologous transplantation of gingival fibroblast-like cells and a hydroxylapatite complex graft in the treatment of periodontal osseous defects: cell cultivation and long-term report of cases

Autogenous cell transplantation via hydroxylapatite (HA) vehicle has been reported to have beneficial effects on the treatment of human periodontal osseous defects. The aim of this study was to explore the possibility of using gingival fibroblast-like cells in the therapy of osseous defects caused by inflammatory periodontitis by reporting long-term results of gingival fibroblast-coated hydroxylapatite (GF-HA) grafting for healing these defects. Gingival fibroblasts were cultured from healthy gingivae of treated subjects. Growth of cells on HA particles was established in vitro, and then the GF-HA complex was transplanted into the periodontal osseous defects. Clinical parameters of gingival and plaque indices, probing depth, and periapical x-ray were monitored at baseline and at various periods from 50 months to 6 years after surgery. Grafting with only HA in the osseous defects of the same patient was used for comparison. The present study shows that GF-HA-treated sites could achieve marked pocket reduction and probing attachment gain at reentry and later recalls. Good clinical bone filling of osseous defects in GF-HA-treated sites was also demonstrated in periapical radiographs (increased bone height and reappearance of the crestal cortex) and in some reentry sites. One HA-treated site was filled with connective tissue only, and the absence of new bone formation was noted during a reentry operation. Another HA-treated site exhibited a comparable increase in radiographic density, while part of HA particles were gradually lost in longer recalls. These limited observations conclude that GF-HA grafting may provide a treatment modality leading to regeneration of periodontal tissues in periodontitis-affected osseous defects. Further studies including more cases and demonstration of the deposition of differentiated periodontal tissues are necessary before further application of this therapy.

The efficacy of bone replacement grafts in the treatment of periodontal osseous defects. A systematic review

BACKGROUND

Bone replacement grafts (BRG) are widely used in the treatment of periodontal osseous defects; however, the clinical benefits of this therapeutic practice require further clarification through a systematic review of randomized controlled studies.

RATIONALE

The purpose of this systematic review is to access the efficacy of bone replacement grafts in proving demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

FOCUSED QUESTION

What is the effect of bone replacement grafts compared to other interventions on clinical, radiographic, adverse, and patient-centered outcomes in patients with periodontal osseous defects?

SEARCH PROTOCOL

The computerized bibliographical databases MEDLINE and EMBASE were searched from 1966 and 1974, respectively, to October 2002 for randomized controlled studies in which bone replacement grafts were compared to other surgical interventions in the treatment of periodontal osseous defects. The search strategy included screening of review articles and reference lists of retrieved articles as well as hand searches of selected journals.

INCLUSION CRITERIA

All searches were limited to human studies in English language publications.

EXCLUSION CRITERIA

Non-randomized observational studies (e.g., case reports, case series), publications providing summary statistics without variance estimates or data to permit computation, and studies without BRG intervention alone were excluded.

DATA COLLECTION AND ANALYSIS

The therapeutic endpoints examined included changes in bone level, clinical attachment level, probing depth, gingival recession, and crestal resorption. For purposes of meta-analysis, change in bone level (bone fill) was used as the primary outcome measure, measured upon surgical re-entry or transgingival probing (sounding).

MAIN RESULTS

1. Forty-nine controlled studies met eligibility criteria and provided clinical outcome data on intrabony defects following grafting procedures. 2. Seventeen studies provided clinical outcome data on BRG materials for the treatment of furcation defects.

REVIEWERS' CONCLUSIONS

1. With respect to the treatment of intrabony defects, the results of meta-analysis supported the following conclusions: 1) bone grafts increase bone level, reduce crestal bone loss, increase clinical attachment level, and reduce probing depth compared to open flap debridement (OFD) procedures; 2) No differences in clinical outcome measures emerge between particulate bone allograft and calcium phosphate (hydroxyapatite) ceramic grafts; and 3) bone grafts in combination with barrier membranes increase clinical attachment level and reduce probing depth compared to graft alone. 2. With respect to the treatment of furcation defects, 15 controlled studies provided data on clinical outcomes. Insufficient studies of comparable design were available to submit data to meta-analysis. Nonetheless, outcome data from these studies generally indicated positive clinical benefits with the use of grafts in the treatment of Class II furcations. 3. With respect to histological outcome parameters, 2 randomized controlled studies provide evidence that demineralized freeze-dried bone allograft (DFDBA) supports the formation of a new attachment apparatus in intrabony defects, whereas OFD results in periodontal repair characterized primarily by the formation of a long junctional epithelial attachment. Multiple observational studies provide consistent histological evidence that autogenous and demineralized allogeneic bone grafts support the formation of new attachment. Limited data also suggest that xenogenic bone grafts can support the formation of a new attachment apparatus. In contrast, essentially all available data indicate that alloplastic grafts support periodontal repair rather than regeneration. 4. The results of this systematic review indicate that bone replacement grafts provide demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

A systematic review of graft materials and biological agents for periodontal intraosseous defects

OBJECTIVES

To determine the adjunctive effect of grafting biomaterials/biological agents with open flap debridement (OFD) in the treatment of deep intraosseous defects.

BACKGROUND

No systematic review of treatment outcomes in patients who received graft biomaterials or biological agents have been published.

METHODS

A rigorous systematic review of randomized controlled trials of at least 6-month duration was conducted comparing grafting biomaterials/biological agents (alone or in combination) + OFD (test group) to OFD alone or in combination with a placebo (control group).

RESULTS

The difference in CAL change between test and control groups varied from -1.45 mm to 1.40 mm with respect to different biomaterials/biological agents. Meta-analysis showed that CAL change significantly improved after treatment for coralline calcium carbonate (weighted mean difference 0.90 mm; 95% CI: 0.53-1.27), bioactive glass (weighted mean difference 1.04 mm; 95% CI: 0.31-1.76), hydroxyapatite (weighted mean difference 1.40 mm, 95% CI 0.64-2.16), and enamel matrix proteins (weighted mean difference 1.33 mm, 95% CI 0.78-1.88). However, heterogeneity in results between studies was highly statistically significant for most of biomaterials/biologicals and could not be fully explained.

CONCLUSIONS

Overall, the use of specific biomaterials/biologicals was more effective than OFD in improving attachment levels in intraosseous defects. Difference in CAL gain varied greatly with respect to different biomaterial/biological agent. Due to a significant heterogeneity in results between studies in most treatment groups, general conclusions about the expected clinical benefit of graft biomaterials/biologicals need to be interpreted with caution. Further research should focus on understanding this variability.

Evaluation of proliferation and protein expression of human bone marrow cells cultured on coral crystallized in the aragonite of calcite form

The two crystalline forms of CaCO3, aragonite (from natural coral) and calcite (from natural limestone), have been used with success as bone graft substitutes. However, natural coral transformed into calcite by heating has never been tested. The objective of this work was to study the proliferation and alkaline phosphatase, osteonectin, and osteocalcin expression of human bone marrow cells cultured on CaCO3 crystallized both in the aragonite form (natural coral) and in the calcite form (natural coral modified by heating). The methods used to characterize calcite obtained from the coral were volumic porosimetry, scanning electron microscopy (SEM) and X-ray diffraction. Cell colonization of the material was assessed by SEM performed on days 1, 7, 20, and 30 and [3H]thymidine incorporation was performed on days 3, 7, 12, 18, 25, and 32. Phenotypic expression was assessed by using in situ cytochemistry (alkaline phosphatase), immunocytochemistry (osteonectin and osteocalcin), and hybridization (osteocalcin, beta-actin, and alkaline phosphatase mRNA). Results showed the transformation of aragonite into calcite after heating, the conservation of macroporosity, and a modification of the surface. Calcite appeared to have a smoother and more uniform surface than aragonite crystals. As for [3H]thymidine there was an increase incorporation from days 3 to 18, a stabilization from days 18 to 25, and a decrease from days 25 to 32. After 20 days of culture, immunological studies using monoclonal antibodies to osteocalcin, osteonectin, cytochemical analysis of alkaline phosphatase activity, and in situ hybridization using osteocalcin, beta-actin, and alkaline phosphatase cDNA indicated that the cells had not lost their osteoblastic phenotype. These experiments demonstrate that coral crystallized in the aragonite or calcite form present a similar degree of specific cytocompatibility.

Adaptive crystal formation in normal and pathological calcifications in synthetic calcium phosphate and related biomaterials

Mineralization and crystal deposition are natural phenomena widely distributed in biological systems from protozoa to mammals. In mammals, normal and pathological calcifications are observed in bones, teeth, and soft tissues or cartilage. We review studies on the adaptive apatite crystal formation in enamel compared with those in other calcified tissues (e.g., dentin, bone, and fish enameloids) and in pathological calcifications, demonstrating the adaptation of these crystals (in terms of crystallinity and orientation) to specific tissues that vary in functions or vary in normal or diseased conditions. The roles of minor elements, such as carbonate, magnesium, fluoride, hydrogen phosphate, pyrophosphate, and strontium ions, on the formation and transformation of biologically relevant calcium phosphates are summarized. Another adaptative process of crystals in biology concerns the recent development of calcium phosphate ceramics and other related biomaterials for bone graft. Bone graft materials are available as alternatives to autogeneous bone for repair, substitution, or augmentation. This paper discusses the adaptive crystal formation in mineralized tissues induced by calcium phosphate and related bone graft biomaterials during bone repair.

Clinical evaluation of natural coral and porous hydroxyapatite implants in periodontal bone lesions: results of a 1-year follow-up

This study examines the suitability of 2 bone graft substitutes, natural coral skeleton (NCS) and porous hydroxyapatite (PHA) for treating periodontal bone defects in human subjects, and compares them to debridement alone (DEBR). A total of 30 sites in 10 patients were treated. Measurements were made before treatment and during surgical reexamination 12 months after treatment on lesions filled with NCS (10 sites), PHA (10 sites), or DEBR (10 sites). There was no significant difference in the use of NCS or PHA for 1, 2 wall, or combined defects for the group of parameters measured in this study (clinical probing depth, clinical attachment, gingival recession, bone fill, % bone fill, and crest remodelling). Statistical analysis (Wilcoxon non-parametric test for paired values and ANOVA for repeated measurements) revealed the beneficial effects of using each the biomaterials (57.4% for NCS, 58.1% for PHA, p < 0.86) as opposed to simple debridement (22.2%; p < 0.002; p < 0.004).

Regenerating periodontal support: a comparison of today's procedures

Today's practice of periodontology focuses not only on stopping the progression of periodontal diseases but also on regenerating lost periodontal supporting structures. The use of guided tissue regeneration and bone grafting techniques may enable clinicians to save teeth that previously would have been lost. Thanks to technological advances in the production of growth factors, the future of reconstructing lost support holds even greater promise.

Evaluation of the osteogenic potential of biomaterials implanted in the palatal connective tissue of miniature pigs using undecalcified sections

Calcium phosphate or calcium carbonate biomaterials are widely used as bone substitutes in periodontal surgery. This study evaluates the osteogenic potential of five different alloplastic biomaterials implanted in the connective tissue of the palatal papilla in miniature pigs. A porous hydroxyapatite (PHA), a dense hydroxyapatite (DHA), a semi-porous hydroxyapatite (SPHA), a tricalcium phosphate (TCP) and a calcium carbonate natural coral (NC) were implanted in a tunnel in the palatal papillae of seven miniature pigs. Undecalcified sections were examined histologically at 1, 2, 3, 4, 8, 12 and 24 wk intervals. Resorbable materials (TCP and NC) were totally resorbed by 24 wk. DHA, PHA and HA showed very limited resorption, although there were multinucleated giant cells in contact with PHA and SPHA. There was no histologically detectable bone formation in contact with or near any of the biomaterials tested. However, several particles of NC, and sometimes of PHA, were surrounded by a dense, mineralized matrix. It is concluded that none of these biomaterials, in their presently available forms, has any bone inducing capacity.

A 4-year controlled clinical study into the use of a ceramic hydroxylapatite implant material for the treatment of periodontal bone defects

10 patients with chronic adult periodontitis who had greater than 1 tooth with infra-bony pockets were treated at the test defects by periodontal flap procedures with implantation of hydroxylapatite particles; the control defects were treated by the same surgical procedures but without the implant. A total of 58 test defects and 59 control defects were treated. Each defect had measurements carried out at given sites on the involved tooth surfaces, the sites being considered for subsequent tabulation purposes under the category of shallow (less than 3 mm) moderate (3-6 mm) and deep (greater than 6 mm) initial pocket depths. There were 146 and 152 shallow sites, 216 and 241 moderate sites and 140 and 133 deep sites, at test and control sites, respectively. Measurements of recession, probing pocket depths and probing attachment levels were made at 6 months and 1, 2, 3 and 4 years. At all sites over the period of the study, for the moderate and deep initial pockets there was a significant reduction in probing depths and an increase in the probing attachment levels. At the 4th year of assessment for the initially deep pockets, the reduction in probing depths was significantly greater for the sites treated with the implant material. In view of the difficult clinical problem posed by the treatment of teeth with deeper periodontal bone defects, further research using either this type of implant material or similar material should be considered.

Ultrastructural and ultracytochemical characteristics of multinucleated cells after hydroxyapatite implantation into rat periodontal tissue

Multinucleated cells (MNCs) that appeared after hydroxyapatite (HAP) implantation into experimentally-produced bone defects in rat periodontal tissues were investigated both ultrastructurally and ultracytochemically. At day 5 after implantation, MNCs first appeared along the HAP surface. They had no features of typical osteoclasts such as ruffled border and clear zone. By d 14, these cells acquired features similar to osteoclasts, including ruffled border and clear zone. With the appearance of ruffled borders in MNCs, new bone deposited around the implanted HAP. MNCs appeared to excavate both newly-formed bone and implanted HAP simultaneously. Ingested HAP particles were observed not only in MNCs but also in macrophages. MNCs contained both tartrate-resistant acid phosphatase (ACPase) and carbonic anhydrase (CAase). ACPase activity was detected along all the biosynthesizing pathways in MNCs. Extracellular ACPase activity around the ruffled border region was also demonstrable. CAase activity could be detected only in the cytosol, vesicles and mitochondrial cristae of the MNCs. These cytochemical characteristics were almost the same regardless of the time elapsed after implantation.

Computerized densitometric analysis of interproximal bone levels in a controlled clinical study into the treatment of periodontal bone defects with ceramic hydroxyapatite implant material

The aim of this controlled clinical study was to utilize computer-assisted densitometric analysis of radiographs to assess the effectiveness of treating periodontal osseous defects with a sintered hydroxyapatite implant material. It was found that over the 2-year period of the study for the osseous defects treated by the implant material, there was a gain in the height of the hard tissue relative to the cemento-enamel junction; this gain was statistically significant compared with the results for the control sites.

HTR polymer grafts in human periodontal osseous defects. I. 6-month clinical results

HTR polymer was evaluated as a grafting material in periodontal osseous defects in 21 adult patients. Following initial preparation and pre-surgical documentation with standardized measurements, radiographs, and photographs, vertical osseous defects were treated with surgical open flap debridement alone (DEBR) or with DEBR plus placement of HTR polymer graft material. Patients were followed with frequent recalls until surgical re-entry at about 6 months for documentation and any needed remedial therapy. Re-entry data show that use of HTR polymer grafts resulted in significantly better mean defect fill of 2.2 mm (60.8%) compared to 1.0 mm (32.2%) with DEBR alone (P less than .001). Other hard tissue findings such as residual defect depth, crestal resorption, and percent defect resolution showed similar clinically superior results with the use of HTR polymer. Soft tissue findings showed significant differences in favor of HTR for decrease in probing depth and gain in clinical attachment. These results are similar to those reported with other graft materials. Over a 6-month period, HTR polymer was found to show promise for the repair of periodontal osseous defects.

Bone formation in tricalcium phosphate-filled periodontal intrabony lesions. Histological observations in humans

The capacity of a tricalcium phosphate (TCP) ceramic to promote bone formation after grafting in intrabony defects was studied in humans. Five biopsies were collected from 4 patients during reentry surgery 16 to 40 months after implantation. They were processed without demineralization for histological examination. In the less mature samples, the grafted material was surrounded by a highly fibrous, highly cellular, and poorly vascularized connective tissue. Howship's lacuna-like cavities were clearly visible at the surface of the material. They contained resorbing mononuclear phagocytes. At a more mature stage, TCP granules were embedded in an acellular fibrous material which underwent mineralization from the medullary spaces towards the granules. The bone formed was subsequently remodeled. The implanted material itself was progressively modified. It first acquired the staining appearance of bone. After its structure became loose and vacuolated, it was invaded by cells and vessels. The present data indicate that TCP has osteogenic potential and is subject to degradation. Unlike in experimental wounds, these processes are of long duration in human defects.

Restoration of mandibular continuity defects using combinations of hydroxylapatite and autogenous bone: microscopic observations

The purpose of this investigation was to assess by light, transmission, and scanning electron microscopy the healing of mandibular continuity defects reconstructed with varying ratios of an alloplastic hydroxylapatite implant material (HA) mixed with autogenous bone (AB). This study reports the microscopic observations of implant and control sites at 6 and 18 months postsurgery. The results confirm the biocompatibility of dense HA granules. Specimens exhibited differing degrees of osseous regeneration that appeared related to the percent composition of HA. At 18 months, 86% and 91% of the HA granules were completely surrounded by bone in those specimens reconstructed with implants consisting of 25% and 50% HA, respectively. In contrast, specimens receiving implants consisting of 75% and 100% HA features osseous encapsulation of 75% and 66% of the granules, respectively. The results of this limited study indicate that dense HA granules mixed with AB in ratios ranging from 3:1 to 1:1 (AB:HA) may be successfully used as a bone extender during reconstructive surgery.

5-year evaluation of durapatite ceramic alloplastic implants in periodontal osseous defects

Six patients who participated in a clinical study comparing the response of periodontal osseous defects to either grafting with Periograf (durapatite) hydroxylapatite (HA) ceramic or debridement alone (DEBR) were followed under an active maintenance program for 5 years. Mean values for gingival recession and attachment levels remained essentially stable following either treatment over the 5 year period. However, mean probeable pocket depths shifted from being significantly (P less than 0.05) shallower for DEBR sites at 6 months and 1 year to being significantly shallower for HA sites at 5 years. The probing pocket depth change for grafted sites was steady and the change from presurgical values was significantly greater than the change for DEBR areas, which became about 1.5 mm deeper over the 5 year postsurgical period. Intrapatient comparisons showed that recession, attachment gain, and pocket depth decrease were most frequently greater for the Periograf-treated sites. Assessment of the pattern of clinical changes during the 5 year postsurgical period demonstrated that the attachment level of grafted sites improved or stayed the same 86% of the time compared to only 62% stability or improvement in the DEBR only sites. In fact, 38% of the DEBR sites were worse at 5 years than at the time of surgery, a 3 times greater failure rate than that found in the HA-grafted sites. Pocket depth measurements showed that 98% of the Periograf-treated sites were better or the same as presurgically (2% worse), while only 80% of DEBR sites showed positive results and 20% had deeper pockets than at the time of surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonporous hydroxylapatite in the repair of alveolar clefts in a primate model: clinical and histologic findings

Twelve adult Rhesus monkeys with surgically created alveolar clefts (ACs) underwent repair that used nonporous hydroxylapatite (NPHA) granules on one side and autogenous particulate bone in the contralateral defect. Clinical and radiographic evaluations at 1, 2, 3, 6, and 12 months postoperatively disclosed some displacement of granules initially, but this stabilized by 2 months. Three of 12 sites repaired with NPHA and four of 12 sites repaired with bone dehisced; however, all of these healed by 2 months. No untoward inflammatory or resorptive changes were observed beyond 3 months. The repaired alveolar processes were similar in bulk and contour in sites grafted with NPHA and with bone. Histologically, giant cells were noted at 3 months, but the number decreased at 6 months and remained at that level up to 12 months. The NPHA granules were embedded in mature fibrous connective tissue with osseous ingrowth evident in eight of the 12 defects. It was concluded that NPHA granules are an acceptable implant material for repair of residual alveolar clefts in which erupting teeth and orthodontic movements are not factors.

Osseous defect responses to hydroxylapatite grafting versus open flap debridement

Data from a large number of defects (152) treated with hydroxylapatite (HA) grafts were compared to those from a large number of defects (111) treated by surgical debridement alone (DEBR). Comparison of initial and re-entry surgery measurements showed that both the analysis of relative defect fill and the intrapatient comparisons demonstrated an advantage to the use of HA graft material. 58% of the HA-grafted defects were judged to have a positive (greater than or equal to 50% defect fill) hard tissue response compared to 30% for DEBR. Minimal responses (failures) were 4 times as numerous with DEBR. Similarly, within each patient, HA grafting proved of benefit, particularly regarding hard tissue changes. The use of HA graft materials appears to be of clinical benefit in a majority of defects and a majority of patients.

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.

Fibrin and fibronectin sealing system in a guided tissue regeneration procedure. A case report

A case is reported showing an iatrogenic, chronic abscess of six years' duration associated with a bony defect between the maxillary right central and lateral incisors. The osseous defect was treated by a guided tissue regeneration procedure with the use of a fibrin and fibronectin sealing system. The system was employed to fix the membranes and keep them apart from the root surface, thereby maintaining room for bone regeneration. This operation resulted in a 9-mm clinical attachment gain and in an 11-mm filling of the osseous defect. The second surgical stage after a three-month reentry procedure was strictly for cosmetic improvement by means of a free gingival graft.

The effect of supracrestal tricalcium phosphate ceramic-microfibrillar collagen grafting on postsurgical soft tissue levels

In this clinical study, a combined tricalcium phosphate ceramic (TCP) microfibrillar collagen supracrestal graft was used in conjunction with pocket elimination surgery as a soft tissue space filler to maintain marginal and interproximal tissue heights. Fifteen volunteer adult patients (8 male, 7 female) aged 37 to 48 years were selected. Standardized clinical probing measurements were used to evaluate soft tissue recession, clinical attachment, and probing pocket depths. Intraoral photographs and radiographs supplemented documentation. Twenty-five paired test and control sites were evaluated. Following flap surgery and minor osteoplasty, test defects received supracrestal grafts of TCP microfibrillar collagen prior to flap closure. Intrabony defects were excluded. Treatment modalities were compared by analyzing changes in clinical probing measurements over four months using the students t test for paired samples at the 0.01 level of significance. Supracrestal grafting resulted in 16.74% less soft tissue recession than the control sites. In addition, there was a significant gain in clinical attachment levels compared with the controls. All implanted sites demonstrated an advantage in the use of supracrestal TCP-collagen grafts compared with the controls. This treatment modality may have value in reducing esthetic deformities, food impaction areas, and root exposure that often occur following periodontal surgery.

Histologic and clinical responses to porous hydroxylapatite implants in human periodontal defects. Three to twelve months postimplantation

Twelve intrabony periodontal lesions in three volunteers received surgical debridement followed by site implantation of porous hydroxylapatite implants. These patients were followed over a total of a 1-year observation period. Blocks of treated sites were surgically removed at 3 months, 6 months and 12 months after implantation. Clinical observation indicated a reduction in pocket depth consisting of both recession and clinical gain of attachment. No ill effects were observed. Histologic examination of the treated sites showed ossification of the implant pores and the implant periphery as early as 3 months after implantation, which became pronounced 12 months after placement. At times, peripheral ossification linked with crestal osseous seams. This ossification occurred in the presence of an adjacent root covering, long junctional epithelium, and thus there was no new attachment. On the other hand, this graft material offers the potential of increasing new bone mass within a human intrabony lesion.

Clinical evaluation of porous and nonporous hydroxyapatite in the treatment of human periodontal bony defects

The purpose of this study was to investigate the effectiveness of a synthetic nonporous hydroxyapatite graft material (OrthoMatrix HA-500), a porous replamineform hydroxyapatite graft material (Interpore 200), and a debrided control with respect to defect fill. Twelve adult patients having periodontitis and three similar angular osseous defects as verified by radiographic analysis and clinical probe depths greater than or equal to 5 mm were selected. Clinical parameters gathered prior to surgical intervention and at identified postoperative visits included plaque index, probing depth, and standardized radiographic examination. Customized acrylic stents were used as fixed reference guides for the insertion of endodontic silver points to the base of each defect during both initial and 6-month reentry surgeries. A total of 36 defects were randomly assigned to one of three treatment modalities such that 12 defects received OrthoMatrix HA-500, 12 received Interpore 200, and 12 served as debrided controls. Comparison of nonporous hydroxyapatite, porous replamineform hydroxyapatite, and debrided control treatment modalities revealed a statistically significant improvement (P less than 0.05) in the mean per cent of defect resolved in only those sites treated with nonporous hydroxyapatite. Similar positive trends were seen in the sites treated with nonporous hydroxyapatite for mean reentry defect depth and mean defect fill although these were not statistically significant (P greater than 0.05). No other significant differences were noted.

Histological evaluation of human intraosseous healing responses to the placement of tricalcium phosphate ceramic implants. I. Three to eight months

Eight intrabony lesions in four patients were removed en bloc 3 to 8 months after periodontal flap debridement. At the time of debridement, the position of the gingival margin and the most apically located calculus were notched to serve as reference points. All lesions received "Synthograft" implants and lesions healed uneventfully. Even though these were severely involved periodontal sites, clinical measurements at time of block removal demonstrated gingival recession (average = 2.9 mm) and a gain in clinical closure (average = 2.6 mm). Histologically, graft particles were present in each specimen. They were walled off by collagen and did not appear to enhance new attachment nor did they induce an inflammatory infiltrate. Thus, they seemed to act as nonirritating fillers. Microscopically, closure of the lesions demonstrated repair with limited evidence of new connective tissue attachment. Histologic expression of the clinical gain in closure was the result of closure by long epithelial adhesion (long junctional epithelium) and possible linkage of dentinal collagen with gingival fibers at areas of dentinal resorption. These variations in closure were often seen within the same clinical site.

Ultrastructure of durapatite-periodontal tissue interface in human intrabony defects

The ultrastructure of the interface between Durapatite (hydroxylapatite) and human periodontal tissues was examined. Durapatite was implanted into the intrabony periodontal defects during periodontal surgery. Reentry procedures were performed after 1 year and the tissues in the defects were biopsied and processed for transmission electron microscopy. Nineteen tissue blocks from four patients were examined, 17 contained Durapatite particles embedded in fibrous tissue and two contained particles encased in bone, all without inflammation. The fibrous connective tissue consisted of densely packed collagen fibrils surrounding the implant particles. The bone surrounding the Durapatite consisted in one case of relatively mature bone, and in the other of osteoid tissue. A granular, amorphous, collagen-free, electron-dense layer was routinely observed between implant and tissue. This layer was thicker in the bone-encased samples than in those surrounded by fibrous connective tissue. Except for the particle surrounded by mature bone, this layer was continuous with an organic meshwork located on the periphery of the implant spaces. The ultrastructural features of the interface are consistent with the existence of a mucopolysaccharide "bonding zone" described by other investigators. The organic meshwork appears to outline areas similar in size and shape to the individual crystallites of hydroxylapatite. This may indicate that the reactive surface of hydroxylapatite is much larger than merely the exterior surface of the implant, a finding which may explain the apparently good tissue adhesion to the implant.

Evaluation of durapatite ceramic as an alloplastic implant in periodontal osseous defects. II. Twelve month reentry results

Thirteen patients received Durapatite, a hydroxylapatite ceramic (Periograf), as a bone implant material in various types of intrabony defects following internally beveled full thickness flaps, root planing, and defect debridement. All osseous margins and defects were measured from the cemento-enamel junction (CEJ) at specific locations using a standardized periodontal probe. Similarly debrided, nonimplanted defects served as controls. Defect selection as either experimental or control site was based on an alternating defects design after local therapy was completed. Periodontal dressing and systemic tetracycline were used for 10 days. Postsurgical visits for documentation and plaque control were at 10, 20 and 30 days, and 3, 6, 9 and 12 months. Measurements relating to defect changes were made at the 12-month surgical reentry. For evaluation purposes original defect depths were divided into three groups. In Group I (less than 3 mm) defect fill was 1.0 mm (47%) for the implanted defects and 0.3 mm (33%) for the control sites (significantly different at P less than 0.05). In Group II (3-6 mm) defect fill of 1.7 mm (44%) for implanted sites was significantly better (P less than 0.05) than the 0.8 mm (29%) found in control sites. In the deepest group (Group III, greater than 6 mm) Durapatite placement yielded 2.1 mm (32%) of defect fill while debridement alone resulted in 1.8 mm (26%) of fill (P greater than 0.05). Hard tissue responses demonstrated a substantial advantage for use of Durapatite over controls, while soft tissue changes were similar for both.(ABSTRACT TRUNCATED AT 250 WORDS)