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

Preclinical evaluation of a new synthetic carbonate apatite bone substitute on periodontal regeneration in intrabony defects

OBJECTIVE

To evaluate the potential of a novel synthetic carbonate apatite bone substitute (CO3 Ap-BS) on periodontal regeneration.

BACKGROUND

The use of various synthetic bone substitutes as a monotherapy for periodontal regeneration mainly results in a reparative healing pattern. Since xenografts or allografts are not always accepted by patients for various reasons, a synthetic alternative would be desirable.

METHODS

Acute-type 3-wall intrabony defects were surgically created in 4 female beagle dogs. Defects were randomly allocated and filled with CO3 Ap-BS (test) and deproteinized bovine bone mineral (DBBM) or left empty (control). After 8 weeks, the retrieved specimens were scanned by micro-CT, and the percentages of new bone, bone substitute, and soft tissues were evaluated. Thereafter, the tissues were histologically and histometrically analyzed.

RESULTS

Healing was uneventful in all animals, and defects were present without any signs of adverse events. Formation of periodontal ligament and cementum occurred to varying extent in all groups without statistically significant differences between the groups. Residues of both bone substitutes were still present and showed integration into new bone. Histometry and micro-CT revealed that the total mineralized area or volume was higher with the use of CO3 Ap-BS compared to control (66.06 ± 9.34%, 36.11 ± 6.40%; p = .014, or 69.74 ± 2.95%, 42.68 ± 8.68%; p = .014). The percentage of bone substitute surface covered by new bone was higher for CO3 Ap-BS (47.22 ± 3.96%) than for DBBM (16.69 ± 5.66, p = .114).

CONCLUSIONS

CO3 Ap-BS and DBBM demonstrated similar effects on periodontal regeneration. However, away from the root surface, more new bone, total mineralized area/volume, and higher osteoconductivity were observed for the CO3 Ap-BS group compared to the DBBM group. These findings point to the potential of CO3 Ap-BS for periodontal and bone regeneration.

Combination of hydroxyapatite, platelet rich fibrin and amnion membrane as a novel therapeutic option in regenerative periapical endodontic surgery: Case series

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Our article was an attempt to focus on combined benefits of Bio-Gen mix^®, PRF and amnion membrane to provide a viable regenerative option in periapical surgery.

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To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Our presented case reports provide an insight into this novel therapeutic option.

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The presented case reports confirm that the amnion membrane combined with bone graft and PRF have enhanced the healing outcomes and provided endodontists a sustainable tool while performing surgeries in the esthetic zone.

Introduction

Periapical surgery is the last resort in the arsenal of an endodontist to effectively deal with periapical lesions that result from necrosis of the pulp. Bone grafts, growth factors and membranes form an array of regenerative materials that influence the healing outcome of periapical surgery.

Presentation of case

The main purpose of the two cases reported here was to assess the potential benefits of a combination of bone graft, platelet-rich fibrin (PRF) and amnion membrane in terms of reduced post-operative discomfort, radiographic evidence of accelerated periapical bone healing and present a novel therapeutic option in the management of large periapical lesions. Two cases of radicular cysts were treated through a combined regenerative approachof Bio-Gen mix^®, PRF and amnion membrane. The patients were assessed for discomfort immediate post-operatively and after a week. The patients were recalled every month for the next 6 months for radiographic assessment of the periapical healing.

Discussion

Literature is replete with articles that have substantiated the role of demineralized bone matrix comprising a mixture of cancellous and cortical bone graft particles in enhancing regeneration. To the best of our knowledge, there has been no evidence related to the application of a human placental membrane in periapical surgery. Hence, the rationale of using a combined approach of Bio-Gen mix^®, PRF and amnion membrane was to combine the individual advantages of these materials to enhance clinical and radiographic healing outcomes. Our present case reports provide an insight into this novel therapeutic option.

Conclusion

The results of this case seriessubstantiatesthe credibility of using a combination ofamnion membrane with a bone graft and PRF to enhance radiographic healing outcome with decreased post-operative discomfort and present a viable regenerative treatment modality in periapical surgery.

Comparative Evaluation of Bioactive Synthetic NovaBone Putty and Calcified Algae-derived Porous Hydroxyapatite Bone Grafts for the Treatment of Intrabony Defects

Introduction

To compare and evaluate clinically and radio-graphically the bone regeneration and the amount of bone fill in intrabony component of periodontal osseous defects through the osteoconductive and osteostimulative effect of bioactive synthetic NovaBone Putty - CMF and osteoconductive effect of calcified algae-derived porous hydroxyapatite Frios^® Algi-pore^® bone grafts.

Materials and methods

Twenty-two sites in 11 patients, within the age range of 25 to 60 years, showing intrabony defects were selected according to split mouth design and divided into group I (Frios^® Algipore^®) and group II (NovaBone Putty - CMF). All the selected sites were assessed with the clinical and radiographic parameters like plaque index, gingival index (full mouth and site specific), sulcus bleeding index, probing pocket depth, clinical attachment level, gingival recession, and radiographic bone fill. All the clinical and radiographic parameter values obtained at different intervals (baseline, 3, and 6 months) were subjected to statistical analysis.

Results

A statistically significant reduction in pocket depth of 2.55 ± 0.52 mm (group I), 2.64 ± 0.67 mm (group II) and gain in clinical attachment level of 7.55 ± 1.44 mm (group I), 7.55 ± 2.38 mm (group II) were recorded at the end of the study. A slight increase in gingival recession was observed. The mean percentage change in amount of radiographic bone fill of group II (71.34%) was more than group I (61.93%).

Conclusion

Both NovaBone Putty - CMF and Frios^® Algipore^® improve healing outcomes and lead to a reduction of probing depth, a resolution of osseous defects, and a gain in clinical attachment, but radiographic observation found better results with NovaBone Putty.

How to cite this article

Bembi NN, Bembi S, Mago J, Baweja GK, Baweja PS. Comparative Evaluation of Bioactive Synthetic NovaBone Putty and Calcified Algae-derived Porous Hydroxyapatite Bone Grafts for the Treatment of Intrabony Defects. Int J Clin Pediatr Dent 2016;9(4):285-290.

Preparation of resorbable carbonate-substituted hollow hydroxyapatite microspheres and their evaluation in osseous defects in vivo

Hollow hydroxyapatite (HA) microspheres, with a high-surface-area mesoporous shell, can provide a unique bioactive and osteoconductive carrier for proteins to stimulate bone regeneration. However, synthetic HA has a slow resorption rate and a limited ability to remodel into bone. In the present study, hollow HA microspheres with controllable amounts of carbonate substitution (0-12 wt.%) were created using a novel glass conversion route and evaluated in vitro and in vivo. Hollow HA microspheres with ~12 wt.% of carbonate (designated CHA12) showed a higher surface area (236 m(2) g(-1)) than conventional hollow HA microspheres (179 m(2)g(-1)) and a faster degradation rate in a potassium acetate buffer solution. When implanted for 12 weeks in rat calvarial defects, the CHA12 and HA microspheres showed a limited capacity to regenerate bone but the CHA12 microspheres resorbed faster than the HA microspheres. Loading the microspheres with bone morphogenetic protein-2 (BMP2) (1 μg per defect) stimulated bone regeneration and accelerated resorption of the CHA12 microspheres. At 12 weeks, the amount of new bone in the defects implanted with the CHA12 microspheres (73±8%) was significantly higher than the HA microspheres (59±2%) while the amount of residual CHA12 microspheres (7±2% of the total defect area) was significantly lower than the HA microspheres (21±3%). The combination of these carbonate-substituted HA microspheres with clinically safe doses of BMP2 could provide promising implants for healing non-loaded bone defects.

Histological and Histometrical Evaluation of two Synthetic Hydroxyapatite Based Biomaterials in the Experimental Periodontal Defects in Dogs

AIM

The present study was to evaluate histologically and histometrically the efficacy of Chitra granules in the regeneration of alveolar bone and to compare it with that of OsteoGenR (HA Resorb)(TM) in iatrogenically created alveolar bone defects in mongrel dogs.

MATERIALS AND METHODS

Four dogs (16 sites) were used for this split-mouth study. The animals were divided randomly into two groups of two animals. Same animals were used as control and test. Each dog had four implantation sites. The periodontal defects were prepared by acute defect model. Animals were sacrificed at 3 months (n=2), 6 months (n=2) and histologic and histometric evaluation was carried out.

STATISTICAL ANALYSIS

The data was analysed using statistical package Graph pad Software. Comparison of the hard and soft tissue parameters in the two groups was done using the Wilcoxan (Man Whitney), two tailed t-test. A p-value less than 0.05 were considered significant.

RESULTS

Maturing bone with immature periodontal ligament fibers were observed at three months and advanced osteogenesis at six months with both the types of bone graft materials. The mean values showed that amount of new bone formed with OsteoGenR (HA Resorb)(TM) was slightly more than that obtained by Chitra granules in histometric evaluation.

CONCLUSION

Histological study showed similar healing pattern with both the types of bone graft materials with maturing bone at 3 months and advanced osteogenesis at six months in experimental intraosseous periodontal defects in dogs. However, histological evaluation for longer period is necessary to determine the time taken for complete replacement of the bone graft materials with new bone.

Regenerative periodontal therapy: 30 years of lessons learned and unlearned

In this review, we reflect upon advances and hindrances encountered over the last three decades in the development of strategies for periodontal regeneration. In this soul-searching pursuit we focus on revisiting lessons learned that should guide us in the quest for the reconstruction of the lost periodontium. We also examine beliefs and traditions that should be unlearned so that we can continue to advance the field. This learned/unlearned body of knowledge is consolidated into core principles to help us to develop new therapeutic approaches to benefit our patients and ultimately our society.

Bone substitutes for peri-implant defects of postextraction implants

Placement of implants in fresh sockets is an alternative to try to reduce physiological resorption of alveolar ridge after tooth extraction. This surgery can be used to preserve the bone architecture and also accelerate the restorative procedure. However, the diastasis observed between bone and implant may influence osseointegration. So, autogenous bone graft and/or biomaterials have been used to fill this gap. Considering the importance of bone repair for treatment with implants placed immediately after tooth extraction, this study aimed to present a literature review about biomaterials surrounding immediate dental implants. The search included 56 articles published from 1969 to 2012. The results were based on data analysis and discussion. It was observed that implant fixation immediately after extraction is a reliable alternative to reduce the treatment length of prosthetic restoration. In general, the biomaterial should be used to increase bone/implant contact and enhance osseointegration.

Calcium orthophosphates in dentistry

Dental caries, also known as tooth decay or a cavity, remains a major public health problem in the most communities even though the prevalence of disease has decreased since the introduction of fluorides for dental care. Therefore, biomaterials to fill dental defects appear to be necessary to fulfill customers' needs regarding the properties and the processing of the products. Bioceramics and glass-ceramics are widely used for these purposes, as dental inlays, onlays, veneers, crowns or bridges. Calcium orthophosphates belong to bioceramics but they have some specific advantages over other types of bioceramics due to a chemical similarity to the inorganic part of both human and mammalian bones and teeth. Therefore, calcium orthophosphates (both alone and as components of various formulations) are used in dentistry as both dental fillers and implantable scaffolds. This review provides brief information on calcium orthophosphates and describes in details current state-of-the-art on their applications in dentistry and dentistry-related fields. Among the recognized dental specialties, calcium orthophosphates are most frequently used in periodontics; however, the majority of the publications on calcium orthophosphates in dentistry are devoted to unspecified "dental" fields.

Combination of platelet rich fibrin, hydroxyapatite and PRF membrane in the management of large inflammatory periapical lesion

Periapical inflammatory lesion is the local response of bone around the apex of tooth that develops after the necrosis of the pulp tissue or extensive periodontal disease. The final outcome of the nature of wound healing after endodontic surgery can be repair or regeneration depending on the nature of the wound; the availability of progenitor cells; signaling molecules; and micro-environmental cues such as adhesion molecules, extracellular matrix, and associated non-collagenous protein molecules. The purpose of this case report is to add knowledge to the existing literature about the combined use of graft material [platelet rich fibrin (PRF) and hydroxyapatite (HA)] and barrier membrane in the treatment of large periapical lesion. A periapical endodontic surgery was performed on a 45 year old male patient with a swelling in the upper front teeth region and a large bony defect radiologically. The surgical defect was filled with a combination of PRF and HA bone graft crystals. The defect was covered by PRF membrane and sutured. Clinical examination revealed uneventful wound healing. Radiologically the HA crystals have been completely replaced by new bone at the end of 2 years. On the basis of the results obtained in our case report, we hypothesize that the use of PRF in conjunction with HA crystals might have accelerated the resorption of the graft crystals and would have induced the rapid rate of bone formation.

Alveolar ridge preservation with guided bone regeneration and a synthetic bone substitute or a bovine-derived xenograft: a randomized, controlled clinical trial

OBJECTIVES

The aim of this randomized, controlled clinical trial was to compare the potential of a synthetic bone substitute or a bovine-derived xenograft combined with a collagen membrane to preserve the alveolar ridge dimensions following tooth extraction.

METHODS

Twenty-seven patients were randomized into two treatment groups following single tooth extraction in the incisor, canine and premolar area. In the test group, the alveolar socket was grafted with Straumann Bone Ceramic (SBC), while in the control group, Bio-Oss deproteinized bovine bone mineral (DBBM) was applied. In both groups, a collagen barrier was used to cover the grafting material. Complete soft tissue coverage of the barriers was not achieved. After 8 months, during re-entry procedures and before implant placement, the horizontal and vertical dimensions of the residual ridge were re-evaluated and trephine biopsies were performed for histological analysis in all patients.

RESULTS

Twenty-six patients completed the study. The bucco-lingual dimension of the alveolar ridge decreased by 1.1+/-1 mm in the SBC group and by 2.1+/-1 in the DBBM group (P<0.05). Both materials preserved the mesio-distal bone height of the ridge. No differences in the width of buccal and palatal bone plate were observed between the two groups. The histological analysis showed new bone formation in the apical part of the biopsies, which, in some instances, was in direct contact with both SBC and DBBM particles. The coronal part of the biopsies was occupied by a dense fibrous connective tissue surrounding the SBC and DBBM particles.

CONCLUSION

Both biomaterials partially preserved the width and the interproximal bone height of the alveolar ridge.

Application of Glass Reinforced Hydroxyapatite Composite in the Treatment of Human Intrabony Periodontal Angular Defects – Two Case Reports

Bony defects caused by periodontitis are often treated by regenerative therapy using autografts and/or allografts. Alloplasts such as hydroxyapatite or ceramics and bioactive glasses are used as osteoconductive materials that serve as scaffold for new bony ingrowth. The purpose of this study was to ascertain the possible regenerative capability of glass reinforced hydroxyapatite (Bonelike¬)¬¬¬ an osteoconductive synthetic graft in the treatment of human periodontal intrabony angular defects. The material was placed in 2 defects in 2 individual patients and clinical parameters such as probing depth (PD) and clinical attachment level (CAL) have been included. Bone fill was determined using an intra oral periapical radiograph (IOPA) and Autocad Software. After 3 months implantation period, there was an improvement in CAL and reduction in PD along with bone fill was observed.

Regeneration of periodontal tissue: bone replacement grafts

Bone replacement grafts are widely used to promote bone formation and periodontal regeneration. Conventional surgical approaches, such as open flap debridement, provide critical access to evaluate and detoxify root surfaces as well as establish improved periodontal form and architecture; however, these surgical techniques offer only limited potential in restoring or reconstituting component periodontal tissues. A wide range of bone grafting materials, including bone grafts and bone graft substitutes, have been applied and evaluated clinically, including autografts, allografts, xenografts, and alloplasts (synthetic/semisynthetic materials). This review provides an overview of the biologic function and clinical application of bone replacement grafts for periodontal regeneration. Emphasis is placed on the clinical and biologic goals of periodontal regeneration as well as evidence-based treatment outcomes.

Clinical evaluation of anorganic bovine-derived hydroxyapatite matrix/cell-binding peptide (P-15) in the treatment of human infrabony defects

The purpose of the present study was to compare the clinical outcomes of infrabony periodontal defects following treatment with an anorganic bovine-derived hydroxyapatite matrix/cell-binding peptide (ABM/P-15) flow to open flap debridement. Twenty-six patients, each displaying one infrabony defect with probing depth>or=6 mm and vertical radiographic bone loss>or=3 mm participated in the present study. Patients were allocated randomly to be treated with ABM/P-15 flow (test group) or open flap debridement (control group). At baseline and at 12 months after surgery, the following clinical parameters were recorded by a blinded examiner: plaque index, gingival index, probing depth (PD), clinical attachment level (CAL), and gingival recession. Both treatments resulted in significant improvements between baseline and 12 months, in terms of PD reduction and CAL gain (p<0.001). At 12 months following therapy, the test group showed a reduction in mean PD from 7.8+/-1.6 mm to 3.5+/-1.0 mm and a change in mean CAL from 8.5+/-2.1 mm to 4.6+/-1.2 mm, whereas in the control group the mean PD decreased from 7.5+/-0.8 mm to 4.9+/-0.7 mm and mean CAL from 8.2+/-1.2 mm to 6.4+/-1.4 mm. The test group demonstrated significantly greater PD reductions (p=0.002) and CAL gains (p=0.001) compared to the control group. In conclusion, treatment of infrabony periodontal defects with ABM/P-15 flow significantly improved clinical outcomes compared to open flap debridement.

New composite endpoints to assess efficacy in periodontal therapy clinical trials

BACKGROUND

Clinical attachment level (CAL) and bone height (radiographic or clinical) are two well-accepted endpoint measures for periodontal clinical trials; however, neither one has been shown to be more predictive of long-term success than the other. We propose using a composite endpoint analysis combining clinical and radiological parameters to assess the beneficial effects on both hard and soft tissues following periodontal therapy using a single statistical test. To address this need, two composite endpoint alternatives are offered as a yardstick for clinical success; each includes the improvement in CAL and either improvement in linear bone growth or percent bone fill.

METHODS

The data for composite endpoint analyses were derived from a clinical trial evaluating two concentrations of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) with beta-tricalcium phosphate (beta-TCP) compared to beta-TCP plus buffer as follows: group I, beta-TCP + 0.3 mg/ml rhPDGF-BB; group II, beta-TCP + 1.0 mg/ml rhPDGF-BB; and group III, beta-TCP + buffer. The construction of composite endpoints was based on the greatest values for change, accepted by the U.S. Food and Drug Administration (FDA), for clinical attachment level (DeltaCAL), mean change in radiographic linear bone gain (LBG), and mean radiographic percent bone fill (%BF), with the following dual standards defining a successful clinical result: CAL gain > or =2.67 mm and radiographic LBG > or =1.1 mm at 6 months and CAL gain > or =2.67 mm and radiographic %BF > or =14.1% at 6 months.

RESULTS

Group I (beta-TCP + 0.3 mg/ml rhPDGF-BB) demonstrated statistically significant differences from group III (active control) for both composite endpoints. For the CAL/LBG composite endpoint, 61.7% of sites in group I versus 30.4% of sites in group III met the composite endpoint benchmarks (P <0.001). For the CAL/%BF composite endpoint, 70% of sites in group I versus 44.6% of sites in group III met the composite endpoint benchmarks (P = 0.003). A non-significant trend was observed for group II versus group III with 37.9% (P = 0.20) and 55.2% (P = 0.13) of sites meeting the CAL/LBG and CAL/%BF composite endpoints, respectively. These results are further emphasized by findings demonstrating a low correlation between the individual efficacy endpoints (DeltaCAL and %BF; DeltaCAL and LBG) for each of the three treatment groups.

CONCLUSIONS

Composite endpoints are advantageous in periodontal clinical trials where no single efficacy endpoint has been established as the most important. A composite endpoint, combining outcome measures of both hard and soft tissue components of the periodontium, may be preferable for assessing efficacy of periodontal regenerative therapies. Two composite endpoints are offered to meet this need.

Platelet-derived growth factor stimulates bone fill and rate of attachment level gain: results of a large multicenter randomized controlled trial

BACKGROUND

Growth factors are generally accepted to be essential mediators of tissue repair via well-established mechanisms of action that include stimulatory effects on angiogenesis and cellular proliferation, ingrowth, differentiation, and matrix biosynthesis. The aim of this study was to evaluate in a large-scale, prospective, blinded, and randomized controlled clinical trial the safety and effectiveness of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (beta-TCP) matrix for the treatment of advanced periodontal osseous defects at 6 months of healing.

METHODS

Eleven clinical centers enrolled 180 subjects, each requiring surgical treatment of a 4 mm or greater intrabony periodontal defect and meeting all inclusion and exclusion criteria. Subjects were randomized into one of three treatment groups: 1) beta-TCP + 0.3 mg/ml rhPDGF-BB in buffer; 2) beta-TCP + 1.0 mg/ml rhPDGF-BB in buffer; and 3) beta-TCP + buffer (active control). Safety data were assessed by the frequency and severity of adverse events. Effectiveness measurements included clinical attachment levels (CAL) and gingival recession (GR) measured clinically and linear bone growth (LBG) and percent bone fill (% BF) as assessed radiographically by an independent centralized radiology review center. The area under the curve (AUC), an assessment of the rate of healing, was also calculated for CAL measurements. The surgeons, clinical and radiographic evaluators, patients, and study sponsor were all masked with respect to treatment groups.

RESULTS

CAL gain was significantly greater at 3 months for group 1 (rhPDGF 0.3 mg/ml) compared to group 3 (beta-TCP + buffer) (3.8 versus 3.3 mm; P = 0.032), although by 6 months, this finding was not statistically significant (P = 0.11). This early acceleration of CAL gain led to group 1 exhibiting a significantly greater rate of CAL gain between baseline and 6 months than group 3 as assessed by the AUC (68.4- versus 60.1-mm weeks; P = 0.033). rhPDGF (0.3 mg/ml)-treated sites also had significantly greater linear bone gain (2.6 versus 0.9 mm, respectively; P < 0.001) and percent defect fill (57% versus 18%, respectively; P < 0.001) than the sites receiving the bone substitute with buffer at 6 months. There was less GR at 3 months in group 1 compared to group 3 (P = 0.04); at 6 months, GR for group 1 remained unchanged, whereas there was a slight gain in gingival height for group 3 resulting in comparable GR. There were no serious adverse events attributable to any of the treatments.

CONCLUSIONS

To our knowledge, this study is the largest prospective, randomized, triple-blinded, and controlled pivotal clinical trial reported to date assessing a putative periodontal regenerative and wound healing therapy. The study demonstrated that the use of rhPDGF-BB was safe and effective in the treatment of periodontal osseous defects. Treatment with rhPDGF-BB stimulated a significant increase in the rate of CAL gain, reduced gingival recession at 3 months post-surgery, and improved bone fill as compared to a beta-TCP bone substitute at 6 months.

Platelet-Rich Plasma Combined With a Porous Hydroxyapatite Graft for the Treatment of Intrabony Periodontal Defects in Humans: A Comparative Controlled Clinical Study

BACKGROUND

The aim of the present controlled clinical study was to compare platelet-rich plasma (PRP) combined with a biodegradable ceramic, porous hydroxyapatite (HA) with a mixture of HA and saline in the treatment of human intrabony defects.

METHODS

Seventy interproximal intrabony osseous defects in 70 healthy, non-smoking subjects diagnosed with chronic periodontitis were included in this study. Thirty-five subjects each were randomly assigned to either the test group (PRP and HA) or control group (HA with saline). Clinical and radiographic measurements were determined at baseline and the 12-month evaluation.

RESULTS

When compared to baseline, the 12-month results indicated that, while both treatment modalities resulted in significant changes in all clinical parameters (gingival index, bleeding on probing, probing depth, clinical attachment level, and intrabony defect fill; P <0.001), the test group exhibited statistically significant changes compared to the control sites in probing depth reduction: 4.7 +/- 1.6 mm versus 3.7 +/- 2.0 mm (P <0.05); clinical attachment gain: 3.4 +/- 1.7 mm versus 2.0 +/- 1.2 mm (P <0.001); and vertical relative attachment gain: 70.3% +/- 23.4% versus 45.5% +/- 29.4% (P <0.001).

CONCLUSION

Treatment with a combination of PRP and HA compared to HA with saline led to a significantly more favorable clinical improvement in intrabony periodontal defects.

Bone Grafting Procedures for Osseous Defects Associated with Dental Implants

The purpose of this study was to clinically and radiographically evaluate the use of bone grafting therapy for treatment of osseous defects before implant surgery. After bone graft reconstruction, implants may be placed in previous areas of osseous defect with the expectation of long-term positive results.

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.

Healing of human intrabony defects following regenerative periodontal therapy with a bovine-derived xenograft and guided tissue regeneration

The purpose of the present study was to histologically evaluate the healing of human intrabony defects following treatment with either a bovine-derived xenograft (BDX) and guided tissue regeneration (GTR) [BDX + GTR] or a bovine-derived xenograft mixed with collagen (BDX Coll) and GTR [BDX Coll + GTR]. Eight patients with chronic periodontitis and each with one very deep intrabony defect around a tooth scheduled for extraction were treated with either a combination of BDX + GTR (five patients) or with BDX Coll + GTR (three patients). The postoperative healing was uneventful in all eight cases. After a healing period of 6 months, the teeth or roots were extracted together with some of their surrounding soft and hard tissues and subsequently fixed in 10% buffered formalin. Following decalcification in EDTA, the specimens were embedded in paraffin and 8-microm histological sections were cut in the mesio-distal direction, parallel to the long axes of the teeth. The sections were alternatively stained with hematoxylin and eosin, van Giesson's connective tissue stain or with the Ladevig's connective tissue staining method and examined under the light microscope. Generally, formation of new cementum with inserting collagen fibers was found in seven out of the eight treated cases, whereas in the remaining case (treated with BDX + GTR) the healing was characterized by formation of a long junctional epithelium along the debrided root surface and no formation of cementum or bone. In the specimens demonstrating periodontal regeneration the new cementum was always of a cellular type. In most cases, the graft particles were surrounded by bone. In some areas, the bone tissue around the graft particles was connected by perpendicularly inserting collagen fibers to the newly formed cementum on the root surface. The epithelium downgrowth stopped always at the most coronal part of the newly formed cementum. No remnants of the membrane material were observed in any of the biopsies. Connective tissue encapsulation of the graft particles was rarely observed and was limited to the most coronal part of the defects. The findings of the present study provide evidence that treatment of intrabony defects with both BDX + GTR and BDX Coll + GTR may enhance periodontal regeneration in humans.

Enamel Matrix Protines Bovine Porous Bone Mineral in the Treatment of Intrabony Defects: Comparative Controlled Clinical Trial

BACKGROUND

Various clinical studies have demonstrated that applying commercially available enamel matrix proteins (EMP) on the instrumented root surface during access flap surgery promotes clinically significant gains of clinical attachment and bone in intrabony defects. The aim of the present controlled clinical trial was to evaluate the adjunctive effect of filling the intrabony lesion with bovine porous bone mineral (BPBM) to a simplified papilla preservation (SPP) flap and EMP surgical procedure.

METHODS

Sixty deep interproximal intrabony lesions in 60 patients with chronic periodontitis were treated with the SPP flap and EMP. In the 30 test defects, the intrabony component was filled with BPBM particles previously reconstituted with the EMP gel. A stringent infection control program was adopted for 1 year. The clinical and radiographical reevaluation was made 1 year after surgery.

RESULTS

Both techniques resulted in clinically and statistically significant improvements between baseline and 1 year, in terms of clinical attachment level (CAL) gain, probing depth (PD) reduction, and radiographic bone fill; however, the BPBM test treatment showed statistically significantly greater CAL (5.8 +/- 1.1 versus 4.9 +/- 1.0) and radiographic bone (DEPTH) level gains (5.3 +/- 1.1 versus 4.3 +/- 1.5), and less increase in gingival recession (0.4 +/- 0.6 versus 0.9 +/- 0.5) than the control surgical procedure.

CONCLUSION

The present study data supported the hypothesis that the adjunctive use of BPBM in grafting intrabony defects has the ability to improve clinical and radiographical outcomes achievable with EMP alone.

Tissue response to titanium implantation in the rat maxilla, with special reference to the effects of surface conditions on bone formation

Tissue responses to titanium implantation with two different surface conditions in our established implantation model in rat maxillae were investigated by light and transmission electron microscopy and by histochemistry for tartrate-resistant acid phosphatase (TRAPase) activity. Here we used two types of implants with different surface qualities: titanium implants sandblasted with Al2O3 (SA-group) and implants coated with hydroxyapatite (HA-group). In both groups, bone formation had begun by 5 days postimplantation when the inflammatory reaction had almost disappeared in the prepared bone cavity. In the SA-group, however, the bone formation process in the bone cavity was almost identical to that shown in our previous report using smooth surfaced implants (Futami et al. 2000): new bone formation, which occurred from the pre-existing bone toward the implant, was preceded by active bone resorption in the lateral area with a narrow gap, but not so in the base area with a wide gap. In the HA-group, direct bone formation from the implant toward the pre-existing bone was recognizable in both lateral and base areas. Many TRAPase-reactive cells were found near the implant surface. On the pre-existing bone, new bone formation occurred with bone resorption by typical osteoclasts. Osseointegration around the implants was achieved by postoperative day 28 in both SA- and HA-groups except for the lateral area, where the implant had been installed close to the cavity margin. These findings indicate that ossification around the titanium implants progresses in different patterns, probably dependent on surface properties and quality.

Healing of intrabony defects following treatment with a bovine-derived xenograft and collagen membrane. A controlled clinical study

AIM

: The purpose of the present study was to compare clinically the treatment of deep intrabony defects with a combination of a bovine-derived xenograft (BDX) and a bioresorbable collagen membrane to access flap surgery.

METHODS

: Twenty-eight patients suffering from chronic periodontitis, and each of whom displayed one intrabony defect, were randomly treated with BDX + collagen membrane (test) or with access flap surgery (control). Soft tissue measurements were made at baseline and at 1 year following therapy.

RESULTS

: No differences in any of the investigated parameters were observed at baseline between the two groups. Healing was uneventful in all patients. At 1 year after therapy, the test group showed a reduction in mean probing depth (PD) from 9.2+/-1.3 to 3.9+/-0.7 mm (p<0.001) and a change in mean clinical attachment level (CAL) from 10.2+/-1.5 to 6.2+/-0.5 mm (p<0.0001). In the control group, the mean PD was reduced from 9.0+/-1.2 to 5.2+/-1.8 mm (p<0.001) and the mean CAL changed from 10.5+/-1.5 to 8.4+/-2.1 mm (p<0.01). The test treatment resulted in statistically higher PD reductions (p<or=0.05) and CAL gains (p<0.001) than the control one. In the test group all sites (100%) gained at least 3 mm of CAL. In the control group no CAL gain occurred in four sites (29%), whereas at six sites (43%) the CAL gain was 2 mm. A CAL gain of 3 mm or more was measured in four defects (29%).

CONCLUSIONS

: Within the limits of the present study, it can be concluded that: (i) at 1 year after surgery both therapies resulted in significant PD reductions and CAL gains, and (ii) treatment with BDX+collagen membrane resulted in significantly higher CAL gains than treatment with access flap surgery.

Clinical evaluation of an enamel matrix protein derivative combined with a bioactive glass for the treatment of intrabony periodontal defects in humans

BACKGROUND

The purpose of the present study was to compare the treatment of deep intrabony defects with a combination of an enamel matrix protein derivative (EMD) and a bioactive glass (BG) to BG alone.

METHODS

Twenty-eight patients with chronic periodontitis, each of whom displayed 1 intrabony defect, were randomly treated with a combination of EMD and BG or with BG alone. Soft tissue measurements were made at baseline and at 1 year following therapy.

RESULTS

No differences in any of the investigated parameters were observed at baseline between the 2 groups. Healing was uneventful in all patients. At 1 year after therapy, the sites treated with EMD and BG showed a reduction in mean probing depth (PD) from 8.07 +/- 1.14 mm to 3.92 +/- 0.73 mm and a change in mean clinical attachment level (CAL) from 9.64 +/- 1.59 mm to 6.42 +/- 1.08 mm (P < 0.0001). In the group treated with BG, the mean PD was reduced from 8.07 +/- 1.32 mm to 3.85 +/- 0.66 mm and the mean CAL changed from 9.78 +/- 1.71 mm to 6.71 +/- 1.89 mm (P < 0.0001). No statistically significant differences in any of the investigated parameters were observed between the test and control group.

CONCLUSIONS

Within the limits of the present study, it can be concluded that both therapies led to significant improvements of the investigated clinical parameters, and the combination of enamel matrix derivative and bioactive glass does not seem to additionally improve the clinical outcome of the therapy.

Histopathological morphometric evaluation of 2 different hydroxyapatite-bone derivatives in sinus augmentation procedures: a comparative study in humans

BACKGROUND

Xenografts to augment the maxillary sinus have been used extensively. The aim of the present study was to evaluate, qualitatively and quantitatively, two different HA derivatives of natural and synthetic sources on newly formed bone in the augmented sinus.

METHODS

A bilateral sinus augmentation procedure with simultaneous (16 out of 20 sites) or subsequent implant placement was performed in 10 patients. The antrum was randomly filled with a deproteinized, bovine hydroxyapatite mineral (B-HA) on one side and a non-ceramic resorbable hydroxyapatite (NC-HA) on the other. Cylindrical specimens were harvested from the augmented core at 12 months. Decalcified specimens were sectioned at a cross-horizontal plane and stained with hematoxylin and eosin for histopathologic and histomorphometric examinations. Tissue area fractions of bone, marrow, and the grafted particles were calculated for each specimen from the lateral to the deep region, and changes in values were compared within each material and between them.

RESULTS

New bone formation was evident. B-HA and NC-HA particles were observed in all specimens surrounded by newly formed bone in direct connection or by soft tissue marrow. Morphometrically in the B-HA sites, from the lateral to deeper area, bone area fraction increased from 29.8% to 54.2% (average 42.1%) and marrow area fraction decreased from 37.9% to 26.7% (average 33.3%). The mineral area fraction decreased from 32.3% to 19.1% (average 24.7%). All increasing/decreasing patterns were statistically significant (P < 0.001). In the NC-HA sites, from the lateral to deeper area, bone area fraction increased from 25% to 36.5% (average 32.3%) and marrow area fraction decreased from 51.6% to 41.9% (average 43.2%) (P <0.001). The mineral area fraction decreased from 29% to 21.7% (average 24.6%) (P = 0.038). Comparison between the two HA derivative groups showed a significant difference between the bone area fraction averages (P = 0.0053) and between the increasing patterns along the core depth (P = 0.0006). There was also a significant difference between the decreasing marrow patterns (P = 0.003), but not between their averages. Comparison between the mineral area fractions showed no differences.

CONCLUSIONS

B-HA and NC-HA were proven to be biocompatible materials. Although the B-HA-augmented sites showed a higher percentage of bone formation at 12 months, both are suitable bone derivatives in sinus augmentation procedures and can accommodate osseointegrated implants.

Multi-center clinical comparison of combination anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) and ABM in human periodontal osseous defects. 6-month results

BACKGROUND

Intraosseous periodontal defects present a particular treatment problem. New bone replacement grafts offer promise for improved results.

METHODS

The role of a synthetic cell-binding peptide (P-15), combined with anorganic [corrected] bovine-derived hydroxyapatite bone matrix (ABM), was compared to ABM alone in human periodontal osseous defects in a controlled, monitored, multi-center trial. Following appropriate initial preparation procedures, flap surgery with defect and root debridement was performed. Two osseous defects per patient were treated randomly with each procedure after surgical preparation. Appropriate periodontal maintenance schedules were followed, and at 6 to 7 months, re-entry flap surgery was performed for documentation and finalization of treatment.

RESULTS

T test and Mann-Whitney U analyses of patient mean values from 33 patients revealed that the combination ABM/P-15 grafts demonstrated significantly better mean defect fill of 2.9 +/- 1.2 mm (72.9%) versus a mean defect fill of 2.2 +/- 1.4 mm (50.67%) for defects treated with ABM (P<0.05). Other hard tissue findings showed similar clinically superior results with the use of ABM/P-15. Relative defect fill results showed 81% positive (50% to 100% defect fill) responses with ABM/P-15 and 67% positive responses with ABM. There were 3.5 times as many optimal results (> or = 90% defect fill) with ABM/P-15 and twice as many failures (minimal response) with ABM. Soft tissue findings showed no significant differences between treatments.

CONCLUSIONS

These results suggest that the use of the P-15 synthetic cell-binding peptide combined with ABM yields better clinical results than the ABM alone in intrabony periodontal defects.

The bone regenerative effect of platelet-derived growth factor-BB delivered with a chitosan/tricalcium phosphate sponge carrier

BACKGROUND

In order to achieve optimal effects, growth factors including platelet-derived growth factor (PDGF) should be delivered with a biodegradable carrier that will release therapeutic concentrations over a sufficient length of time. The purpose of this study was to evaluate the bone regenerative effect of PDGF-BB delivered with a chitosan/tricalcium phosphate (TCP) sponge carrier in a rat calvarial defect model.

METHODS

The PDGF-BB-loaded chitosan/TCP sponge carrier was fabricated by freeze-drying a mixture of chitosan solution and TCP powder and soaking in a PDGF-BB solution. The release kinetics of PDGF-BB loaded onto the sponge were measured in vitro with 125I-labeled PDGF-BB. Chitosan/TCP sponges with and without PDGF-BB were implanted into 8 mm calvarial defects in rats. Rats were sacrificed at 2 and 4 weeks following implantation, and histologic and histomorphometrical examinations were performed.

RESULTS

In vitro evaluation demonstrated that an effective therapeutic concentration of PDGF-BB following a high initial burst release was maintained throughout the examination period. In the histologic examination, the chitosan/TCP sponge carrier promoted osseous healing of the rat calvarial defects as compared to controls. The addition of PDGF-BB to the carrier further enhanced bone regeneration. Evidence of the degraded sponge matrix was observed mingled within the newly formed bone without connective tissue encapsulation.

CONCLUSIONS

The results of this study support the use of chitosan/TCP sponges as a delivery system for growth factors and demonstrate that PDGF-BB loaded onto chitosan/TCP sponge carriers has an osteogenic effect on bone regeneration in vivo.

Use of bovine-derived anorganic bone associated with guided tissue regeneration in intrabony defects. Six-month evaluation at re-entry

BACKGROUND

Different filling materials have been associated with guided tissue regeneration (GTR) in order to improve its regenerative potential and predictability. Anorganic bovine bone (ABB) has demonstrated biocompatibility and osteoconductive properties; however, there are limited data regarding its performance in the treatment of intrabony defects. This investigation aimed to evaluate the clinical outcome of the association of anorganic bovine bone with cellulose membranes in intrabony defects after 6 months.

METHODS

Twenty-six paired intrabony defects were selected from 11 non-smoking patients with no relevant medical history. The defects were similar regarding the number of bony walls and defect depth, and presented pocket depths > or = 6 mm. Four weeks after completion of basic therapy, probing depth (PD), clinical attachment level (CAL), and gingival margin position (GP) were recorded (baseline values). The defects were then surgically accessed and debrided, and the intrabony component measured to the nearest millimeter with periodontal probes and customized acrylic stents (distance from the stent to the base of the defect and from the stent to the alveolar crest). Each intrabony defect was randomly assigned to receive the membrane alone (control, C) or the membrane with anorganic bovine bone (test, T). The patients were re-evaluated after 6 months, and re-entry procedures were performed.

RESULTS

Significant (P <0.01) improvement in all variables was observed: mean pocket reduction of 4.61+/-1.60 mm (C) and 4.46+/-1.50 mm (T) and clinical attachment gain of 2.85+/-1.46 mm (C) and 3.15+/-1.40 mm (T); the difference between groups was not significant (P >0.05). Nevertheless, gingival recession in the control group (1.84+/-0.89 mm) was significantly (P <0.05) more pronounced than that observed in the test group (1.30+/-0.48 mm). Bone measurements indicated a significant resolution of the defects (P <0.01). A mean defect resolution of 2.76+/-0.72 mm (C) and 2.69+/-1.03 mm (T) and crestal resorption of 1.07+/-0.64 mm (C) and 1.30+/-0.85 mm (T) were detected (P >0.05). Stepwise multiple regression analysis indicated that for both groups, the baseline depth of the defects and the alveolar crest resorption accounted for 82% of the variability of bone fill observed in the control group (F = 23.65, P <0.001) and 89% in the test group (F = 41.32, P <0.001).

CONCLUSIONS

ABB may be used in conjunction with GTR in the treatment of intrabony defects. Its use, however, did not result in a better outcome than the use of membranes alone. Studies employing more patients would be of interest in order to determine the advantages and indications of the tested approaches on a more predictable basis.

Clinical evaluation of bioactive glass in the treatment of periodontal osseous defects in humans

The purpose of this study was to compare the use of bioactive glass to demineralized freeze-dried bone allograft (DFDBA) in the treatment of human periodontal osseous defects. Fifteen systemically healthy patients (6 males and 9 females, aged 30 to 63) with moderate to advanced adult periodontitis were selected for the study. All patients underwent initial therapy, which included scaling and root planing, oral hygiene instruction, and an occlusal adjustment when indicated, followed by re-evaluation 4 to 6 weeks later. Paired osseous defects in each subject were randomly selected to receive grafts of bioactive glass or DFDBA. Both soft and hard tissue measurements were taken the day of surgery (baseline) and at the 6-month re-entry surgery. The clinical examiner was calibrated and blinded to the surgical procedures, while the surgeon was masked to the clinical measurements. Statistical analysis was performed by using the paired Student's t test. The results indicated that probing depths were reduced by 3.07 +/- 0.80 mm with the bioactive glass and 2.60 +/- 1.40 mm with DFDBA. Sites grafted with bioactive glass resulted in 2.27 +/- 0.88 mm attachment level gain, while sites grafted with DFDBA had a 1.93 +/- 1.33 mm gain in attachment. Bioactive glass sites displayed 0.53 +/- 0.64 mm of crestal resorption and 2.73 mm bone fill. DFDBA-grafted sites experienced 0.80 +/- 0.56 mm of crestal resorption and 2.80 mm defect fill. The use of bioactive glass resulted in 61.8% bone fill and 73.33% defect resolution. DFDBA-grafted defects showed similar results, with 62.5% bone fill and 80.87% defect resolution. Both treatments provided soft and hard tissue improvements when compared to baseline (P < or = 0.0001). No statistical difference was found when comparing bioactive glass to DFDBA; however, studies with larger sample sizes may reveal true differences between the materials. This study suggests that bioactive glass is capable of producing results in the short term (6 months) similar to that of DFDBA when used in moderate to deep intrabony periodontal defects.

Multi-center clinical evaluation of combination anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) as a bone replacement graft material in human periodontal osseous defects. 6-month results

A synthetic cell-binding peptide (P-15) combined with anorganic bovine-derived hydroxyapatite bone matrix (ABM) was compared to demineralized freeze-dried bone allograft (DFDBA) and open flap debridement (DEBR) in human periodontal osseous defects in a controlled, monitored, multi-center trial. Following appropriate initial preparation procedures, flap surgery with defect and root debridement was performed. Three osseous defects per patient were treated randomly with one of three procedures after surgical preparation. Appropriate periodontal maintenance schedules were followed, and at 6 to 7 months re-entry flap surgery was performed for documentation and finalization of treatment. Analysis of variation (ANOVA) and t test analyses of patient mean values from 31 patients revealed that the combination ABM/P-15 grafts demonstrated significantly better mean defect fill of 2.8 +/- 1.2 mm (72.3%) versus a mean defect fill of 2.0 +/- 1.4 mm (51.4%) for defects treated with DFDBA (P <0.05) and a mean defect fill of 1.5 +/- 1.3 mm (40.3%) (P <0.05) for defects treated with DEBR. Other hard tissue findings showed similar clinically superior results with the use of ABM/P-15. Relative defect fill results showed 87% positive (50% to 100% defect fill) responses with ABM/P-15, 58% positive responses with DFDBA, and 41% positive responses with DEBR. There were 8 to 9 times more failures (minimal response) with DFDBA and DEBR (26% to 29% frequency) than with ABM/P-15. Soft tissue findings showed no significant differences among treatments except for greater clinical attachment level gain with ABM/P-15 compared to DEBR. These results suggest that the use of the P-15 synthetic cell-binding peptide combined with ABM yields better clinical results than either DFDBA or DEBR. Further studies are needed to determine the relative roles of the ABM and/or the P-15 in these improved results.

Comparison of bioactive glass synthetic bone graft particles and open debridement in the treatment of human periodontal defects. A clinical study

The purpose of this study was to compare the repair response of bioactive glass synthetic bone graft particles and open debridement in the treatment of human periodontal osseous defects. Fifty-nine defects in 16 healthy adults were selected. Each patient had at least 2 sites with attachment loss of at least 6 mm with clinical and radiographic evidence of intrabony or furcation defects. One to 3 months after cause-related therapy (oral hygiene instructions, scaling and root planing), the following measurements were recorded prior to surgery: probing depths, clinical attachment level, and gingival recession. Each defect was surgically exposed and measurements made of the alveolar crest height and base of osseous defect. The test defects were implanted with bioactive glass. The other sites served as unimplanted controls. Flaps were sutured at or close to the presurgical level. Radiographs and soft tissue presurgical measurements were repeated at 6, 9, and 12 months. At 12 months all sites were surgically re-entered to record osseous measurements. At the 12-month evaluation, significantly greater mean probing depth reduction was noted in the bioactive glass group compared to the controls (4.26 mm versus 3.44 mm; P = 0.028). Clinical attachment level gain was significantly improved (P = 0.0004) in the bioactive glass sites (2.96 mm) compared to the control sites (1.54 mm). There was significantly less gingival recession in the bioactive glass sites (1.29 mm) compared to the control sites (1.87 mm). Defect fill was significantly greater in the bioactive glass sites (3.28 mm) compared to the control sites (1.45 mm). Defect depth reduction was significantly greater in the bioactive glass sites (4.36 mm) compared to the control sites (3.15 mm). In conclusion, bioactive glass showed significant improvement in clinical parameters compared to open flap debridement.

A clinical evaluation of an allograft combined with a bioabsorbable membrane versus an alloplast/allograft composite graft combined with a bioabsorbable membrane. 100 consecutively treated cases

The purpose of this study was to evaluate and compare the clinical effectiveness of 2 surgical techniques in treating periodontal defects. Both techniques involved tetracycline treatment of a root planed root, grafting the osseous defect with a bone graft, and placement of a bioabsorbable membrane. In group A, the bone graft was a mix of demineralized freeze-dried allograft, tetracycline, and porous hydroxyapatite and in group B, the bone graft was a mix of demineralized freeze-dried allograft and tetracycline. There was a statistically significant increase in recession (group A, 0.7 mm; group B, 0.6 mm), decreases in probing depth (group A, 6.1 mm; group B, 5.6 mm), and gains in attachment levels (group A, 5.4 mm; group B, 5.0 mm). There were no statistically significant differences between the results for either group. The defects associated with furcations and those that were not associated with furcations had similar results, except for the percent attachment gain. Smoking and age (> or =60 years old) could not be associated with results. Defects with > or =10 mm probing depths (PD) had greater PD reductions (group A, 7.7 mm; group B, 7.1) and attachment gains (group A, 6.6 mm; group B, 6.4 mm) than the defects with probing depths less than 10 mm (probing reduction group A, 4.8 mm; group B, 4.5 mm; attachment gain group A, 4.4 mm; group B, 4.0 mm). Both surgical procedures improved the clinical situation. However, neither technique seemed to offer a statistical advantage over the other. The inclusion of porous hydroxyapatite did not improve or diminish the results.

Hydroxyapatite cement implant for regeneration of periodontal osseous defects in humans

A newly developed calcium phosphate cement used to promote bone regeneration in craniofacial defects was examined to determine its potential for treatment of periodontal osseous defects. Sixteen patients with moderate to severe periodontal disease and 2 bilaterally similar vertical bony defects received initial therapy including scaling and root planing followed by treatment with either calcium phosphate cement, flap curettage (F/C) or debridement plus demineralized freeze-dried bone allograft (DFDBA). Standardized radiographs were exposed at baseline and 12 months postsurgery for computer assisted densitometric image analysis (CADIA). The extent of the bony defect was determined during initial and 12 month re-entry surgery. Within 6 months of implant placement, 11 of 16 patients treated with calcium phosphate cement exfoliated all or most of the implant through the gingival sulcus. At all 16 test sites, a narrow radiolucent gap formed by 1 month postsurgery at the initially tight visual interface between the radiopaque calcium phosphate cement and the walls of the bony defect. Mean probing depth reduction and clinical attachment gain at sites treated with calcium phosphate cement were 1.6 mm and 1.3 mm, respectively at 1 year. Minimal bony defect fill was accompanied by mean crestal resorption of 1.4 mm. Alveolar crestal resorption at sites with calcium phosphate cement was statistically significant (P=0.001). These findings contrasted with the more favorable outcomes for controls treated with DFDBA or F/C. DFDBA sites exhibited probing depth reduction of 3.1 mm, clinical attachment gain of 2.9 mm, and defect fill of 2.4 mm. Respective clinical changes at F/C sites were 2.4 mm, 1.4 mm, and 1.1 mm. CADIA revealed clinically significant trends between the three treatment modalities at various areas-of-interest. Based on the findings of this study, there is no rationale available to support the use of hydroxyapatite cement implant in its current formulation for the treatment of vertical intrabony periodontal defects.

Guided tissue regeneration in conjunction with hydroxyapatite-collagen grafts for intrabony defects. A clinical and radiological evaluation

This clinical and radiological study evaluated the healing of 3 + 2 + 1 wall-combined intrabony defects treated using the guided tissue regeneration technique (GTR) with and without hydroxyapatite-collagen alloplastic graft materials (HAC), in comparison to that of HAC alone and conventional flap surgery (CF). 40 interproximal defects with probing depth > 6 mm were treated in 18 adult periodontitis patients of ages 35-60 years. After non-surgical therapy, the defects were randomly grouped into 4 groups of 10 defects each. These groups were designated: (1) expanded polytetrafluoroethylene membrane (e-PTFE), (2) e-PTFE + HAC, (3) HAC alone and (4) CF. At 6 months, the following changes in parameters were recorded. Mean PPD reduction for each group was 5.83, 5.85, 3.80 and 3.17 mm respectively. PPD reduced very significantly in all groups (p < 0.01), the highest and lowest reductions in PPD being for the e-PTFE + HAC and CF group respectively. Comparison between the 4 groups showed higher PPD reduction in both membrane groups than in either of the non membrane groups (p < 0.05) with the difference between the e-PTFE and CF groups being very highly significant (p < 0.001). Mean attachment gain for the 4 groups was 3.70, 3.80, 2.60 and 2.1 mm, respectively. Similarly attachment gain for all groups was very significant (p < 0.01) and the highest and lowest attachment gains were for the e-PTFE + HAC and CF group respectively. Both membrane groups showed significantly more attachment gain than the CF group (p < 0.05). Change in probing bone level (BL) for the 4 groups was 1.60, 1.90, 1.0 and 0.65 mm respectively. Again the highest changes in BL were recorded for the e-PTFE + HAC group. Significant differences were found between both membrane groups and the CF group (p < 0.05). Radiological evaluation using standardized radiographs and millimeter grids showed change in radiographic bone level at the deepest point of the defect on the radiograph to be 1.50, 1.55, 0.85 and 0.60 mm, respectively and this was significantly higher in both membrane groups than in the CF group (p < 0.05). This study therefore found e-PTFE membranes both alone and when combined with HAC to lead to more attachment gain and bone fill than did HAC alone or CF. It found HAC combined with e-PTFE to perform better although not significantly better than e-PTFE alone.

Effects of calcium phosphate bioceramics on skeletal muscle cells

With advances in ceramics technology, calcium phosphate bioceramics have been applied as bone substitutes. The effects of implants on bony tissue have been investigated. The effects upon adjacent skeletal muscles have not been determined. The focus of this work is to elucidate the biological effects of various calcium phosphate bioceramics on skeletal muscles. Four different kinds of powder of calcium phosphate biomaterials including beta-tricalcium phosphate (beta-TCP), hydroxyapatite (HA), beta-dicalcium pyrophosphate (beta-DCP) and sintered beta-dicalcium pyrophosphate (SDCP), were tested by myoblast cell cultures. The results were analyzed by cell count, cell morphology and concentration of transforming growth factor beta 1 (TGF-beta 1) in culture medium. The cell population and TGF-beta 1 concentration of the control sample increased persistently as the time of culture increased. The changes in cell population and TGF-beta 1 concentration in culture medium of the beta-TCP and HA were quite low in the first 3 days of culture, then increased gradually toward the seventh day. The changes in cell population and TGF-beta 1 concentration in culture medium of the silica, beta-DCP, and SDCP were quite similar. They were lower during the first day of culture but increased and reached that of the control medium after 7 days' culture. Most cells on B-TCP and HA diminished in size with radially spread, long pseudopods. We conclude that HA and beta-TCP are thought to have an inhibitory effect on growth of the myoblasts. The HA and beta-TCP may interfere with the repair and regeneration of injured skeletal muscle after orthopedic surgery.

Periodontal regeneration around natural teeth

1. Evidence is conclusive (Table 2) that periodontal regeneration in humans is possible following the use of bone grafts, guided tissue regeneration procedures, both without and in combination with bone grafts, and root demineralization procedures. 2. Clinically guided tissue regeneration procedures have demonstrated significant positive clinical change beyond that achieved with debridement alone in treating mandibular and maxillary (buccal only) Class II furcations. Similar data exist for intraosseous defects. Evidence suggests that the use of bone grafts or GTR procedures produce equal clinical benefit in treating intraosseous defects. Further research is necessary to evaluate GTR procedures compared to, or combined with, bone grafts in treating intraosseous defects. 3. Although there are some data suggesting hopeful results in Class II furcations, the clinical advantage of procedures combining present regenerative techniques remains to be demonstrated. Additional randomized controlled trials with sufficient power are needed to demonstrate the potential usefulness of these techniques. 4. Outcomes following regenerative attempts remain somewhat variable with differences in results between studies and individual subjects. Some of this variability is likely patient related in terms of compliance with plaque control and maintenance procedures, as well as personal habits; e.g., smoking. Variations in the defects selected for study may also affect predictability of outcomes along with other factors. 5. There is evidence to suggest that present regenerative techniques lead to significant amounts of regeneration at localized sites on specific teeth. However, if complete regeneration is to become a reality, additional stimuli to enhance the regenerative process are likely needed. Perhaps this will be accomplished in the future, with combined procedures that include appropriate polypeptide growth factors or tissue factors to provide additional stimulus.

Effects of polyglactin mesh combined with resorbable calcium carbonate or replamineform hydroxyapatite on periodontal repair in dogs

This study evaluates periodontal repair and biomaterial reaction following implantation of a polyglactin mesh with or without porous resorbable calcium carbonate (RCC) or porous replamineform hydroxyapatite (RHA) in conjunction with reconstructive surgery. Ligature- and surgically-induced interproximal periodontal defects of left and right mandibular premolar teeth in 7 dogs were used. Bilaterally, mesial defects of the 2nd, 3rd and 4th premolar teeth were treated with polyglactin mesh, polyglactin mesh and RHA, or polyglactin mesh and RCC, respectively. The polyglactin mesh, shaped according to the contour of the defect, was adapted to the experimental teeth; its coronal margin positioned immediately apical to the cemento-enamel junction. Gingival flap margins were adapted and sutured to cover the polyglactin mesh completely. Clinical healing was generally uneventful. The dogs were sacrificed to provide block sections for histologic evaluation at 1, 3, 6, 12, 26, 32 and 56 weeks following wound closure. Generally, cementum regeneration was observed beginning at week 6 in all groups. Bone regeneration was observed from week 3 in polyglactin mesh-treated groups, and from week 6 in polyglactin mesh+RCC or polyglactin mesh+RHA treated groups. Bone regeneration appeared enhanced in polyglactin mesh+RCC or polyglactin mesh+RHA treated defects at week 12 and 26, with little difference between the three experimental conditions at week 56. Polyglactin mesh degradation was observed at week 3 and appeared complete at week 12. The RHA did not appear to resorb, while the RCC was gradually replaced by bone from week 3. Within limitations of the study conditions, periodontal regeneration was observed following implantation of a polyglactin mesh with or without RCC or RHA in conjunction with reconstructive surgery. As a conclusion, there seems to be no significant difference in periodontal regeneration after 12 months of healing between the group treated with the membrane only, and the group treated with the membrane and the bone substitution material. Changes in connective fiber orientation over the 1st 12 weeks of healing may suggest that "fibrous encapsulation" observed in earlier studies may only represent a transient stage in periodontal regeneration.

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).

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.

Periodontal regeneration updated

Techniques in treating periodontal disease are discussed to provide insight about which technique fits each clinical situation. New developments provide possible regeneration of new cementum, periodontal ligament and alveolar bone, resulting in a new periodontal attachment.

Osseointegration of macroporous calcium phosphate ceramics having a different chemical composition

Calcium phosphate macroporous ceramics are biocompatible for bone surgery. Their osseointegration is, however, sometimes very poor. To measure the effect of the calcium phosphate content of the ceramic on its osseointegration, macroporous ceramics, differing in their chemical composition, were implanted into sheep femurs. The ceramics were composed of different percentages of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP). All other characteristics were the same. Results were assessed histologically with image analysis and showed significant differences in the amount of bone formed at the contact of the different ceramics. Ceramics containing beta-TCP induced better osseointegration than pure HA ceramics.