Deproteinized bovine bone and gentamicin as an adjunct to GTR in the treatment of intrabony defects: a randomized controlled clinical study

Nanostructured Zn-Substituted Monetite Based Material Induces Higher Bone Regeneration Than Anorganic Bovine Bone and β-Tricalcium Phosphate in Vertical Augmentation Model in Rabbit Calvaria

The capacity of a nanostructured multicomponent material composed of Zn-substituted monetite, amorphous calcium phosphate, hydroxyapatite and silica gel (MSi) to promote vertical bone augmentation was compared with anorganic bovine bone (ABB) and synthetic β-tricalcium phosphate (β-TCP). The relation between biological behavior and physicochemical properties of the materials was also studied. The in vivo study was conducted in a vertical bone augmentation model in rabbit calvaria for 10 weeks. Significant differences in the biological behavior of the materials were observed. MSi showed significantly higher bone regeneration (39%) than ABB and β-TCP (24%). The filled cylinder volume was similar in MSi (92%) and ABB (91%) and significantly lower in β-TCP (81%) implants. In addition, β-TCP showed the highest amount of non-osteointegrated particles (17%). MSi was superior to the control materials because it maintains the volume of the defect almost full, with the highest bone formation, the lowest number of remaining particles, which are almost fully osteointegrated and having the lowest amount of connective tissue. Besides, the bone formed was mature, with broad trabeculae, high vascularization and osteogenic activity. MSi resorbs gradually over time with an evident increment of the porosity and simultaneous colonization for vascularized new bone. In addition, the osteoinductive behavior of MSi material was evidenced.

The impact of a "successfully treated stable periodontitis patient status" on patient-related outcome parameters during long-term supportive periodontal care

AIM

To assess the importance of achieving a successfully treated stable periodontitis patient status (PPS) during long-term supportive periodontal care (SPC).

MATERIALS AND METHODS

This retrospective cohort study included 100 periodontitis patients, who continued for ≥7.5 years after active periodontal treatment with SPC and were judged as overall adherent. The effect of various predictors on three patient-related outcome parameters was assessed: (1) number of diseased teeth at last SPC, (2) number of teeth lost due to periodontitis, and (3) number of teeth lost due to any reason.

RESULTS

One-fifth of the patients were classified as stable after active periodontal treatment. After a mean follow-up of 10.77 years, 24 patients lost 38 teeth due to periodontitis. An unstable PPS and a higher number of diseased teeth per patient at first SPC, and inadequate oral hygiene levels over time, significantly increased the risk for a higher number of diseased teeth per patient at last SPC and for more lost teeth due to periodontitis. However, high adherence to SPC appeared to mitigate the negative effect of an unstable PPS, especially regarding tooth loss due to periodontitis. Further, tooth loss due to any reason was about 3 times higher than tooth loss due to periodontitis and was affected by a larger number of predictors.

CONCLUSIONS

Successfully treated patients with a stable PPS maintained a small number of diseased teeth and barely lost any teeth during long-term SPC compared to patients who did not achieve a stable PPS after active periodontal therapy.

Evaluating Change of Marginal Bone Height with Cone-Beam Computed Tomography Following Surgical Treatment with Guided Tissue Regeneration (Bone Grafting) or Access Flap Alone: A Retrospective Study

Background and Objectives: This study aimed to evaluate the change of bone height following treatment of human intrabony defects with guided tissue regeneration (GTR) with bone grafting or access flap alone by cone-beam computed tomography (CBCT) scan. Materials and methods: This study was conducted as a retrospective longitudinal study. In this study, a total of 2281 teeth sites were included: the GTR group had 1210 sites, and the Flap group had 1071 sites. In the GTR group, demineralized freeze-dried bone (DFDBA) particles in combination with resorbable collagen membrane were used. No regenerative material was applied to the Flap group. CBCT images were taken twice at baseline and at least 2.5 months postoperatively. Bone heights were measured using software on CBCT images. Results: The bony change between the GTR and Flap groups was significantly different (p = 0.00001). Both males and females in the GTR group had smaller bone loss than in the Flap group. In age groups, significant differences of bony height between the GTR and Flap groups were observed in the subgroups consisting of those 29–45 and 46–53 years old. The non-smoking subjects in the GTR group had higher bone heights than those in the Flap group. In the absence of systemic disease and medicine, bone formation was higher in the GTR group than in the Flap group. In terms of oral position, the #14–17, #34–37, and #44–47 subgroups of the GTR group showed higher levels of bone heights than those of the Flap group. Conclusions. The results of this study indicated that the GTR procedure offers the additional benefit of higher bone heights than the Flap procedure does.

Periodontal infrabony defects: Systematic review of healing by defect morphology following regenerative surgery

BACKGROUND

It is thought that infrabony defect morphology affects the outcome of periodontal regenerative surgery. However, this has not been systematically investigated.

AIMS

To investigate how well defect morphology is described in papers reporting regenerative therapy of periodontal infrabony defects and to investigate its effect on clinical and radiographic outcomes.

MATERIALS AND METHODS

A search was conducted in 3 electronic databases for publications reporting clinical and radiographic outcomes of periodontal intra-bony defects after regenerative therapy, divided by defect morphology.

RESULTS

The initial search resulted in 4487 papers, reduced to 143 after first and second screening. Fifteen of these publications were suitable for a fixed-effects meta-analysis. Initial defect depth was found to influence radiographic bone gain 12 months post-surgery, while narrower angles and increased number of walls influenced both radiographic bone gain and clinical attachment level (CAL) gain at 12 months. These associations seemed to occur irrespective of biomaterials used. Risk of bias ranged from low to high.

CONCLUSION

Deeper defects with narrower angles and increased number of walls exhibit improved CAL and radiographic bone gain at 12 months post-regenerative surgery. More data are needed about other aspects of defect morphology such as extension to buccal/lingual surfaces.

Biphasic ceramic biomaterials with tunable spatiotemporal evolution for highly efficient alveolar bone repair

Alveolar bone defects, which are characterized by a relatively narrow space and location adjacent to the cementum, require promising substitute biomaterials for their regeneration. In this study, we introduced novel yolk-shell biphasic bio-ceramic granules with/without a customized porous shell and evaluated their biological effect together with structural transformation. Firstly, a self-made coaxial bilayer capillary system was applied for the fabrication of granules. Secondly, thorough morphological and physicochemical characterizations were performed in vitro. Subsequently, the granules were implanted into critical-size alveolar bone defects (10 × 4 × 3 mm) in New Zealand white rabbits, with Bio-Oss® as the positive control. Finally, at 2, 4, 8, and 16 weeks postoperatively, the alveolar bone specimens were harvested and assessed via radiological and histological examination. Our results showed that the yolk-shell biphasic bio-ceramic granules, especially those with porous shells, exhibited a tunable ion release performance, improved biodegradation behavior and satisfactory osteogenesis compared with the homogeneously hybrid and Bio-Oss® granules both in vitro and in vivo. This study provides the first evidence that novel yolk-shell bio-ceramic granules, on account of their adjustable porous microstructure, have great potential in alveolar bone repair.

Antibacterial effects of polymeric PolymP-n Active nanoparticles. An in vitro biofilm study

OBJECTIVE

to study the antibacterial effect of polymeric PolymP-n Active nanoparticles using an in vitro subgingival biofilm model.

METHODS

Hydroxyapatite discs coated with five modalities of nanoparticles (NPs): NPs, NPs doped with zinc, calcium, silver and doxycycline, PBS as control, and Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were studied in a static in vitro biofilm model (12, 24, 48, and 72h). Nano-roughness of the different disc surfaces (SRa, in nm) and morphological characteristic of the biofilms (thickness (μm) and bacterial viability) were studied by different microscopy modalities. Quantitative Polymerase Chain Reaction was used to assess the effect of the nanoparticles on the bacterial load (colony forming unit per milliliter) (CFUmL^-1). Analysis of variance and post-hoc testing with T3 Dunnett́s, and Student Newman Keuls correction was used. Results were considered statistically significant at p<0.05.

RESULTS

Surfaces containing the different nanoparticles showed significant increments in roughness when compared to controls (p<0.05). A similar biofilm formation and dynamics was observed, although reductions in bacterial viability were detected in biofilms in contact with the different nanoparticles, more pronounced with silver and doxycycline NPs. Doxycycline-NPs biofilms resulted in unstructured biofilm formation and significantly lower number of the six species when compared with the other nanoparticles specimens and controls (p<0.001 in all cases).

SIGNIFICANCE

Polymeric PolymP-n Active nanoparticles when combined with silver and doxycycline showed a significant antibacterial effect when tested in an in vitro subgingival biofilm model.

Evaluation of moxifloxacin-hydroxyapatite composite graft in the regeneration of intrabony defects: A clinical, radiographic, and microbiological study

Background:

The formation of new connective periodontal attachment is contingent upon the elimination or marked reduction of pathogens at the treated periodontal site. An anti-microbial agent, i.e. moxifloxacin has been incorporated into the bone graft to control infection and facilitate healing during and after periodontal therapy.

Materials and Methods:

By purposive sampling, 15 patients with at least two contralateral vertical defect sites were selected. The selected sites in each individual were divided randomly into test and control sites according to split-mouth design. Test site received moxifloxacin-hydroxyapatite composite graft and control site received hydroxyapatite-placebo gel composite graft. Probing depth (PD) and Clinical attachment level (CAL) were assessed at baseline, 3, 6, 9, and 12 months. Bone probing depth (BPD) and hard tissue parameters such as amount of defect fill, percentage of defect fill, and changes in alveolar crest were assessed at baseline, 6, and 12 months. Changes in subgingival microflora were also assessed by culturing the subgingival plaque samples at baseline and at 3-month follow-up. The clinical, radiographic, and microbiological data obtained were subjected to statistical analysis using descriptive statistics, paired sample t-test, independent t-test, and contingency test.

Results:

On intragroup comparison at test and control sites, there was a significant improvement in all clinical and radiographic parameters. However, on intergroup comparison of the same, there was no statistically significant difference between test and control sites at any interval. Although test sites showed slightly higher amount of bone fill, it was not statistically significant. There was a significant reduction in the counts of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis at both sites from baseline to 3 months. In addition, there was a significant reduction at test sites as compared to control sites at 3-month follow-up (P = 0.003 and P = 0.013).

Conclusion:

The reduction in microbial counts found in test sites at 3-month follow-up could not bring similar significant improvements in the clinical and radiographic parameters though the test sites showed slightly higher bone fill.

A new method to standardize CBCT for quantitative evaluation of alveolar ridge preservation in the mandible: a case report and review of the literature

Cone-beam computerized tomography (CBCT) is an effective technique for assessment of changes to the alveolar ridge (AR). However, its accuracy and reliability could be improved by standardization of imaging positions to remain unchanged during measurements. In this study, an alveolar ridge preservation procedure was performed on a left third molar (38) socket by filling it with a radiotransparent synthetic bone graft, mineralized collagen (MC). Photographic, X-ray and CBCT images were captured before and 3, 6 and 12 months after surgery. A new method was developed to standardize CBCT for quantitative evaluation. Obtained CBCT images showed good comparability. The post-extraction alveolar width and height were both over 95% of the original values, but some resorption of the lingual bone wall (>50%) and inter-crestal bone (>30%). It is concluded that an effective positional standardization method was developed for CBCT assessment of AR dimensional changes in the posterior mandible. The use of MC in combination with a collagen membrane improved dimensional preservation of the AR.

Clinical outcomes following regenerative therapy of non-contained intrabony defects using a deproteinized bovine bone mineral combined with either enamel matrix derivative or collagen membrane

BACKGROUND

The purpose of this study is to compare clinical outcomes in the treatment of deep non-contained intrabony defects (i.e., with ≥70% 1-wall component and a residual 2- to 3-wall component in the most apical part) using deproteinized bovine bone mineral (DBBM) combined with either enamel matrix protein derivative (EMD) or collagen membrane (CM).

METHODS

Forty patients with multiple intrabony defects were enrolled. Only one non-contained defect per patient with an intrabony depth ≥3 mm located in the interproximal area of single- and multirooted teeth was randomly assigned to the treatment with either EMD + DBBM (test: n = 20) or CM + DBBM (control: n = 20). At baseline and after 12 months, clinical parameters including probing depth (PD) and clinical attachment level (CAL) were recorded. The primary outcome variable was the change in CAL between baseline and 12 months.

RESULTS

At baseline, the intrabony component of the defects amounted to 6.1 ± 1.9 mm for EMD + DBBM and 6.0 ± 1.9 mm for CM + DBBM sites (P = 0.81). The mean CAL gain at sites treated with EMD + DBBM was not statistically significantly different (P = 0.82) compared with CM + DBBM (3.8 ± 1.5 versus 3.7 ± 1.2 mm). No statistically significant difference (P = 0.62) was observed comparing the frequency of CAL gain ≥4 mm between EMD + DBBM (60%) and CM + DBBM (50%) or comparing the frequency of residual PD ≥6 mm between EMD + DBBM (5%) and CM + DBBM (15%) (P = 0.21).

CONCLUSION

Within the limitations of the present study, regenerative therapy using either EMD + DBBM or CM + DBBM yielded comparable clinical outcomes in deep non-contained intrabony defects after 12 months.

A primer on network meta-analysis for dental research

In the last decade, a new statistical methodology, namely, network meta-analysis, has been developed to address limitations in traditional pairwise meta-analysis. Network meta-analysis incorporates all available evidence into a general statistical framework for comparisons of all available treatments. A further development in the network meta-analysis is to use a Bayesian statistical approach, which provides a more flexible modelling framework to take into account heterogeneity in the evidence and complexity in the data structure. The aim of this paper is therefore to provide a nontechnical introduction to network meta-analysis for dental research community and raise the awareness of it. An example was used to demonstrate how to conduct a network meta-analysis and the differences between it and traditional meta-analysis. The statistical theory behind network meta-analysis is nevertheless complex, so we strongly encourage close collaboration between dental researchers and experienced statisticians when planning and conducting a network meta-analysis. The use of more sophisticated statistical approaches such as network meta-analysis will improve the efficiency in comparing the effectiveness between multiple treatments across a set of trials.

Radiographic and clinical outcomes of implants placed in ridge preserved sites: a 12-month post-loading follow-up

OBJECTIVE

The aim of this clinical study was to evaluate the interproximal radiographic bone levels and the survival/success rate of dental implants placed in alveolar ridges previously preserved with a synthetic bone substitute or a bovine xenograft.

MATERIAL AND METHODS

Alveolar ridge preservation was performed in 27 patients who were randomly assigned in two groups. In the test group (n = 14), the extraction socket was treated with a synthetic bone graft Straumann Bone Ceramic; SBC and a collagen barrier, whereas in the control group (n = 13) a deproteinized bovine bone mineral (DBBM) and the same collagen barrier were used. After 8 months of healing, titanium dental implants with a hydrophilic surface were placed in the preserved ridges. During surgery, 9/13 implants in the SBC group and 8/12 implants in the DBBM group presented with either dehiscence or fenestration defects and required additional bone augmentation. The implants were loaded at 4 months following placement and were followed up for 1 year post-loading. Interproximal radiographic bone levels were evaluated in standardized periapical radiographs at loading and 1 year post-loading. Probing pocket depth, gingival recession and bleeding upon probing were recorded at implants and neighbouring teeth. The success rate of the implants was evaluated according to criteria set by Albrektsson et al. (1986).

RESULTS

The survival rate of the implants in both groups was 100% at 1-year post-loading. No statistically significant differences in any of the clinical and radiographic measurements were detected between the two groups (P < 0.05). The success rate of the implants was 84.6% (11/13) in the SBC group and 83.3% (10/12) in the DBBM group.

CONCLUSION

Equivalent success and survival rates (as well as similar radiographic changes) of dental implants placed in alveolar ridges previously preserved with SBC or DBBM should be anticipated.

Radiographic alveolar bone changes following ridge preservation with two different biomaterials

OBJECTIVES

The aim of this randomized controlled trial was to evaluate radiographical bone changes following alveolar ridge preservation with a synthetic bone substitute or a bovine xenograft.

METHODS

Alveolar ridge preservation was performed in 27 patients randomized in two groups. In the test group (n=14), the extraction socket was treated with Straumann bone ceramic(®) (SBC) and a collagen barrier membrane (Bio-Gide(®)), whereas in the control group (n=13) with deproteinized bovine bone mineral and the same barrier. Standardized periapical X-rays were taken at 4 time points, BL: after tooth extraction, GR: immediately after socket grafting, 4M: 16 weeks, 8M: 32 weeks post-operatively. The levels of the alveolar bone crest at the mesial (Mh), and distal (Dh) and central aspects of the socket were measured at all time points. All the radiographs obtained were subtracted from the follow-up images. The gain, loss and unchanged areas in terms of grey values were tested for significant difference between the two groups.

RESULTS

In the test group, the Mh and Dh showed a mean difference (± standard deviation) of 0.9 ± 1.2 and 0.7 ± 1.8 mm, respectively, among BL-8M. In the control group, the Mh and Dh showed a mean difference of 0.4 ± 1.3 and 0.7 ± 1.3 mm, respectively (P>0.05). Both treatments presented similar gain in grey values between BL-GR, BL-4M and BL-8M. The SBC presented less loss in grey values between BL-4M and BL-8M (P<0.05). Radiographic assessment underestimated the intrasurgical measurements (mesial and distal) of an average 0.3 mm (95% CI, 0.02-0.6).

CONCLUSION

Both types of bone grafts presented similar radiographic alveolar bone changes when used for alveolar ridge preservation.

Regeneration of periodontal tissues: guided tissue regeneration

The concept that only fibroblasts from the periodontal ligament or undifferentiated mesenchymal cells have the potential to re-create the original periodontal attachment has been long recognized. Based on this concept, guided tissue regeneration has been applied with variable success to regenerate periodontal defects. Quantitative analysis of clinical outcomes after guided tissue regeneration suggests that this therapy is a successful and predictable procedure to treat narrow intrabony defects and class II mandibular furcations, but offers limited benefits in the treatment of other types of periodontal defects.

Surgical guided tissue regeneration treatment of advanced periodontal defects: a 5-year follow-up study

OBJECTIVES

To study the 5-year outcome of combined use of guided tissue regeneration (GTR) barriers and bovine bone in advanced periodontal defects.

MATERIAL AND METHODS

In each of 24 patients, one defect was surgically exposed, debrided, filled with bovine bone, and covered with a bioresorbable barrier. Re-examinations were made after 1, 3, and 5 years.

RESULTS

Average full-mouth plaque scores (FMPS) were 14.5% at baseline and 10.7%, 9.8%, and 18.9% after 1, 3, and 5 years, respectively. Mean probing pocket depth (PPD) was 10.0 mm at baseline. Mean PPD reduction was 5.2 mm after 1 year, 5.6 mm after 3 years, and 5.3 mm after 5 years. Mean gingival recession was 1.0 mm after 1 year, 1.6 mm after 3 years, and 1.3 mm after 5 years. Mean gain in clinical attachment level (CAL) was 4.2 mm at the 1-year, 4.1 mm at the 3-year, and 4.3 mm at the 5-year examination. Smoking significantly influenced CAL change at all re-examinations. FMPS were significantly correlated with radiographic defect depth at the 5-year examination and CAL with smoking and FMPS at the 3-year examination.

CONCLUSION

Advanced periodontal defects can be successfully treated with the combined use of GTR barriers and bovine bone to substantially reduce PPD and achieve a stable, long-term gain of CAL.

Microbial colonization patterns predict the outcomes of surgical treatment of intrabony defects

AIM

To explore the impact of bacterial load and microbial colonization patterns on the clinical outcomes of periodontal surgery at deep intrabony defects.

MATERIALS AND METHODS

One hundred and twenty-two patients with advanced chronic periodontitis and at least one intrabony defect of >3 mm were recruited in 10 centres. Before recruitment, the infection control phase of periodontal therapy was completed. After surgical access and debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. Microbial colonization of the defect-associated pocket was assessed using a DNA-DNA checkerboard analysis.

RESULTS

Total bacterial load and counts of red complex bacteria were negatively associated with CAL gains 1 year following treatment. The probability of achieving above median CAL gains (>3 mm) was significantly decreased by higher total bacterial counts, higher red complex and T. forsythensis counts immediately before surgery.

CONCLUSIONS

Presence of high bacterial load and specific periodontal pathogen complexes in deep periodontal pockets associated with intrabony defects had a significant negative impact on the 1 year outcome of surgical/regenerative treatment.

Five-year results of guided tissue regeneration in combination with deproteinized bovine bone (Bio-Oss) in the treatment of intrabony periodontal defects: a case series report

The aim of this study was to report on the clinical and radiographic results 5 years following treatment of intrabony defects with guided tissue regeneration (GTR) in combination with deproteinized bovine bone (DBB) (Bio-Oss). Fifteen patients, with at least one intrabony periodontal defect with probing pocket depth (PPD)>or=7 mm and radiographic presence of an intrabony component (IC)>or=4 mm, were treated with a PLA/PGA bioabsorbable membrane. Prior to placement of the membrane, the defect was filled with DBB impregnated with gentamicin sulfate 2 mg/ml. Standardized intraoral radiographs were taken prior to treatment and at the control examinations after 1 and 5 years. At baseline, the average PPD was 9.2+/-1.1 mm, and the average probing attachment level (PAL) was 10.1+/-1.6 mm; the radiographic bone level (RBL) was 10.4+/-2.45 mm, and an IC of 6.2+/-2.3 mm was present. One year after membrane placement, treatment had resulted in a PAL gain of 3.8+/-1.8 mm, a residual PPD of 4.2+/-1.3 mm, an RBL gain of 4.7+/-2.0 mm, and a residual IC of 2.1+/-1.2 mm. At the 5-year examination, two patients did not show up, and two patients had lost the treated tooth. However, both teeth were endodontically treated, and progressive periodontal destruction might not necessarily have been the reason for extraction. At the 5-year control (11 patients), the PAL gain was 4.1+/-1.6 mm, and the residual PPD was 4.6+/-1.2 mm; an RBL gain of 4.9+/-2.7 mm and a residual IC of 1.8+/-0.8 mm were observed. Statistically significant clinical improvements had occurred between baseline and the 1- and 5-year controls, whereas there were no significant differences between the 1- and 5-year results. The results of GTR with bioabsorbable membranes in combination with Bio-Oss in the treatment of periodontal intrabony defects are basically stable on a long-term basis.

Clinical outcomes following treatment of human intrabony defects with GTR/bone replacement material or access flap alone. A multicenter randomized controlled clinical trial

AIM

This prospective multicenter randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of a guided tissue regeneration (GTR)/bone replacement material.

MATERIALS AND METHODS

One hundred and twenty-four patients with advanced chronic periodontitis were recruited in 10 centers in seven countries. All patients had at least one intrabony defect of > or = 3 mm. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CALs), probing pocket depths (PPDs), recession, full-mouth plaque scores and full-mouth bleeding scores (FMBS) were assessed.

RESULTS

One year after treatment, the test defects gained 3.3 +/- 1.7 mm of CAL, while the control defects yielded a significantly lower CAL gain of 2.5 +/- 1.5 mm. Pocket reduction was also significantly higher in the test group (3.7 +/- 1.8 mm) when compared with the controls (3.2 +/- 1.5 mm). A multivariate analysis indicated that the treatment, the clinical centers, baseline PPD and baseline FMBS significantly influenced CAL gains. Odds ratios (ORs) of achieving above-median CAL gains were significantly improved by the test procedure (OR = 2.6, 95% CI 1.2-5.4) and by starting with deeper PPD (OR = 1.7, 1.3-2.2) but were decreased by receiving treatment at the worst-performing clinical center (OR = 0.9, 0.76-0.99).

CONCLUSIONS

The results of this trial indicated that regenerative periodontal surgery with a GTR/bone replacement material offers an additional benefit in terms of CAL gains, PPD reductions and predictability of outcomes with respect to papilla preservation flaps alone.

Gentamicin used as an adjunct to GTR

OBJECTIVES

To evaluate in a discriminating "capsule" model whether local application of gentamicin may have an added effect on bone formation produced by Bio-Oss and guide tissue regeneration (GTR).

MATERIAL AND METHODS

Thirty male 3-month-old Wistar rats were used. After elevation of muscle-periosteal flaps, a rigid hemispherical Teflon capsule, loosely packed with 0.025 g of Bio-Oss impregnated with 2 mg/ml gentamicin sulfate (Garamycin), was placed with its open part facing the lateral bone surface of the mandibular ramus (test) in one side of the jaw. A capsule filled only with Bio-Oss (control) was placed on the contralateral side of the jaw. After healing periods of 1, 2 and 4 months, groups of 10 animals were sacrificed and the specimens were processed for histological examination. The volumes of (1) the space created by the capsule, (2) newly formed bone, (3) Bio-Oss particles, (4) loose connective tissue, and (5) acellular space in the capsule were estimated by a point-counting technique in three to four histological sections of each specimen, taken by uniformly random sampling.

RESULTS

The histological evaluation showed limited but increasing bone fill in the capsules from 1 to 4 months in both the test and control sides. After 4 months, the newly formed bone occupied 11.9% (CV: 0.39) of the space created by the capsules at the test sides versus 13.2% (CV: 0.41) at the control sides. There was no statistical significant difference between test and control specimens at any observation time (p>0.05).

CONCLUSION

It is concluded that local application of gentamicin has no added effect on bone formation when combined with Bio-Oss and GTR.