Bioactive glass granules for regeneration of human periodontal defects

Bioactive glass for periodontal regeneration: a systematic review

BACKGROUND

One of the major clinical challenges of this age could be represented by the possibility to obtain a complete regeneration of infrabony defects. Over the past few years, numerous materials and different approaches have been developed to obtain bone and periodontal healing. Among all biomaterials, bioglasses (BG) are one of the most interesting due to their ability to form a highly reactive carbonate hydroxyapatite layer. Our aim was to systematically review the literature on the use and capability of BG for the treatment of periodontal defects and to perform a meta-analysis of their efficacy.

METHODS

A search of MEDLINE/PubMed, Cochrane Library, Embase and DOSS was conducted in March 2021 to identify randomized controlled trials (RCTs) using BG in the treatment of intrabony and furcation defects. Two reviewers selected the articles included in the study considering the inclusion criteria. The outcomes of interest were periodontal and bone regeneration in terms of decrease of probing depth (PD) and gain of clinical attachment level (CAL). A network meta-analysis (NMA) was fitted, according to the graph theory methodology, using a random effect model.

RESULTS

Through the digital search, 46 citations were identified. After duplicate removal and screening process, 20 articles were included. All RCTs were retrieved and rated following the Risk of bias 2 scale, revealing several potential sources of bias. The meta-analysis focused on the evaluation at 6 months, with 12 eligible articles for PD and 10 for CAL. As regards the PD at 6 months, AUTOGENOUS CORTICAL BONE, BIOGLASS and PLATELET RICH FIBRIN were more efficacious than open flap debridement alone, with a statistically significant standardized mean difference (SMD) equal to -1.57, -1.06 and - 2.89, respectively. As to CAL at 6 months, the effect of BIOGLASS is reduced and no longer significant (SMD = -0.19, p-value = 0.4) and curiously PLATELET RICH FIBRIN was more efficacious than OFD (SMD =-4.13, p-value < 0.001) in CAL gain, but in indirect evidence.

CONCLUSIONS

The present review partially supports the clinical efficacy of BG in periodontal regeneration treatments for periodontal purposes. Indeed, the SMD of 0.5 to 1 in PD and CAL obtained with BG compared to OFD alone seem clinically insignificant even if it is statistically significant. Heterogeneity sources related to periodontal surgery are multiple, difficult to assess and likely hamper a quantitative assessment of BG efficacy.

Bioactive Glasses in Periodontal Regeneration A Systematic Review

Bioactive glasses (BAGs) are surface-active ceramic materials that can be used in bone regeneration due to their known osteoconductive and osteoinductive properties. This systematic review aimed to study the clinical and radiographic outcomes of using BAGs in periodontal regeneration. The selected studies were collected from PubMed and Web of Science databases, and included clinical studies investigating the use of BAGs on periodontal bone defect augmentation between January 2000 and February 2022. The identified studies were screened using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A total of 115 full-length peer-reviewed articles were identified. After excluding duplicate articles between the databases and applying the inclusion and exclusion criteria, 14 studies were selected. The Cochrane risk of bias tool for randomized trials was used to assess the selected studies. Five studies compared using BAGs with open flap debridement (OFD) without grafting materials. Two of the selected studies were performed to compare the use of BAGs with protein-rich fibrin, one of which also included an additional OFD group. Also, one study evaluated BAG with biphasic calcium phosphate and used a third OFD group. The remaining six studies compared BAG filler with hydroxyapatite, demineralized freeze-dried bone allograft, autogenous cortical bone graft, calcium sulfate β-hemihydrate, enamel matrix derivatives, and guided tissue regeneration. This systematic review showed that using BAG to treat periodontal bone defects has beneficial effects on periodontal tissue regeneration. OSF Registration No.: 10.17605/OSF.IO/Y8UCR.

[Bone substitutes used for sinus lift]

In dental surgery today a variety of bone substitutes are used for sinus lift. After the increased application of synthetics during the last decade there has now been a move back to autologous bone transplants, combined with allogenic and xenogenic augmentation materials. The effects of transforming growth factors and recombinant equivalents of bone morphogenetic proteins remain to be seen. Covering the augmented area with a collagen membrane is the basic standard in many cases. Concomitant illnesses of dental origin or of the maxillary sinus have to be assessed prior to any sinus lift. Once complications such as laceration of the Schneiderian membrane, infection or adverse reaction have occurred, early and consistent therapy is required.

An evaluation of bioactive glass in the treatment of periodontal defects: a meta-analysis of randomized controlled clinical trials

BACKGROUND

The regenerative surgical treatment of intrabony defects caused by periodontal disease has been examined in several systematic reviews and meta-analyses. The use of bioactive glass (BG) as a graft material to treat intrabony defects has been reported, but all data have not been synthesized and compiled. Our objective was to systematically review the literature on the use of BG for the treatment of intrabony defects and to perform a meta-analysis of its efficacy.

METHODS

A search of PubMed, EMBASE, and Cochrane Database of Systematic Reviews, as well as a manual search of recently published periodontology journals, were conducted to identify randomized controlled trials of the use of BG in the treatment of intrabony and furcation defects. Criteria included publication in English, follow-up duration of ≥6 months, baseline and follow-up measures of probing depth (PD) and clinical attachment levels (CAL) with 95% confidence intervals (CIs), and an appropriate control arm. Twenty-five citations were identified, 15 of which were included in the final analysis. Data, including study methods and results, as well as CONSORT (Consolidated Standards of Reporting Trials) criteria, were extracted from eligible studies and cross-checked by at least two reviewers.

RESULTS

Meta-analyses of eligible studies were performed to ascertain summary effects for changes in PD and CAL among experimental and control groups, using the mean change plus standard deviation for each study. Pooled analyses showed that BG was superior to control for both measures: the mean (95% CIs) difference from baseline to follow-up between BG and controls was 0.52 mm (0.27, 0.78, P <0.0001) in reduction for PD and 0.60 mm (0.18, 1.01, P = 0.005) in gain for CAL. Analyses of CAL revealed heterogeneity across studies (I(2) = 60.5%), although studies reporting PD measures were homogeneous (I(2) = 0.00%). CAL heterogeneity appeared secondary to active controls versus open flap debridement (OFD) alone and to defect-type modifying BG treatment success. Per subgroup analyses, the benefit of BG over control treatment was highly significant only in studies comparing BG to OFD (P <0.0001), with mean difference change in CAL being 1.18 mm (95% CI = 0.74, 1.62 mm) between the BG and OFD group.

CONCLUSION

Treatment of intrabony defects with BG imparts a significant improvement in both PD and CAL compared to both active controls and OFD.

Histological evaluation of healing after transalveolar maxillary sinus augmentation with bioglass and autogenous bone

OBJECTIVES

The aim was to evaluate histologically the outcome of a bioglass and autogenous bone (at 1 : 1 ratio) composite implantation for transalveolar sinus augmentation.

METHODS

In 31 patients, during implant installation ca. 4 months after sinus augmentation, biopsies were harvested through the transalveolar osteotomy by means of a trephine bur and non-decalcified sections through the long axis of the cylinder were produced. After a strict selection process, taking into account the presurgical residual bone height and biopsy length, 8 and 15 biopsies representing the new tissues formed inside the sinus and the transalveolar osteotomy, respectively, qualified for analysis. The tissue fractions occupied by newly formed bone (mineralized tissue+bone marrow), soft connective tissue, residual biomaterial+empty spaces, and debris inside the sinus cavity or the transalveolar osteotomy were estimated.

RESULTS

Bone and connective tissue fraction in the newly formed tissues inside the sinus cavity averaged 23.4 ± 13.2% and 54.1 ± 23.5%, respectively. Residual biomaterial, empty spaces, and debris averaged 1.9 ± 3.5%, 10.5 ± 6.3%, and 8.4 ± 14.5%, respectively. In the transalveolar osteotomy, bone and connective tissue fraction averaged 41.6 ± 14.3% and 46.1 ± 13%, respectively, while the amount of residual biomaterial, empty spaces, and debris was 2.8 ± 5%, 4.7 ± 1.9%, and 3.2 ± 2.6%, respectively. Statistically significant differences between the sinus cavity and the transalveolar osteotomy were found only for bone and empty spaces' values (P=0.02 and 0.04, respectively).

CONCLUSION

Sinus augmentation with a bioglass and autogenous bone composite is compatible with bone formation that, in a short distance from the floor of the sinus, shows similar density as that reported previously for other commonly used bone substitutes. New bone fraction inside the transalveolar osteotomy was almost twice as much as in the sinus cavity, while the amount of residual biomaterial was much less than that inside the sinus.

Predictability of clinical outcomes following regenerative therapy in intrabony defects

BACKGROUND

Demineralized bone matrix (DBM) and guided tissue regeneration (GTR) support substantial gains in clinical attachment level (CAL), reductions in probing depth (PD), and gains in defect fill compared to open flap debridement (OFD) in intrabony defects. Although these regenerative therapies support improvements in mean clinical parameters, it is unclear whether the procedures improve the predictability of clinical outcome. The purpose of this study was to examine the relative variability in clinical outcome measures, independent of the magnitude of gains, in regenerative studies comparing DBM or GTR to OFD therapy for the management of intrabony defects. For comparative purposes, a similar analysis was performed evaluating the consistency of clinical outcomes with other (non-DBM) bone replacement graft (BRG) materials relative to OFD alone.

METHODS

Fifty-five randomized controlled clinical trials comparing regenerative therapy (seven DBM, 22 BRG, and 26 GTR) to OFD and meeting inclusion criteria provided mean change scores (pretreatment to post-treatment) and variance estimates for CAL, PD, and bone fill, allowing for calculation of a coefficient of variability (CV) for each measure within studies. The mean CV for each measure was submitted to an analysis of variance or covariance with repeated measures (P < or =0.05) to compare relative variation in treatment outcomes.

RESULTS

DBM was associated with a significantly lower relative variability (mean +/- SE) in CAL gain (96.3 +/- 38.6 versus 137.7 +/- 30.9) and defect fill (69.1 +/- 11.2 versus 133.1 +/- 15.3) compared to OFD alone. As a group, other BRGs were found to support significant reductions in variation in CAL and defect fill. GTR therapy was associated with significantly lower CV for CAL compared to OFD (50.6 +/- 5.0 versus 68.7 +/- 8.2, respectively). Variability in defect fill was similar for GTR and OFD.

CONCLUSIONS

DBM and GTR therapy support more consistent improvements in clinical parameters; however, with the exception of defect fill following bone grafting, the reduction in variability in clinical outcomes was relatively modest compared to OFD alone. Overall, the treatment of intrabony defects is associated with a relatively high degree of variability in clinical outcome, regardless of therapeutic approach.

Bioabsorbable Membrane and Bioactive Glass in the Treatment of Intrabony Defects in Patients With Generalized Aggressive Periodontitis: Results of a 5-Year Clinical and Radiological Study

BACKGROUND

The aim of this clinical and radiological prospective 5-year study was to compare the long-term effectiveness of a bioabsorbable membrane and a bioactive glass in the treatment of intrabony defects in patients with generalized aggressive periodontitis.

METHODS

Sixteen patients (11 women and five men) with generalized aggressive periodontitis were enrolled in the study. The investigations were confined to 1- to 3-walled intrabony defects with a depth >/=4 mm and with preoperative probing depths (PDs) >/=7 mm. Teeth with furcation involvement were excluded. Twenty-two of the defects were treated with the membrane (RXT group) and 20 with the bioactive glass (PG group). Allocation to the two groups was randomized. The clinical parameters plaque index (PI), gingival index (GI), PD, bleeding on probing (BOP), gingival recession (GR), clinical attachment level (CAL), and tooth mobility were recorded before surgery and at 6 months and every year for 5 years after surgery. Intraoral radiographs were taken using a standardized paralleling technique at baseline and every year for 5 years. Statistical analysis was based on Kolmogorov-Smirnov and Wilcoxon signed-rank tests, analysis of covariance, and Spearman's bivariate correlation analysis.

RESULTS

After 5 years, a reduction in PD of 3.6 +/- 0.8 mm (P = 0.016) and a gain in CAL of 3.0 +/- 2.0 mm (P = 0.01) were registered in the RXT group. There was a slight increase in GR by 0.6 +/- 1.4 mm (P = 0.334). In the PG group, a reduction in PD of 3.5 +/- 1.4 mm (P = 0.01) and a gain in CAL of 3.3 +/- 2.1 mm (P = 0.01) were recorded, whereas GR increased by 0.2 +/- 1.7 mm (P = 0.525). The 1-, 2-, 3-, and 4-year results did not differ significantly from the 5-year results. Radiographically, the defects (the point on the proximal surface of the defective tooth at which the projected alveolar crest intersected the root surface [xCA] to the most coronally located point at the proximal surface of the tooth on the defect side up to which the periodontal ligament space still displayed a uniform width [xBD]) were found to be filled by 47.5% +/- 38.3% (P = 0.001) in the RXT group and by 65.0% +/- 50.5% (P = 0.001) in the PG group. Crestal resorption (the most apical point of the enamel at the proximal surface of the tooth on the defect side [xCEJ] to the xCA) was 19.0% +/- 30.2% (P = 0.374) in the RXT group and 12.3% +/- 38.6% (P = 0.647) in the PG group. The xCEJ to the xBD was significantly more in the PG group (28.4 +/- 24.6 versus 7.3 +/- 21.8, P = 0.048). A good standard of oral hygiene and inflammation-free periodontal tissue in the postoperative phase improved the treatment outcome. No dependence of attachment gain was found on the tooth type, number of walls involved in the defects (r = 0.075; P = 0.319), or intraoperative depth (r = 0.114; P = 0.307).

CONCLUSIONS

Highly significant improvements in the parameters PD and CAL were recorded after 5 years with both regenerative materials. Radiographically, the defects (the xCED to the xBD) were found to be filled significantly more in the bioactive glass group. A good standard of oral hygiene and inflammation-free periodontal tissue in the postoperative phase improved the treatment outcome.

Bone Regeneration Around Implants Using Spherical and Granular Forms of Bioactive Glass Particles

PURPOSE

It has been reported that previous Biogran (3i Implant Innovations, Inc., Palm Beach Gardens, FL) can be converted in vitro into hydroxyapatite (Biogran II) to accelerate new bone formation. The purpose of this study was to evaluate the bone regeneration around implants placed in critical-sized defects in rabbit tibia using granular and spherical forms of Biogran II in regards to implant contact, bone-to-graft contact, bone graft area, and total bone volume.

MATERIALS AND METHODS

Twelve adult New Zealand rabbits were used, offering 24 surgical sites (1 in each tibia), where 6-mm round defects were created allowing the homocentric insertion of a screw type experimental implant with Osseotite (3i Implant Innovations, Inc.) surface. Half of the defects (group A) were filled up with spherical and half (group B) with granular forms of Biogran II. Ossix (3i Implant Innovations, Inc.) membranes covered the surgical sites.

RESULTS

The histological evaluation after 8 weeks showed new bone formation in both groups, without any statistically significant differences in regards to bone-to-implant contact, bone-to-graft contact, bone graft area, and bone volume. Both dissolution of the outer shell and inner silica gel of the particles were observed mostly in spherical particles. In addition, new bone formation within the protected pouch interconnected with the surrounding new bone was observed exclusively in spherical particles of Biogran II.

CONCLUSION

Faster dissolution of both outer and inner portions of spherical particles of Biogran II led to better integration with the surrounding new bone during an 8-week period of healing.

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.

Bioabsorbable membrane and bioactive glass in the treatment of intrabony defects in patients with generalized aggressive periodontitis: results of a 12-month clinical and radiological study

BACKGROUND

Guided tissue regeneration can be achieved using membranes. In recent years, some evidence has been provided that bioactive glass is also capable of supporting the regenerative healing of periodontal lesions. The aim of this clinical and radiological prospective study was to compare the effectiveness of a bioabsorbable membrane and a bioactive glass in the treatment of intrabony defects in patients with generalized aggressive periodontitis.

METHODS

Twelve patients (9 females, 3 males) with generalized aggressive periodontitis were enrolled in the study. The investigations were confined to 1- to 3-walled intrabony defects with a depth > or = 4 mm and with preoperative probing depths > or = 7 mm. Teeth with furcation involvement were excluded. Fifteen of the total 30 defects were treated with the membrane (RXT group) and 15 with the bioactive glass (PG group). Allocation to the groups was randomized. The clinical parameters plaque index (PI), gingival index (GI), probing depth (PD), bleeding on probing (BOP), gingival recession (GR), clinical attachment level (CAL), and mobility were recorded prior to surgery as well as 6 and 12 months after surgery. Intraoral radiographs were taken in standardized paralleling technique at baseline and 12 months after the surgery. Following digitization, changes in the distances from the alveolar crest (xCA) to the defect base (xBD) and from the CEJ (xCEJ) to the xCA were determined. Statistical analysis was based on Kolmogorov-Smirnov test, Wilcoxon signed-ranks test, analysis of covariance, and Spearman's bivariate correlation analysis.

RESULTS

After 12 months, a reduction in PD of 4.0 +/- 2.1 mm (P < 0.001) and a gain in CAL of 3.4 +/- 2.3 mm (P < 0.001) was registered in the RXT group. There was a slight increase in GR by 0.6 +/- 1.5 mm (P = 0.074). In the PG group, a reduction in PD of 3.8 +/- 1.9 mm (P < 0.001) and a gain in CAL of 2.8 +/- 1.9 mm (P < 0.001) was recorded, whereas GR increased by 1.0 +/- 1.4 mm (P = 0.007). The 6-month results did not differ significantly from the stated values. Radiographically, the defects (xCA to xBD) were found to be filled by 57.2 +/- 33.5% (P = 0.001) in the RXT group and by 50.5 +/- 22.8% (P = 0.001) in the PG group. Crestal resorption (xCEJ to xCA) was 6.1 +/- 34.5% (P = 0.910) in the RXT group and 15.1 +/- 39.7% (P = 0.433) in the PG group. Only the change in gingival recession after 12 months was significantly greater (P = 0.031) in the PG group, with -1.0 +/- 1.4 mm, compared to the RXT group, with -0.6 +/- 1.5 mm. Changes in the other clinical and radiological parameters showed no significant differences. The attachment gain correlated negatively with the preoperative PI (r = -0.574; P = 0.004) and with BOP after 6 months (r = -0.315; P = 0.021).

CONCLUSIONS

Highly significant improvements in the parameters PD, CAL, and xCA-xBD were recorded after 6 and 12 months, respectively, with both regenerative materials. A good standard of oral hygiene and inflammation-free periodontal tissue in the postoperative phase improved the treatment outcome.

A new resorbable bone void filler in trauma: early clinical experience and histologic evaluation

Six patients with traumatic bone injuries were treated by packing ultraporous beta-tricalcium phosphate (beta-TCP), a synthetic bone void filler, into defect sites using firm finger pressure. Radiographs showed new bone consolidating in treated sites after as little as 2 months. A biopsy obtained from a fractured calcaneus 9 months after surgery showed new bone growing within the ultraporous scaffold. Regions of newly mineralized bone and woven bone in the scaffold suggested that the defect site was undergoing repair. Some new bone had developed lamellar architecture. Higher radiodensity and slower resorption of ultraporous bone void filler in this human case, relative to that seen in a canine study, is attributed to slower metabolism in humans relative to dogs and to greater packing pressures used in the clinic. The histology specimen did not indicate untoward inflammatory response or significant foreign body reaction. Thus, this first human histology report supports the use of biocompatible ultraporous beta-TCP to enhance new bone formation in bone defects.