|Year : 2014 | Volume
| Issue : 1 | Page : 13-23
Evaluation of bioactive glass and autogenous bone in the treatment of Grade II furcation involvement: A randomized controlled trial
Sally Abd El-Meniem El-Haddad1, Mona Yehia Abd-El Razzak2, Hussein Ibrahem Saudi2, Nada Mohammad El Ghorab3
1 Department of Preventive Dental sciences, College of Dentistry, Salman bin Abdulaziz University, Saudi Arabia
2 Department of Preventive Dental sciences, Tanta University, Egypt
3 Department of Periodontology, College of Dentistry, King Abdulaziz University, Saudi Arabia
|Date of Web Publication||21-Jun-2014|
Sally Abd El-Meniem El-Haddad
Department of Preventive Dental sciences, College of Dentistry, Salman bin Abdulaziz University
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: Furcation involvement is an inflammatory process that results in a breakdown of the supporting connective tissue and bone as a result of extension of periodontal destruction between the roots of multi-rooted teeth. Class II furcation lesions are a challenging scenario for periodontal therapy and a serious threat for tooth prognosis where the teeth mortality has been reported to occur more frequently in furcated teeth than in similar teeth without furcation defects. Aims and Objectives: The aim of this study was to compare the efficacy of bioactive glass (BG) grafting material versus autogenous bone grafting in the treatment of Grade II furcation involvement clinically and radiographically. Materials and Methods: A total of 30 patients with buccal mandibular Grade II furcation involvement were divided- by a split-mouth design- into three groups; group (Gp) I involved 30 sites grafted with BG; Gp II involved 30 sites grafted with autogenous bone and Gp III involved 10 sites treated with scaling and root planing only after flap reflection. Results: The postoperative healing periods were, generally uneventful with no postoperative complications. At the last follow-up period, the previous furcation sites were covered with healthy gingiva and there was a great reduction in the surface area of the furcation defects with a marked increase in the gray level in both Gp I and II with no significant difference, while there was a statistically significant difference between Gp I and Gp III and between Gp II and Gp III at 3 months and at 6 months of follow-up periods. Conclusion: The use of BG and autogenous bone grafts has better outcomes in the treatment of Grade II furcation involvement when compared with open debridement alone. The use of bony glass has nearly the same successful outcomes of the autogenous bone graft; however, it is less traumatic to the patient.
Clinical Relevance to Interdisciplinary Dentistry
- Periodontal regenerative procedure using bioactive glass material can be performed to enhance bone formation
- Class II furcation lesions are a challenging scenario for periodontal therapy and a serious threat for tooth prognosis.
Keywords: Autogenous bone, bioactive glass, Grade II furcation, periodontal regeneration
|How to cite this article:|
El-Haddad SA, Abd-El Razzak MY, Saudi HI, El Ghorab NM. Evaluation of bioactive glass and autogenous bone in the treatment of Grade II furcation involvement: A randomized controlled trial. J Interdiscip Dentistry 2014;4:13-23
|How to cite this URL:|
El-Haddad SA, Abd-El Razzak MY, Saudi HI, El Ghorab NM. Evaluation of bioactive glass and autogenous bone in the treatment of Grade II furcation involvement: A randomized controlled trial. J Interdiscip Dentistry [serial online] 2014 [cited 2020 Oct 22];4:13-23. Available from: https://www.jidonline.com/text.asp?2014/4/1/13/134999
| Introduction|| |
Periodontal regeneration of the lost attachment apparatus especially in the furcation region continues to be the ultimate goal of the periodontal therapy. It is defined as the restoration of the tooth supporting tissues, including cementum, periodontal ligament and alveolar bone over a previously diseased root surface.  Furcation involvement is an inflammatory process that results in a breakdown of the supporting connective tissue and bone as a result of extension of periodontal destruction between the roots of multi-rooted teeth, or as a result of mechanical trauma and comprises a unique and challenging problem for the periodontist. , The interrelationships between the size and shape of the teeth, the roots, their alveolar housing, the varying nature and pattern of periodontal destruction, together with the particular morphological and anatomical problems of the furcation area, all complicate the treatment of the involved teeth and affect their ultimate prognosis. Hence, the predictable successful treatment of periodontitis-affected furcations of multi-rooted teeth is one of the most important problems in clinical periodontology. , Clinically, successful regeneration of furcation sites is determined by the elimination or reduction of horizontal and vertical components of the lesion, but the conclusive evidence of true regeneration can only be achieved by histological means.  Regeneration of affected bone in furcation areas can be achieved by bone grafting, guided tissue regeneration, periodontal regeneration using combined techniques, polypeptide growth factors, bone morphogenic proteins, or tissue engineering.  The interest in bone replacement grafts has emerged from the desire to fill a furcation defect rather than radically resecting the surrounding intact bone tissues. Bone grafting, widely used in reconstructive periodontal surgery, is a technique used to fill periodontal defects and enable regeneration of periodontal tissue.  The ideal bone replacement graft should be able to trigger osteogenesis, cementogenesis, and formation of a functional periodontal ligament. 
Schallhorn et al. demonstrated that, the only way to achieve osteogenesis by the formation of mineralized bone through transplanted osteoblasts, is with autogenous bone, which contains within its matrix some live cells (osteocytes, osteoblasts, and osteoclasts) and osteogenic proteins and so it has osteoinductive capacity.  Williams, (1987), proposed that, bioactive denotes a material which induces specific biological activity such as bonding to bone. Bioactive glass (BG) is an alloplastic, synthetic bone grafting material composed of calcium and sodium ions, phosphate, and silicon dioxide. , When BG comes into contact with tissue fluids, a series of chemical reactions occur, resulting in the formation of a hydroxycarbonate apatite (HCA) layer on the surface of the graft particles. Organic ground substance proteins such as glycosaminoglycans are incorporated into the HCA as it forms. Osteoblasts are attracted to the HCA layer and release organic constituents; this is followed by mineralization. Therefore, BG is an effective material for the treatment of periodontal bone defects. , Owing to its advantages, the dentists have begun exploring the BG first used in plastic surgery. It was demonstrated to be both osteoconductive and osteoinductive by having a biocompatible interface and a bioactive surface that is colonized by osteogenic stem cells. Furthermore, it has the ability to bind to soft tissue and bone an optimal pore size for vascularization; this differentiates BG from the other available alloplasts. , Immunohistochemical analysis in gingival epithelium has demonstrated increased epithelial cell proliferation after treatment with BG, when compared to treatment with bioabsorbable membrane. Overall, the literature indicates that these materials may provide osteoconduction but not necessarily periodontal regeneration.  However, the use of BG for treating periodontal bone defects has produced satisfactory clinical and radiographic results. ,
| Materials and methods|| |
A total of 30 patients (26 males and 4 females, ages ranged from 35 to 55 years old) with chronic periodontitis according the criteria described by Armitage,  and the total number of 70 sites with buccal mandibular Grade II furcation involvement according to the classification of Lindhe,  were selected in this randomized controlled clinical study. Each patient should have at least two buccal Grade II furcations at lower molars.
The exclusion criteria were patient with relevant systemic disease affecting the bone healing process, previous periodontal surgery at the selected sites, nonvital or symptomatic tooth, traumatic occlusion, and smokers.
Randomization was carried out in each case via computer- generated random number list for treatment and control groups. The person who recorded the randomization codes did not participate in this study.
Via a split-mouth design, all furcation sites were classified and treated as:
Gp I involved 30 sites grafted with bony glass, Gp II involved 30 sites grafted with autogenous bone and Gp III involved 10 sites treated with scaling and root planing only after flap reflection.
The presurgical phase
The enrolled patients signed an informed consent form after receiving information about the study. The study protocol and consent forms were approved by the Faculty Review Board. All patients were enrolled in a phase I therapy including professional plaque control program, scaling, and root planing, every week in the 1 st month of treatment, polishing, and reinforcement of the plaque control program with patient motivation and education. Alginate impression for the upper and lower jaws was taken for patients with edentulous areas opposing the treated furcated teeth to insert a partial removable prosthesis in those areas after surgery. For patients who had extracted sites in the maxilla near to the maxillary sinus, where the autogenous bone were taken from that sites, a presurgical periapical X-ray was taken to evaluate the location and the amount of bone in the area of the maxillary sinus to avoid perforation or cutting along the sinus during harvesting the autograft. A clinical re-evaluation was assessed 1 month after phase I therapy and teeth showed remaining signs of clinical pathosis (probing depth ≥5 mm and clinical attachment loss ≥6 mm) were subjected to the surgical phase. Systemic doxymycin 100 mg capsule was prescribed for all patients every 12 h 2 days presurgically and for 2 weeks postoperative.
The clinical assessments
Probing pocket depth (PPD),  clinical attachment level (CAL),  assessment of furcation involvement  using Nabers furcation probe, tooth mobility,  (according to Lindhe, 1989, 13 teeth involved in this study were in degree 1 and 57 teeth were in degree 2), and gingival recession.  The amount of recession postoperatively was calculated according to Meadows et al., by subtracting the attachment gain plus the postsurgical PPD after 3 and 6 months from the presurgical PPD. The amount of recession postoperatively = Preoperative PPD - (attachment gain + postsurgical PPD).
The radiographic assessment
Standardized periapical radiographs were taken for every patient. For each site, a specialized bite block of polyether attaching to a Rinn XCP bite block (Rinn Corporation, Elgin, IL, USA) device was fabricated to register the bite for maximum parallelism.  All radiographs were taken using the Imago dental X-ray machine DenOptix (Gendex, Milano, Italy) with a fixed exposure time (0.4 s). After diagnosis of furcation involvement both clinically and radiographically, another baseline radiographic X-rays were taken and stored in a refrigerator with the 6-month postsurgical radiographic X-rays until the trial was completed. Ten the films were developed with new chemicals and at the same time to ensure uniform processing and to reduce errors.  All periapical radiographs were developed automatically using an automatic processor (Durr-Dental Gmbh and Co. KG, Bissingen, Germany) then digitized using a flat bed Umax scanner (Umax Comp., USA) at 300 dot/inch, then saved as bitmap format. 
A specially developed Visual Basic program (Microsoft ExcelTM/Visual Basic, DSS) was developed to detect the furcation surface area and the mean gray level for the selected area in each study group.
The surgical phase
Proper and adequate local anesthesia in the selected furcation areas was given to patients and a sulcular incision was made to save as much interdental tissues as possible to cover the grafting material. Vertical releasing incisions were placed at least one tooth apart from the molar receiving the bony glass or autogenous bone on the buccal aspect bilaterally extending into the alveolar mucosa with the aim of achieving proper access to the defect, as well as for obtaining moderate coronal displacement of the flap and so primary closure over the graft.  A full-thickness flap was raised at both the buccal and lingual sides of the operated teeth, followed by thorough scaling and root planning of the furcation area by Gracey curettes and ultrasonic tips especially in deep furcations. Magnifying lenses were employed to detect any remaining calculus. For furcations with entrance dimension <2.5 mm, a rotatory fine diamond or finishing bur was used to gain access to the furcation area and to remove of the granulation tissues from defect in order to obtain a smooth and hard root surface. All enamel projections, when present, were removed by diamond bur. Sites in each patient were randomly assigned to one of the treatment procedures. The BG used in this study has a particle size range from 90 μm to 710 μm. It is supplied in powder form in vials containing 1 g of sterilized surface activated BG [Figure 1]a. BG grafting powder material was prepared by mixing it with saline to allow for protein adsorption and maximize the number of bone cells in contact with the bony glass, in a disposable dappen dish and wait 3 min for adhesion to occur between the particles of the bony glass to form a thick paste [Figure 1]e. The autogenous bone graft was harvested [Figure 1]d from either an old or recent extracted site, if present, or from th maxillary tuberosity using a power trephine no. 4 [Figure 1]b bur at low speed and cooling system [Figure 1]c. The cancellous portion of the autograft was used and the cortical layer was removed. The autograft was placed in a disposable dappen dish, immersed in saline prior to transfer to the grafted site and was covered with a sterile moistened gauze to prevent drying of the graft  [Figure 1]f, then it was packed firmly in the furcation defect using an overfill approach to ensure that adequate graft material remains in the desired area. 10 patients of all the 30 patients had nearly similar three mandibular Class II furcation defects, the third furcation defects were curetted without grafts representing the Gp III. A horizontal releasing incision through the periosteum on the inner aspect of each flap was performed in order to facilitate the adaptation and coronal repositioning of the flap (regenerative type flap).  The flap was closed using interrupted or mattress nonresorbable sutures (4ʹ0). Periodontal pack was passively applied over the surgical area to adapt the flap to the root surface and ensure that the flap remains in the correct position during healing.
|Figure 1: The materials and techniques used in this study. (a) The bony glass material used in this study. (b) The trephine bur no. 4. (c) The trephine technique with cooling. (d) Harvesting a suitable piece of autograft at the end of the trephine bur. (e) Bony glass mixed with saline. (f) Autograft stored in normal saline until used|
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The postsurgical phase
All patients received written instructions which included; administration of systemic doxymycin 100 mg capsule every 12 h for 2 weeks postoperatively, 0.12% chlorhexidine gluconate mouth wash twice daily for 8 weeks postoperatively as an adjunctive antimicrobial agent which is effective in reducing supragingival plaque and periodontal inflammation.  The patients were instructed not to brush or floss the operated area for as long as 4 weeks. Periodontal pack and sutures were removed 10 days postoperatively coupled with gentle debridement of the area and supragingival plaque removal and reinforcement of oral hygiene instructions.
The follow-up design
The patients were recalled weekly for 8 weeks, and then once a month until the 4 th month following surgery for plaque control and gentle scaling. At the 3 rd month postoperatively, all the clinical parameters were recorded which included; PPD, CAL, tooth mobility and gingival recession. At the 6 th month postoperatively, the clinical parameters were recorded again plus the radiographic assessment.
The clinical data were collected at baseline; 3 and 6 months postoperatively, tabulated and statistically analyzed using the SPSS software software for statistical analysis (M J Norus Inc, 2002). Quantitative data were expressed as mean and standard deviation, while qualitative data were expressed as the number and percentage. Student t-test was used for comparison of mean between two groups.  Paired t-test was employed to assess statistical significance between time points within each group.  The level of significance was set as P < 0.05.
| Results|| |
28 out of 30 patients (93%) completed the follow-up periods of this study, while two patients failed to return for the follow-up recalls. Male patients were 86.7%, while female patients were 13.3% of all participants. The mean age of the patients was 44.4 ± 6.34 years. All clinical parameters were homogenous with no statistically significant difference at baseline and represented an acceptable intra-individual study model. At the last follow-up period, the previous furcation sites were covered with healthy gingiva in both Gp I and Gp II [Figure 2],[Figure 3],[Figure 4] and [Figure 5] and there was a great reduction in the surface area of the furcation defects with a marked increase in the gray level [Figure 6],[Figure 7],[Figure 8] and [Figure 9]. The postoperative healing periods were generally uneventful with no postoperative complications. Two patients (4 from 66 sites "6.06%") showed complete graft failure at the last follow-up period. Two of the four failed sites were grafted with bony glass, and the other two sites were grafted with autogenous bone.
|Figure 2: The clinical photographs of male patient with 44-year-old represent Gp I and Gp II showing: (a) Preoperative view of lower left first molar with furcation involvement detected by Nabers probe. (b) Preoperative view of lower left second molar with furcation involvement detected by Nabers probe. (c) Decumentation of Grade II furcation involvement. (d) Grafting of the furcation area of the fi rst molar with bony glass (Gp I) and the second molar with autogenous bone (Gp II) harvested from the maxillary tuberosity. (e) Suturing of the mucoperiostael flaps for both donor and recipient sites. (f) 6-month postoperative view of the grafted side showing healthy gingiva with complete closure of the previously exposed furcation areas|
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|Figure 3: The clinical photographs of a male patient with 53-year-old. Right first and second lower molars represent Gp III and Gp I respectively: (a) Preoperative view of the affected lower right fi rst and second molars. (b) Surgical exposure of the furcations with proper scaling and root planing. (c) Grafting of the furcation area of the second molar with bony glass (Gp I) while the first molar is a negative control (Gp III). (d) Suturing of the mucoperiostael flap. (e) 6-month postoperative view of the grafted side showing healthy gingiva with complete closure of the previously exposed furcation areas|
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|Figure 4: The clinical photographs of left side the same patient in Figure 3 represent Gp II showing: (a) Exposure of the donor site from an old extracted site of the upper left second molar. (b) Surgical exposure of the furcation with proper scaling and root planing. (d) Grafting the furcation defect with autogenous bone (Gp II). (c) Suturing of the upper and lower flaps. (d) 6-month postoperative view of the grafted side showing healthy gingiva with complete closure of the previously|
exposed furcation areas
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|Figure 5: The clinical photographs of male patient with 46-year-old. Case no. 2 represent Gp I and Gp II showing: (a) Preoperative furcation involvement of lower right fi rst and second molars with PPD of 9 mm of second molar. (b) Surgical exposure of the previous furcations with proper scaling and root planing. (c) Grafting of the furcation area of the second molar with bony glass (Gp I). (d) Grafting of the furcation area of the first molar with autogenous bone harvested from an old extracted site of the upper right fi rst molar. (e) Suturing of the mucoperiostael flaps for both donor and recipient sites. (f) 6-month postoperative view of the grafted side showing healthy gingiva with complete closure of the previously exposed furcation areas|
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|Figure 6: Pre and postoperative digitized periapical radiographic images representing Gp I (second molar) and Gp II (first molar). (a) Preoperative view demonstrating the surface area of bone loss at the furcation of the first and second mandibular molars. (b) Postoperative view demonstrating marked surface area reduction and gray level gain|
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|Figure 7: Pre and post-operative digitized periapical radiographic images representing Gp I (second molar) and Gp II (first molar). (a) Preoperative view demonstrating the surface area of bone loss at the furcation of the first and second mandibular molars. (b) Postoperative view demonstrating marked surface area reduction and gray lelevel gain|
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|Figure 8: Pre and postoperative digitized periapical radiographic images representing Gp II (grafted with autogenous bone) in the first mandibular molar. (a) Preoperative view demonstrating the surface area of bone loss at the furcation of the first mandibular molar. (b) Postoperative view demonstrating marked surface area reduction and gray level gain|
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|Figure 9: Pre and postoperative digitized periapical radiographic images representing Gp III (the +ve control). (a) Preoperative view demonstrating the surface area of bone loss at the furcation of the second mandibular molar. (b) Postoperative view demonstrating little surface area reduction and gray level gain|
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No statistically significant difference in the mean probing pocket depth (mPPD) and mean clinical attachment level were found between Gp I and Gp II at base line, 3 and 6 months follow-up periods while there was a statistically significant difference of mPPD between Gp I and Gp III and between Gp II and Gp III at 3 months and at 6 months of follow-up periods (P < 0.05 and P < 0.001 respectively) [Table 1] and [Table 2].
|Table 1: The difference in the mean±SD of the PPD for Gp I, Gp II and Gp III at baseline, 3 and 6 months postoperative|
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|Table 2: The difference in the mean±SD of the CAL for Gp I, Gp II and Gp III at baseline, 3 and 6 months postoperative|
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Temporarily after a short period of the surgical intervention (3-4 weeks), the mobility of all teeth was increased. However, at the 3 rd month follow-up period, the mobility of the teeth in the three groups was reduced with no statistically significant difference between any two groups of them (P > 0.05). At the 6 th month follow-up period, the mobility of the teeth in Gp I and Gp II was reduced again. While in Gp III, the mobility of the teeth did not change from the 3 rd month follow-up period. There was no statistically significant difference between Gp I and Gp II (P > 0.05), but there was a statistically significant difference between Gp I and Gp III (P < 0.001) and between Gp II and Gp III (P < 0.01) [Table 3]. There was a statistically significant difference between Gp I and Gp III and between Gp II and Gp III (P < 0.05) regarding the gain of the gingival margin. At the 6 th month follow-up, there was a slight recession in the position of the gingival margin from the 3 rd month follow-up period in Gp I and II which was not statistically significant for each of the groups, whereas, in Gp III, it was statistically significant difference between Gp I and Gp III (P < 0.01) and between Gp II and Gp III (P < 0.001) [Table 4].
|Table 3: The difference between degrees of mobility for Gp I, Gp II and Gp III at baseline, 3 and 6 months postoperative|
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|Table 4: The difference in the mean±SD of the gingival recession for Gp I, Gp II and Gp III at 3 and 6-month postoperative|
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At the 6 th month of the follow-up period, there was a marked reduction of the furcation surface areas of both Gp I and Gp II, while in Gp III, the reduction of the furcation surface areas was significantly low [Table 5]. The mean gray level gain for Gp I, Gp II and Gp III at the 6 th month of the follow-up period was 28 ± 12.67, 30 ± 10.14 and 9 ± 35.91 respectively, which denotes that there is no statistically significant difference between Gp I and Gp II (P > 0.05), while there is a statistically significant difference between Gp III and both Gp I and Gp II (P < 0.05) [Table 6].
|Table 5: The difference in the mSAR±SD of the furcation for Gp I, Gp II and Gp III at 6-month postoperative|
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|Table 6: The mGLG±SD for Gp I, Gp II and Gp III at 6-month postoperative|
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| Discussion|| |
Tooth mortality has been reported to occur more frequently in teeth with periodontal furcation defects than in similar teeth without furcation involvements, Therefore, the predictable successful treatment of periodontitis-affected furcations of multi-rooted teeth is one of the most important and unsolved problems in clinical periodontology. Periodontal regenerative therapy is applied to reproduce or reconstitute the lost part of the periodontium.  BG was selected from the available alloplastic synthetic bone grafting materials to treat furcation defects in the current study, due to the results of histological studies and various clinical reports. ,,,,
In this study, the patients' ages were selected to be within 35-55 years where aging influences specific components of the healing process in surgical wounds, such as early ischemia, lower levels of platelet-derived growth factor and reduced levels or quality of collagen. Hence, there is a somewhat greater risk for problems in regenerative therapy in patients over the age of 65. , Moreover, regaining bone and in fact, "turning back the clock" to bone levels possessed could be achieved when the patient was much younger. 
The bony glass was quick to prepare, easy to mix and place. It also remained where placed in osseous defects even with suctioning adjacent to the surgical site as it forms a cohesive mass when mixed with saline or blood and does not show any tendency to flow with bleeding. Consequently, the particles were easy to pack. Also, it acted like a hemostatic agent and maintained the blood clot in the periodontal defects. On the other hand, the autogenous bone was reported to be a gold-standard graft material which has a substantial biologic potential to achieve periodontal regeneration as evidenced by Schallhorn et al.,  through histological biopsy analysis which showed new cementum, alveolar bone and periodontal ligament. Also, it is the preferred bone graft material during a reconstructive procedure where it carries proteins such as bone-enhancing substrates, minerals and vital bone cells as evidenced by Hunt and Jovanovic.  So, the autogenous bone graft was selected, in this study, as a comparative graft to evaluate the efficacy of bony glass grafting material. We used the cancellous part of the autogenous bone only without the cortical element for obliteration of the furcation defects in this study which was harvested from either recent or old extracted sites or from the maxillary tuberosity. This is because the cancellous bone chips encompasses the neurovascular complexes and can be vascularized rapidly because of their honey-comb structure and thin lamellar bone after only 3 weeks. Furthermore, it heals primarily by osteogenesis, while the cortical element was found to be more prone to initial osteoclastic induction and the metabolic turnover and the remodeling of cortical bone is much slower than cancellous bone.  The trephine technique was used to harvest the autograft as it is recommended in cases when a particulate bone is needed and it is less traumatic for the patient.  There were no complications associated with donor sites of autogenous bone postsurgically whether these sites were recent or old extracted sites or even a maxillary tuberosity. We made horizontal releasing incisions through the periosteum on the inner aspect of the flap to facilitate the coronal repositioning of the flap and in the same time not to compromise the blood supply. The coronal repositioned flap was found to protect the blood clot/root surface interface at the early time of healing where proper clotting appears to be critical for normal wound healing and subsequently regeneration of the tissues. Besides, the coronal repositioned flap controls the marginal shrinkage during the early healing stages and enhances regeneration of the lost attachment apparatus.  All patients received doxymycin (doxycycline hyclate) 100 mg capsule every 12 h for 2 weeks starting 2 days before surgery as recommended by Jorgensen and Slots, to enhance regenerative healing.  Doxymycin is a long acting tetracycline with less susceptibility to chelating than tetracycline hydrochloride. Its beneficial effects include; an antimicrobial effect, concentration in crevicular fluid, fibroblast stimulating activity so, enhancing bone regeneration. Also, it inhibits crestal bone resorption and prevents or reduces gingival recession, so favors a potentially more complete regenerative response.  Chlorhexidine mouth wash was used at the follow-up periods as a chemical plaque control where it showed the most positive results in inhibiting the development of dental plaque, calculus and gingivitis in the human model. 
All patients did not complain of bony glass particle loss during the follow-up examinations. The overlying mucoperiosteal flaps at 10 days after surgery were very healthy in appearance with either autogenous bone or bony glass with minimal interproximal gapping, except in two patients (4 from 66 sites "6.06%") who showed complete graft failure at the last follow-up period with gingival recession and furcation recurrence. Two of the four failed sites were grafted using bony glass, and the other two sites were grafted using autogenous bone. Flap dehiscence was evident 7 days after suture removal, followed by marginal gingival recession together with exposure of the graft material. Then, the graft particles started to exfoliate gradually with signs of infection and inflammation until complete graft loss. However, all efforts were done to avoid complete graft failure through local and systemic measures. The local measures were performed by daily specific site irrigation with normal saline and 0.2% chlrohexidine solution with prescription of 0.12% chlrohexidine mouth wash twice daily. The systemic measures were in the form of prescription of another dose of doxymycine 100 mg twice daily to control the infection process. This failure may be attributed to the lack of oral hygiene measures by the patients and negligence of postoperative instructions to maintain the proper healing conditions where the regenerative procedure is a highly technique sensitive and contingent on patient compliance with effective plaque control and appropriate periodontal maintenance which has changed the regenerative procedures from a future altruistic goal to a current clinical reality.
In general, bony glass appeared to be well tolerated by the overlying gingival tissues and represented an excellent soft tissue healing that provides an evidence of the biocompatibility of bony glass by virtue of the neutral or slightly basic pH of its surface in the initial reactions, which can be more supportive for healing. Also, bony glass may have contributed to an increase in wound stability which is a crucial factor for obtaining periodontal regeneration. BG has been demonstrated to be biocompatible, make direct contact with bone, and have an ability to enhance regenerative healing.  Moreover, Bony glass may exert an antibacterial effect and it has the potential to reduce bacterial colonization of its surface by virtue of the alkaline nature of its surface reactions as evidenced by Allan et al., which may due to the highly alkaline solution reactions of BG. This feature is relevant to postsurgical excellent periodontal wound healing and also lead to osseointegration. ,
This study showed that both bony glass and autogenous bone grafting materials are effective in treating Grade II furcation involvement as they induced a significant improvement in all clinical parameters such as a reduction of PPD, gain in CAL, improvement of tooth mobility, less gingival recession, reduction of the furcation surface area and an increase in the gray scale level. Gp II (autograft) showed slightly more improvement in these clinical parameters than Gp I (bony glass), but without statistically significant differences. While, there was a statistically significant difference between the results of both Gp I and Gp II compared to Gp III (control group), which demonstrate the necessity of using a proper graft material in the treatment of Grade II furcation defects.
The improvement in the mobility of the teeth in both Gp I and Gp II may be attributed in the tooth support provided by the graft materials in the furcation defects and better periodontal tissue support which is evidenced clinically, by the reduction of PPD, gain of CAL as stated before, and radiographically.
At the last follow-up period, there was less mean gingival recession from the 3 rd month postoperative for both Gp I and Gp II which determined the success of the new attachment that occurs during healing. This difference may be attributed to the benefits of using bone grafts as supporting the flap and regenerating the periodontal apparatus.
Bioactive glass was evaluated in the treatment of periodontal defects through a meta-analysis of randomized controlled clinical trials and it was showed that, the treatment of intrabony defects with BG imparts a significant improvement in both PD and CAL compared to both active controls and open flap debridement. 
To evaluate the changes in hard tissue around teeth, we used the standardized periapical radiographs, which provide the only noninvasive method without the need for surgical re-entry procedure. In this study, the radiographic analysis was planned to use the digitized periapical radiographs to detect the bone changes (both surface area reduction and gray scale level) because they are more precise and sensitive in detecting any minute bony changes than the conventional radiographic methods. ,
All the periapical radiographs, obtained in this study, were stored in a refrigerator until the end of the study, and then the films were developed with new chemicals at the same time. This method of developing was performed according to Reddy,  who concluded that, there is one solution for short clinical trial is to save all films until the study is completed and develop the films with new chemicals at the same time to ensure uniform processing and to reduce errors where processing might significantly impact on the analysis of data and contrast changes.
By digitization of radiographs with a computer assisted method for making linear radiographic measurements of the regions of interest, the mean surface area reduction for Gp I and Gp II was 59.68% and 72.03.03% respectively of the base line surface areas with slightly more reduction in Gp II, but with no significant difference. These values of bone fill measured radiographically were commensurable to improvement in the clinical parameters at the third and 6 th month follow-up periods.
There was an approximate gain in bone density from the baseline to the 6 th month postsurgery for both Gp I and Gp II. The mean gray level gain was 28 and 30 scales for Gp I and Gp II respectively which was significantly higher than the mean gain in Gp III which was 9 scales.
Histologically, new bone formation has been demonstrated in human extraction defects treated with BG after 6 months.  There is also evidence that almost entirely osteoconductive bone growth occurs after 6 months of BG implantation in dogs.  Data suggest that the transformation of BG particles and infiltration of bone tissue start at 4 months, and all BG particles disappear through resorption at 16 months following the grafting procedure in humans. 
Sumer et al., 2013, compared the effectiveness of autogenous cortical bone (ACB) and BG grafting for the regenerative treatment of intraosseous periodontal defects. They reported that both ACB and BG grafting led to significant improvements in clinical and radiographic parameters 6 months postoperatively. Either an ACB graft, which is completely safe with no associated concerns about disease transmission and immunogenic reactions, or a BG graft, which has an unlimited supply, can be selected for regenerative periodontal treatment. 
The results of this study provide a much better understanding of BG efficacy as a graft material, indicating that both the autogenous bone and bony glass grafts provided statistically significant improvement (P < 0.05) in all of the clinical and radiographic parameters tested compared with control group. They are equally effective in treating Grade II furcation involvement by regenerative therapy. Moreover, bony glass is available in the market and relatively cheap without needing for second surgical sites to achieve autogenous graft.
There is no doubt that new approaches of regeneration will be proven or developed in the future. Regeneration is a reality and it is available and allows the clinician to save teeth that were extracted in the past.
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]