Sodium hyaluronate accelerates the healing process in tooth sockets of rats

Objective

In this study we evaluated the effects of sodium hyaluronate (HY) in the healing process of tooth sockets of rats.

Design

Immediately after the extraction of the upper first molars of male Holtzman rats, right sockets were treated with 1% HY gel (∼0.1 ml), while left sockets were used as control (blood clot). The animals were sacrificed at 2, 7, and 21 days after tooth extraction and upper maxillaries processed for histological and morphometric analysis of the apical and medium thirds of the sockets. Carbopol, an inert gel, was used to evaluate the mechanical effect of gel injection into sockets. Expression of bone morphogenetic protein-2 (BMP-2) and osteopontin (OPN) was determined by immunohistochemistry at 1, 2, 3, 4, 5, and 7 days after tooth extraction.

Results

Histological analysis showed that HY treatment induced earlier trabecular bone deposition resulting in a bone matrix more organized at 7 and 21 days after tooth extraction. Also, HY elicited significant increase in the amount of bone trabeculaes at 7 and 21 days after tooth extraction (percentage of trabecular bone area at 7 days: 13.21 ± 4.66% vs. 2.58 ± 1.36% in the apical third of control sockets) and in the vessels counting at 7 days. Conversely, the number of cell nuclei was decreased in HY-treated sockets. Additionally, expression of BMP-2 and OPN was enhanced in HY-treated sockets compared with control sockets.

Conclusions

These findings suggest that HY accelerates the healing process in tooth sockets of rats stimulating the expression of osteogenic proteins.     

Effects of lithium on extraction socket healing in rats assessed with micro-computed tomography

Abstract

Objective. Lithium is an activator of β-catenin signaling and β-catenin plays an important role in regulating bone formation and remodeling. The purpose of this study was to investigate the effects of lithium on bone repair in tooth extraction sockets in rats. Material and methods. Twenty male Wistar rats were subjected to maxillary left second molar extraction. The animals received a daily injection of lithium chloride (LiCl) or the same dose of sodium chloride (NaCl) starting 7 days before tooth extraction until sacrifice 14 days after extraction. Rats were randomly divided into: (1) a pre-treated group that received LiCl injection from 7 days before to 3 days after tooth extraction; (2) a post-treated group that received LiCl injection starting 4 days after tooth extraction; (3) a continuously treated group that received LiCl injection for the entire 21 days; and (4) a control group that received NaCl injection only. The volume of new bone and the bone density in the extraction socket were quantified by micro-computed tomography. Results. The percentage of new bone formation in the extraction socket was as follows: 63.2 ± 13.4% (pre-treated group), 53.9 ± 9.8% (post-treated), 23.8 ± 8.0% (continuously treated) and 37.5 ± 4.2% (control). The difference in percentage was statistically significant between each pair of groups. Pre- and post-treated groups also showed a significant increase in the density of new bone. Conclusions. Lithium enhances bone repair in extraction sockets when delivered before or after tooth extraction. Tooth extraction during lithium treatment may impair bone healing.     

Beta-tricalcium phosphate/type I collagen cones with or without a barrier membrane in human extraction socket healing: clinical,histologic, histomorphometric,and immunohistochemical evaluation

The aim of this study was to investigate the healing of human extraction sockets filled with β-tricalcium phosphate and type I collagen (β-TCP/Clg) cones with or without a barrier membrane. Twenty patients were divided in two groups: (A) β-TCP/Clg non-membrane and (B) β-TCP/Clg + barrier membrane. Clinical examination and biopsies from the grafted sites were collected 9 months later. Bone samples were analyzed using histomorphometry and immunohistochemistry. The horizontal dimension of the alveolar ridge was significantly reduced 9 months after socket preservation in the non-membrane group. There was bone formation with no significant differences between the two groups in the areas occupied by new bone (A = 42.4%; B = 45.3%), marrow (A = 42.7%; B = 35.7%), or residual graft (A = 9.7%; B = 12.5%). Immunohistochemistry revealed osteonectin expression in both groups. Both groups demonstrated sufficient amounts of vital bone and socket morphology to support dental implant placement after the 9-month healing period. A future trial to evaluate the alveolar outcomes at an earlier 6-month time point rather than the 9 months used in this study would be of interest.     

Volumetric analysis of extraction sockets using cone beam computed tomography: a pilot study on ex vivo jaw bone

Aim: The aim of this study was to determine the accuracy of volumetric analysis of extraction sockets using cone beam computed tomography (CBCT). Material and Methods: The volume of 40 dental alveoli in nine dry skull specimens (four mandibles and five maxillae) was determined by measuring the volume of the tooth socket impression using the water displacement technique. This was considered as the gold standard. Then, the tooth socket was scanned with CBCT and data were uploaded in the semi‐automated Livewire^® segmentation software. The software segments the tooth socket in consecutive 1 mm‐thick two‐dimensional slices. After segmentation, the total volume of the delineated socket was computed. The statistical difference between direct volumetric measurements and those obtained with CBCT imaging was assessed using the Student paired t‐test. Result: The mean socket volume of the skull specimens was 227±91 mm³ when obtained by direct measurement and 225±90 mm³ when obtained by CBCT imaging. Student paired t‐test showed no significant differences between both volume measurements (p>0.1). Conclusions: CBCT permits imaging of anatomical structures in three planes and allows for reliable volume estimates. The results should be verified in clinical circumstances and might have potential applicability for evaluation of extraction socket healing under different conditions.     

Histological comparison of healing extraction sockets implanted with bioactive glass or demineralized freeze-dried bone allograft: a pilot study

BACKGROUND: Various materials have been used immediately following tooth extraction to fill and/or cover the socket in an attempt to limit or prevent ridge resorption. The purpose of the present pilot study was to establish a reliable model to investigate the effect of various bone graft and bone replacement materials on extraction socket healing. This study also compared healing extraction sockets 6 to 8 months postimplantation of a bioactive glass (BG) or demineralized freeze-dried bone allograft (DFDBA) to an unfilled socket control (C). METHODS: Following tooth extraction, a total of 30 sockets in 19 patients were randomly divided into 3 treatment groups: 10 sockets received BG, 10 sockets DFDBA, and 10 sockets served as unfilled controls. Primary coverage was achieved by flap advancement over each socket. Six to 8 months postextraction at time of implant placement, histological cores of the treatment sites were obtained. These cores were processed, undecalcified sections prepared and stained with Stevenel blue/van Gieson's picric fuchsin, and histomorphometrically analyzed. Vital bone, connective tissue and marrow, and residual graft particles were reported as a percentage of the total core. RESULTS: A model system was described in humans and used to evaluate the healing response in the 3 treatment groups. Results concluded that mean vital bone present was 59.5% for BG-, 34.7% for DFDBA-, and 32.4% for C-treated sites. These differences were not statistically significant. However, the residual implant material was significantly higher in DFDBA-treated (13.5%) versus BG-treated sockets (5.5%). CONCLUSIONS: Although the differences in percent vital bone were not statistically significant among the 3 treatment groups in this pilot study, BG material was observed to act as an osteoconductive material which had a positive effect on socket healing at 6 to 8 months postextraction. Further research following implant placement in treated and control sockets is warranted to determine if bone implant contact is improved in BG-filled versus unfilled sockets.     

成骨诱导剂对拔牙创愈合的影响

目的 探讨以明胶海绵为载体,地塞米松、维生素C和β-甘油磷酸钠组成的成骨诱导剂对拔牙创愈合和牙槽嵴形态改建的影响。方法选用50只家兔,拔除双侧上颌第一前磨牙,右侧拔牙创内填入载有成骨诱导剂的明胶海绵,作为实验侧;左侧填入空载明胶海绵,作为对照侧。拔牙后第1、2、4、8、12周各处死10只动物,取双侧牙槽骨标本,拍摄X线片,并测量骨缺损区新骨密度;用组织学方法评价拔牙创愈合情况;并于12周时,测量拔牙区牙槽嵴高度吸收值。结果X线片骨密度测量显示：术后2、4、8、12周,实验侧骨密度值均高于对照侧,差异有统计学意义（P<0.01）。组织学检查显示：实验侧拔牙创内成骨现象较对照侧早,成骨细胞分化和增殖更活跃。
12周时实验侧牙槽嵴高度吸收值小于对照侧,差异有统计学意义（P<0.01）。结论 由地塞米松、β-甘油磷酸钠和维生素C组成的成骨诱导剂能促进拔牙创愈合,加速成骨和骨改建。     

The effect of ultrasound on bone dimensional changes following extraction: a pilot study

BACKGROUND: Because of bone resorption following tooth extraction, preservation of adequate bony dimension is performed often for subsequent treatment with dental implants. This study evaluated a novel, non-invasive treatment using ultrasound to accelerate healing following extraction to minimize alveolar bone loss. The objective of this study was to evaluate the effect of ultrasound on the dimensional healing changes of alveolar bone following tooth extraction using cone-beam volumetric tomography (CBVT). METHODS: This randomized, split-mouth trial involved 12 subjects requiring extraction of two contralateral erupted permanent teeth. Baseline CBVT scans were captured 7 to 10 days following extraction, after which time ultrasound therapy commenced in test sites. Ultrasound therapy was delivered for 20 minutes using a piezoelectric transducer for 10 sessions over the subsequent 4 weeks. Follow-up radiographic scans were obtained at 4 weeks and 3 months postextraction. Analyses of variance and covariance were performed to assess dimensional changes over the 3-month healing period. RESULTS: Analysis of dimensional changes in all measures of vertical height and horizontal width demonstrated no statistically significant differences between the ultrasound and control groups from baseline to 3 months postextraction. Evaluation of correlations between dimensional changes demonstrated a moderately strong correlation (r = 0.67; P = 0.023) in the ultrasound group between the change in buccal vertical height and the baseline crestal ridge width. Analysis of the change in buccal vertical height relative to baseline crestal width demonstrated a statistically significant benefit to ultrasound compared to control (P = 0.016). This benefit was more pronounced in wider sockets compared to narrow sockets. CONCLUSIONS: In this pilot study, there was no significant benefit to ultrasound in absolute bony dimensional changes following tooth extraction. There was a significant interaction between the treatment rendered (ultrasound versus control) and the change in buccal ridge height relative to baseline ridge width at the crest and 3 mm apical to the crest. This benefit was apparent in wide sockets compared to narrow sockets; however, the clinical importance of these relative dimensional changes in the ultrasound group are difficult to determine given the inclusion of all tooth types in a pilot study with a small sample size.     

Extraction socket preservation graft before implant placement with calcium sulfate hemihydrate and platelet-rich plasma: a clinical and histomorphometric study in humans

Background: The aim of this investigation is to evaluate clinical and histologic outcome of using medical‐grade calcium sulfate hemihydrate (MGCSH) mixed with platelet‐rich plasma (PRP) for extraction socket preservation graft before implant placement. Methods: This study is a single‐site, randomized and controlled investigation. Sixteen patients with a non‐restorable tooth requiring extraction followed by implant placement were enrolled in this study. After extraction of a tooth, eight selected patients randomly received MGCSH mixed with PRP in the extraction sockets (test group), and eight selected patients randomly received collagen resorbable plug dressing material (control group). At the time of extraction and 3 months later (at implant placement surgery), vertical and horizontal socket dimensions were measured. Bone core samples were retrieved from the center of the healed socket before implant placement for histomorphometric analysis. Results: There was a statistically significant difference between the two groups based on histomorphometric analysis (P <0.05). New vital bone percentage regenerated after 3 months of healing was 66.5% ± 10.4% in sockets grafted with MGCSH mixed with PRP compared to 38.3% ± 9.3% collagen resorbable plug. There was no statistically significant difference in the amount of vertical and horizontal bone resorption (P >0.05) between groups. In all cases but two in the control group, implants were placed with primary stability. Conclusion: MGCSH mixed with PRP showed greater vital bone volume at 3 months with rapid enhancement of bone healing compared to PRP‐free collagen resorbable graft.     

The use of leukocyte- and platelet-rich fibrin in the management of soft tissue healing and pain in post-extraction sockets: A randomized clinical trial

This study aimed to evaluate the clinical effect of leukocyte- and platelet-rich fibrin (L-PRF) to improve epithelialization and decrease postoperative pain in post-extraction sockets. Thirty two participants requiring extractions of posterior teeth were randomized into two groups: 1) extractions and socket filling with L-PRF membrane (test group) and 2) extraction with spontaneous healing (control group). One week after extraction, an assessment of soft tissue healing around the sockets was performed using the healing index. Also, postoperative pain by visual analog scale (VAS) and number of consumed analgesic tablets were recorded. In the first week, the sockets of the test group presented a significantly (mean of 3.81 ± 0.54; p = 0.0138) higher level of healing when compared to the sockets of the control group (mean of 3.18 ± 0.65). The participants of control group reported a significantly (mean of 5.12 ± 1.08; p = 0.0128) higher level of postoperative pain when compared to the test group (mean of 4 ± 1.15). Also, the control group consumed a greater number of analgesics (mean of 1.75 ± 0.85; p = 0.0136) when compared to the test group (mean of 1 ± 1.15). The results of the present study demonstrate that whenever improved healing of the extraction socket is needed, the use of L-PRF should be considered. In addition, the use of L-PRF decreases postoperative pain and discomfort.     

锂盐对大鼠拔牙创愈合的影响

目的:观察锂盐对大鼠拔牙创愈合过程中新骨形成的影响。方法:取20只Wistar大鼠,拔除左侧上颌第二磨牙,随机分为2组。实验组从拔牙前7d起至拔牙后第3天每天腹腔注射LiCl,对照组给予相同剂量NaCl。拔牙后3d、7d处死大鼠。通过HE染色定量分析新骨的形成,BrdU标记增殖细胞。采用Image-Pro Plus生物图像分析系统对增殖细胞及新骨量作半定量分析,应用SPSS 13.0软件包对数据进行统计学分析。结果:拔牙后3d,拔牙创内间充质细胞增殖,实验组细胞增殖明显,BrdU阳性细胞数为对照组的1.8倍,两者有显著差异(P<0.05)。拔牙后7d,拔牙创底部新生骨小梁生成,相对新骨量实验组为27.0%±6.5%,对照组为12.7%±5.1%,实验组与对照组有显著差异(P<0.01)。结论:在大鼠拔牙创愈合中,前期给予锂盐可促进间充质细胞增殖,使新骨形成增加。     

Bone marrow aspirate concentrate and platelet-rich fibrin in fresh extraction sockets: A histomorphometric and immunohistochemical study in humans

The aim of this study was to evaluate the level of mineralized tissue and expression of bone markers in sockets grafted with platelet-rich fibrin and bone marrow aspirate concentrate (BMAC).Patients requiring extraction of one maxillary anterior tooth were randomized into three groups. After tooth extraction, the sockets in the control group (CG) were permitted to fill with blood clot. In the platelet-rich fibrin group (PRFG), after blood processing, the sockets were grafted with PRF plug. In the bone marrow aspirate concentrate combined with platelet-rich fibrin group (BM/PG), after blood and bone marrow processing, the sockets were grafted with a mixture of PRF plug and BMAC. After 6 months, the sites were reopened and bone cores were harvested and prepared for histomorphometric and immunohistochemical evaluation. The following levels were measured: mineralized tissue, expression of RUNX-2, and osteocalcin.Fifteen patients were included in this study. The histomorphometric analysis showed a more pronounced level of mineralized tissue in PRFG and BM/PG (54.20 ± 4.31% and 64.70 ± 6.74%, respectively) when compared with CG (40.60 ± 5.98%) (p = 0.0283 and p = 0.0090, respectively). The expression of RUNX-2 was very low in BM/PG (0.80 ± 0.84%) and absent in CG and PRFG (p = 0.0528). Osteocalcin expression was higher for BM/PG (23.40 ± 1.52%) when compared with CG and PRFG (18.40 ± 2.07% and 16.20 ± 1.92%, respectively) (p = 0.0117 and p = 0.0088, respectively).This preliminary study indicates that clinical use of bone marrow aspirate concentrate, when combined with platelet-rich fibrin as a carrier, might have some potential to increase mineralization in fresh extraction sockets.     

Effect of alendronate on healing of extraction sockets and healing around implants

Oral Diseases (2011) 17 , 705–711 Objectives: The purpose of this study was to evaluate the effect of alendronates on healing of extraction sockets and healing around implants in the maxilla of rats. Materials and Methods: Twenty‐four Sprague–Dawley rats were used. The rats in bisphosphonate group were subcutaneously injected with alendronate (5.0 mg kg^‐‐1) three times a week for 4 weeks. Both sides of the maxillary first molars were extracted, and customized titanium implants (Ø1.5 × 2.0 mm) were placed immediately into one side. Rats were killed at 3, 7, 14, or 28 days following surgery. Results: New bone formation in extraction sockets, bone area around the implant site, and bone–implant contact were not delayed in the bisphosphonate group. The tartrate‐resistant acid phosphatase positive cell count did not differ between bisphosphonate and control groups; however, empty lacunae were observed significantly more in bisphosphonate group. The differences in empty lacunae were shown at different time points between the implant sites and extraction sites: at 7 days after extraction, and at 14 and 28 days after implantation. Conclusions: Alendronates seemed to decrease bone resorption but not to decrease bone formation. Empty lacunae were observed significantly more at later time points in implant sites compared to extraction sockets.     

Enhanced osteogenic healing process of rat tooth sockets using a novel simvastatin-loaded injectable microsphere-hydrogel system

PurposeTo evaluate the effects of simvastatin in a new injectable microsphere hydrogel system on bone healing process of tooth sockets.Materials and methodsSimvastatin was loaded in poly (lactic-co-glycolic acid) (PLGA) microspheres using an emulsion process, and the drug-loaded PLGA microspheres were further entrapped in a gelatin hydrogel to form an injectable microsphere-hydrogel system. Simvastatin-free hydrogel and blank microspheres hydrogel were used as controls. A rat tooth extraction socket model was generated, and the simvastatin-loaded microsphere-hydrogel composite was injected in the defect area of a tooth socket. At 1, 2, 5, and 8 weeks after the surgery, all the animals were sacrificed and the mandibles were harvested. The samples were examined using X-ray, hematoxylin and eosin staining, and histological evaluations.ResultsFive weeks after the surgery, significantly more bone tissue was formed in the simvastatin-loaded hydrogel group than in the simvastatin-free hydrogel group and the blank microspheres hydrogel group as control (p < 0.05).ConclusionThe injectable simvastatin-loaded microsphere hydrogel promoted new bone formation in the tooth extraction socket after 5 weeks, and has a promising potential for bone repair and regeneration.     

Histological comparison of healing following tooth extraction with ridge preservation using enamel matrix derivatives versus Bio-Oss Collagen: a pilot study

The goal of the present clinical study was to evaluate new bone formation in human extraction sockets augmented with enamel matrix derivatives (EMD) and Bio-Oss Collagen. Patients with symmetrical single-rooted teeth in the bilateral quadrants of the upper jaw condemned for extraction participated in this study. Following extraction, the sockets (20 sockets) were randomly augmented using either EMD or Bio-Oss Collagen. After 3 months of healing, bone biopsies were obtained and prepared for histological analyses. Dental implants were then placed. Implant stability quotient (ISQ) readings were obtained for each implant at the time of surgery and at 1 and 3 months postoperatively. The mean new bone formation was 34.57 ± 25.67% in the EMD sites and 28.80 ± 16.14% in the Bio-Oss Collagen sites. There was no significant difference between the groups. The ISQ values were significantly higher for the implants placed in the EMD sites at the first and third months, but no significant differences were observed in the ISQ values for the implants placed in the Bio-Oss Collagen sites. The augmentation of the extraction sockets with EMD or Bio-Oss Collagen leads to similar behaviour in bone regeneration.     

Accuracy of cone beam dental CT,intraoral digital and conventional film radiography for the detection of periapical lesions. An ex vivo study in pig jaws

To compare the accuracy of cone beam CT scanning (NewTom 3G) with intraoral periapical radiography (Dixi2, Planmeca CCD sensor and Insight film) for the detection of periapical bone defects. Ten frozen pig mandibles were used. All soft tissues were removed and the jaws were sagittally sectioned to obtain three blocks from each side of the jaw containing the premolars and the molars with surrounding jaw bone. All teeth with intact roots were then “extracted”. First, 15 blocks were used to define defect size and exposure parameters; then, the remaining 45 blocks were divided into three equal groups. In one group, cylindrical defects of 1 × 1 mm were prepared beyond the apices of the extraction sockets, in another group defects of 2 × 2 mm were similarly prepared, while no defects were prepared in the last group. The teeth were replaced into their sockets and digital and conventional radiographs of all blocks were taken under reproducible conditions. In addition, all blocks were CT scanned with the same volumetric data and then reconstructed to provide sagittal and coronal 2-D sections. Masked evaluation of the images (defect present vs no defect) was performed by four calibrated examiners. Statistical analysis was performed with ANOVA and the significance level was set to P < 0.05. NewTom 3G was statistically significantly better in terms of sensitivity (54%), positive (82.6%) and negative (44.5%) predictive values, and diagnostic accuracy (61%) when compared with digital radiographs (23%, 60%, 31%, 39%), and with conventional ones (28%, 70%, 35%, 44%)—except in the positive predictive value. Specificity was similar for all three methods. No difference was observed between the two periapical (digital vs conventional) radiographs. NewTom 3G may be useful in cases of immediate implants intended to replace teeth with suspicion for possible existing endodontic pathology, or in candidate implant sites neighboring such teeth.     

局部应用芦荟膏对大鼠拔牙窝早期愈合的影响

目的 研究拔牙窝内填塞芦荟膏对牙槽窝骨愈合的影响,为临床应用提供实验依据.方法 采用20只Wister大鼠,拔除左右上颌第一磨牙,建立拔牙窝动物模型.右侧拔牙窝中放入300g/L的芦荟膏作为实验组,左侧拔牙窝不放置任何药品作为对照组,观察拔牙窝愈合情况.于拔牙后第4、8、15、30、60d分5批处死大鼠,制取拔牙创标本,并行X线检查和扫描电镜观察.结果 X线检查结果显示实验组拔牙窝愈合较快,新骨形成速度及骨密度明显优于对照组.扫描电镜显示实验组拔牙窝愈合速度明显优于对照组,术后30d时,实验组拔牙窝基本愈合,对照组仍可见明显的骨吸收陷窝,直至60d时拔牙窝基本愈合.结论 芦荟膏对大鼠拔牙窝的早期愈合具有促进作用.     

Alveolar wound healing alteration under uranyl nitrate intoxication

The deposit of uranium compounds in calcifying zones has been demonstrated in bone. Nevertheless, no studies on the effect of uranium on osteogenesis have been performed. A histologic and histometric study of the effect of a single intraperitoneal injection of 2 mg/kg of body weight of uranyl nitrate on bone formation is presented. It was performed on rats' healing sockets, 14 days after tooth extraction. The alveolar bone volume (15 X 10(5) micron vs. 34 X 10(5) micron2), total bone formation areas (4.85% vs. 19.55%), and volume density of bone in the alveolar apical third (0.26 vs. 0.40) were significantly lower in intoxicated animals than in the controls. These results indicate the inhibitory effect of uranyl nitrate on bone formation.     

Delayed immediate implants: alveolar bone chamzes durinrr the healing period

Delaying the placement of immediate fixtures by 6–8 weeks after extraction of the natural dentition allows for the elimination of associated infective processes, the achievement of maximum osteoblastic activity that theoretically could help the osseointegration process and complete wound covering that simplifies the placement of grafts or membranes. This study examines the healing associated with 21 fixtures in 14 patients. The fixtures were placed into sockets 6–8 weeks after tooth extraction without the use of barrier membranes or bone substitutes. Measurements were taken immediately prior to fixture placement and 3–6 months later at the abutment placement. Alveolar bone height, the remaining socket depth and diameter and the depth to which a 3.75 mm fixture could be inserted into the socket were measured. After fixture placement the vertical and horizontal measurements from the cover screw to the surrounding alveolar bone and the distance from the cover screw to the CEJ of the adjacent tooth were recorded. All fixtures were integrated at exposure with 1 failure during the follow-up period. The distance from the cover screw to the buccal plate decreased by a mean of 2.17 mm. There was an increase in the mean vertical bone height at all 4 surfaces. When horizontal defects were present, the mean vertical distance decreased from 2.5±0.37 mm to 0.36±0.64 mm. When horizontal defects were absent, the mean vertical distance decreased from 3.86±0.58 mm to 0.48±0.25 mm. There was also a marked decrease in the horizontal distance between the bone margin and the surface of the fixture from 1.6±l.73 mm 1 to 0.02±0.02 mm. These results indicate a strong tendency for the defects to fill-in in the horizontal plane and for bone growth to occur in the vertical plane to the height of the cover screw. In conclusion the delayed immediate placement of fixtures has a good short-term prognosis with bone regeneration occurring around the defect without the use of barrier membranes or bone substitutes.     

Bone healing in osteoporotic female rats following intra-alveolar grafting of bioactive glass

We have investigated the effect of ovariectomy combined with a low Ca diet on bone healing following the implantation of bioactive glass into extraction sockets, in rats. Ovariectomized rats received a low Ca diet from the day of surgery until sacrifice while sham-operated animals were fed a standard laboratory chow. Two weeks after surgery the upper incisors were extracted and the alveolar sockets in both groups were partially filled with a particulate bioglass (PerioGlas^®). The animals were killed 1, 2, 3 and 9 weeks after tooth extraction and the relative volume fraction of the healing components (bone trabeculae, connective tissue and coagulum remnants) was estimated in histological paraffin sections by a histometric differential point-counting method. The bioglass particles persisted inside the socket for all the experimental periods and, as bone repair proceeded, they were progressively enclosed in newly formed bone trabeculae which in some cases established a close contact with their surface. The volume fraction of neoformed bone trabeculae relative to the volume fraction of connective tissue and coagulum remnants was greater in the sockets of ovariectomized animals implanted with bioglass than in those of the overiectomized non-implanted groups.     

Hyaluronic Acid Improves Bone Formation in Extraction Sockets With Chronic Pathology: A Pilot Study in Dogs

Background: Previous studies on ridge preservation focusing on fresh extraction sockets using graft materials for ridge preservation procedures have reported a delay in the tissue modeling and remodeling phases. The objective of this study is to evaluate the effect of hyaluronic acid (HA) on healing of infected sockets. Methods: Six beagle dogs were used in this study. Both mandibular third premolars were hemisected, and the distal roots were extracted. Subsequently, periodontal and endodontic lesions were induced at the remaining mesial root. After communication of the periodontal lesion, an endodontic periapical lesion was observed at 4 months, and the mesial roots of both the right and left sides were extracted. HA was applied into the socket of the test group, and no treatment was administered to the other group (control group). Three months after extraction of the mesial roots, the dogs were sacrificed, and histologic evaluations were performed. Results: The sockets were filled by mineralized bone (47.80% ± 6.60%) and bone marrow (50.47% ± 6.38%) in the control group, whereas corresponding values were 63.29% ± 9.78% and 34.73% ± 8.97% for the test group, respectively. There was a statistically significant difference between the groups. Reversal lines and a copious lineup of osteoblasts were observed in the middle and apical parts of the sockets in the test group. Conclusion: An infected socket shows delayed healing of the socket wound, and HA, because of its osteoinductive, bacteriostatic, and anti‐inflammatory properties, may improve bone formation and accelerate wound healing in infected sockets.