The use of bovine porous bone mineral in combination with collagen membrane or autologous fibrinogen/fibronectin system for ridge preservation following tooth extraction

Preservation of the alveolar ridge following tooth extraction is desirable since it facilitates placement of endosseous implants and may improve the adverse esthetics often associated with fixed partial dentures. The purpose of this study was to compare the clinical effectiveness of bovine porous bone mineral (BPBM) used as a graft material combined with either guided tissue regeneration (GTR) or with the autologous fibrinogen/fibronectin system (AFFS) in preserving alveolar ridges following tooth extraction. Twenty-six patients who required extraction of two or more anterior or bicuspid teeth participated in a split-mouth design study. Following tooth extraction and elevation of a buccal full thickness flap, sockets were filled with bovine porous bone mineral which was then covered with either a collagen membrane or mixed and covered with an AFFS system. An acrylic stent served as a reference point for measurements. Primary flap closure was achieved in all surgical sites, and reentry surgery was performed at 6 months. Reentry surgery showed that BPBM/GTR sites presented with [1] significantly more internal socket bone fill (6.04 +/- 0.21 mm vs. 4.98 +/- 0.26 mm), [2] less, although not statistically significant, resorption of alveolar bone height (0.23 +/- 0.28 mm vs. 0.3 +/- 0.21 mm), and [3] significantly less horizontal resorption of the alveolar bony ridge as compared to BPBM/AFFS (1.06 +/- 0.28 mm vs. 2.60 +/- 0.25 mm). This study suggests that treatment of extraction sockets with a combination of bovine porous bone mineral and guided tissue regeneration is of slightly more benefit in preserving alveolar ridge dimensions following tooth extraction than treatment with a combination of bovine porous bone mineral and the autologous fibrinogen/fibronectin system.     

Influence of bioactive glass on changes in alveolar process dimensions after exodontia

BACKGROUND: Preservation of the alveolar process after tooth extraction is desirable because it facilitates placement of endosseous implants and minimizes adverse esthetic results associated with fixed partial dentures. The purpose of this study was to evaluate the clinical effectiveness of bioactive glass used as a graft material combined with calcium sulfate used in the form of a mechanical barrier in preserving alveolar ridges after tooth extraction. METHODS: Sixteen patients who required extraction of 2 anterior teeth or bicuspids participated in the study (split mouth design). After tooth extraction and elevation of a buccal full-thickness flap, experimental sockets were filled with bioactive glass, which in turn was covered with a layer of calcium sulfate. Control sites did not receive any graft or calcium sulfate. Titanium pins served as fixed reference points for measurements. No attempt was made to advance the flap to cover the socket areas on control or experimental sites (open socket approach). Reentry surgeries were performed at 6 months. RESULTS: Reentry surgeries showed that experimental sites presented with (1) significantly more internal socket bone fill (6.43 +/- 2.78 mm vs 4.00 +/- 2.33 mm on control sites), (2) less (although not statistically significantly less) resorption of alveolar bone height (0.38 +/- 3.18 mm vs 1.00 +/- 2. 25 mm on control sites), and (3) similar degree of horizontal resorption of the alveolar bony ridge as compared with controls (3. 48 +/- 2.68 mm vs 3.06 +/- 2.41 mm on control sites). CONCLUSIONS: This study suggests that treatment of extraction sockets with a combination of bioactive glass and calcium sulfate is of some benefit in preserving alveolar ridge dimensions after tooth extraction.     

Effects of a putty-form hydroxyapatite matrix combined with the synthetic cell-binding peptide P-15 on alveolar ridge preservation

BACKGROUND: Various grafting materials have been used for preservation of the dimensions of the residual alveolar ridge following tooth extraction. The purpose of this study was to evaluate clinical, histomorphometric, and radiographic healing 4 months after tooth extraction with or without placement of a putty-form anorganic bovine-derived hydroxyapatite matrix combined with a synthetic cell-binding peptide P-15 (Putty P15) to determine the effect on alveolar ridge preservation following exodontia. METHODS: Twenty-four consecutive subjects in need of extraction of maxillary premolars were recruited. Recruited subjects were randomly assigned to the test (Putty P15 and bioabsorbable collagen wound dressing material) or control (bioabsorbable collagen wound dressing material only) group. Data were recorded at 1, 2, 4, 8, and 16 weeks after ridge preservation procedures. At 16 weeks, a reentry surgery was performed, clinical measurements were repeated, and bone core biopsies were obtained for histomorphometric analysis prior to dental implant placement. RESULTS: The control group had a mean reduction in ridge height of -0.56 +/- 1.04 mm, whereas alveolar ridge height appeared to remain unchanged in the test group (0.15 +/- 1.76). The test group showed a mean reduction in ridge width of -1.31 +/- 0.96 mm, whereas the mean value for the control group was -1.43 +/- 1.05 mm. No statistical significance was observed between the groups. Mean bone density was significantly superior in the test group (2.08 +/- 0.65 versus 3.33 +/- 0.65). Histomorphometric analyses revealed similar percentages of bone vitality (test: 29.92% +/- 8.46%; control: 36.54% +/- 7.73%). Comparable percentages of bone marrow and fibrous tissue also were observed (test: 65.25% +/- 6.41%; control: 62.67% +/- 7.41%). Only 6.25% of the Putty P15 particles remained at 4 months in the analyzed biopsies. CONCLUSION: A favorable response was observed when Putty P15 was applied to extraction sockets, suggesting that it may be useful for alveolar ridge preservation prior to dental implant placement.     

Medical grade calcium sulfate hemihydrate in healing of human extraction sockets: clinical and histological observations at 3 months

BACKGROUND: Following tooth extraction, remodeling and resorption of the alveolar bone at the extraction site characterize wound healing. This produces a reduction in ridge volume and difficulties in delayed placement of implants in an ideal position. Medical grade calcium sulfate hemihydrate (MGCSH) has been proposed as a graft material in extraction sockets to minimize the reduction in ridge volume. The aim of the present study was to investigate the influence of MGCSH on the histopathologic pattern of intrasocket regenerated bone and to evaluate histologically the healed MGCSH grafted extraction socket site 3 months postextraction METHODS: MGCSH was grafted in 10 fresh human extraction sockets in 10 patients. Five post-extraction sockets were used as controls. At 3 months a cylindrical tissue specimen, 2.5 mm in diameter, was trephined from the previously grafted site followed by implant placement. Non-decalcified specimens were sectioned at a cross-horizontal plane and stained with fast green, toluidine blue, and Van Kossa stains for histological and histomorphometrical examination. RESULTS: Histologically, MGCSH was not observed in most of the specimens. Newly formed bone with lamellar arrangements was identified in all the horizontal sections with no difference between apical, medium, and coronal areas. The mean trabecular area in the coronal sections was 58.6% +/- 9.2%; in the medium sections, 58.1% +/- 6.2%; and in the apical sections, 58.3% +/- 7.8%. The differences were not statistically significant. CONCLUSION: MGCSH seems to be an ideal graft material in extraction socket bone regeneration because it is almost completely resorbable, and it allows a new trabecular bone arrangement at 3 months.     

Healing of human extraction sockets filled with Bio-Oss

The aim of this study was to investigate the healing of human extraction sockets filled with Bio-Oss particles (Geistlich Pharma AG, Wolhusen, Switzerland). In 21 subjects, providing a total of 31 healing sites, at least one tooth was scheduled for extraction and the extraction sites for implant therapy. The dimensions of the alveolar ridge at the extraction sites were considered insufficient and required augmentation concomitant with tooth extraction. There were three treatment groups. In group A, the extraction sockets were covered with a Bio-Gide membrane (Geistlich Pharma AG) and in group B the extraction sockets were filled with Bio-Oss. The extraction sockets in group C were left to heal spontaneously. Biopsies from the extraction sites were collected at the time of implant installation. Samples from group A showed large amounts of lamellar bone and bone marrow and small proportions of woven bone. Sites grafted with Bio-Oss (group B) were comprised of connective tissue and small amounts of newly formed bone surrounding the graft particles. Only 40% of the circumference of the Bio-Oss particles was in contact with woven bone. Sites from group C were characterized by the presence of mineralized bone and bone marrow.     

Porcine‐Derived Xenograft Combined with a Soft Cortical Membrane versus Extraction Alone for Implant Site Development: A Clinical Study in Humans

Background: An adequate alveolar crest is essential for implant placement in terms of esthetics and function. The objective of this randomized clinical trial was to compare the preservation of the alveolar ridge dimensions following tooth extraction using porcine‐derived xenograft combined with a membrane versus extraction‐alone (EXT) sites. Methods: Fifteen patients who required double extraction of contralateral premolars and delayed implant placement were randomly selected to receive both ridge‐preservation procedure and EXT. The test sites (alveolar ridge preservation [ARP]) included 15 sockets treated using a corticocancellous porcine bone xenograft (OsteoBiol® Gen‐Os; Tecnoss srl, Giaveno, Italy) associated with a soft cortical membrane (OsteoBiol® Lamina; Tecnoss srl), while the corresponding control sites (EXT) were left without grafting for EXT. Horizontal and vertical ridge dimensions were recorded at baseline and 6 months after extractions. Results: After 6 months, the EXT sites showed a significantly greater reabsorption of the buccolingual/palatal dimension of the alveolar ridge (3.7 ± 1.2 mm) compared with the ARP sites (1.8 ± 1.3 mm). The mean vertical ridge height reduction in the control sockets was 3.1 ± 1.3 mm at the buccal sites and 2.4 ± 1.6 mm at the lingual sites compared with 0.6 ± 1.4 and 0.5 ± 1.3 mm, respectively, in the test sockets. The differences between test and control sockets were not significant for the mesial and distal measurements. Conclusions: The placement of a porcine xenograft with a membrane in an extraction socket can be used to reduce the hard tissue reabsorption after tooth extraction compared with EXT.     

牙槽嵴保存术对不同牙槽骨缺损患者延迟种植效果的影响

目的:探讨牙槽嵴保存术对不同牙槽嵴骨缺损患者延迟种植效果的影响。方法:94例行下颌单颗后牙拔除术患者,根据牙拔除术前牙槽嵴骨缺损量不同将患者分为轻度组(n=53)和中重度组(n=41),行拔牙术后再将轻度组和中重度组分别随机分为保存术组和对照组,保存术组对牙槽窝采取牙槽嵴保存术,对照组对牙槽窝不做处理。结果:轻度组和中重度组患者术后6个月保存术组患者宽度减少量和高度减少量均小于对照组(P<0.05);轻度组和中重度组中保存术组和对照组患者术后6月时GRL较拔牙前增加,而PD和AL则较拔牙前减少;轻度组种植体直径4.1 mm和4.8 mm分别占26.4%和73.6%,而中重度组则分别为46.3%和53.7%,两组相比差异具有统计学意义(χ²=4.029,P=0.045);轻度组种植体长度分布与中重度组相比差异具有统计学意义(χ²=21.207,P=0.000)。结论:牙槽嵴保存术可有效减少拔牙术后植骨区牙槽嵴骨量损失,有利于延迟种植操作的开展,尤其对患牙拔除前牙槽嵴骨缺损量>5 mm的患者,效果尤为显著。     

新型复合矿化胶原膜用于牙槽嵴保存的实验研究

目的:探讨新型复合矿化胶原膜用于犬拔牙位点牙槽嵴保存实验研究的可行性.方法:12只杂种犬拔除下颌双侧第三前臼齿,共有24个牙槽窝,将其随机分为3组,A组植入人工骨修复材料并覆盖新型复合矿化胶原膜,B组植入人工骨修复材料,C组为空白对照组.术后3个月通过大体观察、形态学测量、螺旋CT以及X射线显微CT检查评价牙槽窝愈合情况.结果:3个月时牙槽窝水平宽度和新骨小梁结构参数A组大于B组(P＜0.05),B组大于C组(P＜0.05);感兴趣区域CT值A组均高于B组和C组(P＜0.05).结论:新型复合矿化胶原膜可起到减缓牙槽嵴吸收、诱导新骨再生、保存牙槽嵴的作用.     

聚乳酸-羟基乙酸-辛伐他汀对拔牙术后剩余牙槽嵴吸收影响的实验研究

目的探讨聚乳酸-羟基乙酸(PLGA)复合辛伐他汀对剩余牙槽嵴吸收的预防作用。方法选用60只Wistar雄性大鼠,随机分为实验组和对照组各30只,拔除右下中切牙后,实验组即刻植入PLGA-辛伐他汀支架材料,对照组植入PLGA支架材料。术后7、14、28、56、84d分别处死实验组和对照组大鼠各6只,用软X线、骨密度、测量组织学等方法进行药效评价。结果剩余牙槽嵴相对长度:术后14、28、56、84d对照组比实验组[(0·997±0·007)、(0·965±0·139)、(0·996±0·021)、(0·960±0·026)]明显降低,差异有统计学意义(P<0·05)。牙槽骨骨密度:术后28、56、84d实验组[(7·101±0·025)、(7·178±0·039)、(7·162±0·052)g/cm2]与对照组[(7·074±0·014)、(7·117±0·012)、(7·059±0·037)g/cm2]相比明显升高,差异有统计学意义(P<0·05)。组织学观察显示实验组成骨速度和质量优于对照组。结论以PLGA为载体局部应用辛伐他汀可诱导拔牙窝内骨形成,保存了剩余牙槽嵴的长度和骨量。     

Ridge alterations following implant placement in fresh extraction sockets: an experimental study in the dog

OBJECTIVE: To study dimensional alterations of the alveolar ridge that occurred following implant placement in fresh extraction sockets. MATERIAL AND METHODS: Five beagle dogs were included in the study. In both quadrants of the mandible, incisions were made in the crevice region of the third and fourth pre-molars. Buccal and minute lingual full-thickness flaps were elevated. The mesial root of the four pre-molars root was filled and the teeth were hemi-sected. Following flap elevation in (3)P(3) and (4)P(4) regions, the distal roots were removed. In the right jaw quadrants, implants with a sand blasted and acid etched (SLA) surface were placed in the fresh extraction sockets, while in the left jaws the corresponding sockets were left for spontaneous healing. The mesial roots were retained as surgical control teeth. After 3 months, the animals were examined clinically, sacrificed and tissue blocks containing the implant sites, the adjacent tooth sites (mesial root) and the edentulous socket sites were dissected, prepared for ground sectioning and examined in the microscope. RESULTS: At implant sites, the level of bone-to-implant contact (BC) was located 2.6+/-0.4 mm (buccal aspect) and 0.2+/-0.5 mm (lingual aspect) apical of the SLA level. At the edentulous sites, the mean vertical distance (V) between the marginal termination of the buccal and lingual bone walls was 2.2+/-0.9 mm. At the surgically treated tooth sites, the mean amount of attachment loss was 0.5+/-0.5 mm (buccal) and 0.2+/-0.3 mm (lingual). CONCLUSIONS: Marked dimensional alterations had occurred in the edentulous ridge after 3 months of healing following the extraction of the distal root of mandibular pre-molars. The placement of an implant in the fresh extraction site obviously failed to prevent the re-modelling that occurred in the walls of the socket. The resulting height of the buccal and lingual walls at 3 months was similar at implants and edentulous sites and vertical bone loss was more pronounced at the buccal than at the lingual aspect of the ridge. It is suggested that the resorption of the socket walls that occurs following tooth removal must be considered in conjunction with implant placement in fresh extraction sockets.     

上颌单颗前牙位点保存后邻面牙槽嵴高度的早期变化

目的 探讨位点保存术对上颌单颗前牙拔除后邻面牙槽嵴高度早期变化的影响,为种植修复龈乳头美学效果提供参考依据。方法 选择需拔除上颌单颗前牙的30例患者为研究对象,将其随机分为试验组和对照组,每组15例。试验组在拔牙同时进行位点保存术（牙槽窝内植入 Bio-Oss骨粉,表面游离龈移植缝合固定）,对照组拔牙后未行其他处理。术后7 d及术后6个月,佩戴个性化数字化放射导板行锥形束CT检查,测量2组近远中邻面牙槽嵴及唇侧中央牙槽嵴高度的变化。结果 试验组近中、远中邻面及唇侧中点的牙槽嵴吸收高度分别为（0.358±0.151）mm、（0.322±0.180）mm、（0.826±0.307）mm,对照组近远中邻面及唇侧中点的牙槽嵴吸收高度分别为（0.653±0.260）mm、（0.667±0.274）mm、（1.510±0.625） mm。统计分析表明,试验组的牙槽嵴吸收高度小于对照组（P<0.05）,近中、远中邻面牙槽嵴的吸收高度均小于唇侧（P<0.05）。结论 位点保存术可以减少牙拔除后牙槽嵴高度的吸收,提高种植修复龈乳头美学效果。     

上颌单颗前牙位点保存后邻面牙槽嵴高度的早期变化

目的 探讨位点保存术对上颌单颗前牙拔除后邻面牙槽嵴高度早期变化的影响,为种植修复龈乳头美学效果提供参考依据。方法 选择需拔除上颌单颗前牙的30例患者为研究对象,将其随机分为试验组和对照组,每组15例。试验组在拔牙同时进行位点保存术（牙槽窝内植入 Bio-Oss骨粉,表面游离龈移植缝合固定）,对照组拔牙后未行其他处理。术后7 d及术后6个月,佩戴个性化数字化放射导板行锥形束CT检查,测量2组近远中邻面牙槽嵴及唇侧中央牙槽嵴高度的变化。结果 试验组近中、远中邻面及唇侧中点的牙槽嵴吸收高度分别为（0.358±0.151）mm、（0.322±0.180）mm、（0.826±0.307）mm,对照组近远中邻面及唇侧中点的牙槽嵴吸收高度分别为（0.653±0.260）mm、（0.667±0.274）mm、（1.510±0.625） mm。统计分析表明,试验组的牙槽嵴吸收高度小于对照组（P<0.05）,近中、远中邻面牙槽嵴的吸收高度均小于唇侧（P<0.05）。结论 位点保存术可以减少牙拔除后牙槽嵴高度的吸收,提高种植修复龈乳头美学效果。     

Ridge Preservation After Tooth Extraction With Buccal Bone Plate Deficiency Using Tunnel Structured β‐Tricalcium Phosphate Blocks: A 2‐Month Histologic Pilot Study in Beagle Dogs

Background: Reduction in alveolar ridge volume is a direct consequence of tooth extraction. Tunnel β‐tricalcium phosphate (β‐TCP) blocks were manufactured from randomly organized tunnel‐shaped β‐TCP ceramic. Efficacy of these blocks compared to extraction alone for alveolar ridge preservation after tooth extraction with buccal bone deficiency was evaluated. Methods: Maxillary first premolars of six beagle dogs were extracted after removing the buccal bone, and bone defects of 4 × 4 × 5 mm (mesio‐distal width × bucco‐palatal width × depth) were created. Fresh extraction sockets with buccal bone defects were filled with tunnel β‐TCP blocks at test sites. Two months after the operation, histologic and histometric evaluations were performed. Results: Regarding histologic sections, coronal and middle horizontal widths of the alveolar ridge were significantly greater at test sites (3.2 ± 0.5 and 3.6 ± 0.4 mm, respectively) than at control sites (1.2 ± 0.3 and 2.0 ± 0.6 mm, respectively). The amount of woven bone was significantly greater at test sites (62.4% ± 7.9%) than at control sites (26.8% ± 5.3%), although that of connective tissue and bone marrow was significantly greater at control sites (38.1% ± 6.2% and 16.0% ± 6.9%, respectively) than at test sites (10.7% ± 5.7% and 4.1% ± 2.2%, respectively). Regarding basic multicellular units, no statistically significant difference was found between the test and control sites (0.5% ± 0.1% and 0.6% ± 0.1%, respectively). Conclusion: Tunnel β‐TCP blocks represent an effective bone‐graft material for alveolar ridge preservation in fresh extraction sockets with buccal bone defects.     

Medial-grade calcium sulfate hemihydrate (surgiplaster) in healing of a human extraction socket--histologic observation at 3 months: a case report

PURPOSE: Following tooth extraction, wound healing is characterized by remodeling and resorption of the alveolar bone at the extraction site. This produces reduction in ridge volume. Medical-grade calcium sulfate hemihydrate (MGCSH) has been proposed as a graft material for extraction sockets to minimize the reduction in ridge volume. The aim of this study was to investigate the influence of MGCSH on the histopathologic pattern of intrasocket regenerated bone and to evaluate histologically the healed MGCSH-grafted extraction socket site at 3 months postextraction. MATERIALS AND METHODS: MGCSH was grafted in a fresh human extraction socket, and at 3 months a cylindric tissue specimen, 2.5 mm in diameter, was trephined from the previously grafted site and an implant was placed. Non-decalcified specimens were sectioned at a horizontal plane and stained for histologic and histomorphometric evaluation. RESULTS: The mean trabecular area was 58.6% +/- 9.2% in the coronal sections, 58.1% +/- 6.2% in the middle sections, and 58.3% +/- 7.8% in the apical sections. The differences in mean trabecular area between sections were not statistically significant. DISCUSSION: It is significant that the MGCSH underwent complete resorption and replacement by newly formed bone because the most important negative attribute of other graft materials is the resorption time. Moreover, calcium sulfate shows great potential for guided bone regeneration in surgical sites. CONCLUSION: MGCSH seems to be an acceptable graft material for extraction socket bone regeneration because it is completely resorbable and allows new trabecular bone arrangement in a limited 3-month period.     

Acellular dermal matrix and hydroxyapatite in prevention of ridge deformities after tooth extraction

The aim of this study was to evaluate the role of acellular dermal matrix graft (ADMG) acting as a membrane, associated with a resorbable hydroxyapatite (RHA) in bone regeneration to prevent ridge deformities after tooth extraction. Fifteen patients who had at least 2 noncontiguous, uniradicular teeth indicated for extraction were selected. In group I, the extraction sockets were covered by ADMG alone; and in group II, the alveoli were filled with RHA before the placement of the ADMG. After 6 months, re-entry surgeries and biopsies were performed. Although ridge thickness had been preserved in both groups, the means were significantly greater (P < 0.05) for group II when compared to group I (6,8 +/- 1.26 and 5.53 +/- 1.06). The histologic analysis showed small bone formation in some samples for group II, where the presence of a highly vascularized fibrous connective tissue surrounding the particles was a common finding. Based on the results, it can be concluded that the ADMG was able to preserve ridge thickness and that the additional use of RHA favored the preservation of the ridges along with an increase in the width of keratinized tissue.     

Ridge preservation following tooth extraction using a polylactide and polyglycolide sponge as space filler: a clinical and histological study in humans

BACKGROUND: The placement of different graft materials and/or the use of occlusive membranes to cover the extraction socket entrance are techniques aimed at preserving/reducing alveolar ridge resorption. The use of grafting materials in fresh extraction sockets has, however, been questioned because particles of the grafted material have been found in alveolar sockets 6-9 months following their insertion. AIM: The aims of the study were to (i). evaluate whether alveolar ridge resorption following tooth extraction could be prevented or reduced by the application of a bioabsorbable polylactide-polyglycolide sponge used as a space filler, compared to natural healing by clot formation, and (ii). evaluate histologically the amount and quality of bone tissue formed in the sockets, 6 months after the use of the bioabsorbable material. MATERIAL AND METHODS: Thirty-six patients, undergoing periodontal therapy, participated in this study. All patients were scheduled for extraction of one or more compromised teeth. Following elevation of full-thickness flaps and extraction of teeth, measurements were taken to evaluate the distance between three landmarks (mesio-buccal, mid-buccal, disto-buccal) on individually prefabricated stents, and the alveolar crest. Twenty-six alveolar sockets (test) were filled with a bioabsorbable polylactide-polyglycolide acid sponge (Fisiograft), while 13 sockets (controls) were allowed to heal without any filling material. The flaps were sutured with no attempt to achieve primary closure of the surgical wound. Re-entry for implant surgery was performed 6 months following the extractions. Thirteen biopsies (10 test and three control sites) were harvested from the sites scheduled for implant placement. RESULTS: The clinical measurements at 6 months revealed, in the mesial-buccal site, a loss of bone height of 0.2 mm (1.4 SD) in the test and 0.6 mm (1.1 SD) in the controls; in the mid-buccal portion a gain of 1.3 mm (1.9 SD) in the test and a loss of 0.8 mm (1.6 SD) in the controls; and in the distal portion a loss of 0.1 mm (1.1 SD) in the test and of 0.8 (1.5 SD) mm in the controls. The biopsies harvested from the test sites revealed that the new bone formed at 6 months was mineralized, mature and well structured. Particles of the grafted material could not be identified in any of the 10 test biopsies. The bone formed in the control sites was also mature and well structured. CONCLUSION: The results of this study indicate that alveolar bone resorption following tooth extraction may be prevented or reduced by the use of a bioabsorbable synthetic sponge of polylactide-polyglycolide acid. The quality of bone formed seemed to be optimal for dental implant insertion.     

Socket preservation using bovine bone mineral and collagen membrane: a randomized controlled clinical trial with histologic analysis

After tooth extraction, varying amounts of bone resorption occur because of qualitative and quantitative changes at the edentulous site of the alveolar process. The aims of this randomized controlled clinical trial were (1) to compare the postextraction changes in residual ridge dimensions during spontaneous healing with those during socket preservation, (2) to analyze the histologic and histomorphometric aspects of the grafted sockets, and (3) to compare probing procket depth (PPD) and clinical attachment level (CAL) changes at teeth adjacent to extraction sites. Forty-eight teeth were extracted from 41 patients referred for extraction of 1 or more maxillary or mandibular premolars or molars. The edentulous sites were randomly assigned to the control (EXT, extraction alone) or experimental groups (SP, extraction and socket preservation). In the SP group, the sockets were filled with bovine bone mineral and covered with porcine collagen membrane. At baseline and after 4 months, PPD, gingival recession (REC), and CAL were measured at teeth adjacent to the edentulous sites. The changes in ridge dimensions from baseline to 4 months were assessed on dental casts. At 4 months, bone was harvested from the grafted areas in the SP group and the edentulous areas in the EXT group. PPD, REC, and CAL were comparable between groups. However, from baseline to 4 months, the SP group showed significantly less reduction in ridge width (1.04 ± 1.08 mm vs 4.48 ± 0.65 mm, P < .001) and height (0.46 ± 0.46 mm vs 1.54 ± 0.33 mm, P < .001). Histologically, the grafted sockets exhibited various stages of bone maturation and formation without inflammatory responses. No significant difference in the mineralized and nonmineralized fractions was noted between the groups. Socket preservation using bovine bone mineral and porcine collagen membrane considerably limits the amount of horizontal and vertical bone resorption when compared with extraction alone.     

Xenograft versus extraction alone for ridge preservation after tooth removal: a clinical and histomorphometric study

BACKGROUND: The preservation of bone volume immediately after tooth removal might be necessary to optimize the success of implant placement in terms of esthetics and function. The objectives of this randomized clinical trial were two-fold: 1) to compare the bone dimensional changes following tooth extraction with extraction plus ridge preservation using corticocancellous porcine bone and a collagen membrane; and 2) to analyze and compare histologic and histomorphometric aspects of the extraction-alone sites to the grafted sites. METHODS: Forty subjects who required tooth extraction and implant placement were enrolled in this study. Using a computer-generated randomization list, the subjects were randomly assigned to the control group (EXT; extraction alone) or to the test group (RP; ridge-preservation procedure with corticocancellous porcine bone and collagen membrane). The following parameters were assessed immediately after extraction and 7 months prior to implant placement: plaque index, gingival index, bleeding on probing, horizontal ridge width, and vertical ridge changes. A bone biopsy was taken from the control and test sites 7 months after the surgical treatment. Histologic and histomorphometric analyses were also performed. RESULTS: A significantly greater horizontal reabsorption was observed at EXT sites (4.3+/-0.8 mm) compared to RP sites (2.5+/-1.2 mm). The ridge height reduction at the buccal side was 3.6+/-1.5 mm for the extraction-alone group, whereas it was 0.7+/-1.4 mm for the ridge-preservation group. Moreover, the vertical change at the lingual sites was 0.4 mm in the ridge-preservation group and 3 mm in the extraction-alone group. Forty biopsies were harvested from the experimental sites (test and control sites). The biopsies harvested from the grafted sites revealed the presence of trabecular bone, which was highly mineralized and well structured. Particles of the grafted material could be identified in all samples. The bone formed in the control sites was also well structured with a minor percentage of mineralized bone. The amount of connective tissue was significantly higher in the extraction-alone group than in the ridge-preservation group. CONCLUSIONS: The ridge-preservation approach using porcine bone in combination with collagen membrane significantly limited the resorption of hard tissue ridge after tooth extraction compared to extraction alone. Furthermore, the histologic analysis showed a significantly higher percentage of trabecular bone and total mineralized tissue in ridge-preservation sites compared to extraction-alone sites 7 months after tooth removal.     

Socket grafting with the use of autologous bone: an experimental study in the dog

Background: Studies in humans and animals have shown that following tooth removal (loss), the alveolar ridge becomes markedly reduced. Attempts made to counteract such ridge diminution by installing implants in the fresh extraction sockets were not successful, while socket grafting with anorganic bovine bone mineral prevented ridge contraction. Aim: To examine whether grafting of the alveolar socket with the use of chips of autologous bone may allow ridge preservation following tooth extraction. Methods: In five beagle dogs, the distal roots of the third and fourth mandibular premolars were removed. The sockets in the right or the left jaw quadrant were grafted with either anorganic bovine bone or with chips of autologous bone harvested from the buccal bone plate. After 3 months of healing, biopsies of the experimental sites were sampled, prepared for buccal–lingual ground sections and examined with respect to size and composition. Results: It was observed that the majority of the autologous bone chips during healing had been resorbed and that the graft apparently did not interfere with socket healing or processes that resulted in ridge resorption. Conclusion: Autologous bone chips placed in the fresh extraction socket will (i) neither stimulate nor retard new bone formation and (ii) not prevent ridge resorption that occurs during healing following tooth extraction. To cite this article:
Araújo MG, Lindhe J. Socket grafting with the use of autologous bone: an experimental study in the dog.
Clin. Oral Impl. Res. 22 , 2011; 9–13.
doi: 10.1111/j.1600‐0501.2010.01937.x     

Alveolar ridge reconstruction and/or preservation using root form bioglass cones

Abstract. Extraction of a tooth necessitated by factors such as developmental problems, trauma, severe periodontal disease and endodontic problems often causes deformities of the residual alveolar ridge in the maxillary anterior region. These cases are usually difficult to restore prosthetically and they result in poor esthetics and insufficient occlusal function. This study investigated the efficacy of root form bioactive glass cones implanted into (a) artificial sockets produced by bone splitting of previous extraction sites (group BS) and (b) fresh extraction sockets (group FES), We included conventional extraction sockets sutured without implanting the root form bioactive glass cones as a control (group C). A total of 16 patients were treated for whom extractions had been indicated due to severe periodontitis, 6 patients with 7 implant sites having Class II or III alveolar ridge deformities comprised the BS group. 5 patients with 10 implant sites comprised the FES group. Group C, comprised 5 patients with 10 extraction sites. Alveolar ridge width and height measurements were obtained using study casts preoperatively, immediately postoperatively. and at 3 and 12 months after operation. In the BS group, while the width of the alveolar ridge increased by 2.8 ± 1.18mm immediately after ridge augmentation procedure and by 2.4±0.93 mm at 1 year after operation (p<0.01), the height of the alveolar ridge increased by 1.8±1.99 mm and 1.4±1.74 mm respectively (p<0.05). In the FES group, the differences between preoperative original ridge height and width and postoperative measurements were not statistically significant, which demonstrated the efficiency of this method in preserving the alveolar ridge. In group C, while alveolar ridge width after 12 months had not Significantly changed, alveolar ridge height decreased significantly (1.35±1.05 mm. p<0.01). After 12 months, no dehiscences were detected and the differences in height between the groups remained significant. The results of this study indicate that this procedure is efficient in reconstructing alveolar ridges deformed as a result of extraction, particularly relevant in relation to preparation for subsequent restorative treatment.