Evaluation of Freeze-Dried Dura Mater Allograft as a Collagen Based Barrier (an experimental animal study)

Freeze-dried dura mater allograft (FDDMA) was evaluated as a cost-effective collagenous barrier using an experimental animal model to determine its biocompatibility and 'cell-occlusivity' potential. The FDDMA was processed at the Civil Hospital Ahmedabad, in accordance with the guidelines provided by the South-Eastern Organ Procurement Foundation, U.S.A. Fifteen Charles Foster rats were selected for a study period of 9 weeks. The 1st set graft procedure was performed in an abdominal pouch and after 1 week bilateral mandibular defects were created. One defect was covered by the FDDMA barrier (2nd set graft procedure) and the other defect served as the control. The post operative autopsy and morphological and histological assessments were carried out at 2 and 4 weeks for the 1st set graft, and 3, 6 and 9 weeks for the 2nd set graft procedure. There was acceptance of the 2nd set graft in a pre-exposed animal and no significant inflammatory response. The processed FDDMA demonstrated optimal 'cell-occlusivity' potential for guided bone regeneration to take place in Charles Foster rats.     

The Masquelet Technique for Membrane Induction and the Healing of Ovine Critical Sized Segmental Defects

The healing of critical sized segmental defects is an ongoing clinical problem. No method has achieved pre-eminence. The Masquelet technique is a relatively new innovation involving the induction of a fibrous tissue membrane around the bone defect site taking advantage of the body’s foreign body reaction to the presence of a polymethylmethacrylate (PMMA) spacer. The aim of this study was to investigate the properties and characteristics of this induced membrane and its effectiveness when used in conjunction with allograft or an allograft/autograft mix as filler materials in an ovine critical sized defect model. The resultant induced membrane was found to be effective in containing the graft materials in situ. It was demonstrated to be an organised pseudosynovial membrane which expressed bone morphogenic protein 2 (BMP2), transforming growth factor- beta (TGFβ), vascular endothelial growth factor (VEGF), von Willerbrand factor (vWF), interleukin 6 (IL-6) and interleukin 8 (IL-8). While more new bone growth was evident in the test groups compared to the controls animals at 12 weeks, the volumes were not statistically different and no defects were fully bridged. Of the two graft material groups, the allograft/autograft mix was shown to have a more rapid graft resorption rate than the allograft only group. While the Masquelet technique proved effective in producing a membrane to enclose graft materials, its ability to assist in the healing of critical sized segmental defects when compared to empty controls remained inconclusive.     

Osteogenesis in cranial defects: reassessment of the concept of critical size and the expression of TGF-beta isoforms

Transforming growth factor-betas (TGF-beta) have been demontstrated to be upregulated during osteoblast function in vitro and during cranial suture fusion in vivo. The authors hypothesized that spontaneous reossification of calvarial defects was also associated with upregulation of TGF-beta. The present study was designed to (1) evaluate the concept of a critical-size defect within the calvaria in an adult guinea pig model and (2) investigate the association between the ossification of calvarial defects and TGF-beta upregulation. Paired circular parietal defects with diameters of 3 and 5 mm and single parietal defects with diameters of 8 or 12 mm were made in 45 six-month-old skeletally mature guinea pigs. Three animals per defect size were killed after survival periods of 3 days, 1 week, 4 weeks, 8 weeks, or 12 weeks. New bone ingrowth was evaluated by assessing for linear closure by a traditional linear method and by a modified cross-sectional area method using an image analysis system in which the thickness of new bone was taken into account. Immunohistochemistry was performed using rabbit polyclonal antibodies to localize TGF-beta1, -beta2, and -beta3. All specimens were photographed, and the intensity of immunostaining was graded based on subjective photographic assessment by three independent reviewers. No defect demonstrated any measurable bone replacement after a survival period of 3 days. All 3- and 5-mm defects were completely reossified after 12 weeks based on the linear analysis of new bone, indicating these defects to be less than critical size. However, new bone formation in the 5-mm defects never exceeded a mean of 40 percent by cross-sectional area of new bone. Percent of new bone formation by cross-sectional area was significantly higher within 3-mm defects than in all larger defects 4 weeks after the craniotomy, reaching a mean of 89 percent new bone by 12 weeks. Persistent gaps were noted on linear analysis of the 8- and 12-mm wounds by 12 weeks, and mean percent new bone by cross-sectional area remained below 30 percent. Immunolocalization demonstrated osteogenic fronts at the advancing bone edge and the endocranial side, in which the osteoblasts stained strongly for all isoforms of TGF-beta. The intensity of osteoblast expression waned considerably after the majority of the defect had reossified. These data indicate that histometric analysis based on cross-sectional area more accurately reflects the osteogenic potential of a cranial defect than does linear inspection of defect closure. Although the interpretation of immunolocalization studies is highly subjective, independent assessment by three reviewers indicates that isoforms of TGF-beta were upregulated during a limited "window" of time corresponding to the period of active calvarial reossification, and expression of TGF-beta corresponded to osteoblast activity within osteogenic fronts.     

Reconstructing Tumour Defects: Lyophilised, Irradiated Bone Allografts

Tumour excision leaves behind large defects. Allografts provide an excellent alternative to autografts without donor site morbidity and are especially useful in large defects or in children where the quantity of available autograft is limited. In this paper we discuss our experience with indigenously procured and processed lyophilised, irradiated bone allografts. Bone allografts were used in 41 patients. They were used morsellised and used in 32 cases. Of these, 25 cases were available for follow-up. These included 21 patients in whom the allograft was used in contained cavities. Complete incorporation of the graft was seen between 6 and 9 months in all these 21 patients. In 4 patients the allograft was layered onto autograft. In only one of these the allograft incorporated with the host bone. Struts were used in 9 cases (3 cases complete intercalary segmental defect, 3 cases of hemicortical defects, 2 cases of allograft-prosthesis composite around the hip, in 1 case an iliac-crest block was used to stop bleeding from an anterior sacral defect). Of these, 2 full segment struts showed no incorporation. Both these patients were on chemotherapy and radiotherapy. There was no follow-up in sacral defect case. All the other struts incorporated with the host bone within 6-9 months.In 5 cases there was sterile postoperative drainage. All these cases went on to uneventful. Deep infection was observed in 4 patients (10%). In one, the graft was removed, another settled uneventfully with subsequent incorporation of graft, and two have a persisting sinus but good incorporation.To restore part of the strength of the struts it was necessary to hydrate them for 30 min prior to use. Autogenous marrow or autograft was used to provide osteoinductive properties.Conclusion. In selected cases the lyophilised, irradiated bone allografts proved to be very useful in reconstruction of large tumour defects.     

The Use of Irradiated Allografts in Reconstruction of Tumor Defects – the Tata Memorial Hospital Experience

A Tissue Bank is a valuable adjunct to tumour management. In bone tumours, the defects produced by ablative surgery can be reconstructed using banked tissue, thereby obviating the donor site morbidity associated with autografts. Allografts are especially useful in large defects or in children where the quantity of available autograft is limited. The use of bone allografts in India has been limited by the availability of good quality, affordable grafts. In this article we share our experience with the use of indigenously produced allografts in limb salvage, as bone graft expanders and as struts. Lyophilised, irradiated bone allografts were morcellised and used in 32 patients. In 21 of these patients the allograft was used in contained cavities. Complete incorporation of the graft was seen between 6-9 months in all the 25 cases available for follow-up. In 4 patients the allograft was layered onto autograft. The allograft incorporated with the host bone in only one of these patients.Struts were used in 9 cases (3 cases complete intercalary segmental defect, 3 cases of hemicortical defects, 2 cases of allograft-prosthesis composite around the hip, 1 case an iliac-crest block was used to stop bleeding from an anterior sacral defect). Of these, no incorporation of the full segment struts was observed in 2 patients who were on chemotherapy and radiotherapy. The sacral defect case was lost to follow-up. All the other struts incorporated with the host bone within 6-9 months. In 5 cases there was sterile postoperative drainage. Overall infection was observed in 4 patients (10%). In one the graft was removed, another settled uneventfully with subsequent incorporation of graft, and two have a persisting sinus but good incorporation. Since radiation and lyophilisation are known to affect the material properties of bone, the grafts were rehydrated in saline for 30 minutes prior to transplantation. Autogenous marrow or autograft was used to provide osteoinductive properties. In selected cases the lyophilised, irradiated bone allografts proved to be clinically useful in the reconstruction of large tumour defects.     

Amniotic membrane transplantation for ocular surface reconstruction in neurotrophic corneal ulcera

The purpose of this study is to analyze clinical experience about the effects of human amniotic membrane transplantation in eyes with neurotrophic ulcers. In 11 eyes the application of amniotic membrane was performed since January 1999 because of neurotrophic ulcers. The follow up period was longer than 12 months: 19.7+/-6.0 months. The average healing period after the surgery was 1.6+/-0.6 weeks. All corneas were fluorescein negative even 12 months after operation. Visual acuity after the transplantation was similar to the one before the surgery in 8 eyes. In 3 eyes the visual acuity after the surgery was better than before. Amniotic membrane transplantation can be considered an effective alternative for treating persistent epithelial defects such as neurotrophic ulcers. It has some advantages over corneal transplantation: a relatively simple procedure, no allograft rejection and it could be particularly beneficial in countries where cornea shortage is apparent.     

Structural and functional healing of critical-size segmental bone defects by transduced muscle-derived cells expressing BMP4

BACKGROUND: Our previous studies have shown that muscle-derived cells, including a population of muscle stem cells, transduced with a retroviral vector expressing bone morphogenetic protein 4 (BMP4) can improve the healing of critical-size calvarial defects. However, we did not evaluate the functionality of the healed bone. The purpose of this study was to determine whether primary muscle-derived cells transduced with retroBMP4 can heal a long bone defect both structurally and functionally. METHODS: Primary muscle-derived cells were genetically engineered to express BMP4 and were implanted into 7-mm femoral defects created in syngeneic rats. Muscle-derived cells transduced with retroLacZ were used in the control group. Bone healing was monitored by radiography, histology, and biomechanical testing at designated time points. RESULTS: Most of the defects treated with muscle-derived cells expressing BMP4 formed bridging callous by 6 weeks after surgery, and exhibited radiographically evident union at 12 weeks after cell implantation. Histological analysis at 12 weeks revealed that the medullary canal of the femur was restored and the cortex was remodeled between the proximal and distal ends of each BMP4-treated defect. In contrast, the defects treated with muscle-derived cells expressing beta-galactosidase displayed nonunion at all tested time points. An evaluation of the maximum torque-to-failure in the treatment group indicated that the healed bones possessed 77 +/- 28% of the strength of the contralateral intact femora. Torsional stiffness and energy-to-failure were not significantly different between the treated and intact limbs. CONCLUSIONS: This study demonstrated that primary muscle-derived cells transduced with retroBMP4 can elicit both structural and functional healing of critical-size segmental long bone defects created in rats.     

Bone morphogenetic protein 2-induced cellular chemotaxis drives tissue patterning during critical-sized bone defect healing: an in silico study

Critical-sized bone defects are critical healing conditions that, if left untreated, often lead to non-unions. To reduce the risk, critical-sized bone defects are often treated with recombinant human BMP-2. Although enhanced bone tissue formation is observed when BMP-2 is administered locally to the defect, spatial and temporal distribution of callus tissue often differs from that found during regular bone healing or in defects treated differently. How this altered tissue patterning due to BMP-2 treatment is linked to mechano-biological principles at the cellular scale remains largely unknown. In this study, the mechano-biological regulation of BMP-2-treated critical-sized bone defect healing was investigated using a multiphysics multiscale in silico approach. Finite element and agent-based modeling techniques were combined to simulate healing within a critical-sized bone defect (5 mm) in a rat femur. Computer model predictions were compared to in vivo microCT data outcome of bone tissue patterning at 2, 4, and 6 weeks postoperation. In vivo, BMP-2 treatment led to complete healing through periosteal bone bridging already after 2 weeks postoperation. Computer model simulations showed that the BMP-2 specific tissue patterning can be explained by the migration of mesenchymal stromal cells to regions with a specific concentration of BMP-2 (chemotaxis). This study shows how computational modeling can help us to further understand the mechanisms behind treatment effects on compromised healing conditions as well as to optimize future treatment strategies.

     

Biological Healing of Large Diaphyseal Deep-frozen Allograft Transplants

The biological healing of large, deep-frozen, diaphyseal allografts was studied in 24 cats. Deep-frozen allograft stored at –80°C was used to replace a large defect, at least two-thirds of the cat's tibial diaphysis. Intra-medullary rod fixation was used. The healing was studied at observation periods of 4, 6, 8, 12, 16, 24 and 36 weeks. Biological parameters studied included microangiography for revascularisation and fracture healing, bone resorption, new bone formation and callus encasement. Deep-frozen allografts united without difficulty by 12 weeks. However, minimal revascularisation of the allograft occurred even at 9 months. Likewise, minimal biological repair activity was seen even at 9 months as shown by the parameters of bone resorption, cortical new bone formation and callus encasement. Biologically, deep-frozen cortical allografts remained inert for a long period of time in the adult cat.     

Improved osteogenesis in rat femur segmental defects treated with human allograft and zinc adjuvants

Bone allograft is widely used to treat large bone defects or complex fractures. However, processing methods can significantly compromise allograft osteogenic activity. Adjuvants that can restore the osteogenic activity of processed allograft should improve clinical outcomes. In this study, zinc was tested as an adjuvant to increase the osteogenic activity of human allograft in a Rag2 null rat femoral defect model. Femoral defects were treated with human demineralized bone matrix (DBM) mixed with carboxy methyl cellulose containing ZnCl₂ (0, 75, 150, 300 µg) or Zn stearate (347 µg). Rat femur defects treated with DBM-ZnCl₂ (75 µg) and DBM-Zn stearate (347 µg) showed increased calcified tissue in the defect site compared to DBM alone. Radiograph scoring and µCT (microcomputed tomography) analysis showed an increased amount of bone formation at the defects treated with DBM-Zn stearate. Use of zinc as an adjuvant was also tested using human cancellous bone chips. The bone chips were soaked in ZnCl₂ solutions before being added to defect sites. Zn adsorbed onto the chips in a time- and concentration-dependent manner. Rat femur defects treated with Zn-bound bone chips had more new bone in the defects based on µCT and histomorphometric analyses. The results indicate that zinc supplementation of human bone allograft improves allograft osteogenic activity in the rat femur defect model.     

改良Masquelet技术治疗胫骨感染性缺损的临床疗效分析

摘要 目的：探讨和分析使用改良Masquelet技术在胫骨感染性缺损中的临床疗效。方法：回顾性分析2018.01-2022.01范围内,使用改良Masquelet治疗胫骨感染性缺损的共计21患者。通过骨愈合(Samantha X 线评分),软组织愈合,感染控制,下肢功能,并发症等方面对临床疗效进行评价。结果：21例患者均获得完整随访,随访时间为12-36个月,平均为18.6个月。所有患者均达到骨愈合标准（3.2±8.3个月）。Samantha X 线评分：1例为4分,8例为5分,12例6分。PALEY功能评分为：优9人,良11人,可1人,差0人,优良率为95.2%。患者中均未出现严重并发症(P>0.05)。结论：在胫骨感染性缺损的治疗中,改良Masquelet技术是一种简单,安全,有效的治疗方法,在临床中可以进一步推广。     

Applications of a mouse model of calvarial healing: differences in regenerative abilities of juveniles and adults

Young children are capable of healing large calvarial defects, whereas adults lack this endogenous osseous tissue-engineering capacity. Despite the important clinical implications, little is known about the molecular and cell biology underlying this differential ability. Traditionally, guinea pig, rabbit, and rat models have been used to study the orchestration of calvarial healing. To harness the research potential of knockout and transgenic mice, the authors developed a mouse model for calvarial healing. Nonsuture-associated parietal defects 3, 4, and 5 mm in diameter were made in both juvenile (6-day-old, n = 15) and adult (60-day-old, n = 15) mice. Calvariae were harvested after 8 weeks and analyzed radiographically and histologically. Percentage of healing was quantified using Scion Image software analysis of calvarial radiographs. A significant difference in the ability to heal calvarial defects was seen between 6-day-old and 60-day-old mice when 3-, 4-, or 5-mm defects were created. The authors' analysis revealed that juvenile mice healed a significantly greater percentage of their calvarial defects than adult mice (juvenile mean percentage of healing: 3-mm defects, 59 percent; 4-mm defects, 65 percent; 5-mm defects, 44 percent; adult mean percentage of healing: <5 percent in all groups; p < 0.05). All three defect sizes were found to be critical in the adult, whereas significant healing was seen regardless of the size of the defect in juvenile mice. The establishment of this model will facilitate further, detailed evaluation of the molecular biology underlying the different regenerative abilities of juvenile versus adult mice and enhance research into membranous bone induction by making available powerful tools such as knockout and transgenic animals.     

水激光与超声洁治对中度慢性牙周炎的疗效对比

目的:探讨水激光与超声洁治对中度慢性牙周炎的疗效。方法:选取81例中度慢性牙周炎患者,年龄27-62岁,随机分为两组:激光组(41例)采用水激光治疗,超声组(40例)采用超声洁治法治疗。通过患者治疗后1个月,3个月的菌斑指数(plaque index,PLI),牙龈指数(gingival index,GI),牙周袋深度(probing depth,PD),牙周附着水平(clinical attachment level,CAL),治疗过程中的VAS评分等观察指标,对水激光与超声洁治进行疗效对比。结果:与基线各项牙周指数相比,激光组和超声组治疗后1个月,3个月的各项牙周指数均明显降低(P0.05)。与超声组相比,激光组治疗后1个月的GI值明显低于超声组,治疗后1个月和3个月的PD值和CAL值均低于超声组(P0.05)。治疗前,两组VAS评分相比,差异没有统计学意义(P0.05),治疗后,激光组的VAS评分明显低于超声组(P0.05)。结论:水激光治疗中度慢性牙周炎,治疗过程痛觉感受轻微,能轻易清除引起炎症的牙石及菌斑,促进牙周组织愈合。     

Bone defect repair in rat tibia by TGF-β1 and IGF-1 released from hydrogel scaffold

Bone repair is one of the major challenges facing reconstructive surgery. Bone regeneration is needed for the repair of large defects and fractures. The ability of TGF-β1 and IGF-1 incorporated into hydrogel scaffold to induce bone regeneration was evaluated in a rat tibia segmental defect model. External fixation was performed prior to the induction of the segmental bone defect in order to stabilize the defect site. Hydrogel scaffold containing either TGF-β, IGF-1, TGF-β + IGF-1, hydrogel containing saline or saline, were inserted in the defect. Calcified material was observed in the defects treated with TGF-β 2 weeks following the start of treatment. Bone defects treated with TGF-β, IGF-1 or TGF-β + IGF-1 revealed significant bone formation after 4 and 6 weeks when compared to the control specimens. X-ray images showed that solid bone was present at the defect site after 6 weeks of treatment with TGF-β or TGF-β + IGF-1. A less pronounced bone induction was observed in the control specimens and bones treated with IGF-1. Percent closure ratio of bone defects after 6 weeks were 40, 80, 89, and 97% for saline, hydrogel, IGF-1, TGF-β and IGF-1 + TGF-β groups, respectively. It is concluded that hydrogel scaffold can serve as a good osteoconductive matrix for growth factors, and that it provides a site for bone regeneration and enhances bone defect healing and could be used as alternative graft material. This revised version was published online in July 2006 with corrections to the Cover Date.     

A novel nonsurgical therapy for peri-implantitis using focused pulsed electromagnetic field: A pilot randomized double-blind controlled clinical trial

Pulsed electromagnetic field (PEMF) therapy modulates the immune response and is successfully used in orthopedics to treat osteoarthritis and improve bone regeneration. This may suggest that this treatment may consequently reduce peri-implant soft tissue inflammation and marginal bone loss. To compare clinical, radiographic, and immunological results following nonsurgical treatment for peri-implantitis with or without PEMF therapy. Patients with peri-implantitis were included: pocket probing depth (PPD) between 6 and 8 mm with bleeding on probing (BOP); crestal bone loss between 3 and 5 mm. A novel healing abutment that contained active (test) or inactive (control) PEMF was connected. PEMF was administered via the abutment at exposure ratio of 1/500–1/5000, intensity: 0.05–0.5 mT, frequency: 10–50 kHz for 30 days. Nonsurgical mechanical implant surface debridement was performed. Patients were examined at baseline, 1 and 3 months. Clinical assessment included: plaque index, BOP, PPD, recession, and bone crest level which was radiography measured. Samples of peri-implant crevicular fluid were taken to analyze interleukin-1β (IL-1β). Twenty-three patients (34 implants; 19 control, 15 test) were included. At the follow-up, mean crestal bone loss was lower in the test group at 1 and 3 months (2.48 mm vs. 3.73 mm, p < 0.05 and 2.39 vs. 3.37, p < 0.01). IL-1β levels were also lower in the test group at 2 weeks (72.86 pg/mL vs. 111.7, p < 0.05). Within all the limitation of this preliminary study, the test group improved clinical parameters after a short-term period compared to the control group.     

Fresh cortical autograft versus fresh cortical allograft effects on experimental bone healing in rabbits: radiological, Histopathological and Biomechanical evaluation

Bone grafting is used to enhance healing in osteotomies, arthrodesis, and multifragmentary fractures and to replace bony loss resulting from neoplasia or cysts. They are source of osteoprogenitor cells and induce bone formation and provide mechanical support for vascular and bone ingrowth. Autografts are used commonly but quantity of harvested bone is limit. This study was designed to evaluate fresh cortical autograft and allograft effects on bone healing process. Twenty male White New Zealand rabbits were used in this study. In autograft group the defect was filled by fresh autogenous cortical graft, in allograft group the defect was filled by a segment of fresh allogenous cortical bone which was harvested at the time of surgery during the creation of radius bone defect. Then all surface soft tissue, such as muscle attachments, were removed from the harvested bone and changed between rabbits as a fresh allogenous cortical bone graft and was fixed by cercelage wire. Radiological, histopathological and biomechanical evaluations were performed blindly and results scored and analyzed statistically. Statistical tests did not support significant differences between two groups at the 14th and 56th postoperative day radiographically (P > 0.05). There was a significant difference radiologically for the 28th and the 42nd postoperative (P < 0.05). Autograft was superior to allograft at the 28th and 42nd postoperative day in radiological evaluation (P < 0.03). Histopathological and biomechanical evaluation revealed no significant differences between two groups.     

Efficacy of Ankaferd Blood Stopper on bone healing in diabetic rats: a stereological and histopathological study

We evaluated the effects of Ankaferd Blood Stopper (ABS) and routine antibiotic prophylaxis (AP) on early healing of bone defects in diabetic rats. We used 48 rats in the study. Diabetes was induced in 24 rats using streptozotocin; the remaining 24 healthy untreated rats served as controls. Twelve of the diabetic rats and 12 of the healthy rats were treated with AP for 3 days before surgery. Bilateral bone defects were created in the mandible of all animals. ABS was applied to the defects on the left sides of the mandibles, while nothing was applied to the right sides. Animals were sacrificed on days 7 and 14 after operation and examined for histopathology and by stereology. The volume of newly formed bone was significantly less in the diabetic rats on both days 7 and 14. Local administration of ABS significantly increased the mean volume of newly formed bone in both diabetic and nondiabetic rats at days 7 and 14. No significant difference in new bone formation was found between AP and ABS treatment in diabetic rats. Both AP and local administration of ABS have beneficial effects on bone healing in diabetic animals.     

On the influence of mechanical conditions in osteochondral defect healing

Despite the introduction of new surgical techniques, the treatment of cartilage defects remains challenging. Delay or complete failure of cartilage healing is associated with problems in biological regeneration. The influence of mechanical conditions on this process, however, remains unevaluated. Osteochondral defects were generated on the left femoral condyle in 18 Yucatan minipigs. After 4, 6 and 12 weeks the defect filling, trabecular orientation and bone density were compared to the intact contralateral side. The mechanical straining during this period was then analyzed using an adaptive finite element technique. Histologically, the osteochondral defects showed bone resorption at the base and bone formation from the circumference. At 12 weeks, the macroscopically healed specimens showed fibrous cartilage formation, a minimally organized trabecular structure and increased trabecular volume fraction compared to the controls (p < 0.002). The amount of cancellous, cartilagineous, and fibrous tissue and the defect size as measured in histomorphometric analysis for the three time points (4, 6 and 12 weeks) was comparable in magnitude to that predicted by finite element analysis. The simulated osteochondral healing process was not fully capable of re-establishing a hyaline-like cartilage layer. The correlation between simulation and histology allows identification of mechanical factors that appear to have a larger impact on the healing of osteochondral defects than previously considered.     

Effect of a subgingival chlorhexidine chip on the clinical parameters and the levels of alkaline phosphatase activity in gingival crevicular fluid during the non-surgical treatment of periodontitis

The main therapeutic approaches for inflammatory periodontal diseases include the mechanical treatment of root surfaces. Multi-center clinical trials have demonstrated that the adjunctive use of a chlorhexidine (CHX) chip is effective in improving clinical results compared to scaling and root planing (SRP) alone. However, some recent studies failed to confirm these clinical results, nor have any data been reported regarding the capability of the CHX chip in affecting the activity of alkaline phosphatase (ALP) in the gingival crevicular fluid (GCF). This enzyme has been related to a condition of destructive activity of periodontitis. The aim of this study is to provide further data on the clinical and biochemical effects of CHX chips when used as an adjunct to SRP. Eighty-two systemically healthy patients, aged 31-63, with moderate and advanced periodontitis were recruited from the departments of Periodontology of the University of Chieti. In each patient 2 experimental sites, located in two symmetric quadrants, were chosen with a probing depth of > or = 5 mm and bleeding on probing. The 2 sites were selected randomly at the split-mouth level; control sites received SRP alone, and test sites SRP plus 1 CHX chip. Clinical indices, including probing depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), and the ALP activity in GCF were evaluated at baseline and after 6 months. Alkaline phosphatase activity was assayed spectrophotometrically. The PPD and CAL were significantly lower at 6 months as compared to the baseline scores in both treatments (p less than 0.01). The PPD reduction was 2.7 mm in the CHX+SRP group and 1.9 mm in the SRP alone group. The CHX+SRP group showed a significantly greater gain of clinical attachment (mean: 1.4 mm) in comparison with the SRP group (mean: 0.9; p less than 0.05). No differences were observed in the decrease of the percent of BOP-positive sites between the experimental groups. Conversely, the CHX+SRP group underwent a significantly greater decrease (p less than 0.01) of the GCF-ALP activity 6 months after treatment in comparison with the SRP alone group. The adjunctive use of the CHX chip resulted in a significant improvement of pocket reduction and clinical attachment gain as compared with SRP alone. These results were concomitant with a significantly greater reduction of the GCF-ALP activity levels.     

Reconstruction of orbital floor fracture using solvent-preserved bone graft

The orbital floor is one of the most frequently damaged parts of the maxillofacial skeleton during facial trauma. Unfavorable aesthetic and functional outcomes are frequent when it is treated inadequately. The treatment consists of spanning the floor defect with a material that can provide structural support and restore the orbital volume. This material should also be biocompatible with the surrounding tissues and easily reshaped to fit the orbital floor. Although various autografts or synthetic materials have been used, there is still no consensus on the ideal reconstruction method of orbital floor defects. This study evaluated the applicability of solvent-preserved cadaveric cranial bone graft and its preliminary results in the reconstruction of the orbital floor fractures. Twenty-five orbital floor fractures of 21 patients who underwent surgical repair with cadaveric bone graft during a 2-year period were included in this study. Pure blowout fractures were determined in nine patients, whereas 12 patients had other accompanying maxillofacial fractures. Of the 21 patients, 14 had clinically evident diplopia (66.7 percent), 12 of them had enophthalmos (57.1 percent), and two of them had gaze restriction preoperatively. Reconstruction of the floor of the orbit was performed following either the subciliary or the transconjunctival approach. A cranial allograft was placed over the defect after sufficient exposure. The mean follow-up period was 9 months. Postoperative diplopia, enophthalmos, eye motility, cosmetic appearance, and complications were documented. None of the patients had any evidence of diplopia, limited eye movement, inflammatory reactions in soft tissues, infection, or graft extrusion in the postoperative period. Providing sufficient orbital volume, no graft resorption was detected in computed tomography scan controls. None of the implants required removal for any reason. Enophthalmos was seen in one patient, and temporary scleral show lasting up to 3 to 6 weeks was detected in another three patients. Satisfactory cosmetic results were obtained in all patients. This study showed that solvent-preserved bone, which is a nonsynthetic, human-originated, processed bioimplant, can be safely used in orbital floor repair and can be considered as another reliable treatment alternative.