Comparison of different bone substitutes in the repair of rat calvaria critical size defects: questioning the need for alveolar ridge presentation

OBJECTIVE

This study aimed to evaluate the effectiveness of biomaterials in bone healing of critical bone defects created by piezoelectric surgery in rat calvaria.

METHOD AND MATERIALS

Histomorphologic analysis was performed to assess bone regeneration and tissue response. Fifty animals were randomized into five groups with one of the following treatments: Control group (n = 10), spontaneous blood clot formation with no bone fill; BO group (Bio-Oss, Geistlich Pharma; n = 10), defects were filled with bovine medullary bone substitute; BF group (Bonefill, Bionnovation; n = 10), defects were filled with bovine cortical bone substitute; hydroxyapatite group (n = 10), defects were filled with hydroxyapatite; calcium sulfate group (n = 10), defects were filled with calcium sulfate. Five animals from each group were euthanized at 30 and 45 days. The histomorphometry calculated the percentage of the new bone formation in the bone defect.

RESULTS

All data obtained were evaluated statistically considering P < .05 as statistically significant. The results demonstrated the potential of all biomaterials for enhancing bone regeneration. The findings showed no statistical differences between all the biomaterials at 30 and 45 days including the control group without bone grafting.

CONCLUSION

In conclusion, the tested biomaterials presented an estimated capacity of osteoconduction, statistically nonsignificant between them. In addition, the selection of biomaterial should consider the specific clinical aspect, resorption rates, size of the particle, and desired bone healing responses. It is important to emphasize that in some cases, using no bone filler might provide comparable results with reduced cost and possible complications questioning the very frequent use of ridge presentation procedures.

Vacuum sealing drainage combined with eggshell-like debridement antibiotic-loaded calcium sulphate for calcaneal osteomyelitis

BACKGROUND

To compare the clinical efficacy of vacuum sealing drainage, eggshell-like debridement combined with antibiotic calcium sulphate implantation and conventional debridement combined with antibiotic calcium sulphate implantation in the treatment of calcaneal osteomyelitis.

METHODS

Sixty-six patients with calcaneal osteomyelitis who were treated in our department between January 2017 and August 2021 were included in this study. Thirty-one patients underwent VSD and eggshell-like debridement combined with antibiotic calcium sulphate implantation. Thirty-five patients underwent conventional debridement combined with antibiotic calcium sulphate implantation. The inflammatory markers, operation time, wound healing time, hospital stay, full weight bearing time after operation, recurrence rate of infection, complications, and American Orthopedic Foot and Ankle Society (AOFAS) scores were compared between the two groups.

RESULTS

The operation time and full weight bearing time after operation of observation group were longer than that of control group. Compared with preoperative results, WBC, ESR, CRP and PCT in both groups were significantly decreased at 14 days after operation, and there was no statistical significance between the two groups. The wound healing time and hospital stay in the observation group were shorter than those in the control group (P < 0.05). There were four patients with aseptic exudation in the observation group and ten patients with aseptic exudation in the control group, and the wounds healed well after multiple dressing changes. Seven patients in the observation group underwent secondary bone grafting due to bone defects, and four patients in the control group received secondary bone grafting due to bone defects. In the observation group, three patients received debridement combined with antibiotic calcium sulphate implantation again due to recurrent infection, compared with seven patients in the control group. One year after operation, the observation group had a better AOFAS scores than the control group, especially in terms of foot function (P < 0.05).

CONCLUSION

Compared with conventional debridement and antibiotic calcium sulphate implantation, VSD and eggshell-like debridement combined with antibiotic calcium sulphate implantation in the treatment of calcaneal osteomyelitis can shorten the wound healing and hospital stay of patients, reduce postoperative aseptic exudation complications and infection recurrence rate, and better preserve the foot function, which is a simple and effective method.

[Effect of acrylic bone cement mixed with calcium sulfate combined with percutaneous kyphoplasty in the treatment of osteoporotic fractures]

OBJECTIVE

To investigate the clinical efficacy of acrylic cement (PMMA) mixed with calcium sulfate combined with percutaneous kyphoplasty (PKP) in the treatment of osteoporotic fracture (OVCF).

METHODS

The clinical data of 191 patients with OVCF treated with PKP from January 2020 to March 2021 were retrospectively analyzed. Among them, 82 patients with 94 vertebral bodies were treated with PMMA mixed with calcium sulfate as the observation group, and 109 patients with 125 vertebral bodies were treated with pure PMMA as the control group. Among the 82 patients in the observation group, there were 16 males and 66 females, with a mean age of (75.35±11.22) years old, including 36 thoracic vertebrae and 58 lumbar vertebrae. In the control group, there were 109 patients, 22 males and 87 females, with an average age of (74.51±9.21) years old, including 63 thoracic vertebrae and 62 lumbar vertebrae. The visual analog scale (VAS) before operation and 1 day, 3 months and 1 year after operation were calculated. The Oswestry disability index (ODI), Cobb's angle, vertebral body height and the probability of postoperative bone cement leakage were used to analyze the efficacy of the two groups.

RESULTS

All the patients were followed up for more than one year. Compared with the control group, there was no significant difference in operation time, bleeding volume and bone cement injection volume between the two groups(P>0.05), while the leakage rate of bone cement was significantly lower in the observation group (P<0.05). In addition, there was no significant difference in VAS, ODI, Cobb angle, and vertebral body height between the two groups before operation, and 1 day, 3 months, and 1 year after operation (P>0.05), but each index was improved compared with that before operation (P<0.05).

CONCLUSION

PMMA mixed with calcium sulfate has equivalent efficacy in treating OVCF than PMMA alone, but can effectively reduce the probability of cement leakage.

Calcium sulfate in the management of osteomyelitis: A systematic review and meta-analysis of comparative studies

BACKGROUND

Calcium sulfate (CS) is used extensively as an antibiotic carrier in the treatment of chronic osteomyelitis, largely due to its biodegradable nature. The aim of this systematic review and meta-analysis is to analyze the comprehensive performance of CS in the literature when compared to other biomaterials or treatments for osteomyelitis. We assess the ability of CS to eradicate infection and achieve other key clinical outcomes.

METHODS

All studies comparing the use of CS to any other surgical technique for the surgical management of osteomyelitis were eligible for analysis. The indication for surgery in each case was chronic osteomyelitis. The minimum dataset required included details regarding infection eradication rates, union rates (in cases of nonunion), all-cause revision surgery and wound leakage. The primary outcome variables of concern were infection eradication and all-cause revision surgery. Secondary outcome variables included union and wound leakage. A random effects meta-analysis was performed.

RESULTS

Five studies were deemed eligible for inclusion. The CS group had a significantly higher rate of infection eradication (P = .013) and a significantly lower rate of revision for all causes (P < .001) when compared to the comparative group. In total, the CS group had 30 cases of wound leakage compared to 8 in the comparative group (P = .064).

CONCLUSION

CS demonstrates superior rates of infection eradication and all-cause revision when compared with alternative treatment methods for chronic osteomyelitis. While the current study reports on differing but nonsignificant rates of wound leakage between CS and other treatments, future studies are required to accurately investigate this clinically important complication.

Combining Stellate ganglion block and intravenous regional anesthesia to treat complex regional pain syndrome: A 19-years' experience in a tertiary center

OBJECTIVES

To study reduction in pain score after treatment with intravenous regional anesthesia (IVRA) and Stellate ganglion block (SGB) combination on complex regional pain syndrome (CPRS) patients and to quantify patients' satisfaction with treatment and occurrence of complications.

METHODS

This is a record-based retrospective review carried out in 2020, targeting patients treated in the University of Jordan Hospital, Amman, Jordan, over the years 2002-2020.

RESULTS

Among 99 patients, a significant drop in pain scores occurred in 88% of the patients' sample. Gender, age, type of CRPS, and duration of symptoms didn't affect statistical results. An average of 8.6 sessions needed to achieve 50% drop in pain score, and 2-3 sessions for first clinical improvement. Patients with previous application of plaster of Paris had increased success rates.

CONCLUSION

We find it practical, inexpensive, safe, and straightforward to combine SGB with IVRA for CRPS patients.

Increasing Lateral Ridge Width for Implant Placement Using Calcium Sulphate Bone Cement Technique

Dental implant practitioners are often faced with a presentation of a narrow crest, making it difficult or impossible for implant placement and requiring modification of the ridge to allow implants to be utilized. Many different factors need to be considered when choosing the technique to expand the ridge laterally. Ideally, the technique should facilitate the goal of ridge width increase while reducing inflammation and postoperative pain for the patient. In this study, patients were treated for lateral ridge augmentation to improve ridge width using a calcium sulphate-based bone cement with a protocol that does not require membrane placement at the time of grafting. This minimally invasive, relatively economical surgical technique is aimed at improving postoperative comfort for patients while permitting widening of the lateral ridge.

Development and current use of local antibiotic carriers in spondylodiscitis : Pilot study on reduction of duration of systemic treatment

BACKGROUND

The current study situation regarding the duration of systemic antibiotic treatment for spondylodiscitis is inhomogeneous and varies between 4-12 weeks. Due to the many undesirable side effects the aim is to achieve complete healing without recurrence or hematogenous scatter within the shortest possible period of time. The present pilot study investigated whether the additional application of a local antibiotic carrier to the surgically treated intervertebral disc space can contribute to a further reduction of treatment duration.

MATERIAL AND METHODS

In the pilot study 20 patients with acute spondylodiscitis and indications for surgical intervention were included. Surgical treatment was carried out by dorsal instrumentation, radical debridement of the site of infection, and cage interposition in the affected disc space. The remaining disc space was filled with homologous cancellous bone and antibiotic-loaded calcium sulfate hydroxyapatite pellets. A classification into a long-term and a short-term antibiotic group was performed. Both groups initially received a 10-day parenteral antibiotic administration. This was followed by oral antibiotics for 2 or 12 weeks, depending on the group. During the 12-month follow-up inflammation parameters, the local infection situation as well as the bony fusion and antibiotic tolerance were regularly checked.

RESULTS

The average age of the patients was 66.7 ± 11.2 years. Intraoperative detection of pathogens was successful in 65%. In 60% the antibiotic carrier was loaded with gentamicin, in 40% with vancomycin. At follow-up, all patients except one in the short-term antibiotic group had inflammation parameters within the normal range after 3 months. In the long-term antibiosis group, two patients still showed elevated infection values after 3 months, otherwise the values were within the normal range. After 12 months a complete cure of the infection was achieved in all patients. Antibiotic treatment intolerance occurred in 10% of the short-term antibiotic group and in 50% of the long-term group.

CONCLUSION

The results of the present pilot study show that with the additional use of absorbable local antibiotic carriers in the surgical treatment of bacterial spondylodiscitis it is possible to shorten the duration of systemic antibiotic treatment to 3 weeks. This can reduce the side effects and incompatibility of treatment and still achieve similar healing results.

Calcium sulphate for control of bleeding after oral surgery in anticoagulant therapy patients

Control of bleeding after oral surgery is mandatory in patients taking anticoagulants. There are different haemostatic measures to prevent post-surgical bleeding. The aim of the present paper is to study the use of a haemostatic agent, calcium sulphate (CaS) (P30, Ghimas, Bologna, Italy) for controlling post-surgical bleeding in a group of patients treated with warfarin therapy for thromboembolic states. Twenty teeth (12 mandibular molars, 8 maxillary molars) in 20 patients (14 male and 6 females) with a mean age of 54.3 years (±10.3 years) were included in the study. The patients were divided into 2 groups; in the study group of 10 patients calcium sulphate was used in layers to fill the socket after extraction, while for the 10 patients in the control group put a gauze with tranexamic acid was put in the extraction site immediately after extraction, and half an hour after extraction. The outcome was bleeding in subsequent days. Bleeding at post-operative day 1 was significant in 5 patients of the control group, however, in the study group treated with calcium sulfate there was no bleeding in any patient (p value 0.0055). CaS demonstrated to be a good haemostatic agent for controlling bleeding after oral surgery in patients taking anticoagulants.

Ephedra sinica Stapf and Gypsum Attenuates Heat-Induced Hypothalamic Inflammation in Mice

Ephedra sinica Stapf (EH) exert toxic effects, such as excitability, cardiac arrhythmia, and others. On the contrary, in traditional herbal medicine, EH and gypsum (GF) are used most often to treat symptoms caused by external stressors. The hypothalamus plays a crucial role in thermal homeostasis. Inflammatory response in the hypothalamus by thermal stressors may affect thermal and energy homeostasis. This study investigates the effect of EH and GF against heat-induced mouse model. Mice were divided into four groups: saline, saline plus heat, EH plus heat, and GF plus heat treated groups. Heat stress was fixed at 43 °C for 15 min once daily for 3 days. Weight and ear and rectal temperature measurements were made after terminating heat stress. Hypothalamus tissue was collected to evaluate the HSP70, nuclear factor kappa-Β (NF-kB), and interleukin (IL)-1β protein expression levels. EH and GF treatment suppressed the increased body temperature. EH significantly ameliorated heat-induced body weight loss, compared to gypsum. Regulatory effects of EH and GF for body temperature and weight against heat stress were mediated by IL-1β reduction. EH showed significant HSP70 and NF-kB inhibition against heat stress. EH and GF contribute to the inhibition of heat-induced proinflammatory factors and the promotion of hypothalamic homeostasis.

[Prophylactic application of medicated calcium sulphate in uncemented total hip prosthesis]

The increase in total hip arthroplasty occurs by many factors, such as increasing life expectancy, improving surgical technique as well as innovating the design and implant material. However, despite technological advances, peri-prosthetic infection has remained one of the most devastating complications. This study evaluates the prophylactic application of calcium sulfate pearls medicated in the femoral canal and acetabular surface to prevent peri-prosthetic infections in patients who underwent total uncemented primary hip arthroplasty against a control group by measuring acute phase reactants. 146 patients, 67 were applied calcium sulfate pearls medicated and 79 prophylactic antibiotic intravenous in the period from 2013 to 2016. To perform the diagnosis of peri-prosthetic infection was assessed PCR associated with VSG, communication between fistula and prostheses and positive culture in 2 or more different sites. There was a decrease in the values of acute-phase reactants in patients who were given calcium sulfate pearls. 14 patients presented infection in the control group and 3 in the study group. The prophylactic use of calcium sulphate pearls within the medullary canal and acetabular surface is an option for the prophylaxis of peri-prosthetic infections, however the study deserves follow-up with more patients.

Long-term Follow-up of the Use of a Synthetic Bone Graft Composite in the Surgical Management of Primary Bone Tumors

The surgical management of benign and benign aggressive bone tumors typically involves intralesional curettage and reconstruction of the resulting defect with cement or bone graft material. At the authors' institution, an injectable synthetic calcium sulfate-calcium phosphate composite is now the standard graft material for these cases. This study reports the long-term follow-up, specifically the stability of bone regeneration, for the use of the synthetic graft material for oncologic reconstruction. Fourteen patients who underwent intralesional curettage of a primary bone tumor followed by cavitary reconstruction with synthetic graft material who had at least 4-year follow-up were identified from an institutional orthopedic oncology database. Clinical outcome data, focusing on long-term clinical and radiographic features of the reconstruction, were extracted from electronic and paper medical records. Seven females and 7 males were included (mean age at surgery, 28.1 years; range, 13-64 years). Follow-up ranged from 50 to 105 months (mean, 68 months). Most surgical reconstructions were done for the lower limb (n=11), and giant cell tumor of bone was the most common tumor treated. The mean amount of synthetic graft material used was 18.6 cm³. Complete radiographic resorption and new bone incorporation was observed within the first year, and bone remodeling was complete in all patients. Bone remodeling remained stable throughout the longer-term follow-up (ie, up to 9 years). The use of an injectable synthetic calcium sulfate-calcium phosphate composite is a viable option in the reconstruction of cavitary bone defects following intralesional curettage of primary benign bone tumors. This reconstruction technique was safe, with no long-term complications, and led to complete radiographic resorption and new bone incorporation with long-lasting stability. [Orthopedics. 2018; 41(6):e868-e875.].

Surgical treatment for symptomatic non-ossifying fibromas of the lower extremity with calcium sulfate grafts in skeletally immature patients

BACKGROUND

Non-ossifying fibromas (NOFs) are common benign bone lesions found in children and adolescents. They usually involve metaphysis of long bones, tend to gradually disappear with age and usually do not require surgery, while they are not associated with pathological fractures. The aim of this study was to evaluate the outcome and efficacy of a single-stage procedure, comprising curettage of the lesion and calcium sulfate pellet (CaSP) grafting, in skeletally immature patients with large, symptomatic NOF of the lower extremity, and the possible limitations of the procedure.

METHODS

Nine skeletally immature patients with symptomatic NOF of the lower extremity were treated between 2013 and 2016. Details of age, history of presentation, location and size (in mm) of the lesion, histology and follow-up details were recorded. Lesions were classified in Ritschl radio-morphological stages. CaSP integration was assessed by Irwing's classification. The average size of lesions was 54.6 mm in length (range 31-95). All lesions were symptomatic. The average bone expansion in relation to the bone diameter was 67.4% in the transversal plane (range 31-100) and 77.8% in the sagittal plane (range 55-100). Mean patient age at time of treatment was 9.8 years (range 7-14); mean follow-up was 2 years (range 2-4). All the patients were symptomatic, and 8 out of 9 (89%) NOFs were Ritschl type B. All the patients were treated surgically with a single-step approach, as described.

RESULTS

On average, 86 mL of CaSPs was used per case (range 10-250). None of the patients required internal fixation. At last follow-up visit, CaSPs were fully incorporated in all the patients according to Irwing's classification (Stage 3). No serous drainage from wounds was recorded in any of the patients. No cases of pathological fracture, bone deformity, growth arrest or growth disturbance or infection were observed. At last follow-up visit, all the patients had resumed full sport and daily life activities.

CONCLUSIONS

CaSPs offer a safe, cheap, convenient alternative to the autograft as an implant substitute that helps regeneration of bone in the defects produced by curettage of large, symptomatic NOFs. Chemical cauterization of bone walls does not interfere with CaSP integration into bone tissue.

The effect of temporary restorative materials on fracture resistance of endodontically treated teeth

This study was designed to investigate the fracture strength of endodontically treated teeth temporarily restored with some commonly used interim materials. Of 90 extracted maxillary premolars used in this study, 15 were left intact as the positive control. Endodontic treatment was performed on the remaining 75 teeth. The endodontically treated teeth were then randomly assigned to 5 groups (n = 15). One group was not restored and served as the negative control. In the remaining 4 experimental groups, the teeth were restored with a temporary cement: Zonalin, IRM, Coltosol, or Fuji II LC resin-modified glass ionomer (RMGI). The fracture strengths of all teeth were measured with a universal testing machine. The fracture strength of teeth restored with RMGI was significantly greater than that of other groups (P < 0.001), including intact teeth (P = 0.025). The fracture strength of teeth restored with other temporary materials was significantly lower than that of intact teeth (P < 0.05) but not significantly different from that of the negative control. From a structural resistance standpoint, RMGI may be the best choice for short-term temporary restoration of endodontically treated teeth. Other types of temporary restorative material had no reinforcing effect on tooth structure.

[PHYSICAL PROPERTIES OF PLASTER BANDAGES]

The physical properties of plaster bandages are a very important factor in achieving the basic functions of immobilization (maintaining bone fragments in the best possible position), which directly affects the speed and quality of fracture healing. This paper compares the differences between the physical properties of plaster bandages (mass, specific weight, drying rate, elasticity and strength) and records the differences in plaster modeling of fast bonding 10 cm wide plaster bandages, from three different manufacturers: Safix plus (Hartmann, Germany), Cellona (Lohman Rauscher, Austria) and Gipsan (Ivo Lola Ribar ltd., Croatia). Plaster tiles from ten layers of plaster, dimension 10 x 10 cm were made. The total number of tiles from each manufacturer was 48. The water temperature of 22 °C was used for the first 24 tiles and 34 'C was used for the remainder. The average specific weight of the original packaging was: Cellona (0.52 g/cm3), Gipsan (0.50 g/cm3), Safix plus (0.38 g/cm3). Three days after plaster tile modeling an average specific weight of the tiles was: Gipsan (1.15 g/cm3), Safix plus (1.00 g/cm3), Cellona (1.10 g/cm3). The average humidity of 50% for Safix plus and Cellona plaster tiles was recorded 18 hours after modeling, while for the Gipsan plaster tiles, this humidity value was seen after 48 hours. On the third day after plaster modeling the average humidity of the plaster tiles was 30% for Gipsan, 24% for Safix and 16% for Cellona. Cellona plaster tiles made with 34 °C water achieved the highest elasticity (11.75±3.18 MPa), and Gipsan plaster tiles made with 22 °C had the lowest (7.21±0.9 MPa). Cellona plaster tiles made with 34 °C water showed maximum material strength (4390±838 MPa), and Gipsan plaster tiles made with 22 °C water showed the lowest material strength (771±367 MPa). The rigidity and strength of Cellona and Gipsan plaster are higher in tiles made in warmer water, and for Safix plus are higher in tiles made in cooler water. All three types of plaster differentiate in physical properties. The differences in mass and specific weight before and after plaster modeling are minimal. There are greater differences in drying rate, elasticity and strength between the three different plaster materials.

Treatment of symptomatic intraosseous pneumatocyst using intraoperative navigation

Intraosseous pneumatocysts are benign air-containing lesions that are most often found in the spine and pelvis and are nearly always treated nonoperatively. Although rarely clinically symptomatic, studies have shown pneumatocysts to be present in up to 10% of computed tomography (CT) scans of the pelvis and spine. Radiographic characteristics of these lesions include a localized collection of gas with a thin sclerotic rim, no bony destruction, no soft tissue masses, and no medullary abnormalities. Computed tomography is the diagnostic study of choice, with Hounsfield units ranging from -580 to -950, showing a gas-containing lesion. Few studies have described the management of symptomatic pneumatocysts, and all reported cases concern underwater divers, presumably because of greater pressure cycling and barotrauma encountered while underwater diving. The goal of this report is to describe the intraoperative CT-guided navigation and percutaneous injection of calcium sulfate-calcium phosphate composite bone graft substitute material for the treatment of a symptomatic pneumatocyst in the ilium of a Navy dive instructor. The patient reported a 1-year history of increasing buttock pain with increased depth of diving, consistently reproduced by diving past a depth of 20 to 30 feet. To the authors' knowledge, this is the first description in the English literature of the operative treatment of an intraosseous pneumatocyst of the ilium. The use of intraoperative CT guidance permitted accurate percutaneous localization, decompression, and filling of the lesion with synthetic bone graft substitute, with complete early relief of symptoms. At 6-month follow up, the patient had reached diving depths of 170 feet without pain.

A prospective randomized comparison of PEEK cage containing calcium sulphate or demineralized bone matrix with autograft in anterior cervical interbody fusion

PURPOSE

A variety of bone substitutes have been successfully used to fill PEEK cages in cervical interbody fusion in order to avoid the complications related to bone harvesting from the donor site. However, no controlled study has previously been conducted to compare the effectiveness of PEEK interbody cages containing calcium sulphate/ demineralized bone matrix (CS/DBM) with autogenous cancellous bone for the treatment of cervical spondylosis. The objective of this prospective, randomized clinical study was to evaluate the effectiveness of implanting PEEK cages containing CS/DBM for the treatment of cervical radiculopathy and/or myelopathy.

METHODS

Sixty-eight patients with cervical radiculopathy and/or myelopathy were randomly assigned to receive one- or two-level discectomy and fusion with PEEK interbody cages containing CS/DBM or autogenous iliac cancellous bone (AIB). The patients were followed up for two years postoperatively. The radiological and clinical outcomes were assessed during a two-year follow-up.

RESULTS

The mean blood loss was 75 ± 18.5 ml in the CS/DBM group and 100 ± 19.6 ml (P < 0.01) in the AIB group. The fusion rate was 94.3 % in the CS/DBM group and 100 % in the AIB group at 12-month follow-up. The fusion rate was 100 % at final follow-up in both groups. No significant difference (P > 0.05) was found regarding improvement of JOA score and segmental lordosis as well as neck and arm pain at all time intervals between the two groups. The total complication rate was significantly higher (P < 0.05) in the AIB group than in the CS/DBM group, but there was no significant difference between the two groups (P > 0.05) when comparing the complications in the neck.

CONCLUSIONS

In conclusion, the PEEK interbody fusion cage containing CS/DBM or AIB following one- or two-level discectomy had a similar outcome for cervical spondylotic radiculopathy and/or myelopathy. The rate of fusion and the recovery rate of JOA score between the two groups were the same. The filling of CS/DBM in the PEEK cage instead of AIB has the advantage of less operative blood loss and fewer complications at the donor site.

An evaluation and comparison of the efficacy of nanocrystalline calcium sulfate bone grafts (NanoGen) and medical-grade calcium sulfate bone grafts (DentoGen) in human extraction sockets

BACKGROUND

Grafting a fresh extraction socket is essential for successful regeneration of bone and maximizing volume preservation. Various synthetic grafts have been used to simulate bone formation. The purpose of the present study was to evaluate clinical, histomorphometric, and radiographic healing at 1-month, 3-month, and 4-month time points after tooth extraction with placement of calcium sulfate hemihydrate putty bone grafts NanoGen and DentoGen to determine their efficacy in ridge preservation following tooth extraction.

METHOD

Sixty subjects who were in need of extraction were recruited. The subjects were randomly assigned their group based on computer software for both the test groups (NanoGen and DentoGen). DentoGen is a medical-grade calcium sulfate hemihydrate with particle of 30 µm, and NanoGen is a nanocrystalline version of DentoGen with particle size 400 µm to 800 µm. Data were recorded at 1, 3, and 4 months after extraction socket grafting. Bone biopsies were taken at 4 months for histomorphometric analysis.

RESULTS

The mean percentage of bone formed by NanoGen was 51.19 ± 9.53% and by DentoGen 50.67 ± 16.16% after 4 months. No statistically significant difference was noted in the mean bone formation by NanoGen and DentoGen at various time intervals; no bone graft remnants of DentoGen were found at 4 months. The mean percentage of bone graft remnants left after 4 months for NanoGen was 6.83 ± 16% in the maxilla and 7.38 ± 21% in the mandible. The mean percentage of soft tissue formed was significantly higher with DentoGen in mandibular socket sites. On radiographic evaluation the mean percentage of socket fill with DenoGen was found to be 23.1 ± 11.65%, 50 ± 9.6%, and 76.7 ± 11% and with NanoGen was 29.2 ± 12.8%, 52.8 ± 15.6%, and 76.47 ± 12.43% at 1 month, 3 months, and 4 months postoperative intervals, respectively.

CONCLUSION

Both the materials investigated in the study showed excellent bone forming capacity, but the nanocrystalline version (NanoGen) of calcium sulfate was found to have clinical and biologic advantages over DentoGen.

[One-stage compound grafting of antibiotic-impregnated calcium sulfate and autogenous cancellous bone for the treatment of chronic calcaneal osteomyelitis]

OBJECTIVE

To explore the treatment of chronic calcaneal osteomyelitis with bone defect after debridement and evaluate its clinical outcomes.

METHODS

From June 2009 to June 2011, 52 patients with chronic calcaneal osteomyelitis were treated with stage-one compound grafting of antibiotic-impregnated calcium sulfate and autogenous cancellous bone,including 12 females and 40 males with an average age of 43 years old ranging from 18 to 67. According to Cierny-Mader classification, there were 34 cases with stage III and 18 with stage IV. There were 32 cases on right side and 20 on left,with a course of 6 months to 3 years. The area of soft tissue wound ranged from 3.0 cm x l.5 cm to 23.0 cm x l2.0 cm. The clinical effects were evaluated according to infection controlling, calcium sulfate absorption,bone defect repair and heel functional recovery.

RESULTS

All patients were followed up for 2 to 3.8 years (averaged 2.8 years). Primary healing was achieved in 52 patients. Two cases of recurrence were found post-operatively, 1 case in 3 months and another in 5 months,which were cured after a second operation. Bone repair healing was gained in 1.5 to 3.5 months (averaged 2.5 months). Complete radiological absorption of calcium sulfate was found in 1.2 to 3 months(averaged 2.2 months). Local exudation after removal of drainage tube had been persisting in 10 patients for 2 to 3 months, which was consistent with the time when cacium sulfate were totally absorbed. Flap had partial necrosis in 4 cases,and the wounds were closed after appropriate treatment finally. The mean Maryland score was 88.15±7.70. There were excellent results in 32 cases, good in 14, fair in 6.

CONCLUSION

A satisfactory short-term clinical results can be gained by one-stage compound grafting of antibiotic-impregnated calcium sulfate and autogenous cancellous bone in chronic calcaneal osteomyelitis, but the long-term results need further follow-up. And much more study is also demanded to reduce the exudation of calcium sulfate.

[Efficacy analysis of intermediate screws technique plus injectable calcium sulfate for thoracolumbar fracture in postmenopausal patients]

OBJECTIVE

To explore the clinical efficacies of intermediate screws plus injectable calcium sulfate MIIGX3 for thoracolumbar fracture in postmenopausal patients.

METHODS

A total of 21 postmenopausal patients with vertebral compression fractures reconstructed with posterior internal fixation of intermediate screws technique and anterior vertebral augmentation of MIIGX3 technique in three dimension were retrospectively analyzed. The changes of fracture vertebral height and Cobb's angle were compared.Visual analogue scale (VAS) was performed to evaluate their symptoms. All patients were followed up.

RESULTS

Intermediate screws surgical technique plus MIIGX3 was successfully performed. The average injection dose was 4.6 ml.Leakage occurred intraoperatively in two cases. The average follow-up period was 15 (6-36) months. The VAS system demonstrated that pain decreased significantly (preoperative:7.8, postoperative:2.2). The height and Cobb's angle of fractured vertebra improved greatly. The preoperative values were 45.0 ± 6.4% and 19.4 ± 4.5° and postoperative ones 15.4 ± 3.9% and 8.64 ± 3.18° respectively. There was no occurrence of severe complications related with treatment.Except for 2 patients with a loss of 15% of vertebral height, the average heights of fractured vertebra in other 19 patients recovered to 85% of normal ones.

CONCLUSION

Thoracolumbar fracture in postmenopausal patients may be managed satisfactorily by intermediate screws and injectable calcium sulfate technique.Such a technique is both safe and effective. And its stable and durable reduction offers significant improvement.

MM-MTA for direct pulp capping: a histologic comparison with ProRoot MTA in rat molars

AIM

To compare the histomorphological response of rat dental pulps capped with MM-MTA and ProRoot MTA at 1, 2 and 4 weeks postoperatively.

MATERIALS AND METHODS

Direct pulp capping with MM-MTA and ProRoot MTA, overlaid with light-cured composite resin, was performed on right and left maxillary first molars of 20 Wistar rats. Animals were killed at 1, 2 and 4 weeks postoperatively. Biopsy samples were stained and viewed by light microscopy to determine dentin bridge formation. Data were statistically evaluated with the Kruskal-Wallis test (p < 0.05).

RESULTS

Absence of dentin bridge formation at 1 week, partial dentin bridge formation at 2 weeks and complete dentin bridge formation at 4 weeks are observed with MM-MTA and ProRoot MTA. The results showed no statistically significant difference between both materials at 4 weeks.

CONCLUSION

Both materials produced similar responses in the pulp when used for pulp capping in intact, caries-free molars of rats.

Clinical and radiographic evaluation of single-tooth dental implants placed in grafted extraction sites: a one-year report

OBJECTIVE

The aim of this report was to clinically and radiographically evaluate changes to the hard and soft tissues around implants placed in extraction sockets grafted with medical grade calcium sulfate hemihydrate (MGCSH) mixed with platelet-rich plasma (PRP) and a collagen resorbable plug after one year of function.

METHODS

This evaluation was part of a previous study conducted to evaluate extraction socket grafts. Fourteen subjects out of 16 were evaluated. After tooth extraction, eight subjects received MGCSH mixed with PRP in the extraction sockets (test group), and six subjects received collagen resorbable plug dressing material (control group). After three months of bone healing, dental implants were placed. Three months after implant installation, provisional restorations were placed and implants were loaded in function for one month followed by definitive restorations. Follow-up examinations and intraoral digital radiographs were made at baseline and one year after definitive restorations to evaluate the marginal bone level in each subject.

RESULTS

At the one-year follow-up, the survival and success rate was 100% for all implants. There was no statistically significant difference in the amount of vertical bone loss between groups after 1 year (p > 0.05). For the test group, there was a mean mesial bone loss of -0.8 +/- 0.6mm and a mean distal bone loss of -0.5 +/- 0.4mm. For the control group, there was a mean mesial bone loss of -1.1 +/- 0.7mm and a mean distal bone loss of -0.6 +/- 0.6mm.

CONCLUSIONS

At the one-year follow-up, the implant placement in grafted sockets was not affected by the type of the graft material. Implants placed in sockets grafted with MGCSH mixed with PRP showed less marginal bone loss after one year in comparison to those with collagen resorbable grafts.

Calcium sulfate cement in contained traumatic metaphyseal bone defects

The aim of this study was to evaluate prospective patients with periarticular fractures where a meta physeal bone defect was grafted with high compressive calcium sulfate cement. The calcium sulfate cement MIIG X3, (Wright Medical Technology, Inc, Arlington, TN) was used in 45 patients with periarticular fractures--distal radial, tibial plateau, humeral head, and calcaneal fractures--to fill the metaphyseal defect. All fractures were treated either with open or closed reduction, fracture fixation, and the cement was applied openly or closed. Radiographs were evaluated for fracture reduction, joint line gap, and step, as well as for rate of graft replacement by bone. All fractures united without an additional procedure. There were no wound infections or other complications attributed to the graft. At three-month follow-up, a complete graft replacement by bone was observed in all fractures. Joint line step was not developed in any patient, but a joint line gap of 3 mm was observed postoperatively in one patient with a tibial plateau fracture. Loss of reduction occurred in one patient with an extra-articular distal radial fracture treated with closed reduction and k-wire fixation. Cement that escaped into the joint or the surrounding soft tissues was not visible at the six-week follow-up. In conclusion, the results of this study confirm the safety and the efficacy of this cement when it is used as graft with the appropriate fixation method in traumatic metaphyseal bone defects.

Comparative evaluation of the fracture resistance of teeth prepared with rotary system, filled with single cone gutta-percha and laterally condensed with zinc oxide eugenol and resin based (AH26) sealers to that of Resilon

AIM AND OBJECTIVE

To compare the fracture resistance of teeth prepared with rotary system and filled with single cone guttapercha followed by lateral condensation with different sealers like zinc oxide eugenol and resin based (AH26) to that of resilon.

MATERIALS AND METHODS

A total number of 70 extracted intact human permanent maxillary incisors were selected. All prepared samples were divided into one control group (n = 10) and three experimental groups (n = 20 per group). Group 1 control. This group received no obturation; the root canal opening was sealed with a temporary filling material (Cavit, Premier Dental Products, Plymouth Meeting, PA) Group 2: Gutta-Percha and zinc oxide Eugenol sealer. Group 3: Gutta-Percha and AH26 sealer. (DiaDent, Korea) dipped in AH26 sealer. Group 4: Resilon cones and RealSeal Resin Sealer. Obturation was accomplished using a 0.06 taper size 40 gutta-percha master point. All the root samples were stored in 100% humidity at 37 °C for 2 weeks to allow the sealer to set completely. The root samples were then prepared for mechanical testing and the data was recorded and analyzed statistically.

RESULTS

One-way ANOVA and Post hoc test (Duncan Multiple range test) were employed to determine possible statistical variation among the groups tested in this study. The force for group 2 was significantly greater than that for the control group 1 (no obturation).The force for group 3 was significantly greater than that for group 2. The force for group 4 was significantly greater than that for group 3. All other groupwise comparisons were not significant at 5% level. Group 4 seemed to have the greatest force among the three groups of interest in the study.

CONCLUSION

Root canals filled with Resilon increased the in vitro resistance of single canal extracted teeth compared to other experimental groups. The mean fracture resistance value for the experimental groups in ascending order was as follows: Root canals instrumented but not filled, filled with gutta-percha and zinc oxide eugenol sealer, filled with gutta-percha and AH26 sealer and filled with Resilon.

CLINICAL SIGNIFICANCE

Resilon is a promising material for reinforcement of endodontically treated teeth.

[Injectable borate glass/chitosan composite as drug carrier for treatment of chronic osteomyelitis]

OBJECTIVE

To evaluate the characterization, biocompatibility in vitro and in vivo, and antimicrobial activity of an injectable vancomycin-loaded borate glass/chitosan composite (VBC) so as to lay the foundation for its further clinical application.

METHODS

The solid phase of VBC was constituted by borate glass and vancomycin, liquid phase was a mixture of chitosan, citric acid, and glucose with the proportion of 1 : 10 : 20. Solid phase and liquid phase was mixed with the ratio of 2 : 1. Vancomycin-loaded calcium sulfate (VCS) was produced by the same method using calcium sulfate instead of borate glass and saline instead of chitosan, as control. High performance liquid chromatography was applied to detect the release rate of antibiotics from VBC and VCS, and minimum inhibitory concentration (MIC) was tested by using an antibiotic tube dilution method. The structure of the VBC and VCS specimens before and 2, 4, 8, 16, and 40 days after immersion in D-Hank's was examined by scanning electron microscopy, and the phase composition of VBC was analysed by X-ray diffraction after soaked for 40 days. Thirty-three healthy adult New Zealand white rabbits (weighing, 2.25-3.10 kg; male or female) were used to establish the osteomyelitis models according to Norden method. After 4 weeks, the models of osteomyelitis were successfully established in 28 rabbits, and they were randomly divided into 4 groups (groups A, B, C, and D). In group A (n=8), simple debridement was performed; in groups B and C (n=8), defect was treated by injecting VCS or VBC after debridement; and in group D (n=4), no treatment was given. The effectiveness of treatment was assessed using radiological and histological techniques after 2 months.

RESULTS

The releases of vancomycin from VBC lasted for 30 days; the release rate of vancomycin reached 75% at the first 8 days, then could reached more than 90%. The releases of vancomycin from VCS lasted only for 16 days. The MIC of VBC and VCS were both 2 microg/mL. The VCS had a smooth glass crystal surface before immersion, however, it was almost degradated after 4 days. The fairly smooth surface of the VBC pellet became more porous and rougher with time, X-ray diffraction analysis of VBC soaked for 40 days indicated that the borate glass had gradually converted to hydroxyapatite. After 2 months, the best result of treatment was observed in group C, osteomyelitis symptoms disappeared. The X-ray scores of groups A, B, C, and D were 3.50 +/- 0.63, 2.29 +/- 0.39, 2.00 +/- 0.41, and 4.25 +/- 0.64, respectively; Smeltzer scores were 6.00 +/- 0.89, 4.00 +/- 0.82, 3.57 +/- 0.98, and 7.25 +/- 0.50, respectively. The scores were significantly higher in group D than in groups A, B, and C (P < 0.05), and in group A than in groups B and C (P < 0.05). The scores were higher in group B than in group C, but no significant difference was found (P > 0.05).

CONCLUSION

The VBC is effective in treating chronic osteomyelitis of rabbit by providing a sustained release of vancomycin, in addition to stimulating bone regeneration, so it may be a promising biomaterial for treating chronic osteomyelitis.

Sinus floor augmentation with a hydropneumatic technique: a retrospective study in 40 patients

The use of a hydropneumatic balloon for the elevation of the sinus membrane is a new technique for sinus floor augmentation procedures. Few cases using such a technique are reported in the English medical literature. This report describes 40 patients who were treated with this technique and studied retrospectively. Forty consecutive patients with an alveolar crest-sinus floor distance (bone height) ≤ 12 mm were enrolled. Under microscopy (40x) and using piezosurgical instruments, hydropneumatic sinus membrane elevation was performed, and a calcium sulphate solution was injected under the elevated antral membrane using a syringe. In the same surgical session, 4.00- to 6.50-mm-diameter implants were placed. Bone height at 12 months, complications related to the surgical technique, and implant failure were all recorded. Bone height at 12 months was 14.66 ± 1.48 mm, with a sinus membrane elevation of 9.01 ± 3.01 mm. Fifty-six implants were placed, and no failures were observed after 1 year. One macrolaceration and two microlacerations were the only complications related to the technique. Minimal invasiveness and reduced trauma characterize this new approach. In fact, gradual balloon inflation provides a controlled and atraumatic preparation of the sinus floor membrane. Piezoelectric instruments and microscopy make this technique predictable and safe. The relatively short learning curve of this approach for sinus floor elevation allows for its use in private practice.

The use of an injectable calcium sulphate/calcium phosphate bioceramic in the treatment of osteonecrosis of the femoral head

PURPOSE

The purpose of our study is to describe the rationale, the surgical technique and the early clinical and radiographic results of the treatment of patients with early stage osteonecrosis of the femoral head (ONFH) by performing: core decompression, injection of autologous bone marrow concentrate and the use of a new composite injectable bone substitute (PRO-DENSE(®)), as a mechanical supplementation associated with decompression.

METHODS

The study included 37 hips (31 patients, 14 females, 17 males; mean age 43.9 years, range 24-56 years) with stages IC-IIIA ONFH. The outcome was determined by the changes in the Harris hip score (HHS), by progression in radiographic stages and by the need for hip replacement. The mean follow-up was 20.6 months (range 12-32 months).

RESULTS

At final follow-up the mean HHS increased from 68 points pre-operatively to 86 points post-operatively. The radiological results showed that 29 hips (78.4 %) improved or had no further collapse. The overall clinical success rate of the procedure was 86.5 %, with three conversions to THA, and a failure rate of only 3.3 % in the pre-collapse group.

CONCLUSIONS

We are encouraged by these early results using core decompression, injection of the autologous bone marrow concentrate and backfilling the defect with an injectable bioceramic for the treatment of early stages of ONFH; as far as a conclusion can be drawn from the current data, this treatment seems to relieve hip pain and prevent the progression of ONFH in the majority of the cases.

Preservation of posterior mandibular extraction site with allogeneic demineralized, freeze-dried bone matrix and calcium sulphate graft binder before eventual implant placement: a case series

OBJECTIVE

This case series reports short- and long-term healing, before and after placement of an implant, in posterior mandibular extraction sites grafted with demineralized, freeze-dried bone matrix (DFDBM) allograft mixed with calcium sulphate graft binder.

METHODS

Three patients who underwent surgical extraction of a posterior mandibular molar experienced partial loss of the buccal bone plate at the extraction site. Alveolar bone reconstruction with a DFDBM allograft mixed with calcium sulphate graft binder was performed immediately. The graft was covered with a biodegradable regenerative membrane. For each of the 3 patients, the implant and healing abutment were placed after 6, 9 and 12 months, respectively, followed by crown placement 3, 5 and 5 months later, respectively. The implants were periodically re-evaluated, both clinically and radiographically, between 10 and 39 months after final insertion of the crown. An implant stability device was used to evaluate the long-term biological and functional stability of the implants.

RESULTS

Upon exposure and implant placement, the grafted alveolar ridge in all patients presented appropriately sized, dense and well-vascularized bone, wide enough to receive the planned wide-platform implant. The long-term interface stability quotient ranged from 87 to 90.

CONCLUSIONS

Posterior mandibular extraction sites with compromised buccal alveolar bone may be effectively managed by immediate alveolar augmentation using a mixture of DFDBM allograft and calcium sulphate graft binder. This approach provides ideal alveolar form and consistency for eventual placement of the implant.

Preservation of an injured vital tooth using ultrasonic device and mineral trioxide aggregate

The purpose of this case report is to present a root fracture repair procedure for non devitalized injured tooth. One injured, non-endodontically treated maxillary anterior tooth in which an incomplete vertical root fracture involving only the buccal side was suspected, underwent an exploratory flap to visualize the pattern of bone loss and assess the type of root fracture. The pre-operative diagnosis was confirmed. A groove following fracture line was prepared using retro-tips driven by an ultrasonic device and sealed with Mineral Trioxide Aggregate (MTA), following filling of the bone defect with Calcium Sulphate. At 24 months follow up the case showed clinical and radiographic success. The present surgical approach showed preservation of function and vitality of tooth with a shallow incomplete vertical root fracture.

The efficacy of a cervical barrier in preventing microleakage of Enterococcus faecalis in endodontically treated teeth

The clinical failure of coronal restorations can compromise the healthy periapical status of endodontically treated teeth. The purpose of the present ex vivo study was to assess the effectiveness of the cervical barrier in preventing bacterial microleakage in the eventual loss of the coronal restoration. Following removal of the smear layer and obturation to the cementoenamel junction using gutta-percha, 70 single-rooted mandibular premolars were randomly divided into five different groups: Group 1 received no additional treatment; Groups 2 and 3 had 2 mm and 3 mm of the obturation removed, respectively, followed by placement of a cervical barrier that was the same thickness as the obturation. In Group 4 (positive control), the root canals were filled only with gutta-percha, while in Group 5 (negative control), the root canals were completely impermeabilized following obturation. The filled root canals were incorporated into a split-chamber model system using Enterococcus faecalis as a microbial marker. The apices were suspended in the lower chambers. Leakage was determined daily for 60 days and evaluated for turbidity. According to Fisher's exact test, the cervical barrier in Groups 2 and 3 prevented the microleakage of E. faecalis into the root canals when compared with Groups 1 and 4. This result was similar to that for the completely sealed samples in Group 5 (p = 0.001).

Treatment options for teeth with open apices and apical periodontitis

Three clinical cases involving teeth with open apices and apical periodontitis were treated using different protocols. The first case was managed with intracanal calcium hydroxide paste for 12 months before obturation with gutta-percha and sealer. In the second case, an apical plug of mineral trioxide aggregate (MTA) was used before obturation with gutta-percha and sealer and treatment was completed during 2 appointments. In the third case, the tooth, which had a divergent root canal system, was completely obturated with MTA and treatment was also completed over 2 appointments. In all 3 cases, signs of bone healing were observed after treatment.

Clinical and histologic healing of human extraction sockets filled with calcium sulfate

PURPOSE

The aim of this investigation was to evaluate whether the placement of medical-grade calcium sulfate hemihydrate (MGCSH) in fresh extraction sockets might affect the quality of newly formed bone and influence crestal bone changes.

MATERIALS AND METHODS

Forty patients who needed maxillary single-tooth extraction followed by implant insertion were enrolled in the study. Alveoli were required to have four remaining intact walls. After tooth extraction, 22 patients received MGCSH in the extraction sockets (test group), and 18 received no grafting material (control group). At the time of extraction and 3 months later (at implant placement surgery), vertical and horizontal socket dimensions were measured. In addition, during implant placement, tissue specimens were harvested for histologic and immunohistochemical evaluations. Comparisons of test and control tissues were performed with the unpaired Student t test.

RESULTS

Vertical resorption of the buccal socket walls and reduction of the buccopalatal width were more pronounced at control sites than at MGCSH sites (1.2 mm versus 0.5 mm, and 3.2 mm versus 2.0 mm, respectively). Formation of 100% living trabecular bone with woven and lamellar arrangements was found in both test and control sections. The average trabecular bone area fraction was greater in the grafted specimens than in control specimens (58.8% versus 47.2%). In the test group, the average percentage of lamellar bone increased from 16.4% to 43.6% from the crestal to the apical region and was greater than in unfilled specimens (11.1% coronally, 22.2% apically; P < .0001).

CONCLUSIONS

MGCSH seems to be effective in accelerating the bone healing process and minimizing alveolar ridge resorption in intact fresh extraction sockets.

[Restoration of segmental bone defect by calcium sulfate pellet: experiment with rabbit]

OBJECTIVE

To compare the effects of different calcium sulfate pellets made by different methods in treating segmental defect of bone.

METHODS

Eighty New Zealand white rabbits underwent cutting off a segment in the middle part of radius so as to establish models of radial segmental defect, and than were divided into 4 groups: Group A as control group, Group B with calcium sulfate pellet made by routine method implanted into the defect, Group C with chitosan coated pressed calcium sulfate pellet implanted into the defect, and Group D with chitosan coated pressed calcium sulfate pellet combined with recombinant human bone morphogenetic protein (rhBMP)-2 implanted into the defect: X-ray photography was done every 4 weeks to observe the new bone formation. Four, 8, and 12 weeks 5 rabbits from each group were killed. The defect segments with parts of normal bone at both ends were cut off to undergo fluorescence microscopy and biomechanic three point bending test.

RESULTS

X-ray photography and histological examination showed that new bone formation of cortex and reconstruction of marrow cavity were seen in Groups D and C, especially in Group D. The new bone mineralization rate of Group D was significantly higher than that of Group C (P<0.05) which was significantly higher than that of Group B (P<0.01). The anti-bending strength ratio of Group D was (47.5%+/-2.1%, significantly higher than that of Group C [(39.6+/-1.7)%, F=125.3, P<0.01], and the anti-bending strength ratios of Groups D and C were both significantly higher than those of Groups B and A [(23.6+/-3.3)% and (21.3+/-2.7)%].

CONCLUSION

Chitosan coated pressed calcium sulfate pellet shows relatively higher anti-bending strength and slightly slower resorption that closely coincide with the growth rate of new bone. It can be used to restore segmental bone defect, and particularly when combined with rhBMP-2.

Osteogenic activity of the mixture of chitosan and particulate dentin

To evaluate the healing effect of a mixture of chitosan and particulate dentin, a 8-mm-diameter critical size defect was created in the calvarium of 75 rats. The rats were divided into four experimental groups and a control group (no treatment). The defects in the experimental groups were grafted either with pig particulate dentin (group 1), a mixture of particulate dentin and plaster of Paris (group 2), particulate dentin and chitosan (group 3), or chitosan only (group 4). Rats in each group were sacrificed 2, 4, and 8 weeks after implantation. All experimental groups showed more new bone formation when compared to the control group. Additionally, all groups exhibited more bone growth at 8 weeks than at 4 weeks after implantation. It was concluded from this study that defects treated with particulate dentin powder-chitosan mixture may mediate an excellent effect on the formation of new bones.

[Application of porous composite hydroxyapatite-TCP implants in orthopaedic surgery]

Bone grafts are the basic material in bone deficit filling. Due to difficulties to obtain bone grafts often the bone substitutes are used. Authors presents chemical, mineralogic and biologic properties of hydroxyapatite and ceramic material based on calcium phosphorate. HAp-TCP has a wide applications in bone deficit filling in knee and hip arthroplasty or revision arthroplasty, bone cysts, wrist and ankle joint arthrodesis. Bone substitutes should be mix with bone grafts, in the cases where load bearing is needed, because of their weak mechanical strength. Further clinical and experimental studies should be continued to get new generation of material on the calcium phoshorate base. This new material should present higher mechanical strength with preserving osteocondactive and osteoinductive properties of hydroxyapatite.

[Open-wedge retro-tubercular tibial osteotomy: an innovating technique]

Open-wedge tibial osteotomy for varus correction is a common orthopedic procedure. The rate of complications remains significant: loss of correction, nonunion, patellar infera... We propose a new open-wedge technique for tibial osteotomy which has several advantages: less risk of patella infera, improved bone healing, excellent mechanical stability. The osteotomy involves two cuts with an anterior portion ending distally to the tibial tubercle. This preserves the integrity of the patellar tendon and maintains contact between the proximal tibia and the tibial tubercle. Adjunction of an anteroposterior screw adds stability. The anterior plane of the osteotomy provides an excellent surface contact favoring bone healing. The posterior plane is the same as with a "classical" open-wedge osteotomy. The lateral cortical must always remain intact (hinge). The technique described here does not require any specific instrumentation and is compatible with most of the available osteosynthesis implants.

Experimental Model: Dye Penetration of Extensive Interim Restorations Used during Endodontic Treatment while under Load in a Multiple Axis Chewing Simulator

The purpose of this study was to design an experimental model that allowed extensive endodontic interim restorations to be tested for dye penetration while under simulated masticatory load. Extracted premolar teeth had standardized mesio-occluso-distal cavities prepared, and the root canals were instrumented. A cotton wool pellet was placed in the pulp chamber, and the cavities were restored with Cavit, IRM, Ketac-Fil Plus, Ketac-Silver, or composite resin (Z100). They were subjected to the equivalent of 3 months of clinical load while exposed to methylene blue dye. Results of this study could not support IRM as a suitable interim endodontic restorative material to use in extensive cavities. The dye penetration in the Ketac-Fil Plus and Ketac-Silver specimens was not predictable, and the results suggested Cavit and Z100 composite resin require further investigations as potentially useful materials for this purpose.

The use of osteoconductive bone graft substitutes in orthopaedic trauma

Several bone graft substitutes are now available for use in augmenting bone healing following trauma. Many of these products are osteoconductive and are indicated for filling bone defects in conjunction with standard methods of internal and external fixation. Osteoconduction refers to a process in which the three-dimensional structure of a substance is conducive for the ongrowth and/or ingrowth of newly formed bone. Currently used bone graft substitutes that primarily offer osteoconductive properties include coralline hydroxyapatite, collagen-based matrices, calcium phosphate, calcium sulfate, and tricalcium phosphate. These products vary considerably in chemical composition, structural strength, and resorption or remodeling rates. Understanding these differences is important in selecting a bone graft substitute with the properties desired for a specific clinical situation. The limited number of clinical studies and lack of direct-comparison studies between these products require the surgeon to fully understand the properties of each product when choosing a bone graft substitute.

Histologic evaluation of a provisional implant retrieved from man 7 months after placement in a sinus augmented with calcium sulphate: a case report

Little is known about the in vivo healing processes at the interface of implants placed in different grafting materials. For optimal sinus augmentation, a bone graft substitute that can regenerate high-quality bone and enable the osseointegration of load-bearing titanium implants is needed in clinical practice. Calcium sulphate (CaS) is one of the oldest biomaterials used in medicine, but few studies have addressed its use as a sinus augmentation material in conjunction with simultaneous implant placement. The aim of the present study was to histologically evaluate an immediately loaded provisional implant retrieved 7 months after simultaneous placement in a human sinus grafted with CaS. During retrieval bone detached partially from one of the implants which precluded its use for histologic analysis. The second implant was completely surrounded by native and newly formed bone, and it underwent histologic evaluation. Lamellar bone, with small osteocyte lacunae, was present and in contact with the implant surface. No gaps, epithelial cells, or connective tissues were present at the bone-implant interface. No residual CaS was present. Bone-implant contact percentage was 55% +/- 8%. Of this percentage, 40% was represented by native bone and 15% by newly formed bone. CaS showed complete resorption and new bone formation in the maxillary sinus; this bone was found to be in close contact with the implant surface after immediate loading.

Alveolar ridge preservation prior to implant placement with surgical-grade calcium sulfate and platelet-rich plasma: a pilot study in a canine model

PURPOSE

To evaluate the combination of surgical-grade calcium sulfate (SGCS) and platelet-rich plasma (PRP) for alveolar ridge preservation prior to implant placement.

MATERIALS AND METHODS

Five mongrel dogs were used as subjects. Four enlarged mandibular extraction sockets, 2 on each side, were created in each dog. According to a split-mouth design, the 2 anterior sockets received either SGCS/PRP (SGCS/PRPant) or were left unfilled, while the 2 posterior sockets received either SGCS/PRP (SGCS/PRPpost) or SGCS. Computerized tomographic (CT) scans were conducted at 1 day and 8 weeks postextraction to detect the change in ridge height. Bone scintigraphy was performed at 2, 4, and 6 weeks to investigate new bone formation activity. At 8 weeks, 1 dog was sacrificed for histologic and histomorphometric study. Meanwhile, implants were placed in the remaining 4 dogs. These 4 dogs were sacrificed after 3 months.

RESULTS

Less ridge resorption was observed in the anterior SGCS/PRP-filled sites compared to unfilled sites (P = .001), while no significant difference was found between the SGCS/PRPpost and SGCS groups (P = .544). Bone scintigraphy showed that sites filled with SGCS/PRP showed significantly higher count/pixel at 2 (P = .028), 4 (P = .009), and 6 weeks (P = .037) than the unfilled sites. Nevertheless, the SGCS/PRPpost group achieved significantly higher values than the SGSC group only at 2 weeks (P = .036). Histomorphometrically, the SGCS/PRPant group showed a significantly higher percentage of bone-implant contact than the unfilled group (P = .024), but no significant difference was detected between the SGCS/PRPpost and SGCS groups (P = .979).

CONCLUSION

Grafting SGCS/PRP in fresh extraction sockets reduced alveolar ridge resorption and promoted the bone formation in this canine model. The addition of PRP to SGCS resulted in the enhancement of bone regeneration in the early phase of healing.

A rat osteoporotic spine model for the evaluation of bioresorbable bone cements

BACKGROUND CONTEXT

As the aging population increases, the rising prevalence of osteoporosis-related spine fractures will have a dramatic impact on health care. At present, mainstay treatment relies on systemic medications intended to prevent diminishing bone mineral density (BMD) and bone mass. However, an adjunctive treatment strategy is to target specific areas of the skeletal system that are prone to clinically significant osteoporotic fractures. We term this strategy the "local treatment of osteoporosis" or osteoplasty. Potential use of osteoplasty involves the percutaneous injection of bioresorbable and bioactive bone cements into bones at risk of sustaining osteoporotic fractures. Calcium sulfate (CaSO(4)) is among the candidate bioresorbable bone cements with the material attributes desirable for potential application with osteoplasty, yet previous studies on the osteoconductive properties of CaSO(4) have been limited to animal models exhibiting normal bone biology and architecture. However, osteoporotic bone physiology may potentially interfere with the material properties of common osteoconductive biomaterials, such as that of CaSO(4). To further test this hypothesis, a suitable animal model is needed to evaluate the in vivo behavior of potential biomaterials in osteoporotic bone.

PURPOSE

The purpose of this study is to evaluate the caudal (proximal tail) rat vertebral body as an appropriate system for the in vivo evaluation of bone cement performance in the osteoporotic spine.

STUDY DESIGN

(1) Micro-computed tomography radiomorphometry study and (2) biomechanical vertebral compression analysis.

METHODS

Female Sprague Dawley rats were ovarectomized (OVX) at age 8 weeks and subsequently maintained on a low-calcium diet for 3 months. Normal nonovarectomized female rats (NL) of similar age and size were maintained on regular rodent feed. Micro-CT analysis was performed on both the lumbar and caudal vertebrae (levels 5-7) of both groups. The following bone radiomorphometric parameters were determined: bone mineral density (BMD), average cortical thickness (ACT), average trabecular thickness (TbTh), and average trabecular spacing (TbSp). Strength and stiffness of both NL and OVX vertebral bodies were assessed under axial compression at 0.1 mm/s, whereas displacement (mm) and force (N) were measured at 10 Hz until completion to failure. After the implantation of an injectable form of CaSO(4) bone cement into caudal vertebrae, radiomorphometric analysis of cement volume, based on its unique CT absorption profile, was performed over the 8-week time period, as well as the subsequent bone response of both NL and OVX caudal vertebrae to CaSO4.

RESULTS

OVX caudal vertebrae showed an 18% decrease in BMD, a 28% decrease in diaphyseal ACT, a 55% decrease in TbTh, and a 2.4-fold increase in TbSp compared with NL (p<.05). Additionally, lumbar vertebrae exhibited a 21% decrease in BMD, a 24% decrease in anterior body ACT, a 48% decrease in TbTh, and a 4.7-fold increase in TbSp (p<.05). Failure testing of OVX caudal vertebral bodies revealed a 29% decrease in strength and a 60% decrease in stiffness compared with NL (p<.01). After implantation into OVX caudal vertebrae, CaSO(4) cement exhibited a 50% decrease in initial cement volume at 2 weeks and complete resorption by 4 weeks, whereas CaSO(4) injected into NL vertebrae exhibited a 79% decrease in initial cement volume at 4 weeks, trace amounts at 6 weeks, and complete resorption by 8 weeks. At 8 weeks, NL vertebrae implanted with CaSO(4) cement exhibited increased cortical bone thickness compared with NL sham vertebrae. This CaSO(4) cement-mediated bone augmentation was altered in osteoporotic vertebrae that exhibited porous irregular cortical bone not noted in cement-treated NL vertebrae or OVX sham vertebrae.

CONCLUSIONS

Future investigation of potential biomaterials intended for the local treatment of osteoporosis will require their study within an appropriate osteoporosis animal model. The OVX rat caudal spine exhibits pathologic bone changes consistent with the osteoporosis phenotype, including decreased BMD, diminished trabecular network density, cortical thinning, and decreased mechanical strength. These derangements in bone microarchitecture and physiology may contribute toward the accelerated cement resorption and altered bone response to CaSO4 observed in this study. Important advantages of the OVX rat caudal spine are the rapid and minimally invasive surgical exposure of the vertebral body and the ease of cement injection. We propose that the OVX rat caudal spine represents a valuable and cost-effective tool in the armamentarium of investigators evaluating biomaterials designed for implantation into the osteoporotic spine.

Peri-Implant Bone Regeneration With Calcium Sulfate: A Light and Transmission Electron Microscopy Case Report

BACKGROUND

Calcium sulfate is a simple, biocompatible material with a very long, safe clinical history in several different fields of medicine. It is a rapidly resorbing material that leaves behind calcium phosphate lattice, which promotes bone regeneration.

OBJECTIVE

The aim of this study was a histological and ultrastructural evaluation of the tissues in a peri-implant site regenerated with calcium sulfate.

MATERIALS AND METHODS

The specimens were processed for observation under light and transmission electron microscopes.

RESULTS

In light microscopy, trabecular bone was present. No remnants of calcium sulfate were present. Transmission electron microscopy showed, in the areas of the interface with the implant surface, features of mature bone with many osteocytes. An amorphous layer and/or osteoid seam separated this mature bone from the metal surface.

CONCLUSION

The results confirm the high biocompatibility and rapid resorption of calcium sulfate.

Bone healing in critical-size defects treated with bioactive glass/calcium sulfate: a histologic and histometric study in rat calvaria

OBJECTIVE

The purpose of this study was to analyze histologically the influence of bioactive glass (BG) with or without a calcium sulfate (CS) barrier on bone healing in surgically created critical-size defects (CSD) in rat calvaria.

MATERIAL AND METHODS

A CSD was made in each calvarium of 48 rats. They were divided into three groups: C (control): blood clot only; BG: defect filled with BG; and BG/CS: defect filled with BG covered by a CS barrier. Animals were euthanized at 4 or 12 weeks. Formation of new bone was evaluated histomorphometrically.

RESULTS

No defect completely regenerated with bone. BG particles were observed in Groups BG and BG/CS at both periods of analysis. The thickness throughout the healing area in Groups BG and BG/CS was similar to the original calvarium, while Group C presented a thin connective tissue in the center of the defect in both periods of analysis. At 4 weeks, Groups C and BG/CS presented significantly more bone formation than Group BG. No significant differences were found between Groups C and BG/CS. At 12 weeks, no significant differences in the amount of bone formation were observed among the three groups. When comparing 4 and 12 weeks, there was a significant increase in new bone formation within groups BG and BG/CS, but not C.

CONCLUSION

BG particles, used with or without a CS barrier, maintained the volume and contour of the area grafted in CSD. However, they did not lead to a significant difference in bone formation when compared with control at 12 weeks post-operative.

Locally administered antibiotics for prophylaxis against surgical wound infection. An in vivo study

BACKGROUND

Currently, the standard for prophylaxis against surgical infection consists of perioperative systemic antibiotics. In this study, we investigated the relative efficacy of various methods of antibiotic delivery for the prevention of surgical wound infections. We hypothesized that sustained release of local antibiotics inside the wound cavity by a drug delivery system would be more effective than systemically administered antibiotics.

METHODS

Using a rat model, we inoculated a surgical wound in the quadriceps muscle with 8.0 x 10(5) colony-forming units of Staphylococcus aureus and then administered one of seven types of treatment: no treatment (control), bacitracin irrigation, calcium sulfate flakes, systemic gentamicin, local aqueous gentamicin, local gentamicin-loaded calcium sulfate flakes, and a combination of local gentamicin-loaded calcium sulfate and systemic gentamicin. The seven treatment groups consisted of ten rats each. To further evaluate a trend, the group treated with systemic gentamicin and the one treated with local gentamicin solution were extended to include twenty-five and twenty-seven rats, respectively. At forty-eight hours postoperatively, specimens from the wounds were obtained for quantitative culture.

RESULTS

The control group, the group treated with bacitracin irrigation, and the one treated with plain calcium sulfate had very high bacterial counts and high mortality rates while the groups treated with gentamicin had low bacterial counts and a 100% survival rate. Local gentamicin was significantly more effective than systemic gentamicin in reducing bacterial counts.

CONCLUSIONS

The gentamicin-loaded calcium sulfate flakes did not result in bacterial counts that were significantly lower than those following systemic administration of gentamicin, which refuted our hypothesis. However, gentamicin solution injected directly into the closed wound did result in levels of bacteria that were significantly lower than those following treatment with the systemic gentamicin.

Adult osteomyelitis: debridement versus debridement plus Osteoset T pellets

This long-term retrospective study investigated the value of debridement versus debridement and Osteoset T antibiotic-loaded calcium sulphate pellets in the treatment of adult chronic osteomyelitis. Sixty-five patients were included in the study. The mean follow-up was 75 months (range: 36 to 334). Forty cases were treated by debridement, and 25 by debridement and Osteoset T. The healing rates were 60% and 80%, respectively; however, the difference was not significant. In a subgroup of 39 patients with medullary osteomyelitis and a normal immune system (IA according to the Cierny-Mader classification of adult osteomyelitis), 22 patients were treated with debridement, 17 with debridement and Osteoset T. The healing rates were 59% and 94%, respectively (p < 0.05). Twenty-eight patients with Staphylococcus aureus osteomyelitis were also studied apart; 13 were treated with debridement and 15 with debridement and Osteoset T. The healing rates were 46% and 80%, respectively. The difference was not significant. The results obtained with debridement were less good than with debridement plus Osteoset T, but the difference was not significant, except in a single subgroup. Osteoset T obviates the need for removal, which is the rule after implantation of gentamycin beads. Bony ingrowth is however limited.

In vivo evaluation of teicoplanin- and calcium sulfate-loaded PMMA bone cement in preventing implant-related osteomyelitis in rats

The objective of this study was to evaluate the efficacy of teicoplanin- and calcium sulphate-loaded polymethylmethacrylate (PMMA) bone cements in preventing experimental implant-related osteomyelitis in rats. Four groups of antibiotic-loaded rods were prepared and were implanted into the lateral condylus of the rat femur after inoculation of Staphylococcus aureus. The effectiveness of these were assessed microbiologically, radiographically, and histopathologically. Radiographic evaluation revealed a significant reduction of periostal reaction and osteolysis in rats that received calcium sulphate- and teicoplanin-loaded rods. Histopathological evaluation confirmed these results. Acute infection and bone necrosis were found to be significantly lower in rats that had received calcium sulphate- and teicoplanin-loaded rods. The addition of calcium sulfate to teicoplanin-loaded PMMA bone cement appeared satisfactory as an antibiotic-carrying system for prophylaxis of experimental implant-related osteomyelitis, but further investigations are needed to reach definitive statements for clinical applications.