Implant survival after sinus elevation with Straumann(®) BoneCeramic in clinical practice: ad-interim results of a prospective study at a 15-month follow-up.

OBJECTIVES: Elevation of the sinus floor with Straumann(®) BoneCeramic gave promising results in some recent clinical studies. However, no study has evaluated the long-term survival of implants after this surgical procedure. We are conducting a prospective, observational study to evaluate the long-term implant survival after this surgical procedure in clinical practice. We present here an ad-interim report of this study, including only patients with ≥12-month follow-up after implant placement. METHODS: This prospective cohort study will last until a follow-up of 5 years will be achieved in at least 50 patients. Inclusion criteria are: age ≥18 years; presence of a maxillary partial unilateral or bilateral edentulism involving the premolar/molar areas; elective rehabilitation with oral implants; and physical capability to tolerate conventional surgical and restorative procedures. Patients are treated according to the two-stage technique and the preparation is filled with Straumann(®) BoneCeramic. Implant survival is evaluated every 3 months for the first 2 years, and then every 6 months up to 5 years. RESULTS: Fifteen patients are considered in this ad-interim analysis. Mean follow-up was 14.9 ± 3.1 (range: 6-18 months). In total, three implants failed, in one single patient, 6 months after insertion. The cumulative implant survival rate was 92.5% (95% confidence interval: 83.0-100%). CONCLUSIONS: This ad-interim analysis suggests that the elevation of the sinus floor with Straumann(®) BoneCeramic may be an effective clinical option over >1-year follow-up. A longer term follow-up will allow a deeper characterization of these preliminary findings.

Bone remodeling around implants placed in fresh extraction sockets.

The aim of the present experimental study was to evaluate the physiologic bone remodeling in beagle dogs following the placement of small-diameter (3.25 mm) implants in fresh extraction sites. Five 1-year-old beagle dogs that weighed approximately 10 to 13 kg each were used in this study. The third and fourth premolars (P3, P4) were used as experimental teeth, which were hemisected using a fissure bur; the distal roots were removed carefully using forceps. Implants (3.25-mm wide, 10- or 11.5-mm long) were placed in the fresh extraction sockets with the neck of the implant at the level of the buccal bone crest. The dogs were subsequently put to sleep according to the following schedule: one dog 15 days after implant placement, two dogs after 1 month, and the remaining two dogs after 3 months. The distance from the implant shoulder to the bone wall crest was measured at both the buccal and lingual sites. The width of the buccolingual bone crest was measured using a caliper. Assessments were made immediately after root extraction and at 2, 4, and 12 weeks after implant placement. The mean width of the buccolingual bone crest was 4.5 ± 0.5 mm at the time of root extraction. Subsequently, at 2, 4, and 12 weeks after implant placement, the buccolingual bone width was 4.1 ± 0.5 mm, 3.7 ± 0.3 mm, and 3.5 ± 0.7 mm, respectively. Two weeks after implant placement, the lingual bone crest was measured at 0.2 ± 0.3 mm from the implant shoulder, while the buccal bone crest was 0.3 ± 0.3 mm. After 4 weeks of healing, the mean distance from the implant shoulder to the lingual bone crest was 0.1 ± 0.9 mm, compared to 0.4 ± 0.9 mm for the buccal bone crest. After 12 weeks of healing, the bone crest at the lingual sites was -0.3 ± 0.5 mm from the implant shoulder, compared to 0.8 ± 0.3 mm at the buccal sites. The findings from this study show that although vertical bone remodeling was indeed observed, the mean vertical buccal bone resorption was 0.5 mm. It might be suggested, therefore, that the implant position along the lingual wall and the use of implants with a narrow diameter in relation to the extraction socket width play a key role in reducing the rate of vertical bone resorption at the buccal aspect of implants placed in fresh extraction sockets.

Immediate restoration of single implants placed immediately after implant removal. A case report.

The purpose of this case report is to describe the treatment of implants placed in fresh extraction sockets and immediately restored in cases of failure. A healthy 58-year-old nonsmoking man was referred for an implant that had lost osseointegration because of infection. The prosthesis showed slight mobility. It was therefore decided to remove the implant and replace it with a new one immediately. Since the patient refused to wear a provisional removable prosthesis, the possibility of applying an immediate loading protocol was discussed. The failed implant was removed carefully and the residual extraction socket was thoroughly debrided. Subsequently, the new implant was placed with a sterile surgical technique, as described by the manufacturer. The inserted implant had a titanium plasma-sprayed surface. Immediately following implant placement and with the patient still under local anesthesia, the initial restorative treatment began. The patient was placed on a strict follow-up regimen until soft tissue healing was complete. Subsequent follow-up examinations were performed after 12 months. At each recall, the patient underwent a thorough clinical and radiographic evaluation. The healing period proceeded smoothly. At the end of the follow-up period, the implant was asymptomatic, immobile, and osseointegrated. No peri-implant bony defects were observed on probing. The results of the present case report seem to suggest that implants placed in fresh extraction sockets and restored immediately might provide a valid treatment option for the treatment of failed implants.

Buccal bone augmentation around immediate implants with and without flap elevation: a modified approach.

PURPOSE: The aim of this study was to compare the clinical success and bone healing of implants placed in fresh extraction sockets using a flapless procedure compared to those placed with flap elevation. MATERIALS AND METHODS: Twenty teeth in 20 patients were selected for this study and were scheduled for tooth extraction and immediate implant placement. Ten implants were placed with flap elevation (control group), and 10 implants were placed without flap elevation (test group). All the sites selected showed a complete bone defect at the facial wall. All the implants included in this study were 2-stage implants placed at the level of palatal/lingual bone in augmented bone. Each surgical site was protected with a collagen membrane and, subsequently, a standardized radiograph was taken to evaluate the distance between the implant shoulder and the first bone-implant contact (DIB). Six months after placement, both control and test implants underwent a second-stage surgery and a clinical examination to determine the implant stability quotient, DIB, and the distance between implant shoulder and the crestal bone at the midbuccal aspect (DIC). RESULTS: One implant failed in the test group. Only 1 implant (test group) showed bone growth over the implant neck at the re-entry procedure. Implant stability quotient (ISQ) and DIB did not show any significant differences between the control and test group; however, a higher DIC was found in the test sites compared to the control sites. CONCLUSION: Data from this study showed that immediate implants with and without a mucoperiosteal flap elevation can be successfully used even in the presence of bone defects requiring augmentation procedures. It was also noted that the bone regenerated reached a higher coronal level in the group with flap elevation than in the group without flap elevation.

Connective tissue grafts in postextraction implants with immediate restoration: a prospective controlled clinical study.

Advances in biomaterial technology and clinical research have equipped clinicians with efficient tools to provide advanced treatment options. As a result, some of the original prerequisites for osseointegration have been redefined to satisfy patients' expectations of reduced treatment time, improved aesthetics, and increased comfort. Novel treatment concepts, such as immediate implant loading and early implant loading, have been proposed to reduce the overall treatment time and to allow delivery of the definitive prosthesis in the shortest time possible following implant placement. The purpose of this clinical study was to evaluate the aesthetic results obtained following the placement of transmucosal implants into fresh extraction sockets and immediate restoration with provisional crowns.

Implant placement in fresh extraction sockets and simultaneous osteotome sinus floor elevation: a case series.

The purpose of this study was to evaluate the clinical success of implants placed in fresh extraction sockets with simultaneous maxillary sinus floor elevation using the osteotome technique. Twelve patients were included. All the patients required the extraction of a maxillary premolar--close to the maxillary sinus--and were scheduled for immediate implant placement. One experimental implant was placed per patient, with an 18-month follow-up period. The graft materials used in both sinus augmentation and peri-implant bone defects were a mixture of collagen gel and corticocancellous porcine bone particles. All implants were allowed to heal for 6 months prior to prosthetic rehabilitation. One of the 12 experimental implants failed because of an abscess during early healing. No implants failed after definitive prosthetic rehabilitation. No significant bone loss was detected at the final follow-up visit. The mean bone height before sinus elevation and implant placement was 7.8 mm. Eighteen months after surgery, the mean bone height was 12 mm. When adequately performed, the surgical procedure described in the present study--immediate implant placement and simultaneous sinus floor elevation--appears to be unproblematic and predictable in terms of clinical success.

Connective tissue graft used as a biologic barrier to cover an immediate implant.

BACKGROUND: The purpose of the present study was to evaluate the clinical efficacy of placing implants in fresh extraction sites with simultaneous connective tissue grafting. The teeth selected for this treatment showed gingival recession and/or absence of attached gingiva. METHODS: Ten patients (five men and five women), 42 to 55 years of age, were included in the study. After initial examination and treatment planning, all of the patients selected for the study underwent periodontal treatment that was deemed necessary to favor wound healing. Subsequently, the teeth were extracted, and implants were placed without reflection of a mucoperiosteal flap. Immediately after implantation, a connective tissue graft was placed over the implants to treat the gingival recession. The second stage of surgery was performed 6 months after the initial procedure. The following clinical parameters were evaluated for each patient at 6 and 12 months after implant placement and connective tissue grafting: probing depth, probing attachment level, and mobility. Radiographs were taken using a standardized method to evaluate the marginal bone loss. Esthetic outcomes were evaluated using the measurements before implant placement and 12 months after surgery: width of the keratinized mucosa, emergence profile of the crown, and patient satisfaction. RESULTS: The healing period was uneventful for all patients. All of the implants had osseointegrated. At the end of the 12-month follow-up, the patients were asymptomatic, and the implant sites showed no signs of infection or bleeding when probed. The parameters used to estimate the esthetic outcomes showed an improvement. CONCLUSIONS: Implant placement immediately after tooth extraction with simultaneous connective tissue graft was considered a successful procedure. Moreover, the surgical approach used in this study can be considered a treatment option in cases with non-salvageable teeth showing gingival recession and the absence of attached gingiva.

Vertical crestal bone changes around implants placed into fresh extraction sockets.

BACKGROUND: The aim of this study was to analyze bone healing and vertical bone remodeling for implants placed immediately after tooth removal without guided bone regeneration techniques. METHODS: Twenty patients received 20 implants immediately after the removal of 20 teeth. All implants were placed within the undamaged alveoli confines, and the cervical portion of each implant was positioned at coronal bone level. The distance from implant shoulder and bone crest was measured for each implant at four sites (mesial, buccal, distal, and palatal/lingual). No membranes or filling materials were used. Primary flap closure was performed in all clinical cases. RESULTS: All peri-implant bone defects had healed completely 6 months after implant placement. The pattern of bone healing around the neck of the implants showed an absence of peri-implant defects. The vertical distance between the implant shoulder and bone crest ranged from 0 to 2 mm. CONCLUSIONS: The bone remodeling of implants placed in fresh extraction sockets showed a healing pattern with new bone apposition around the implant's neck and horizontal and vertical bone reabsorption. The vertical bone reabsorption, which has been observed at buccal sites, was not associated with any negative esthetic implications.

Immediate loading of implants with 3-unit fixed partial dentures: a 12-month clinical study.

PURPOSE: The aim of the present clinical trial was to evaluate the 12-month success rate of titanium dental implants placed in the posterior mandible and immediately loaded with 3-unit fixed partial dentures. MATERIALS AND METHODS: Patients with missing mandibular premolars and molars were enrolled in this study. To be included in the study, the implants had to show good primary stability. Implant stability was measured with resonance frequency analysis using the Osstell device (Integration Diagnostics). Implants were included in the study when the stability quotient (ISQ) exceeded 62. Clinical measurements, such as width of keratinized tissue, ISQ, and radiographic assessment of peri-implant bone crest levels, were performed at baseline and at the 12-month follow-up. The comparison between the baseline and the 12-month visits was performed with the Student t test for paired data (statistically significant at a level of alpha = 0.05). RESULTS: Forty implants with a sandblasted, large grit, acid-etched (SLA) surface (Straumann) were placed in 20 patients. At 12 months, only 1 implant had been lost because of an acute infection. The remaining 39 implants were successful, resulting in a 1-year success rate of 97.5%. Neither peri-implant bone levels, measured radiographically, nor implant stability changed significantly from baseline to the 12-month follow-up (P > .05). DISCUSSION: The immediate functional loading of implants placed in this case series study resulted in a satisfactory success rate. CONCLUSION: The findings from this clinical study showed that the placement of SLA transmucosal implants in the mandibular area and their immediate loading with 3-unit fixed partial dentures may be a safe and successful procedure.

Clinical outcome of implants placed immediately after implant removal.

BACKGROUND: The purpose of this study was to evaluate the clinical success of implants placed immediately after the explantation of failed implants due to fracture at 12 months. METHODS: Nine immediate implants were placed in nine patients following explantation of nine fractured implants. Five experimental implants did not require any regenerative procedures; the remaining four immediate implants were grafted with deproteinized porcine bone particles and covered with bioabsorbable membranes. All implants were restored with fixed prostheses. The follow-up period was 12 months. RESULTS: No residual bone defects were observed or probed around any implant at the second-stage surgery, and all implants were asymptomatic and stable. All the implants were successful after prosthetic rehabilitation showing no mobility, pain, suppuration, or absence of peri-implant radiolucency. The radiographic measurements showed no significant bone loss pattern at the 12-month follow-up visit. CONCLUSION: The findings of this study suggested that implants placed immediately after implant explantation due to biomechanical fracture could be performed with results that are similar to results obtained with implants placed immediately after tooth extraction.

A comparison between enamel matrix derivative and a bioabsorbable membrane to enhance healing around transmucosal immediate post-extraction implants.

BACKGROUND: This clinical report compares the use of an enamel matrix derivative (EMD) and bioabsorbable barrier membrane to enhance healing following the immediate placement of transmucosal implants into extraction sockets. METHODS: Thirty-two adult patients scheduled for tooth replacement with dental implants agreed to participate. Following the insertion of a transmucosal implant into the extraction site, the subjects were assigned to one of two treatment alternatives of the remaining bone defects around the implants: 1) the residual bone defects were filled with EMD (EMD group) or 2) the residual bone defects were covered with a bioabsorbable membrane (membrane group). Flaps were then coronally positioned around implant cover screws. Patients followed weekly maintenance recalls for the first 6 weeks and then monthly recalls until the final prosthetic restoration was completed (after 6 months). The treatment outcome was evaluated after 12 months by the use of clinical variables. The null hypothesis of no treatment group differences was tested by the use of analysis of variance (ANOVA). RESULTS: At a 12-month follow-up, all of the implants were completely osseointegrated and successfully functioning, showing a success rate of 100%. The membrane group showed a significantly lower mean probing attachment level than the EMD group at proximal (0.60 mm, standard deviation (SD) 0.37 versus 1.19 mm, SD 1.10), buccal (0.80 mm, SD 0.79 versus 1.77 mm, SD 1.16), and lingual sites (0.44 mm, SD 0.52 versus 1.48 mm, SD 1.46). The difference was statistically significant at all sites (P < 0.05). With respect to the position of the soft tissue margin around the implant shoulder, the membrane group showed a consistently higher value than the EMD group at, respectively, proximal (1.30 mm, SD 2.37 versus 1.16 mm, SD 1.0), buccal (0.90 mm, SD 1.29 versus 0.22 mm, SD 1.47), and lingual sites (1.12 mm, SD 1.10 versus 0.55 mm, SD 1.42). CONCLUSIONS: The membrane group obtained more favorable results in terms of both the probing attachment level and peri-implant position of soft tissues compared to the EMD group. The use of a bioabsorbable membrane around immediately placed transmucosal implants enhanced soft and hard tissue healing and might be an advisable treatment choice particularly in areas with high esthetic demands.

Immediate restoration of implants placed into fresh extraction sockets for single-tooth replacement: a prospective clinical study.

The aim of the present clinical study was to evaluate the placement of transmucosal implants into fresh extraction sockets and their immediate restoration with temporary crowns. A series of 22 cases with a 12-month follow-up is presented. Twenty-two patients (15 women and 7 men; mean age 39 years) who needed a single tooth replaced because of vertical or horizontal root fracture, caries, endodontic lesions, or periodontal disease were treated with immediate postextraction implant placement. The implant was then restored with a screw-retained prosthetic restoration within 24 hours. Radiographic assessments were made at baseline and 12 months after implant placement. Clinical parameters, such as plaque score, mucositis score, probing attachment level, mucosal margin position, variation of gingival level, and variation of papilla position, were also measured at baseline and after 12 months of follow-up. At 12 months, no implants had failed. Radiographic examination revealed mean bone resorption of 0.5 mm at 12 months compared to baseline. The mean variation of gingival level, compared to the neighboring teeth, was -0.75 mm. Probing attachment levels were 0.79, 0.45, and 0.54 mm at proximal, buccal, and lingual sites, respectively. The values for the mucosal margin position were 2.9, 2.2, and 2.4 mm at proximal, buccal, and lingual sites, respectively. Regarding variation of papilla position, according to Jemt's index, 27 papillae presented with a score of 2 (61%) and 17 with a score of 3 (39%). An examination of oral hygiene and peri-implant soft tissue conditions at the 12-month follow-up visit revealed an overall frequency of plaque-carrying implant surfaces of 13%. Furthermore, mucositis (score 2) was not observed at any of the peri-implant units. Primary implant stability did not significantly increase over time. The immediate restoration of dental implants placed into fresh extraction sockets was shown to be a safe and predictable procedure. The success rate and radiographic and clinical results were comparable to those obtained following the standard protocol. Within the limits of the present investigation, immediate restoration of single-tooth implants placed in fresh extraction sockets can be considered a valuable option to replace a missing tooth. However, long-term clinical trials are needed to confirm the present results.

Immediate restoration of single-tooth implants in mandibular molar sites: a 12-month preliminary report.

PURPOSE: The aim of this prospective clinical study was to evaluate the survival rates at 12 months of transmucosal implants placed in the posterior mandible and immediately restored with single crowns. MATERIALS AND METHODS: Thirty ITI dental implants with sandblasted, acid-etched surfaces were placed in 30 patients missing at least 1 mandibular molar and immediately restored if acceptable primary stability was attained. Primary stability was measured with resonance frequency analysis (RFA) using the Osstell device, and only implants with a stability quotient greater than 62 were included in the study. RFA measurement and radiographic assessment were made at baseline and 6 months after implant placement. Plaque Index, Bleeding Index, probing depth, attachment level, and width of keratinized tissue were measured at the 12 month follow-up examination. RESULTS: At 12 months, only 1 implant had been lost; it was removed because of acute infection. Radiographic as well as clinical examination confirmed osseointegration of all implants, with a survival rate of 96.7%. DISCUSSION: Interestingly, implant stability as measured using RFA did not increase significantly from baseline to 12 months (P > .05). CONCLUSION: The present study showed that immediate restoration of transmucosal implants placed in the mandibular area with good primary stability can be a safe and successful procedure. However, larger, long-term clinical trials are needed to confirm the present results.

Maxillary sinus elevation for implant placement using calcium sulfate with and without DFDBA: six cases.

Maxillary sinus lift is a surgical procedure performed to increase the volume of bone mass so that dental implants can be placed in the maxillary arch. Several materials have been suggested to be used for this procedure. The purpose of this study was to present the clinical and histologic results of using calcium sulfate with and without demineralized freeze-dried bone allograft (DFDBA) in sinus lift. Medical-grade sterile calcium sulfate was used alone or in combination with DFDBA in 6 patients undergoing sinus lift surgery for implant placement. Bone biopsies were taken at different times ranging from 6 to 24 months. All samples examined showed bone growth with some possible remnants of the grafted DFDBA. Implants were inserted either at the time of the lift or 6 months later. All of them were secure with primary stability. The cases reported indicate that calcium sulfate can be successfully used alone or in combination with DFDBA for sinus lift procedures and that possible residues of DFDBA can be found within newly generated bone. (Implant Dent 2004;13:270-277)

Immediate implants supporting single crown restoration: a 4-year prospective study.

BACKGROUND: The placement of implants at the time of tooth extraction has several clinical advantages, such as preservation of the alveolar ridge width and height and reduction of the restorative treatment time. The aim of this study was to evaluate the cumulative success rate of dental implants placed in fresh extraction sockets with and without guided bone regeneration (GBR) used to support a single crown restoration. All of the patients were preselected as candidates for implants. METHODS: Ninety-five patients aged 20 to 68 years with 163 implants were included. All patients were partially edentulous and participated in a personally tailored recall schedule. The follow-up period was 48 months. Patients underwent a clinical and radiographic evaluation annually. RESULTS: The 4-year cumulative success rate was 97%. Five of the 163 implants failed, two during the initial healing time, which were considered early failures and three a year after prosthetic rehabilitation, which were considered late failures. No failure of prosthetic rehabilitation was observed. CONCLUSIONS: Implants placed into fresh extraction sockets with or without regenerative procedures and used to support single crown prosthesis showed a very high cumulative success rate (97%) in a 4-year prospective study. Several observations should be made: 1) all the patients were preselected as candidates for implants and were following a strict oral hygiene regimen; 2) all efforts were made to reduce the number of cases requiring GBR procedures; 3) all the implants had an acid etched/sandblasted implant surface; and 4) all the prosthetic restorations were single crowns.

Soft tissue healing around implants placed immediately after tooth extraction without incision: a clinical report.

PURPOSE: The purposes of the present study were to evaluate implants placed immediately after tooth extraction without incision or primary flap closure and to observe the peri-implant soft tissue healing. MATERIALS AND METHODS: Fifteen patients (9 men and 6 women) aged 31 to 54 years were included in this study. Each patient had a tooth that required extraction, and each had at least 4 mm of bone beyond the root apex. Teeth with multiple roots were excluded from this study. After tooth extraction, the implants were immediately placed without incision or flap elevation. Implant sites showing bone fenestrations, bone dehiscences, or peri-implant bone defects exceeding 2 mm were excluded from this study. In these cases, a standard guided bone regeneration procedure with a surgical flap elevation was used. The second-stage surgical procedure was performed 6 months after the first procedure. The following clinical parameters were evaluated at the time of implant placement and at second-stage surgery: levels of mesial and distal papillae, width of keratinized mucosa, position of mucogingival junction relating to the surrounding tissues, and peri-implant radiolucency and marginal bone loss, which were evaluated radiographically. RESULTS: The postsurgical healing period was uneventful for all patients. Soft tissue closure over the implant sites was achieved in 1 to 3 weeks after surgery at all sites. At second-stage surgery, no peri-implant bone defects were observed or detected by probing around all the experimental implants. The soft tissue anatomy was considered clinically acceptable in all patients. DISCUSSION AND CONCLUSION: Successful osseointegration and complete bone healing were observed for all patients. The soft tissue healing and morphology were satisfactory; additional mucogingival surgery was not required before definitive prosthetic rehabilitation.

Effect of enamel matrix derivative (Emdogain) on bone defects in rabbit tibias.

The aim of this study was to assess the effect of an enamel matrix derivative (Emdogain, Biora, AB, Malmö, Sweden) on bone healing. Ten New Zealand rabbits, weighing about 2.5 kg, were used. One 8-mm bone defect was created in each tibia. The defect on the right leg was filled with Emdogain, whereas the defect on the opposite leg was left unfilled as control. A total of 20 defects were created. Five rabbits each were killed at 4 and 8 weeks with an overdose of Tanax. Block sections containing the defects were retrieved and the specimens processed for light microscopy examination. The slides were stained with acid and basic fuchsin and toluidine blue. Histologically, no differences were noted in both groups at each observation period; in the test group, remnants of the implanted Emdogain were not present at 4 weeks. Newly formed bone was detectable in both groups at all observation times. At 8 weeks, both groups showed mature bone, and in the test group the material implanted was not visible. No inflammatory cells were visible in both groups. In conclusion, our results indicate that Emdogain implanted in bone defects is fully resorbed after 4 to 8 weeks and does not adversely affect bone formation.

Deproteinized bovine bone and biodegradable barrier membranes to support healing following immediate placement of transmucosal implants: a short-term controlled clinical trial.

This 6-month clinical study evaluated the use of a porous bone mineral matrix xenograft (Bio-Oss) as an adjunct to a biodegradable barrier membrane (Bio-Gide) to support healing following the immediate placement of transmucosal implants into extraction sockets. Twenty adult patients scheduled for tooth replacement with dental implants were accepted for participation. Following implant placement into the extraction site, subjects were assigned to one of two treatment alternatives for the remaining bone defect around the implant: (1) Bio-Oss + Bio-Gide membrane (test); or (2) Bio-Gide membrane (control). The treatment outcome was evaluated after 6 months by the use of clinical and radiographic variables. The null hypothesis of no treatment group differences was tested by ANOVA. At 6 months, the radiographic bone level remained unchanged compared to baseline in the test and control groups. No differences were observed between test and control groups in terms of mean probing attachment level. At proximal sites, the soft tissue margin was located 2.6 mm more coronal than the shoulder of the implant in the test group, compared to 1.3 mm in the control group. The corresponding figures for the lingual aspect were 2.3 mm and 1.1 mm, respectively, and at buccal sites 2.1 mm and 0.9 mm, respectively. The use of deproteinized bovine bone mineral as a membrane support at immediately placed transmucosal implants may offer an advantage in areas with high esthetic demands in terms of soft tissue support.

Radiographic bone density around immediately loaded oral implants.

OBJECTIVES: The aim of this study was to analyze the bone density around immediately loaded oral implants by a new volumetric CT scan (Maxiscan) and to compare it with that of unloaded implants. MATERIAL AND METHODS: Four patients with an age range from 44 to 65 years old were selected for this study. All the patients needed a prosthetic rehabilitation in partially edentulous posterior maxillas or mandibles. A total of 12 oral implants were placed in the four patients. Six of these implants were immediately loaded while six were left unloaded. Six months after placement, immediately loaded and unloaded oral implants were analyzed by a volumetric CT scan. RESULTS: The overall success rate in this study with immediately loaded oral implants was 100%. The radiological assessments showed that the mean densitometric profile, which is a measure of bone mineralization, was higher in the immediately loaded group than in the unloaded group. The differences observed between the two groups of oral implants (immediately loaded and unloaded) were statistically significant (P<0.05). The bone was significantly more dense around immediately loaded than unloaded oral implants on the basis of a radiological assessment. CONCLUSION: The innovative aspect of this clinical study is to propose a new method to analyze the bone density, reducing the need for histological analysis from human biopsy.

Transforming growth factor-beta 1 expression in the peri-implant soft tissues of healthy and failing dental implants.

BACKGROUND: Transforming growth factor-beta (TGF-beta) is composed of a family of multifunctional polypeptide growth factors involved in embryogenesis, inflammation, regulation of immune response, angiogenesis, wound healing, and extracellular matrix formation. TGF-beta1 is the most common isoform found in human tissues. A role of TGF-beta in the pathogenesis of periodontal disease has been suggested. The aim of the present study was a comparative immunohistochemical evaluation of TGF-beta1 in normal keratinized gingiva and in the peri-implant soft tissues surrounding failing non-submerged implants. METHODS: Twenty patients participated in this study. Ten biopsies from healthy keratinized mucosa and 10 biopsies from peri-implant soft tissues surrounding failing implants were obtained (one biopsy per patient). The biopsies were obtained from different patients. RESULTS: In 5 cases of healthy mucosa, the stromal cells were positive between 1 to 5. In 7 cases, the epithelial layers were positive, between 1 and 18 cells. The superficial epithelial layer was negative in all cases. In 9 cases, there was a positivity of the vascular component, between 2 and 16 vessels. In failing implants, the stromal cells were positive in 6 cases, between 1 and 4. In all cases, cells of the epithelial layers were positive, between 15 and 40. The vascular component was positive in all cases, between 12 and 30 vessels. The differences between TGF-beta1 expression in the epithelium around healthy and failing implants were statistically significant (P < 0.0001). The differences between TGF-beta1 expression in the blood vessels in the soft tissues around healthy and failing implants were also statistically significant (P < 0.0001). No statistically significant difference was observed between the 2 groups in the TGF-beta1 expression in the stromal cells (P = 0.88). CONCLUSION: TGF-beta1 may be one of the most important factors in the regulation of the infiltrate, and in the production of tissue repair with a stimulation of fibroblasts and endothelial cells.