Marginal bone resorption around dental implants placed in grafted sinuses; an up-to-30-month clinical and radiological follow-up

OBJECTIVE

To determine the relative success of two different bone grafting material - putty and powder forms of De-mineralised Bone Matrix (DBM) - used in sinus lift procedure.

METHODS

The retrospective study was conducted at the Department of Oral and Maxillofacial Surgery, Ankara University, Ankara, Turkey, and comprised data related to the patients referred for bilateral maxillary sinus augmentation between 2007 and 2010. During the period, 48 endoosseous implants were placed concurrently with the sinus augmentation in 12 patients. Marginal bone loss around the implants was measured at the time of loading, 12 and 30 months after the treatment. SPSS 11.5 was used for data analysis.

RESULTS

Of the 12 patients, 8 (66.6%) were females and 4 (33.3%) were males. All implants osseointegrated in both the putty and powder groups well without any significant clinical finding. The average volume of marginal bone resorption at implants for the putty side was 0.43 +/- 0.22 mm, 0.8 +/- 0.33 mm and 1.12 +/- 0.49 mm at prosthetic loading, 12-month and 30-month follow-up, respectively. For the powder side, the corresponding numbers were 0.48 +/- 0.32 mm, 0.82 +/- 0.46 mm and 1.24 +/- 0.57 mm. No statistically significant difference in bone loss between the two groups was observed (p > 0.05).

CONCLUSION

Both putty and powder forms of de-mineralised Bone Matrix showed satisfactory results and there was no significant difference in marginal bone loss around dental implants and survival rates.

Bone graft materials in fixation of orthopaedic implants in sheep

Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many orthopaedic procedures, whereas allograft is the gold standard by replacement of extensive bone loss. However, the use of autograft is associated with donor site morbidity, especially chronic pain. In addition, the limited supply is a significant clinical challenge. Limitations in the use of allograft include the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking skeletal bones. The osteoconductive properties of the composite might be improved by adding bone marrow aspirate (BMA), which can be harvested during surgery. Other alternatives to bone graft are demineralised bone matrix (DBM) and human cancellous bone (CB). DBM is prepared by acid extraction of human bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA/Collagen composite alone and in combination with BMA on the early fixation of porous coated titanium implants. In addition, the study compares also the effect of autograft with the gold standard allograft. By using a sheep model, the implants were inserted in the trabecular bone of femoral condyles. The test biomaterials were placed in a well defined peri-implant gap. After the observation period, the bone-implant specimens were harvested and evaluated mechanically by a destructive push-out test and analyzed histologically qualitatively and quantitatively. Study II investigates the effect of DBM alone and in combination with CB or allograft. The control group in study I and II was allograft. Study III is a methodological study and investigates the potential systematic bias by applying the traditional sampling method, which includes evaluating the mechanical fixation by using the superficial part and the histological analysis by using the profound part of the implant. The implants in this study were inserted in the proximal humerus and only allograft was used in the peri-implant gap. In study I, the mechanical testing showed failure by the preloading in the composite group with and without BMA. There were no bone ongrowth and sparely bone formation in the gap by the composite group. Adding BMA to the composite has no beneficial effect on implant fixation. No significant difference between autograft and allograft on mechanical fixation, bone ongrowth and bone formation. In study II the combination of DBM with CB or allograft showed no significant differences on the mechanical testing and histological analysis to the control group, whereas DBM alone showed significant low mechanical fixation, low bone ongrowth and low bone formation. Study III showed no significant difference between the sampling methods. In conclusion, HA/Collagen composite alone or in combination with BMA has no effect on the early fixation of porous coated titanium implants. Autograft has comparable effect on allograft with regard to early implant fixation. The combination of DBM with CB may represent an alternative to allograft. In study III, mechanical testing and histological analysis can be applied either from the superficial or the profound part of the implant. By applying the histological analysis from the superficial part and the mechanical testing from the profound part, an extra section is required.

[Use of the PEEK cage in cervical spondylosis treatment]

BACKGROUND

Decompression and fusion with autograft is the gold standard technique in the treatment of cervical canal strait. Using PEEK cages or boxes of non-absorbable polymer with elasticity similar to bone, radiolucent, reduces morbidity and same degree of fusion.

METHODS

A case series, prospective, longitudinal, deliberate intervention, evaluation panel before and after 2 years follow-up. Discectomy and PEEK housing placement with autologous graft. Arthrodesis were evaluated, cervical lordosis, intervertebral space height, pain evaluated with Visual Analogue Scale, Neck Disability Index, operative time, intraoperative bleeding, hospital stay and complications. Statistical analysis with t Sudent, Wilcoxon and Fisher's exact text.

RESULTS

Of 17 patients studied, 9 (53%) were female. Average age 62 years. The most affected level was C5-6, C6-7 with 5 patients. Melting was found at 100%. There was no sag or migration of the box, space height was conserved, but segmental lordosis was not retained. Clinical improvement in all patients as well as disability index was seen. Bleeding was on average 187 mL.

CONCLUSION

With regard to symptom improvement, conservation of interspace height and back, no segmental lordosis conservation and fusion using PEEK box is consistent with the literature. We suggest using anterior plate to maintain cervical lordosis. We found a melt index of 100%. We found clinical improvement of symptoms, pain and disability, and a global loss of cervical lordosis.

[Biosafety evaluation of collagen-based bone repairing material]

To evaluate the biological safety of collagen-based bone repairing material, we implanted the sample or reference substance into rats, and observed relative signs, including the specific inspection targets in animals, blood examination, analysis of immune organ, the pathological examination of organs and tissues, NK cell killing activity assay, lymphocyte group analysis, serum IL-1, IL-6, TNF-alpha detection, detection of immune globulin. Meanwhile, we set control group, sham group, and immunosuppression group. The final results showed that there was no abnormal mental state before and after the experiment. Compared with the control group, the tested group indicated no significant difference in blood test, immune organ analysis, the pathological examination of organs and tissues, NK cell killing activity assay, lymphocyte subset analysis serum IL-1, IL-6, TNF-alphadetection, and detection of immune globulin. Collagen-based bone repairing material produced a slight and transient stimulation on the rats, but created no significant inflammatory responses.

Layered socket Grafting using an anorganic bovine bone mineral-collagen composite

Following tooth extraction, socket grafts are commonly used to prevent incomplete healing and to optimize the bony site for implant placement (1). Many particulate, composite, and putty-like bone grafting materials either with or without a membrane have been used as socket grafts. This article introduces the layered socket grafting technique for socket grafting without the use of a membrane or primary closure. This technique uses a particulate anorganic bone mineral to graft the apices of sockets and then a composite material consisting of anorganic bovine bone mineral and collagen for the superior or crestal one-third of a socket or defect. When grafting sockets, the technique is fast and does not require the use of releasing flaps or primary closure and can also be used to manage large periapical defects.

A comparison of two dental implant systems in partially edentulous patients: 4-month post-loading results from a pragmatic multicentre randomised controlled trial

PURPOSE

To compare the clinical effectiveness of two implant systems: Way Milano and Kentron (Geass, Pozzuolo del Friuli, UD, Italy).

MATERIALS AND METHODS

A total of 64 patients requiring at least two single crowns or partial fixed dental prostheses supported by a maximum of three implants had their sites randomised according to a split-mouth design to receive both implant systems at six centres. Patients were followed up for 4 months after initial loading. Outcome measures were prosthesis/implant failures, any complication and clinician preference.

RESULTS

In total, 71 Way Milano and 73 Kentron implants were placed. One patient died 45 days after placement of 2 implants, but all remaining patients were followed up to 4 months post-loading. No Way Milano implant failed whereas 3 Kentron implants failed before loading. Two complications were reported, one at each implant type. There were no statistically significant differences for prosthesis/ implant success and complications between the implant systems. Three operators preferred Way Milano implants whereas the other 3 had no preference.

CONCLUSIONS

Preliminary short-term data (4 months post-loading) showed no statistically significant differences between the two implant systems, however trends were suggestive of a better clinical performance for Way Milano implants.

Early healing after ridge preservation with a new collagen matrix in dog extraction sockets: preliminary observations

The aim of the present animal study was to investigate the early healing processes developing in the post-extraction sockets preserved with a new-marketed collagen matrix as, to our knowledge, such investigations have not been reported so far. In both quadrants of the mandible of a mongrel dog, the distal sockets of the second premolars served as experimental sites for ridge preservation. The experimental site 1 was protected with a resorbable membrane and then with the collagen matrix. The experimental site 2 was filled with a xenograft and then covered with the collagen matrix. The samples were harvested after one month of healing. In both experimental sites, the bundle bone lining the inner surface of the alveolus was replaced with trabecular bone containing areas of woven bone. A continuous layer of osteoblasts could be observed on the surface of woven bone areas. Osteoclasts encased within resorptive lacunae lined the outer portions of bone walls for the experimental site 1. The trabecular bone occupied only the apical third of the socket in experimental site 1, but it was obviously more abundant in the experimental site 2, occupying also the central compartment of the socket. Moreover, the trabeculae of the bone occupying the inner area of the alveolus were thicker for the experiment site 2 than for experiment site 1, suggesting an increased osseous deposition in the latter situation. Our preliminary results suggest that the association collagen matrix plus xenograft may be a valuable method for ridge preservation.

1-stage versus 2-stage lateral maxillary sinus lift procedures: 4-month post-loading results of a multicenter randomised controlled trial

PURPOSE

To compare the efficacy of 1-stage versus 2-stage lateral maxillary sinus lift procedures.

MATERIALS AND METHODS

Sixty partially edentulous patients requiring 1 to 3 implants and having 1 to 3 mm of residual bone height and at least 5 mm of bone width below the maxillary sinus, as measured on CT scans, were randomised into two equal groups to receive either a 1-stage lateral window sinus lift with simultaneous implant placement or a 2-stage procedure with implant placement delayed by 4 months using a bone substitute in 3 different centres. Implants were submerged for 4 months and loaded with reinforced provisional prostheses, which were replaced, after 4 months, by definitive prostheses. Outcome measures were augmentation procedure failures, prosthesis failures, implant failures, complications and marginal peri-implant bone loss assessed by a blinded outcome assessor. Patients were followed up to 4 months after loading. Only data of implants placed in 1 to 3 mm of bone height were reported.

RESULTS

Two patients dropped out from the 1-stage group and none from the 2-stage group. No sinus lift procedure failed in the 1-stage group but 1 failed in the 2-stage group, the difference was not statistically significant (P = 1.00). Two prostheses failed or could not be placed in the planned time in the 1-stage group and 1 in the 2-stage group, the difference was not statistically significant (P = 0.51). Three implants failed in 3 patients of the 1-stage group versus 1 implant in the 2-stage group, the difference was not statistically significant (P = 0.28). Two complications occurred in the 1-stage group and 1 in the 2-stage group, the difference was not statistically significant (P = 0.61). There were no statistically significant differences in bone loss between groups at loading (0.05 mm). Sites treated in 1 stage lost an average of 0.56 mm (SD: 0.36; 95% CI: -0.70 to -0.42; P < 0.001) of peri-implant bone and 2-stage sites approximately 0.61 mm (SD: 0.34; 95% CI: -0.74 to -0.48; P < 0.001).

CONCLUSIONS

No statistically significant differences were observed between implants placed according to 1- or 2-stage sinus lift procedures. However, this study may suggest that in patients having a residual bone height between 1 and 3 mm below the maxillary sinus there might be a slightly higher risk for implant failures when performing a 1-stage lateral sinus lift procedure.

[Clinical evaluation of periodontal intrabony defects treated with a reconstituted bovine porous bone mineral containing bone morphogenetic proteins]

OBJECTIVE

To compare the outcomes of bovine porous bone mineral (BPBM) containing bone morphogenetic proteins (BMP) and BPBM alone in periodontal intra-bony defects.

METHODS

In the study, 22 intrabony defects of 9 patients with periodontitis were recruited. All the patients had at least one pair of intrabony defects of ≥3 mm. The split-mouth and single blind methods were used. The defects were randomly assigned to BPBM containing BMP (test) or BPBM alone (control). After debridement, the intrabony defects were treated by bone graft. Assessments at baseline and after 6 months included plaque index, attachment level, probing pocket depth, bleeding indexes on probing and gingival recession. The early wound-healing, adverse effects and patients' perceptions were also recorded.

RESULTS

The gain in clinical attachment was (3.0±1.2) mm in the test group and (3.2±1.1) mm in the control group. The pocket reduction was (3.4±1.5) mm in the test group and (2.8±1.0) mm in the control group. The reduction of bleeding index was 1.9±1.3 in the test group and 2.3±0.8 in the control group. There was no statistical difference between the test group and control group (P>0.05).

CONCLUSION

Both treatment modalities led to similar significant clinical improvements.

A histologic and clinical evaluation of ridge preservation following grafting with demineralized bone matrix, cancellous bone chips, and resorbable extracellular matrix membrane

In an attempt to reduce postextraction alveolar bone resorption, ridge preservation grafting procedures with or without resorbable membranes have become standard-of-care treatments following tooth removal. This prospective case series examined histologic and clinical outcomes following socket grafting with a syringeable paste allograft and a resorbable extracellular matrix membrane at three different time periods following postextraction grafting: 6, 12, and 24 weeks. At each time period, bone core specimens were retrieved for microscopic examination, and implants were placed. Following prosthetic restoration, implants were monitored under long-term occlusal function. At all three time periods, histologic results revealed active bone regeneration. At 6 weeks, localized areas of woven bone were evident, although nonmineralized osteoid was the dominant feature. At 12 and 24 weeks, regenerated woven bone dominated the histologic landscape, with increasing amounts evident in the latter specimens. Regardless of when implants were placed following grafting, implant survival under function occurred.

Enhanced activity of demineralised bone matrix augmented with xenogeneic bone morphogenetic protein complex in rats

INTRODUCTION

Demineralised bone matrix (DBM) is an allograft material widely used as a bone filler and bone graft substitute. DBM contains bone morphogenetic proteins (BMPs), which induce and regulate bone formation during embryogenesis and in postnatal life.

AIMS AND OBJECTIVES

To investigate the osteoinductivity of DBM augmented with xenogeneic BMP-complex at different doses.

MATERIALS AND METHODS

Rat DBM was augmented with BMP-complex purified from porcine diaphyseal bone.

RESULTS

Dorsal subcutaneous implantation of 25 mg rat allogeneic DBM augmented with 0, 3, 6 and 12 mg BMP-complex per gram of DBM resulted in dose dependant up-regulation of bone formation on day 21, as scored histologically and biochemically.

CONCLUSIONS

Allogeneic DBM can be augmented with xenogeneically sourced BMP-complex to improve DBM performance in vivo. This work demonstrates the potential of BMP-complex augmented DBM to induce new bone formation with improved parameters of bone formation.

Histologic and histomorphometric evaluation of an implant retrieved 8 years after insertion in a sinus augmented with anorganic bovine bone and anorganic bovine matrix associated with a cell-binding peptide: a case report

Few histologic and histomorphometric reports are present in the literature regarding the peri-implant bone response around implants inserted in sinuses grafted with different biomaterials. Anorganic bovine bone (ABB) and anorganic bovine matrix with the addition of an active cell-binding peptide (PepGen P-15) are xenogenic materials that have been reported to present biocompatibility and osteoconductivity. A monolateral sinus augmentation procedure with ABB (50%) and PepGen P-15 (50%) was performed in a 54-year-old man. Two titanium implants with a sandblasted and acid-etched surface were inserted after 6 months. After an additional 6 months, a fixed prosthetic restoration was fabricated. One implant fractured in the coronal portion after an 8-year loading period and was removed using a 5-mm trephine bur. Few particles of both grafting materials were present in the peri-implant bone. No graft material particles were found in contact with the implant surface, and bone was always interposed between the graft materials and surface. No inflammatory cell infiltrate, multinucleated giant cells, or foreign body reaction cells were found. The tissues around the implant were composed of 51.4% ± 4.8% bone, 6.2% ± 0.7% ABB particles, 2.4% ± 0.5% PepGen P-15, and 40.0% ± 7.1% marrow spaces. The bone-implant contact percentage was 78.4% ± 4.1%. A sinus augmentation procedure using ABB and PepGen P-15 produced bone formation with subsequent implant osseointegration, which was still present after 8 years of implant loading.

Socket site preservation using bovine bone mineral with and without a bioresorbable collagen membrane

The purpose of this study was to compare extraction sites augmented with bovine bone mineral (BBM) with and without resorbable membrane coverage. BBM particles were grafted in fresh human extraction sockets of 23 patients; in 12 of these patients, a guided tissue regeneration (GTR) membrane was applied. After 9 months of histomorphometric evaluation, cylindric hard tissue specimens were obtained. Percent bone area fractions (BAFs) of the crestal, middle, and apical sections from each specimen were calculated using the point-counting technique. Changes in values were compared. In sites augmented with BBM, the mean BAF ranged from 22.8% (coronal) to 36.3% (apical) compared to sites augmented with BBM and collagen membrane (35.2% [coronal] to 47% [apical]). Comparison between the different depths and the two groups showed a distinct increase in BAF from coronal to apical regions (P < .001). This pattern was observed in both groups (P < .001) and was significantly higher in the group augmented with BBM and collagen membrane (P < .05). In the immediate postextraction phase, BBM as a grafted biomaterial preserved the socket volume and enabled newly formed bone for future implant site preparation. The amount of the osseous fraction increased with GTR membrane.

Treatment of combined endodontic-periodontic lesions using guided tissue regeneration: clinical case and histology

The aim of this case report is to histologically evaluate periapical healing after combined endodontic-periodontic treatment. A maxillary left central incisor was treated with conventional endodontic therapy, followed by periodontal surgery. The facial bony defect was filled with a mixture of autologous bone and Bio-Oss. A resorbable membrane was used. Histology showed the presence of new cementum, ligament, and bone around the apex of the treated tooth. This finding was clinically associated with minimal residual probing depth and maximum attachment gain. This histologic report demonstrates the possibility of true regeneration in a case of severe periodontal attachment loss resulting from an endodontic-periodontic lesion.

Histologic evaluation of an allogeneic mineralized bone matrix in the treatment of periodontal osseous defects

The aim of this study was to evaluate the potential of an allogeneic bone matrix to regenerate new bone, cementum, and periodontal ligament around a previously diseased root surface. Four patients with severe chronic periodontitis and teeth with hopeless periodontal or restorative prognoses participated in this study. One tooth with a severe intraosseous defect was selected per patient. At baseline, measurements of probing depth, gingival recession, and clinical attachment level were obtained. Following flap reflection, a root notch was placed at the apical extent of the calculus; the root was debrided, and the allogeneic bone graft material was placed into the defect. After a minimum of 6 months of healing, the teeth were removed en bloc and prepared for histologic examination. Two of four teeth demonstrated regeneration of new bone, cementum, and periodontal ligament. One tooth healed by new connective tissue attachment, and another by junctional epthelium.

One-year re-entry results of guided bone regeneration around immediately placed implants with immediate or conventional loading: a case series

OBJECTIVE

The aim of this one-year, re-entry case series was to evaluate clinically the amount of bone regeneration following the placement of immediate implants in fresh extraction sockets where bone allograft has been used to treat horizontal gaps and buccal-bone dehiscence defects in periodontally compromised patients.

METHODS

Sixteen patients consented to participate, each having one immediate implant with > 3 mm buccal dehiscence bone defects and > or = 2 mm horizontal defects between the implant and socket wall. Peri-implant defects were treated using a demineralized freeze-dried bone allograft and a bioresorbable collagen membrane. Measurements of the vertical and horizontal bone defects were performed at 4 sites: buccally, mesially, distally and lingually, and were done at baseline and at 1-year follow-up.

RESULTS

The mean reduction in vertical defects between baseline and re-entry for all sites was 2.42 mm (p = 0.0005). Compared to lingual sites, the buccal sites showed the greatest resolution in vertical defects dimension (6.37 mm), followed by proximal sites (0.78 mm). The overall mean reduction in horizontal defects was 1.59 mm (p < 0.0001). Compared to lingual sites, the buccal sites showed the greatest resolution in horizontal gap dimension (3.2 mm), followed by proximal sites (0.8 mm). Age, defect location in the mouth and implant length did not show significant effectson the reduction in defect dimension during the first year.

CONCLUSIONS

A partially missing buccal plate was not a critical factor for implant success and bone regeneration of immediate implants in patients with a history of periodontal disease regardless of the time of implant loading (immediate/conventional).

Mandibular reconstruction with tissue engineering in multiple recurrent ameloblastoma

The aim of this paper is to present a new approach to bone regeneration in a patient with multiple recurrent ameloblastoma of the left mandibular angle. Through an extraoral approach, complete resection of the tumor was achieved. Bone marrow aspirate from the iliac crest was centrifuged to concentrate the mesenchymal cellular fraction. Based on a stereolithographic cast, titanium mesh was bent preoperatively to accurately reconstruct the mandibular angle. The mesh was filled with two blocks of xenogenic material mixed with recombinant bone morphogenetic protein 7 (BMP-7) and stem cells. Nine months later, three endosseous implants were placed in the regenerated bone to restore the patient's masticatory function. At this time, bone samples were obtained for histomorphometric analysis. New bone formation was confirmed around the particles of xenograft material. The results indicate that adequate esthetics and function may be achieved with bone marrow aspirate seeded on a scaffold obtained from bovine xenograft blocks and BMP-7. This technique attains new bone formation with sufficient quantity and quality to allow for implant placement, with decreased patient morbidity and surgical time compared to conventional reconstructive methods.

Impact of recombinant platelet-derived growth factor BB on bone regeneration: a study in rabbits

The aim of this study was to test whether recombinant human platelet-derived growth factor BB (rhPDGF-BB) enhances bone regeneration in combination with Β-tricalcium phosphate (Β-TCP) granules or deproteinized bovine bone mineral (DBBM) compared to empty defects and Β-TCP granules alone. Four titanium cylinders were placed on the external cortical plates of seven rabbits' calvaria and randomly allocated to one of four groups: (1) empty, (2) Β-TCP, (3) Β-TCP + rhPDGF-BB, and (4) DBBM + rhPDGF-BB. The mean area of bone regeneration was 13.9% ± 8.4% (empty), 24.0% ± 14.8% (Β-TCP), 37.1% ± 8.9% (Β-TCP + rhPDGF-BB), and 64.4% ± 5.4% (DBBM + rhPDGF-BB), with the greatest bone regeneration noted for DBBM + rhPDGF-BB (P < .01). The fraction of bone substitute material varied between 48.3% ± 9.3% (DBBM + rhPDGF-BB), 53.1% ± 10.6% (Β-TCP + rhPDGF-BB), and 58.0% ± 14.8% (Β-TCP). rhPDGF-BB combined with DBBM showed the greatest potential to enhance bone regeneration.

Maxillary sinus augmentation with a sonic handpiece for the osteotomy of the lateral window: a clinical report

Several techniques have been proposed to manage patients with insufficient bone height for implant placement in the posterior maxilla. The lateral approach to sinus elevation is a successful procedure, with percentages of success close to 100%. Unfortunately, a frequent complication encountered during sinus elevation procedure is perforation of the Schneiderian membrane. In this clinical report, the authors present the application of a diamond coated sonic tip and an air-driven sonic instrument, commonly used in prosthodontics for the preparation of the lateral window osteotomy during sinus augmentation procedures.

Horizontal and vertical dimensional changes of peri-implant facial bone following immediate placement and provisionalization of maxillary anterior single implants: a 1-year cone beam computed tomography study

PURPOSE

This cone beam computed tomography study (CBCT) evaluated horizontal and vertical dimensional changes to the facial bone following maxillary anterior single immediate implant placement and provisionalization.

MATERIALS AND METHODS

CBCT scans taken immediately after (T1) and 1 year after surgery (T2) were evaluated. The midsagittal cut of each implant was identified, and measurements were made at predetermined levels. Horizontal facial bone thickness (HFBT) was measured at 0, 1, 2, 4, 6, 9, and 12 mm apical to the implant platform. Vertical facial bone level (VFBL) was the perpendicular distance from the implant platform (0) to the most coronal point of the facial bone. Measurements were recorded and changes between T1 and T2 were calculated. The data were analyzed statistically at a significance level of α = 0.05.

RESULTS

CBCT scans of 21 patients were analyzed. At T2, the mean HFBT changes ranged from -1.23 to -0.08 mm at the seven different levels evaluated. The mean VFBL change was -0.82 mm. The HFBT changes at the 1- to 9-mm levels were not significantly different from one another, but they were significantly smaller than the change at the 0-mm level and significantly greater than the change at the 12-mm level. Significant positive correlations were observed only between horizontal and vertical changes and between horizontal change and initial VFBL at the implant platform. While the VFBL of eight implants (38%) was apical to the implant platform at T2, none was noted at T1.

CONCLUSIONS

Dimensional changes to the peri-implant facial bone following maxillary anterior single immediate implant placement and provisionalization should be expected. The greatest HFBT change was noted at the implant platform level, in part because HFBT change is correlated to the initial VFBL and the change in VFBL at that level.

Incidence, diagnosis, and treatment of sinus graft infection after sinus floor elevation: a clinical study

PURPOSE

The aims of this clinical study were to evaluate the occurrence of sinus graft infection and the results of a planned surgical and pharmacologic treatment regimen to eliminate infections and preserve the graft.

MATERIALS AND METHODS

Patients were consecutively treated with sinus floor elevations using the lateral window technique. If a clinical diagnosis of sinus graft infection was made for a patient, a postoperative computed tomographic scan was performed to diagnose involvement of the sinus cavity.

RESULTS

Of 198 patients treated with 274 sinus grafts, 8 (2.3%) developed a sinus graft infection. These patients were treated with the same surgical and pharmacologic regimen. Symptoms of infection were recognized, the infected graft was removed, and the remaining graft material was cleansed. The remaining defect was not filled with new graft material; instead, it was left to heal for an extended healing period (average of 10.6 months), and residual bone defects were corrected during implant placement. Acute symptoms of infection disappeared within 48 hours of treatment and all patients healed uneventfully thereafter. All 24 implants placed have survived to date (with implant loading times ranging from 1 to 9 years), resulting in a 100% implant survival rate for these sites with postoperative infection.

CONCLUSIONS

The overall clinical outcome, including patient satisfaction, achievement of optimal graft volume without subsequent sinus elevation, and long-term implant survival, confirmed the success of this treatment protocol.

A randomized, controlled clinical evaluation of a synthetic gel membrane for guided bone regeneration around dental implants: clinical and radiologic 1- and 3-year results

PURPOSE

The objective of this study was to determine whether a synthetic bioresorbable polyethylene glycol (PEG) hydrogel membrane could provide similar clinical and radiographic outcomes as a standard collagen membrane, both in combination with a membrane-supporting material, during follow-up periods of 1 and 3 years.

MATERIALS AND METHODS

This study enrolled patients requiring implant treatment with an expected osseous defect in the posterior maxilla or mandible. Defects around the implants were grafted with deproteinized bovine bone mineral and covered with either a collagen membrane or a PEG hydrogel membrane, which is applied as a liquid and becomes a solid gel in situ. Surgical re-entry was performed after 6 months, and fixed partial dentures were inserted subsequently. Patients were examined clinically and radiographically 1 and 3 years after loading.

RESULTS

Thirty-six of the 37 included patients were reexamined in the third year. The implant survival rate at 3 years was 100%. The peri-implant tissues were healthy, with no differences between the two groups. Compared to the time of surgery, the mean changes in the distance between the first bone-to-implant contact to the transition point (ie, rough implant surface to polished neck portion) were 0.43 ± 0.56 mm (PEG) and 0.21 ± 0.36 mm (collagen) at 1 year and 0.61 ± 0.89 mm (PEG) and 0.33 ± 0.64 mm (collagen) at 3 years. The respective differences between groups were 0.13 mm (1 year) and 0.31 mm (3 years), which were not significant at either time point (analysis of covariance).

CONCLUSION

The tested PEG hydrogel was as successful as a standard collagen membrane for the treatment of bony dehiscence defects around dental implants after follow-up periods of 1 and 3 years.

Histomorphometric analysis of newly formed bone after bilateral maxillary sinus augmentation using two different osteoconductive materials and internal collagen membrane

Deproteinized bovine bone mineral (DBBM) and human freeze-dried bone allograft (FDBA) were compared in five patients undergoing bilateral maxillary sinus floor augmentation using DBBM on one side and FDBA on the contralateral side. After 9 months, core biopsy specimens were harvested. Mean newly formed bone values were 31.8% and 27.2% at FDBA and DBBM sites, respectively (P = .451); mean residual graft particle values were 21.5% and 24.2%, respectively (P = .619); and mean connective tissue values were 46.7% and 48.6%, respectively (P = .566). Within the limits of the present study, it is suggested that both graft materials are equally suitable for sinus augmentation.

Successful management of peri-implantitis with a regenerative approach: a consecutive series of 51 treated implants with 3- to 7.5-year follow-up

The results of a case series of 51 consecutively treated, peri-implantitis-affected implants in 38 patients with follow-up measurements from 3 to 7.5 years are presented. Each implant displayed bleeding on probing, probing depths ≥ 6 mm, and bone loss ≥ 4 mm prior to surgery. A successful regenerative approach including surface decontamination, use of enamel matrix derivative, a combination of platelet-derived growth factor with anorganic bovine bone or mineralized freeze-dried bone, and coverage with a collagen membrane or a subepithelial connective tissue graft was employed in all cases. Patients were divided into two groups. Group 1 included patients in which the greatest defect depth was visible on radiographs; group 2 included patients in which the greatest loss of bone was on the facial or oral aspect of the implant. Bone level changes in patients in group 2 were determined by probe sounding under local anesthesia. Probing depth reductions at 3 to 7.5 years of follow-up were 5.4 and 5.1 mm in groups 1 and 2, respectively. Concomitant bone level gain was 3.75 mm in group 1 and 3.0 mm in group 2. No implant in either group lost bone throughout the duration of the study. The results to date with this regenerative approach for the treatment of peri-implantitis appear to be encouraging.