A clinical long-term radiographic evaluation of graft height changes after maxillary sinus floor augmentation with a 2 : 1 autogenous bone/xenograft mixture and simultaneous placement of dental implants

Management of combined ridge defect and osteotome sinus floor elevation with simultaneous implant placement--a 36-month follow-up case report

This report demonstrated the management of combined ridge defect and maxillary sinus pneumatization with simultaneous implant placement. One case with vertical and horizontal ridge deficiency and sinus pneumatization in the maxillary premolar area was indicated for ridge augmentation and sinus elevation before implant placement. Implant osteotomy was enlarged using a ridge expansion osteotome to 1 mm short of the sinus floor; sinus elevation was performed using sinus lift osteotomes; the implant was placed; bone graft and resorbable membrane were used to augment the remaining defect. The second stage was done after 6 months, followed by final restoration. The patient was reevaluated for 36 months following the final prosthesis. The surgical site healed without complication following implant placement. During the second stage, the implant was completely surrounded by bone, with bone covering the buccal aspect of the cover screw. The X-ray showed a 5 mm apical shift of the sinus floor at 6 months post surgery. At 12 months post loading, crestal bone loss to the level of the first thread was noted; no changes were observed at the sinus or surrounding teeth. Pocket depth ranged from 3-4 mm. No further bone loss or soft tissue contour change was noted at 18, 24, 30, and 36 months post loading. The combination of these three techniques with simultaneous implant placement as described in this report seems to be successful. Further research is needed to evaluate whether the combination of these techniques with simultaneous implant placement offers similar results when compared with the stage approach.

Anatomic evaluation of maxillary sinus septa: surgery and radiology

The anatomical structure of the maxillary sinus is fundamental to maxillofacial surgery. The presence of septa, located at the inner surface of the maxillary sinus, increases the risk of sinus membrane perforation during sinus elevation for dental implant surgery. The aim of this study was to evaluate the anatomy of maxillary sinus septa.Data in this study was obtained from a total of 205 cases. One hundred and seventy-seven patients were partially edentulous (PE) whereas 28 patients had no teeth. Dental computerized tomography (dental CT) was used in the assessment of 410 sinus segments (205 left and 205 right segments). The prevalence of sinus segments with septa was found to be 145/410. Septa were detected in 91 of the 177 PE cases. There were a total of 26 septa in 18 of the 28 completely edentulous (CE) cases. A total of 165 septa were detected in these segments. The prevalence of septa was 46.4% (26/56) in the CE, and 39.2% (139/354) in the PE segments. Thirty septa were found in the anterior, 110 in the middle and 25 in the posterior region. All detected septa were located mediolateral direction. Their relative position: lateral, middle or medial were also noted. The height measurements of the septa varied amongst the different positions. In view of the fact that septa of various heights and courses can develop in all parts of the maxillary sinus, timely and adequate assessment of the inner aspect of the maxillary sinus is essential to avoid complications during sinus augmentation procedures.

Histomorphometric analysis of human maxillary sinus lift with a new bone substitute biocomposite: a preliminary report

PURPOSE

To analyze radiographic and histological outcomes of maxillary sinus floor augmentation using a calcium-sulfate based allograft containing demineralized bone matrix particles.

MATERIALS AND METHODS

Fifteen maxillary sinus lift procedures with simultaneous placement of titanium implants were performed in 12 patients of both genders aged 36-71 years. Each sinus cavity was filled by the biocomposite. After 3 months of healing, all surgical sites were uncovered and bone biopsies were retrieved for undecalcified histology and histomorphometry. The ratio between the original and the grafted sinus height (GSH/OSH) was computed using a panoramic radiography taken immediately after surgery and at 3 months of healing, and the two ratios were compared by Wilcoxon signed-rank test.

RESULTS

By 3 months, all implants were stable without clinical and radiographic signs of infection. Significant changes in GSH/OSH during healing were seen (2.7 +/- 0.6 initially vs. 2.6 +/- 0.5 after healing; p = 0.01). Histologic findings showed newly formed bone surrounding the residual grafted particles without inflammation. At 3 months, mean regenerated bone density was 33.8 +/- 8.6%; marrow spaces amounted to 32.3 +/- 10.3%; residual graft was 33.9 +/- 9.0%. Similar histomorphometric and radiographic results were obtained independently from patient age or sex.

CONCLUSIONS

The analysed putty seems to be a safe and effective graft material for maxillary sinus floor augmentation by accelerating bone regeneration and thus reducing the healing time.

Comparison of two bone substitute biomaterials consisting of a mixture of fibrin sealant (Tisseel) and MBCP (TricOs) with an autograft in sinus lift surgery in sheep

OBJECTIVES

The aim of this study was to assess the efficacy and safety of macroporous biphasic calcium phosphate (MBCP())/fibrin grafts (TricOs((R)))/(Tisseel((R))) for sinus lift augmentation in sheep. Autologous bone grafts were used as a positive control, and dental implants were placed to assess the efficiency of the composite.

MATERIALS AND METHODS

A total of 12 adult sheep (24 maxillary sinuses) were randomized to receive sinus lift augmentation with MBCP()/fibrin grafts obtained by either simultaneous or sequential addition of thrombin and fibrinogen to MBCP(), or autologous bone grafts. Six months post-sinus lift surgery, dental implants were placed. At 6 months post-sinus lift and 3 months after dental implant placement, the characteristics of newly formed bone and dental implant stability were assessed. The methods used were radiography, scanning electron microscopy, light microscopy, micro-CT analysis, radio frequency analysis (RFA), and image analysis.

RESULTS

There were no clinical adverse events in the post-operative period. New bone formation was similar for MBCP()/fibrin grafts and autografts at 21-20% and 20%, respectively, at 6 months, and at 34-35% and 35%, respectively, at 9 months. Implantability of dental implants was better at the time of placement with MBCP()/fibrin grafts than autografts at 81-88% and 69%, respectively. Three months after placement, RFA showed better implantability with MBCP()/fibrin grafts than with autografts at 75-82% and 71%, respectively. The bone contact measurements were around 50% for the three groups, without significant differences.

CONCLUSIONS

This study shows that following sinus lift augmentation in sheep, MBCP()/fibrin grafts support new bone formation that is comparable to autografts, while providing better support for the dental implants.

Implant survival rates after maxillary sinus augmentation

Implant therapy in the atrophic posterior maxilla becomes challenging in the presence of reduced maxillary bone height. Sinus augmentation can be performed for resolving this condition prior to implant placement. The aim of this article was therefore to evaluate implant survival rates in the grafted sinus taking into account the influence of the implant surface, graft material, and implant placement timing. A systematic review of the literature was performed. Articles retrieved from electronic databases were screened using specific inclusion criteria, and data extracted were divided according to: graft material (autogenous, non-autogenous, composite graft), implant surface (machined or textured), and implant placement (simultaneous with grafting or delayed). Fifty-nine articles were included. Survival rates for implants placed in grafts made of bone substitutes alone and grafts of composite material were slightly better than the survival rates for implants placed in 100% autogenous grafts. Over 90% of implants associated with non-autogenous grafts had a textured surface. Textured surfaces achieved better outcomes compared with machined surfaces, and this was independent of the graft material. Simultaneous and delayed procedures had similar outcomes. It may be concluded that bone substitutes can be successfully used for sinus augmentation, reducing donor-site morbidity. Long-term studies are needed to confirm the performance of non-autogenous grafts. The use of implants with a textured surface may improve the outcome in any graft type.

The Schneiderian membrane contains osteoprogenitor cells: in vivo and in vitro study

Recent studies successfully demonstrated induction of new bone formation in the maxillary sinus by mucosal membrane lifting without the use of any graft material. The aim of this work was to test the osteogenic potential of human maxillary sinus Schneiderian membrane (hMSSM) using both in vitro and in vivo assays. Samples of hMSSM were used for establishment of cell cultures and for histological studies. Flow cytometry analysis was performed on P(0), P(1), and P(2) cultures using established mesenchymal progenitor cell markers (CD 105, CD 146, CD 71, CD 73, CD 166), and the ability of hMSSM cells to undergo osteogenic differentiation in culture was analyzed using relevant in vitro assays. Results showed that hMSSM cells could be induced to express alkaline phosphatase, bone morphogenic protein-2, osteopontin, osteonectin, and osteocalcin and to mineralize their extracellular matrix. Inherent osteogenic potential of hMSSM-derived cells was further proven by in vivo experiments, which demonstrated the formation of histology-proven bone at ectopic sites following transplantation of hMSSM-derived cells in conjunction with an osteoconductive scaffold. This study provides the biological background for understanding the observed clinical phenomena in sinus lifting. Our results show that a genuine osteogenic potential is associated with the hMSSM and can contribute to development of successful sinus augmentation techniques.

Analysis of the healing process in sinus bone grafting using various grafting materials

OBJECTIVES

The purpose of this study was to compare differences in the healing process in the sinus bone grafting using various grafting materials.

STUDY DESIGN

Maxillary sinus bone grafts were divided into 4 groups according to the graft material used: group I, a mixture of autogenous bone and BioOss (Osteohealth Co., Shirley, NY); group II, a mixture of BioOss and Orthoblast II (Greencross; Isotis); group III, BioOss only; and group IV, synthetic bone, Osteon (Genoss, Korea), only. To evaluate the healing status of the graft surgery, bone specimens were collected from the lateral sinus using a 2.0-mm trephine bur at 4 and 6 months after surgery. Histology of the bone specimens was prepared, and the percentage of newly formed bone fraction, lamellar bone/woven bone ratio (LB/WB), and newly formed bone/graft material ratio (NB/GM) were measured to indicate the suitability of the materials and the healing of the grafts.

RESULTS

The LB/WB ratio and NB/GM ratio were markedly increased at 6 months compared with the values at 4 months. It was observed that good bone healing was achieved even for grafts of xenogeneic bone only or synthetic bone only. Cases grafted with a mixture of allogeneic and xenogeneic bone showed no great advantage regarding bone healing.

CONCLUSION

The results indicated that grafts of xenogeneic or synthetic bone can be effective for sinus bone grafting.

A systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation

OBJECTIVES

The objectives of this systematic review were to assess the survival rate of grafts and implants placed with sinus floor elevation.

MATERIAL AND METHODS

An electronic search was conducted to identify studies on sinus floor elevation, with a mean follow-up time of at least 1 year after functional loading.

RESULTS

The search provided 839 titles. Full-text analysis was performed for 175 articles resulting in 48 studies that met the inclusion criteria, reporting on 12,020 implants. Meta-analysis indicated an estimated annual failure rate of 3.48% [95% confidence interval (CI): 2.48%-4.88%] translating into a 3-year implant survival of 90.1% (95% CI: 86.4%-92.8%). However, when failure rates was analyzed on the subject level, the estimated annual failure was 6.04% (95% CI: 3.87%-9.43%) translating into 16.6% (95% CI: 10.9%-24.6%) of the subjects experiencing implant loss over 3 years.

CONCLUSION

The insertion of dental implants in combination with maxillary sinus floor elevation is a predictable treatment method showing high implant survival rates and low incidences of surgical complications. The best results (98.3% implant survival after 3 years) were obtained using rough surface implants with membrane coverage of the lateral window.

Measurement of volume changes of sinus floor augmentation covered with buccal fat pad: a case series study

OBJECTIVES

The purpose of this study was to evaluate the volumetric changes of the maxillary sinus graft in conjunction with buccal fat pad (BFP) covering the lateral sinus wall.

STUDY DESIGN

In this article, the radiographic results are presented on 11 consecutively treated patients using an equal mixture of the autogenous bone harvested from the tuberosity and natural bone mineral (Bio-Oss) used to augment the maxillary sinus. Buccal fat pad was used over the lateral sinus wall in all cases as a membrane to cover the augmentation material. The mean initial bone height (IBH) was 3.82 mm as measured in the posterior maxilla. Three months after sinus elevation, radiographic evaluation was performed for the patients and secondary bone height was measured (SBH(1)). Fifty-two implants were placed in augmented sinuses. Prosthetic rehabilitation of the patients was done 4 months after inserting the implants. Radiographs were taken 6 months after implant placement and secondary bone height was measured (SBH(2)).

RESULTS

Of 52 implants, 51 (98%) were considered clinically successful. One implant was removed because of mobility at the time of surgical exposure. Clinically, no complications were observed, and all implants were considered clinically osseointegrated after 6 months. Mean bone height was measured as 3.82 mm before sinus grafting. SBH(1) and SBH(2) were measured as 12.22 mm and 10.5 mm respectively.

CONCLUSION

The clinical findings suggested that BFP might be a substitute for bioresorbable collagen membranes in maxillary and sinus floor bone grafts.

Maxillary Sinus Augmentation Using Sinus Membrane Elevation and Peripheral Venous Blood for Implant-Supported Rehabilitation of the Atrophic Posterior Maxilla: Case Series

BACKGROUND

Dental implants need appropriate bone volume for adequate stability in the rehabilitation after tooth loss. In the severely atrophic posterior maxilla, the clinical success of implant treatment sometimes requires a vertical ridge augmentation in the maxillary sinus floor.

PURPOSE

The purpose of this investigation was to evaluate a maxillary sinus floor augmentation technique using a replaceable bone window, elevation of the membrane, placement of implants, and injection of the patient's own venous blood to fill the voids.

MATERIALS AND METHODS

Six patients with need of maxillary sinus floor augmentation participated in the study. After preparation of a replaceable bone window in the lateral aspect of the sinus and careful elevation of the Schneiderian membrane, a total of 14 Brånemark implants (TiUnite, MK III, Nobel Biocare AB, Göteborg, Sweden) were installed in the residual bone penetrating into the sinus cavity. The sinus cavity was then filled with peripheral venous blood and the bone window replaced and stabilized with a medical tissue glue (Aron Alpha A, Sankyo, Inc., Tokyo, Japan) to prevent blood leakage from the created compartment in the maxillary sinus.

RESULTS

After a healing period of a minimum of 6 months, new bone was successfully generated in all 14 implant sites as judged from radiographs. One of the 14 implants failed, corresponding to a survival rate of 92.9% after a follow-up period ranging 12 to 34 months.

CONCLUSIONS

The present case series demonstrate that the creation of a secluded space in the maxillary sinus and filling with venous blood results in bone formation at simultaneously installed dental implants over a 6-month period.

[Clinical and radiological results after augmentation procedures - a prospective study]

The clinical follow up of atrophic jaws treated with augmentation procedures and dental implants is demonstrated and evaluated over a period of five years. In total 50 patients (24 male and 26 female) from the department of maxillofacial surgery of the Friedrich Alexander University Erlangen-Nuernberg who received an augmentation procedure were prospectively evaluated. The mean age was 59.1 years on the female and 56.9 years on the male patients. All patients received prior to implant placement an augmentation with autogenous bone or a bone substitute and were reconstructed using a fixed or removable implant borne rehabilitation. Overall 293 implants from five different systems were used, 10 implants on eight patients were lost in the observation period. Three implants were lost during the healing period and seven after prosthetic rehabilitation. This leads to a cumulative survival rate of 96.6%. The success rate, according to the criterions defined by Karoussis et al. [25] was 94.04%. After twelve months in the area of augmentation an overall resorption rate of 26.4 % was found, at five years the rate mounted to 31.67%. Comparing the resorption rates in maxilla and mandible the vertical loss was 35.88%, rsp. 26,05%. Comaring the posterior and anterior augmentation areas the vertical loss was significantly (p: 0.048%) higher in the posterior with 38.72% compared to 28.26% in the anterior region. Measurement of the SFFR (sulcus fluid flow rate) demonstrated a significant (P. 0.03) correlation with bone resorption, meaning that higher SFF rates showed higher rates of vertical resorption. Additionally a high SFF rate correlated with higher pocket depths and reduced keratinized periimplant gingival rates.

Human maxillary tuberosity and jaw periosteum as sources of osteoprogenitor cells for tissue engineering

OBJECTIVE

Bone tissue engineering is a promising approach for bone reconstruction in oral-maxillofacial surgery. This study investigates the suitability of oral skeletal tissues as convenient and accessible sources of osteogenic progenitors as an alternative to the iliac crest bone marrow.

STUDY DESIGN

Samples of maxilla tuberosity (MT) and maxillary and mandibular periosteum (MP) were obtained during routine oral surgery, and donor site morbidity was assessed using a "split-mouth" approach. Cells isolated from MT (bone marrow stromal cells; MT-BMSCs) and from MP (periosteal cells; M-PCs), were analyzed for clonogenicity, phenotype, expression of osteogenic markers, and ability to form bone in vivo.

RESULTS

Both MT-BMSCs and M-PCs included clonogenic cells, showed comparable phenotypic profiles, and expressed early osteogenic markers. Most importantly, both cell populations formed bone upon ectopic in vivo transplantation.

CONCLUSION

MT-BMSCs and M-PCs behaved as osteoprogenitor cells in vitro and in vivo. MT and MP may be considered as suitable sources of cells for bone tissue engineering in humans.

A novel bone scraper for intraoral harvesting: a device for filling small bone defects

AIM

To evaluate histologically the morphology and characteristics of bone chips harvested intraorally by Safescraper, a specially designed cortical bone collector.

MATERIAL AND METHODS

Bone chips harvested near a bone defect or in other intraoral sites were grafted into a post-extractive socket or applied in procedures for maxillary sinus floor augmentation or guided bone regeneration. Core biopsies were performed at implant insertion. Undecalcified specimens embedded in PMMA were studied by histology, histochemistry and SEM.

RESULTS

Intraoral harvesting by Safescraper provided a simple, clinically effective regenerative procedure with low morbidity for collecting cortical bone chips (0.9-1.7 mm in length, roughly 100 microm thick). Chips had an oblong or quadrangular shape and contained live osteocytes (mean viability: 45-72%). Bone chip grafting produced newly formed bone tissue suitable for implant insertion. Trabecular bone volume measured on biopsies decreased with time (from 45-55% to 23%). Grafted chips made up 50% or less of the calcified tissue in biopsies. Biopsies presented remodeling activities, new bone formation by apposition and live osteocytes (35% or higher).

DISCUSSION AND CONCLUSIONS

In conclusion, Safescraper is capable of collecting adequate amounts of cortical bone chips from different intraoral sites. The procedure is effective for treating alveolar defects for endosseous implant insertion and provides good healing of small bone defects after grafting with bone chips. The study indicates that Safescraper is a very useful device for in-office bone harvesting procedures in routine peri-implant bone regeneration.

Bone strains around apically free versus grafted implants in the posterior maxilla of human cadavers

The objective of this study was to compare the bone strains of apically free versus grafted implants in the posterior maxilla. The experiments were undertaken in four edentulous maxillary posterior regions of fresh human cadavers, having a minimum bone height of 8 mm. In each bone fragment, two Ø 4.1 mm x 12 mm Straumann implants were placed, and insertion torque values (ITV) and implant stability quotients (ISQ) of the implants were quantified to determine implant anchorage. Two splinted crowns were fabricated for each experimental model. Strain gauges were bonded on the buccal and sinus floor cortical bones around apically free and grafted implants. Microstrains were recorded by a data acquisition system and corresponding software at a sample rate of 10 KHz under central and buccally oriented lateral-axial static loads of 100 and 150 N in separate cases. The data were compared by independent T test at a significance level set at P<0.05. Bone tissue strains on the buccal cortical areas adjacent to apically free implants were higher than those of apically grafted implants (P<0.05). The differences ranged between 10 and 48 mu epsilon under central and lateral axial loads of 100 and 150 N. The shift in load application from central to buccally oriented lateral axial mode increased strains between 60 and 201 mu epsilon on buccal cortical bone around apically free and grafted implants (P<0.05). Bone strains around anterior implants were higher than those of posterior implants. Microstrains in the sinus floor cortical bone in apically grafted models were slightly higher than apically free models. Bone tissue strains on the buccal cortical areas adjacent to apicallyfree implants are higher than those of apically grafted implants. Sinus lifting, resulting in an enhanced apical support, slightly increases strains at the sinus floor region, but leads to a decrease in bone strains around the collar of supporting implants.

Osteotome sinus floor elevation without grafting material: a 1-year prospective pilot study with ITI implants

OBJECTIVE

The aim of the present pilot study was to evaluate: (1) the predictability of an osteotome sinus floor elevation procedure with ITI-SLA implants without placing a bone grafting material, and (2) the possibility to gain bone height without filling the created space with a bone grafting material.

MATERIAL AND METHODS

Seventeen patients received 25 implants protruding in the sinus. Most implants (21/25) were 10 mm long, eight were inserted in type 2 bone, 12 in type 3 and five in type 4 bone. At implant placement, the mean residual bone height (RBH) under the maxillary sinus was 5.4+/-2.3 mm; it was 5.7+/-2.6 mm on the mesial side and 5.1+/-1.9 mm on the distal side. Nineteen implants had less than 6 mm of bone on at least one side and six implants had less than 6 mm on both sides. A healing period of 3-4 months was allowed before abutment tightening at 35 Ncm. The percentage of stable implants at abutment tightening and at the 1-year control was calculated. The endo-sinus bone gain and the crestal bone loss (CBL) at the mesial and distal sides were measured.

RESULTS

Abutments were tightened after 3.1+/-0.4 months. All implants but one (96%) resisted the applied 35 Ncm torque. At the 1-year control, all implants were clinically stable and supported the definitive prosthesis. All showed endo-sinus bone gain; the mean gain was 2.5+/-1.2 mm. The mean CBL was 1.2+/-0.7 mm. Endo-sinus bone gain and RBH showed a strong negative correlation (r=-0.78 on the mesial side and -0.80 on the distal side). A good correlation (r=0.73) was found between implant penetration in the sinus and endo-sinus bone gain.

CONCLUSION

Elevation of the sinus membrane alone without addition of bone grafting material can lead to bone formation beyond the original limits of the sinus floor. Despite a limited RBH at implant placement, a healing period of 3 months was sufficient to resist a torque of 35 N cm and to lead to a predictable implant function at the 1-year control.

Augmentation procedures for the rehabilitation of deficient edentulous ridges with oral implants

OBJECTIVES

To analyze publications related to augmentation procedures and to evaluate the success of different surgical techniques for ridge reconstruction and the survival/success rates of implants placed in the augmented areas.

MATERIAL AND METHODS

Clinical investigations published in English involving at least 5 patients and with a minimum follow-up of 6 months were included. The following procedures were considered: a) Guided bone regeneration (GBR); 2) Onlay bone grafts; 3) Inlay grafts; 4) Bone splitting for ridge expansion (RE); 5) Distraction osteogenesis (DO); and 6) Revascularized flaps. Success rates of augmentation procedures and related morbidity, as well as survival and success rates of implants placed in the augmented sites were analyzed.

RESULTS

Success rates of surgical procedures ranged from 60% to 100% for GBR, from 92% to 100% for onlay bone grafts, from 98% to 100% for ridge expansion techniques, from 96,7% to 100% for DO, and was 87.5% for revascularized flaps, whereas survival rates of implants ranged from 92% to 100% for GBR, from 60% to 100% for onlay bone grafts, from 91% to 97.3% for RE, from 90.4% to 100% for DO, and, finally, was 88.2% for revascularized flaps.

CONCLUSION

On the basis of available data it was shown that it was difficult to demonstrate that a particular surgical procedure offered better outcome as compared to another. The main limit encountered in this review has been the overall poor methodological quality of the published articles. Therefore larger well-designed long term trials are needed.

Maxillary sinus floor augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement

OBJECTIVE

The aim of this study was to evaluate the use of autogenous bone in combination with platelet-enriched fibrin glue as a grafting material for maxillary sinus augmentation with simultaneous implant placement in dogs.

STUDY DESIGN

The mucous membranes of 12 sinuses in 6 dogs were elevated bilaterally. In the right sinus, autogenous bone mixed with platelet-enriched fibrin glue was grafted into the space between the membrane and the sinus wall. In the left sinus, autogenous bone alone was grafted as a control. At the same time, 2 dental implants were inserted into the grafting material through the maxillary sinus floor. The animals were killed 6 months after surgery.

RESULTS

The mean bone-implant contact was 40.5% on the fibrin glue side and 32.3% on the control side (P < .05). The mean height of newly formed bone in the augmented area was 12.2 mm on the fibrin glue side and 10.7 mm on the control side (P < .05).

CONCLUSION

The results indicate that the use of autogenous bone mixed with platelet-enriched fibrin glue can achieve results superior to those for grafts of autogenous bone alone. The specific improvements of this technique include enhanced osseointegration of dental implants and increased height of new bone.

Clinical Evaluation of Endosseous Implants in Nonvascularized Fibula Bone Grafts for Reconstruction of the Severely Atrophied Mandibular Bone

PURPOSE

The purpose of the present study was to assess changes in graft height after augmentation of the severely atrophied mandibula with the use of avascular fibula bone grafts, as well as evaluation of the clinical success of endosseous implants placed in the grafted mandibula.

PATIENTS AND METHODS

This retrospective study included 10 patients with a mean observation period of 31 months (range, 3 to 76 months). A total of 40 implants were placed. Clinical criteria included implant success, graft success, and crestal bone resorption.

RESULTS

The grafting procedure was successfully performed in all patients. All implants were integrated, 2 implants could not be used for prosthetic rehabilitation. One implant was lost 2 years after abutment connection. The maximum bone resorption of 7.21% (+/- 2.7%) was seen within the first year; no significant resorption was seen thereafter.

CONCLUSION

In this clinical and radiographic evaluation, it was found that nonvascular fibula graft is a reliable material for augmentation procedures. The resorption takes place within the first year after augmentation. The possibility of improving the clinical results in bone grafting situations with avascular fibula grafts will be further evaluated in a prospective follow-up study providing long-term assessment of this procedure.

Lateral bone condensing and expansion for placement of endosseous dental implants: a new technique

Placement of endosseous dental implants can be a problem due to bone resorption if the patient has been missing teeth for a considerable period of time. In the literature, bone-grafting techniques have shown variable results. Additionally, bone grafting requires a longer treatment time and a need for a second surgery, and it adds significant cost to the treatment. These factors often discourage patients from having dental-implant treatment. Another technique for placement of dental implants in narrow bone ridges is repositioning and remodeling of alveolar bone by condensing and expansion with the help of bone osteotomes. This article presents 2 cases, 1 in the maxilla and 1 in the mandible, for placement of endosseous dental implants with the use of a new bone-expansion osteotome kit that utilizes a screw-type configuration for bone condensing and expansion.

Bone Reformation and Implant Integration following Maxillary Sinus Membrane Elevation: An Experimental Study in Primates

BACKGROUND

Recent clinical studies have described maxillary sinus floor augmentation by simply elevating the maxillary sinus membrane without the use of adjunctive grafting materials.

PURPOSE

This experimental study aimed at comparing the histologic outcomes of sinus membrane elevation and simultaneous placement of implants with and without adjunctive autogenous bone grafts. The purpose was also to investigate the role played by the implant surface in osseointegration under such circumstances.

MATERIALS AND METHODS

Four tufted capuchin primates had all upper premolars and the first molar extracted bilaterally. Four months later, the animals underwent maxillary sinus membrane elevation surgery using a replaceable bone window technique. The schneiderian membrane was kept elevated by insertion of two implants (turned and oxidized, Brånemark System, Nobel Biocare AB, Göteborg, Sweden) in both sinuses. The right sinus was left with no additional treatment, whereas the left sinus was filled with autogenous bone graft. Implant stability was assessed through resonance frequency analysis (Osstell, Integration Diagnostics AB, Göteborg, Sweden) at installation and at sacrifice. The pattern of bone formation in the experimental sites and related to the different implant surfaces was investigated using fluorochromes. The animals were sacrificed 6 months after the maxillary sinus floor augmentation procedure for histology and histomorphometry (bone-implant contact, bone area in threads, and bone area in rectangle).

RESULTS

The results showed no differences between membrane-elevated and grafted sites regarding implant stability, bone-implant contacts, and bone area within and outside implant threads. The oxidized implants exhibited improved integration compared with turned ones as higher values of bone-implant contact and bone area within threads were observed.

CONCLUSIONS

The amount of augmented bone tissue in the maxillary sinus after sinus membrane elevation with or without adjunctive autogenous bone grafts does not differ after 6 months of healing. New bone is frequently deposited in contact with the schneiderian membrane in coagulum-alone sites, indicating the osteoinductive potential of the membrane. Oxidized implants show a stronger bone tissue response than turned implants in sinus floor augmentation procedures.

Maxilla Sinus Grafting With Marine Algae Derived Bone Forming Material: A Clinical Report of Long-Term Results

PURPOSE

Autogenous bone grafting continues to be considered the gold standard for sinus grafting. For the past 15 years the author has used an alternative graft material and followed-up the input/output statistic of implants to evaluate if this material results similar to the autogenous bone graft. Histomorphometric evaluations of graft materials show how much new bone is formed and if the graft material is resorbed.

MATERIALS AND METHODS

In our study we used a marine derived carbonated red algae that is chemically converted into hydroxyapatite (HA). This material is distributed worldwide as the Communauté Européenne approved material AlgiPore (Dentsply Friadent, Mannheim, Germany), as the US Food and Drug Administration approved material C GRAFT (The Clinician Preference LLC, Golden, CO), and the Russian approved material AlgOss (Unexim Co, Moscow, Russia). A total of 209 sinus grafts were performed on 118 patients who presented with a severely resorbed maxillary alveolar process with 1 to 5 mm (mean, 3.6 mm) of remaining bone. The available bone was comparable to Class D bone as described by Simion et al. After 6 months implants were placed and 6 months later the implants were loaded.

RESULTS

From September 5, 1990, to September 1, 2004, the author performed 209 sinus grafts on 118 patients. The longest observation period of loaded implants in this study is 156 months (13 years). Implant loss was 27 out of 614 loaded implants (4.4%), showing a survival rate of 95.6%. Smokers and women over 50 are included. Although AlgiPore/C GRAFT/AlgOss (ACA) undergoes a resorption process, we found only 14% volume loss after 6.4 months compared with 49.5% after 6 months when autogenous bone was used.

CONCLUSION

This retrospective study of over 14 years shows once again that the sinus lift procedure with grafting of the sinus floor and subsequent implant placement is a proven method. This 14-year longitudinal study shows that the marine derived HA material ACA in a mixture with approximately 10% autogenous collector bone and blood or platelet rich plasma is able to enhance enough new bone in 6 months to allow implant osseointegration after 6 more months with a high implant survival rate.