Augmentation Height Research Articles

Prediction of the bone volume for sinus augmentation through 3-dimensional analysis

Background/purposeNo consensus has been established regarding the exact amount of bone grafting in maxillary sinus augmentation. The aim of this study was to estimate the minimum bone volume for sinus augmentation and to investigate the factors that influence the augmentation volume (AV). Materials and methodsThis study included patients with cone-beam computed tomography scanning. Dome-shaped sinus augmentation was performed virtually at vertical heights (VH) of 3, 5, 7, and 9 mm in Group A (without implantation) and Group B (with implantation). The augmentation angle (AA) and the sinus width (SW) were measured. The AV was measured using the three-dimensional image processing program 3D Slicer. Univariable and multivariable analyses were conducted. ResultsThis study included 30 patients (120 subjects). In Group A, the mean AVs were 0.062, 0.271, 0.642, and 1.287 cc at VHs of 3, 5, 7, and 9 mm, respectively, in Group B, the mean AVs were 0.037, 0.230, 0.594, and 1.230 cc. Univariable analysis indicated that factors significantly associated with the AV in both groups included SW, AA, and VH (P < 0.001). Multivariable analysis indicated that factors significantly associated with the AV in both groups included AA and VH (P < 0.01). ConclusionClinicians can predict the bone volume for sinus augmentation by measuring the augmentation height and angle.

Radiographic changes in height and volume after lateral GBR procedures with different ratios of deproteinized bovine bone mineral and autogenous bone at different time points. An experimental study.

Estimate changes in augmentation height and volume after lateral guided bone regeneration (GBR) augmentation with different ratios of deproteinized bovine bone mineral (DBBM) and particulate autogenous bone (PAB) and autogenous bone block (ABB), at different time points. Twenty-four minipigs were randomly allocated into three healing periods. Lateral augmentation in 96 sites with standardized quantity of graft material was performed with different ratios of DBBM and PAB (50:50, 75:25, and 100:0) and ABB in combination with DBBM, covered by a collagen membrane. Changes in augmentation height and volume were assessed on CT volumes acquired 10, 20, and 30weeks after surgery. Reduction in bone augmentation height was as follows: 50:50-1.7mm (-33.1%), 75:25-1.8mm (-37.8%), 100:0-1.7mm (-35.8%), and ABB - 0.2mm (-3.7%), after 30weeks. The augmentation height was significantly better preserved with ABB compared to 50:50, 75:25, and 100:0, while no significant difference was present among particulate grafts. No significant difference in volumetric reduction was found among 50:50, 75:25, 100:0 and ABB after 30weeks, while 100:0 presented significant less reduction compared to 50:50, 75:25 and ABB after 10 and 20weeks. Augmentation height following GBR was better preserved with ABB covered with DBBM. Addition of PAB to DBBM did not affect the changes in height of the graft. The volumetric stability seems to be comparable for ABB covered by DBBM and all particulate grafts after 30weeks. However, DBBM alone revealed significant less volume reduction in the early healing phase.

Influence of the position of the antrostomy in sinus floor elevation assessed with cone-beam computed tomography: Arandomized clinical trial.

The aim of the present study was to evaluate dimensional variations of augmented sinus volumes after sinus floor elevation using a lateral approach placing the antrostomy close to the sinus floor or more cranially to it. Twenty-four healthy volunteers in need of sinus floor elevation were included in the study. The lateral approach was adopted placing the antrostomy randomly either close to the level of the sinus floor (group A) or approximately 3-4mm cranially (group B). Cone-beam computed tomography (CBCT) was done before surgery (T0) and after 1week (T1) and 9months (T2), and analyses on dimensional variations were performed. CBCT of 10 patients per group were analyzed. At T1, the sinus floor was found to be elevated by 9.8±2.1mm in group A and 10.9±1.9mm in group B. At T2, shrinkage of 2.0±1.7mm in group A and 1.4±2.5mm in group B was observed. The area was reduced approximately 18-24% between T1 and T2. The sinus mucosa width increased by 4.3-5mm between T0 and T1, and regained the original dimensions at T2. The more cranial the antrostomy, the greater the augmentation height after 9months.

Crestal Sinus Augmentation with Recombinant Human Bone Morphogenetic Protein 2: Clinical and Radiographic Outcomes of 2-Year Pilot Trial.

Recombinant human bone morphogenetic protein 2 (rhBMP-2) together with an absorbable collagen carrier (ACS) was approved for augmentation of the maxillary sinus prior to implant placement. The original registration trial was based on a lateral window approach. Clinical outcomes of crestal sinus augmentation with rhBMP-2 have not been reported so far. An uncontrolled pilot trial in which seven patients with a residual maxillary height below 5 mm were enrolled to receive crestal sinus augmentation with rhBMP-2/ACS was conducted. Elevation of the sinus mucosa was performed by gel pressure. Primary endpoints were the gain in augmentation height and volume measured by computed tomography after 6 months. Evaluation of bone quality at the time of implant placement was based on histology. Secondary endpoints were the clinical and radiologic evaluation of the implants and patient satisfaction by visual analog scale (VAS) at the 2-year follow-up. Median gain in augmentation height was 7.2 mm (range 0.0 to 17.5 mm). Five patients gained at least 5 mm of bone height. Two patients with a perforation of the sinus mucosa failed to respond to rhBMP-2/ACS and underwent lateral window augmentation. The median gain in augmentation volume of the five patients was 781.3 mm³ (range 426.9 to 1,242.8 mm³). Biopsy specimens showed a cancellous network consisting of primary plexiform bone with little secondary lamellar bone. After 2 years, implants were in function with no signs of inflammation or peri-implant bone loss. Patients were satisfied with the esthetic outcomes and chewing function. This pilot clinical trial supports the original concept that rhBMP-2/ACS supports bone formation, also in crestal sinus augmentation, and emphasizes the relevance of the integrity of the sinus mucosa to predict the bone gain.

Early volumetric changes after vertical augmentation of the atrophic posterior mandible with interpositional block graft versus onlay bone graft: A retrospective radiological study

PurposeThe aim of this study was to evaluate volumetric and clinical outcomes of atrophic posterior mandibles treated with inlay or onlay bone grafting techniques. Materials and methodsIn posterior mandibles, alveolar ridges were treated either with interpositional equine cancellous bone block (inlay group) or with onlay autogenous bone block (onlay group). Bone volumes at baseline and at 4 months after surgery were measured by computed tomography. ResultsA total of 20 subjects were enrolled in the present study: 10 in the inlay group and 10 in the onlay group. After surgery, atrophic posterior mandibles showed a mean vertical augmentation height of 6.0 mm in the inlay group and 7.4 mm in the onlay group. No significant differences were recorded between the two groups regarding volume loss of the grafted bone or decrease in vertical bone height of the augmented site (29% and 1.9 mm for the onlay group, and 35% and 1.7 mm for the inlay group) during healing. Two complications (1 wound dehiscence and 1 mandibular fracture) occurred postoperatively in the inlay group; on the other hand, the onlay group had three complications (wound dehiscence). A total of 80 dental implants were placed in augmented areas: 46 in the inlay group with a peri-implant marginal bone loss of 0.8 mm, and 34 in the onlay group with a peri-implant marginal bone loss of 1.3 mm (p = 0.0006). ConclusionsInlay xenogeneic grafts showed volumetric bone remodeling similar to that recorded for onlay autogenous bone. The success of the autogenous onlay blocks (82.4%) appeared to be lower than that registered for the inlay group (93.8%), but the difference was not significant.

Histological and radiological evaluation of sintered and non-sintered deproteinized bovine bone substitute materials in sinus augmentation procedures. A prospective, randomized-controlled, clinical multicenter study.

The objective of this study is to histologically and radiologically compare a sintered and a non-sintered bovine bone substitute material in sinus augmentation procedures. Thirty-three patients were included in the clinically controlled randomized multicentre study resulting in a total of 44 treated sinuses. After lateral approach, sinuses were filled with either a sintered (SBM, Alpha Bio's Graft®) or a non-sintered (NSBM, Bio Oss®) deproteinized bovine bone substitute material. The augmentation sites were radiologically assessed before and immediately after the augmentation procedure as well as prior to implant placement. Bone trephine biopsies for histological analysis were harvested 6months after augmentation whilst preparing the osteotomies for implant placement. Healing was uneventful in all patients. After 6months, radiological evaluation of 43 sinuses revealed a residual augmentation height of 94.65% (±2.74) for SBM and 95.76% (±2.15) for NSBM. One patient left the study for personal reasons. Histological analysis revealed a percentage of new bone of 29.71% (±13.67) for SBM and 30.57% (±16.07) for NSBM. Residual bone substitute material averaged at 40.68% (±16.32) for SBM compared to 43.43% (±19.07) for NSBM. All differences between the groups were not statistically significant (p > 0.05, Student's t test). Both xenogeneic bone substitute materials showed comparable results regarding new bone formation and radiological height changes in external sinus grafting procedures. Both bone substitute materials allow for a predictable new bone formation following sinus augmentation procedures.

水害常襲地域における建築的減災対策に見る地域特性に関する研究

It's threatening as a flood damage tsuneshuu area formerly by this research, baku, flood control construction has been created in all part area as the plan which evades the damage, but it also has the area where he disappeared, and a flood person with experience is decreasing its form gradually from an area already, too, and a hearing of confirmation of flood control construction and the fact that its construction longitude and latitude is historical will be also the difficult situation, and accident culture is put in the situation that I become extinct. So such, I had for my object to catch its common characteristic (the similarity) and singularity (peculiar, ) about the regional characteristics the architectonic gensai measure for which the prototype which is to consider the current state which hangs and is seen in all part was left aimed at a residence and a house from a village area, and by which can be judged in those. (1) Each village After evading flooding by flood damage by forming a village into a natural levee or minute highlands as a gensai measure at the whole village by an area, such as more construction of ring levee itsutsumi is to circle the whole village by a possible place and make sure that it'll be crowded, and avoiding water disaster, I find out that a multiple measure was being done. On the other hand, the occasion of the alluvial fan was to reflect soil property (the gravel), and for almost all water poured to permeate in the ground, embankment was held and didn't take a measure for flood control by the embankment with which the whole village is surrounded only the direction where flood water by river burst flows. (2) Each village There was "equipment" as the regional characteristics by which a storehouse (Mizukura and cupboard for tea-things Mizuzuka and step warehouse), a residence grove and a trench have been damaged for a long time as a flood damage tsuneshuu area at 5 villages at a residence in an area, and moreover the directional common characteristic was seen in arrangement. It's regional in 1 area, peculiar, its arrangement form was judged as the bank I reflected. (3) While fill in a residence, fill in a main building and Mizuzuka's fill as a stylobate in a storehouse were accomplished at 4 villages, without being given to fill in a site in Aikawa area, only each building and an independent embankment raised the ground level. It was to secure the augmentation height grown from flood damage experience in the past since putting it in 4 villages with Mizuzuka, and was to show the difference in the height of two stages or three stages in a site and a main building storehouse, reflect flood experience respectively and be accomplished, and the absolute height which doesn't put on flooding had been secured. It's the architectonic gensai measure going off more than the above, but I think it's necessary to be considering the way to take gensai measures by the multiple stance until "equipment" by each "defense" empty dwelling unit of the whole local community to build society strong in flood damage from now on.

Partially Biodegradable Distraction Implant to Replace Conventional Implants in Alveolar Bone of Insufficient Height: A Preliminary Study in Dogs.

Dental implants have been widely used in the last few decades. However, patients with insufficient bone height need reconstructive surgeries before implant insertion. The distraction implant (DI) has been invented to simplify the treatment procedure, but the shortcomings of DIs have limited their clinical use. We incorporated biodegradable polyester into a novel DI called the partially biodegradable distraction implant (PBDI). The purpose of this study was to assess the radiological, histological, and biomechanical properties of the PBDI in animal models. PBDIs were manufactured and inserted into the atrophied mandibles of nine dogs. Box-shaped alveolar bones were segmented and distracted. The dogs were randomly divided into three groups that were sacrificed 1, 2, and 3 months after the implant insertion. Actual augmentation height (AAH) of the bone segments was measured to evaluate the effect of distraction. X-ray examination and micro-CT reconstruction and analysis were used to evaluate the regenerated bone in the distraction gap and bone around the functional element. Histological sections were used to evaluate the osseointegration and absorption of the PBDI. Fatigue tests were used to evaluate the biomechanical properties of the PBDI. Little change was found in AAH among the three groups. X-ray examination and micro-CT reconstruction showed good growth of regenerated bone in the distraction gap. Alveolar bone volume around the functional element increased steadily. No obvious bone absorption occurred in the alveolar crest around PBDI. Three months after distraction, the functional element achieved osseointegration, and the support element began to be absorbed. All PBDIs survived the fatigue test. The PBDI is a novel and reliable dental implant. It becomes a conventional implant after the absorption of the support element and the removal of the distraction screw. It is a promising replacement for conventional implants in patients with insufficient alveolar bone height.

Prevention of the surface resorption of bone grafts by topical application of bisphosphonate on different carrier materials

The hypothesis of the present study was that topically applied bisphosphonate (BP) on a collagen membrane or alternatively bovine bone mineral prevents surface resorption of onlay bone grafts. In eight adult pigs, bone blocks were harvested bilaterally from the mandible and fixed to the lateral cortex of the horizontal ramus to simulate a ridge augmentation. In a split-mouth study design, we used alendronate in aqueous solution (1mg/ml) on the test-side in three different ways: on a collagen membrane (Bio-Gide®), soaked in bovine bone mineral granules (Bio-Oss®), or applied to the bone graft directly. The same materials without BP were used as controls on the contralateral side. After 3months, the animals were sacrificed. The evaluation included sequential fluorochromic labeling and measurement of bone height in microradiography and toluidine blue staining. In five cases, necrosis of the overlying periosteal tissues with BP was observed macroscopically. A statistically significantly lower loss in graft height was seen on the test-side for Bio-Gide® + alendronate (0.65%) versus Bio-Gide® (1.52%), p = 0.002; Bio-Oss® + alendronate (1.16%) versus Bio-Oss® (4.20%), p = 0.001; and bone graft + alendronate (1.25%) versus bone graft alone (6.01%), p = 0.006. An inhibitory effect on bone remodeling was observed by a statistically significantly lower number of resorption lacunae. The hypothesis was accepted that a bisphosphonate-treated membrane reduced bone graft resorption; however, periosteal necrosis requires better adaptation of the dosage. A bisphosphonate membrane could be a helpful tool to preserve augmentation height of onlay bone grafts.

Highly porous hydroxyapatite with and without local harvested bone in sinus floor augmentation: a histometric study in pigs

Sinus floor augmentation with autologous bone is an accepted treatment option in dental implantology. In this study, an entirely synthetic, nano-structured, hydroxyapatite-based bone substitute material (SBSM, NanoBone(®); Artoss, Rostock, Germany) was supplemented with a mixture of locally harvested bone to enhance osteogenesis. Bilateral sinus augmentation procedures were performed in eight domestic pigs using the lateral window technique. On the right side (control), 2.6 ml of SBSM was used, and on the left side (test), 2.6 ml of SBSM with additional 15% (390 μl) autologous bone was used. At the time of augmentation, a titanium implant (ITI(®)) was inserted from a laterocaudal direction. After 3 months, the sites of augmentation were removed and examined in non-decalcified sections by microradiography and fluorescence microscopy of sequentially labelled specimens and histometry. On both sides, a significant amount of newly formed bone was observed. However, a statistically significant difference in the bone-implant contact was observed in the control group (median, 28.9%) compared with the test side with the additional autologous bone (median, 40.6%) (P = 0.01). Different bone density was achieved from the coronal to apical surfaces (medians, 54.6%, 9.6%, and 27.5%) compared with the test side (medians, 55.2%, 40.6%, and 44.2%). The median of augmentation height was 8.6 mm on the control side and 11.5 mm on the test side (P = 0.01). Bone apposition was observed in both groups after 15 days. The SBSM shows acceptable results in sinus floor augmentation. The additional use of locally harvested autologous bone enhances bone density and osseointegration of the implants.

The transcrestal hydrodynamic ultrasonic cavitational sinuslift: Results of a 2-year prospective multicentre study on 404 patients, 446 sinuslift sites and 637 inserted implants

Introduction: In 2006 an ultrasound-surgery-based method to hydrodynamically detach the sinus-membrane utilizing the ultrasonic cavitation effect—the tHUCSL—was developed and a surgical protocol established. The aim of the study was to determine the indication-range and success-rate of this novelty procedure. Materials & Methods: Between 2007 and 2009, 404 patients were treated by 6 oral surgeons of different experience-levels with the tHUCSL in 446 sinussites. 637 implants were inserted and then prosthodontically treated and observed and documented until December 2011. The subantral space was augmented via the 3 mm transcrestal approach with an augmentation volume of 1.9 ccm (+/? 0.988 ccm) and an augmentation height of 10.7 mm (+/? 2.85 mm). Results: Within the survey-period 15 (2.35%) of the 637 inserted implants were lost, mostly before implant loading due to postsurgical infection and nonosseointegration in the augmentation site. 1 implant was lost after implant loading and prosthetic treatment within 1 year after loading. The overall success rate with functional implants in site is 97.65% evenly distributed among the participating surgeons. 86% of the patients were observed with no postsurgical swelling and 87% no postsurgical pain. Discussion: The results suggest the tHUCSL to be a safe minimal-invasive alternative to traditional lateral approach and transcrestal osteotome sinuslift-procedures applicable to all anatomical situations.

Three Different Strategies to Obtain Porous Calcium Phosphate Cements: Comparison of Performance in a Rat Skull Bone Augmentation Model

Preprosthetic surgery has become a routine procedure to obtain sufficient bone quantity and quality for dental implant installation in patients with an initial inadequate bone volume. Although autologous bone onlay or inlay grafting is still the preferred bone augmentation technique, a broad range of synthetic bone substitutes have been developed, for example, calcium phosphate cement (CPC). The introduction of porosity within CPC can be used to increase CPC degradation and bone ingrowth. Therefore, three different strategies to obtain porous CPCs were evaluated in this preclinical study. Instantaneously porous CPC (CPC-IP) was compared with delayed porous CPC in vitro and in vivo. CPC-IP was obtained by the creation of CO₂ bubbles during setting, whereas delayed porous CPC was obtained after the degradation of incorporated poly(lactic-co-glycolic acid) (PLGA) microspheres. As an additional aspect, delayed porous CPC was created by the incorporation of either hollow or dense degradable PLGA microspheres (CPC-hPLGA and CPC-dPLGA). All CPC compositions showed appropriate clinical handling properties and an interconnected porous structure with a final porosity above 70% (v/v). In vitro degradation studies showed the gradual formation of pores and further CPC-matrix dissolution for CPCs containing PLGA microspheres (dPLGA microspheres > hPLGA microspheres). For in vivo evaluation of the CPCs, an augmentation model was used, allowing a CPC injection into a rigidly immobilized Teflon ring on the rat skull. Histological evaluation after 12 weeks of implantation showed bone formation using all three CPCs. Bone apposition reached volumetric amounts of up to 10% of the augmentation area and a maximum augmentation height of ∼1 mm. CPC-IP showed significantly more bone formation and resulted in a superior bone apposition height compared with both CPCs containing PLGA microspheres. No differences in biological performance were observed between the CPCs containing hPLGA and those containing dPLGA microspheres. Further research is necessary to enhance the bone appositional speed and amount of CPCs for bone augmentation procedures before them being used in a potential clinical setting.

Biological Principles and Physiology of Bone Regeneration under the Schneiderian Membrane after Sinus Lift Surgery: A Radiological Study in 14 Patients Treated with the Transcrestal Hydrodynamic Ultrasonic Cavitational Sinus Lift (Intralift)

Introduction. Sinus lift procedures are a commonly accepted method of bone augmentation in the lateral maxilla with clinically good results. Nevertheless the role of the Schneiderian membrane in the bone-reformation process is discussed controversially. Aim of this study was to prove the key role of the sinus membrane in bone reformation in vivo. Material and Methods. 14 patients were treated with the minimal invasive tHUCSL-Intralift, and 2 ccm collagenous sponges were inserted subantrally and the calcification process followed up with CBCT scans 4 and 7 months after surgery. Results. An even and circular centripetal calcification under the sinus membrane and the antral floor was detected 4 months after surgery covering 30% of the entire augmentation width/height/depth at each wall. The calcification process was completed in the entire augmentation volume after 7 months. A loss of approximately 13% of absolute augmentation height was detected between the 4th and 7th month. Discussion. The results of this paper prove the key role of the sinus membrane as the main carrier of bone reformation after sinus lift procedures as multiple experimental studies suggested. Thus the importance of minimal invasive and rupture free sinuslift procedures is underlined and does not depend on the type of grafting material used.

Reimplantation of cultivated human bone cells from the posterior maxilla for sinus floor augmentation. Histological results from a randomized controlled clinical trial

The aim of the present randomized clinical study was to evaluate histologically whether the addition of cultivated, autogenous bone cells to a composite graft of deproteinized bovine bone mineral (DBBM) and autogenous bone (AB) for sinus floor augmentation (SFA) enhance bone formation compared with what achieved after SFA with DBBM + AB alone. Twenty patients with remaining posterior maxillary alveolar crest height of less than 3 mm received SFA after randomization either with an DBBM and AB composite in a 1 : 1 ratio or with DBBM + AB supplemented with autogenous bone cells, which were cultivated from a bone biopsy harvested earlier from the tuberosity area. Four months after SFA, two cylindrical biopsies were taken from the augmented sinuses concomitantly with the implant site preparation by means of a trephine bur. An additional biopsy was taken from the tuberosity area. Bone density at the augmented sinus and the tuberosity area and the height of augmentation were estimated on non-decalcified histological sections prepared from the biopsies. A relative bone density index (RBD) was also calculated by dividing bone density at the augmented sinus with bone density at the tuberosity area. All patients but one could receive two implants after SFA; in one patient, only one implant could be placed. All implants were osseointegrated and could be loaded. Median bone density in the sinus was 30% and 25% in the cell seeded and no-cells added DBBM + AB groups, respectively. Bone augmentation height averaged 6.0 and 5.4 mm and RBD averaged 0.48 and 0.73 in the cell seeded and no-cells added DBBM + AB groups, respectively. None of the differences between groups was statistically significant. Cultivated autogenous bone cell seeded to a DBBM + AB composite did not significantly improve bone formation (density and height) after SFA, compared with what was achieved with DBBM + AB alone. Both approaches resulted into enough bone to support implant placement and osseointegration.

A prospective, randomized pilot study on the safety and efficacy of recombinant human growth and differentiation factor‐5 coated onto β‐tricalcium phosphate for sinus lift augmentation

The aim of this prospective, randomized clinical trial was to investigate the potential of recombinant human growth and differentiation factor-5 (rhGDF-5) coated onto β-tricalcium phosphate (β-TCP) (rhGDF-5/β-TCP) to support bone formation after sinus lift augmentation. In total, 31 patients participated in this multicenter clinical trial. They required a two-stage unilateral maxillary sinus floor augmentation (residual bone height <5 mm). According to a parallel-group design, the patients were randomized to three treatment groups: (a) augmentation with rhGDF-5/β-TCP and a 3-month healing period, (b) augmentation with rhGDF-5/β-TCP and a 4-month healing period and (c) medical device β-TCP mixed with autologous bone and a 4-month healing period. The primary study objective was the area of newly formed bone within the augmented area as assessed by histomorphometric evaluation of trephine bur biopsies. The osseous regeneration was similar in each treatment group; the amount of newly formed bone ranged between 28% (± 15.5%) and 31.8% (± 17.9%). Detailed analysis of histological data will be published elsewhere. As secondary efficacy variables, the augmentation height at the surgery site was measured by radiography. The largest augmentation was radiologically achieved in the rhGDF-5/β-TCP - 3-month and the rhGDF-5/β-TCP - 4-month treatment groups. As safety parameters, adverse events were recorded and anti-drug antibody levels were evaluated. Most of the adverse events were judged as unrelated to the study medication. Four out of 47 (8.5%) implants failed in patients treated with rhGDF-5/β-TCP, a result that is in agreement with the general implant failure rate of 5-15%. Transiently very low amounts of anti-rhGDF-5 antibodies were detected in some patients who received rhGDF-5, which was not related to the bone formation outcome. rhGDF-5/β-TCP was found to be effective and safe as the control treatment with autologous bone mixed β-TCP in sinus floor augmentation. Thus, further investigation regarding efficacy and safety will be carried out in larger patient populations.

Five-year follow-up of mandibular reconstruction with hydroxylapatite and the mandibular staple bone plate

Purpose: To evaluate the results of hydroxylapatite augmentation of the mandible followed by placement of the mandibular staple. Patients and Methods: Sixty patients 5 or more years postsurgery were evaluated. Patients were followed yearly with clinical and radiographic examinations. Results: The decrease in augmentation height was 2.8 mm (33%) after the first year and only minimal in the following years. The following problems were seen: hyperplastic tissue around posts (eight patients), small dehiscences were seen in the saddle area after 2 years (11 patients), large dehiscences with significant hydroxylapatite loss in five patients. One patient needed a secondary augmentation. Conclusion: Prosthetic stabilization and function were excellent throughout the study period and there was a uniformly high degree of patient satisfaction.