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Purpose: The aim of the present study was to compare the histomorphometrically evaluated new bone formation (NB), the radiographically measured graft stability, and the clinical implant outcome for maxillary sinus augmentation grafted with deproteinized bovine bone mineral (DBBM) with either small (Bio-Oss-S, Geistlich) or large (Bio-Oss-L, Geistlich) particles., Materials and Methods: Using a split-mouth study design, bilateral maxillary sinus augmentation was performed in 13 patients either with Bio-Oss-S particles (0.25 to 1 mm) or Bio-Oss-L particles (1 to 2 mm). After a healing period of 6 months, bone biopsies were axially retrieved in the molar region for histologic/histomorphometric analysis of NB, including subsequent staged implant placement. To determine graft stability, the maxillary sinus augmentation vertical graft heights were radiographically measured immediately after sinus augmentation, at implant placement, and at the 2- and 4-year post-augmentation follow-ups. In addition, the clinical implant-prosthodontic outcome (survival/ success/marginal bone loss) was assessed at 1 and 3 years post-loading., Results: A total of 22 sinuses from 11 patients with split-mouth evaluation were ultimately available for data and statistical analysis. Histomorphometric analysis of the axially retrieved bone biopsies revealed the presence of NB (S: 25.5% ± 7.0% vs L: 23.6% ± 11.9%; P = .640), residual graft particles (S: 19.6% ± 9.2% vs L: 17.5% ± 6.3%; P = .365) as well as connective tissue (S: 54.9% ± 9.2% vs L: 58.9% ± 12.5%; P = .283), without significant differences between the use of small (Bio-Oss-S) and large (Bio-Oss-L) particles. However, there was significantly (P = .021) higher bone-to-graft contact (BGC) for the small-particle graft sites (27.9% ± 14.8%) compared to the large-particle graft sites (19.9% ± 12.9%), representing a significantly higher osteoconductivity. Both particle sizes showed significant (P < .01) vertical graft height reduction over time (4 years) of about 10%, with predominant graft reduction in the time period between sinus augmentation and implant placement compared to any follow-up periods after implant placement. At the 3-year post-loading implant evaluation, all implants and prostheses survived (100%), and the peri-implant marginal bone loss (S: 0.52 ± 0.19 mm; L: 0.48 ± 0.15 mm) as well as the peri-implant health conditions (S: 87.5%, L:81.2%) did not differ between implants inserted with the two different xenograft particles used., Conclusions: The use of small and large bovine xenograft particles for maxillary sinus augmentation provides for comparable bone formation, ensuring stable graft dimensions combined with high implant success and healthy peri-implant conditions. However, small particle size resulted in a higher BGC, providing for higher osteoconductivity than with the larger particle size.

Purpose: To evaluate the efficacy of split-thickness labial eversion periosteoplasty (EPP) for soft tissue closure in horizontal ridge augmentation of posterior mandibular regions using a bone shell onlay grafting technique. Materials and Methods: Sixteen patients (12 female and 4 male; mean age: 46.2 ± 8.7 years) with 18 horizontal bone defects in posterior mandibular regions were included for lateral onlay bone grafting using the bone shell technique. After lateral bone augmentation, the EPP was used for soft tissue closure and was prospectively followed up for wound healing efficacy using a modified scoring index. The scoring index included dichotomous (yes: 0 / no: 1) evaluation of the following items: (1) bleeding on palpation or spontaneously, (2) tissue color difference, (3) presence of hematoma, (4) presence of granulation tissue, (5) incomplete incision margin closure, (6) dehiscence with visible augmentation material, (7) presence of exudation, and (8) presence of suppuration. In addition, a visual analog scale (VAS) was used to quantify and record the amount of pain and swelling (0 = no pain/swelling and 5 = severe pain/swelling); VAS scores of 0, 1, and 2 were rated as 1 in the dichotomous scoring index, and VAS scores of 3, 4, and 5 were rated as 0. A summarized wound healing score consisting of all 10 items was assessed at days 2, 7, and 14 and at months 1 and 4 postoperatively, including a comparison of the follow-up evaluations. Results: The summarized healing score increased significantly ( P < .01) between day 2 (score: 6.6 ± 1.1) and day 7 (score: 8.9 ± 1.0) but showed little difference between day 14 (score: 9.6 ± 0.6) and the 1- and 4-month follow-ups (score: 10.0 ± 0). There was no wound dehiscence and no incomplete incision margin adaptation. For the individual parameters evaluated, bleeding on palpation, hematoma, and exudation were the most frequent side effects at day 2 at 50%, 100%, and 22.2%, respectively, and at day 7 at 16.7%, 55.6%, and 22.2%, respectively. The average pain score and the swelling/edema score were initially 4.0 ± 0 and 3.0 ± 0.77 on day 2, with a significant decrease ( P < .001) by day 7 (pain: 2.0 ± 0; edema/swelling: 2.0 ± 0.59) and day 14 (pain: 1.0 ± 0.42; edema/swelling: 2.0 ± 0.79) and complete absence (score: 0) at months 1 and 4. Conclusions: Labial split-thickness EPP facilitates flap advancement and enables tight soft tissue coverage in large horizontal posterior mandibular bone augmentations as a result of offset double-layer wound closure. Although this procedure is shown to be surgically demanding, the postoperative complication rate may be reduced significantly.

Purpose: To analyze risk factors affecting sinus membrane perforation (SMP) during sinus floor elevation (SFE) procedures using the lateral window technique (LWT)., Materials and Methods: For patients with SFEs using the LWT, patient-related risk factors (age/sex/smoking/diabetes) and surgical-anatomical-related risk factors (stage approach/sinus side/residual ridge height/sinus membrane thickness/previous surgical interventions) were compared between perforated and nonperforated sites and were evaluated for their influence affecting SMP. Additionally, SMPs were further subdivided into small/moderate (< 10 mm) or large (≥ 10 mm) in dimension, which were also analyzed for risk factors and consecutively for their influence on perforation., Results: The study sample comprised 434 SFE procedures in 355 patients; 94/355 patients (26.5%) presented SMP in 103 of 434 SFE procedures (23.8%). SFE procedures with (n = 103) and without (n = 331) SMP did not differ for patient-related risk factors but differed significantly (P = .001) for surgical-anatomical factors as follows: residual ridge height (3.05 ± 1.35 mm vs 4.15 ± 1.46 mm), sinus membrane thickness (1.2 ± 0.5 mm vs 2.6 ± 1.1 mm), prevalence of staged procedures (78.6% vs 57.7%), presence of maxillary sinus septa (75.7% vs 14.2%), presence of thin (< 1.5 mm) mucosa biotype (62.1% vs 29%), and previous oral surgical interventions (37.9% vs 16.3%). In the multivariate analysis, significant associations of SMP were found with the presence of sinus septa (odds ratio [OR] = 31.992; P = .001), residual ridge height (OR = 1.563; P = .007), sinus membrane thickness (OR = 1.057; P = .001), presence of thin (< 1.5 mm) sinus biotype (OR = 8.883; P = .001), previous surgical interventions (OR = 4.689; P = .002), and smoking habits (OR = 2.238; P = .030). For inducing a large (≥ 10 mm) SMP, the presence of thin sinus membrane thickness/thin sinus membrane biotype (OR = 5.319; P = .006; OR = 22.222; P = .001) and reduced alveolar ridge height (OR = 0.629; P = .026) were assessed as being significant risk factors., Conclusion: In general, the presence of sinus septa, thin sinus mucosa, staged procedures, and previous surgical interventions are the main risk factors inducing SMP for SFE using the LWT. In particular, the presence of thin sinus membrane in conjunction with a staged procedure significantly increases the risk for a large SMP.

Purpose: To evaluate the 5-year clinical outcomes for implants placed in a staged sinus floor elevation (SFE) procedure and to compare three patient groups with sinus grafts with three different ratios of bovine bone mineral (BBM) and autogenous bone (AB) mixture., Materials and Methods: A 5-year prospective cohort study was conducted on 81 patients with 119 staged SFEs non-randomly distributed to three groups based on the origin of the AB and the mixture ratio with BBM: group 1 (locally harvested AB [LHB] from osteotomy sites + BBM, ratio: 1:10), 31 patients, 37 SFEs; group 2: (LHB + intraorally harvested peripheral AB [IHPB] from retromolar/chin region + BBM, ratio: 1:4), 22 patients, 29 SFEs; and group 3 (LHB + extraorally harvested peripheral AB [EHPB] from iliac crest/tibia + BBM, ratio 1:1), 28 patients, 53 SFEs. After graft healing (5 to 7 months), 284 dental implants (group 1: 76, group 2: 61, group 3: 147 [overall: 2.3 implants/sinus]) were placed. After an additional healing period (5 to 7 months), all implants placed were functionally loaded and prospectively followed by clinical and radiographic evaluations assessing implant survival/success rate as well as peri-implant marginal bone level (MBL) alteration at 1, 3, and 5 years postloading., Results: A total of 76/81 patients with 267/284 implants were followed for up to 5 years (dropouts: 5 patients/15 implants; implant loss = 2). The 5-year implant survival and implant success rate (group 1: 100%/98.6%; group 2: 98.3%/96.6%; group 3: 99.3%/95.7%) did not differ between the three graft mixture groups. The peri-implant marginal bone alteration (reduction) averaged over all 5 years was 1.40 ± 0.29 mm for group 1, 1.41 ± 0.22 mm for group 2, and 1.46 ± 0.46 mm for group 3 (P = .187). However, over time, a continual and significant MBL reduction (P = .045) was noted for all groups presenting peri-implant MBL changes between 1 year and 5 years of -0.17 mm (group 1), -0.12 mm (group 2), and -0.24 mm (group 3), respectively., Conclusion: According to the clinical results obtained, dental implants inserted in grafted (staged) SFE using a mixture of BBM with a minimal amount of AB harvested from local sites provide for similarly high 5-year implant/augmentation success rates as graft mixtures with AB harvested from peripheral intraoral or extraoral donor sites, confirming no need for additional bone harvesting.

Objective: To measure the deviations of four different cone beam computed tomography (CBCT) devices in three dimensions by means of a three-dimensional (3D) implant-planning program., Materials and Methods: A master radiographic template with two vertical, two transverse, and two sagittal radiopaque markers was fabricated for a human dry skull. The lengths of the markers were measured with a high-precision caliper. The skull and the template were scanned in each of the four CBCT devices (1. Gendex GXCB-500; 2. Sirona Galileos Comfort; 3. Sirona Orthophos XG 3D; 4. Carestream CS 9300) 19 times (10 scans without moving the skull, and 9 scans with repeated repositioning of the skull in the device, according to the manufacturers' instructions). A 3D implant-planning program was used to measure the lengths of the six markers digitally. Actual and digital measurements were compared to determine device-specific errors. The repositioning of the skull examined the reproducibility of the CBCT devices. Linear measurements were analyzed statistically (P < 0.05)., Results: Mean deviations without moving the skull (vertical/sagittal/transverse) for device 1 were 0.023 mm/
0.000 mm/0.025 mm (0.07%/0.19%/0.24%), for device 2 were 0.410 mm/0.115 mm/0.080 mm (-1.75%/0.32%/
0.88%), for device 3 were -0.665 mm/-0.215 mm/
-0.675 mm (-2.71%/-1.82%/-4.42%), and for device 4 were -0.045 mm/-0.135 mm/-0.410 mm (-0.45%/
-1.54%/-2.57%). The overall mean deviation for device 1 was 0.028 mm (0.16%), for device 2 was 0.072 mm (-0.95%), for device 3 was 0.518 mm (-2.97%), and for device 4 was -0.197 mm (-1.53%). The mean deviation after repositioning for device 1 was 0.004 mm (-0.65%), for device 2 was -0.250 mm (0.95%), for device 3 was 0.496 mm (-2.66%), and for device 4 was -0.265 mm (-1.92%). Thus, apart from device 3, the deviations increased., Conclusion: Deviations from the actual measurements were detected with each device. Therefore, respecting safety distances when placing implants is crucial.

Purpose: This retrospective study evaluated implant and prosthodontic survival/success rates of four-implant-supported distal cantilevered mandibular fixed prostheses over more than 5 years of clinical use., Materials and Methods: Patients with mandibular edentulism treated with four-implant mandibular prostheses with distal extensions were evaluated. Cumulative implant survival/success rates, peri-implant conditions, and prosthodontic maintenance efforts were assessed. Relationships between the degree of distal implant tilting, length of cantilevers, and implant-generated supporting zone were evaluated., Results: Thirty-eight patients with 152 implants (90.5% of the original sample) were available for follow-up after 5 to 7 years (mean follow-up, 66.5 ± 3.1 months). The cumulative survival and success rates for included implants were 100% and 98.6%, respectively. Denture cantilever length (mean, 14.7 ± 2.3 mm; range, 9 to 20 mm) and implant-generated supporting zone (mean, 318.9 ± 48.1 mm(2); range, 225 to 410 mm(2)) showed significant positive and negative correlations, respectively, with the inclination of tilted distal implants toward the occlusal plane (76 ± 7.2 degrees; range, 65 to 90 degrees). Peri-implant marginal bone resorption (1.5 ± 0.4 mm) and pocket depths (1.8 ± 0.8 mm) were similar for anterior and posterior implants and were not influenced by degree of tilting or cantilever length. Plaque and calculus conditions were poorer for anterior implants than for posterior implants. No dentures fractured; however, fractures of resin tooth veneer material, denture rebasing, and a strong need for cleaning as a result of resin discoloration were seen., Conclusion: Fixed four-implant rehabilitations with distal cantilevers of a defined length with or without distally tilted implants showed high success rates. Inferior hygiene in the anterior mandible regions may be a result of reduced cleansability and variations in anatomical landmarks. Resin veneering proved advantageous for repair or modification but disadvantageous for discoloration.

Purpose: To determine patient satisfaction and preference for implant-supported mandibular overdentures (IOD) retained with ball or Locator attachments. In addition, peri-implant conditions and prosthodontic maintenance efforts for the final attachments were evaluated after 1 year of function., Material and Methods: In this crossover clinical trial, 20 edentulous patients were recruited to receive two mandibular implants in the canine region and were provided with implant-retained mandibular overdentures and new complete maxillary dentures. Implant-retained mandibular overdentures were stabilized with either ball attachments or Locator attachments, in random order. After 3 months of function, the attachments in the existing denture were changed. Questionnaires on satisfaction/complaints with the prostheses were administered at baseline (with the old dentures) and after 3 months of function with each attachment, thus providing for an intraindividual comparison. The decision for the final attachment chosen was based on the patient's preference. For the definitive attachment, peri-implant conditions (peri-implant marginal bone resorption, pocket depth, and Plaque Index, Gingival Index, and Bleeding Index) as well as prosthodontic maintenance efforts and satisfaction score were evaluated after an insertion period of 1 year., Results: Nineteen (95%) patients completed the study (1 dropout). Patient satisfaction improved significantly (P<.05) from baseline (old dentures) to the new prostheses retained with each of the two attachment types for all domains of satisfaction. However, there were no differences between ball or Locator attachment for any items of satisfaction evaluated and neither attachment had a significant patient preference. No differences for peri-implant parameters or for patient satisfaction were noted between the definitive attachments (ball, n=10; Locator, n=9) after 1 year. Although the overall incidence rate of prosthodontic maintenance did not significantly differ between both retention modalities, the Locator attachment required more postinsertion aftercare (activation of retention) than the ball anchors.

Purpose: The aim of this retrospective study was to evaluate implant survival/success rates and peri-implant parameters as well as patient satisfaction for uniformly designed implant-supported anterior maxillary or mandibular fixed partial dentures (FPDs)., Materials and Methods: A retrospective study was conducted on patients with maxillary or mandibular anterior partial edentulism (all incisors missing) treated between 2002 and 2006 with a two-implant-supported four-unit FPD. All FPDs were of the same design: two implant abutments in the lateral incisor positions and two ovate pontics in the central incisor positions. Cumulative implant survival rates and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, Periotest values) as well as the incidence and type of prosthodontic maintenance were evaluated. The patients' subjective satisfaction rate was surveyed using multiple questionnaires with a 10-point scoring system (0 = not satisfied to 10 = highly satisfied)., Results: Thirty-six of 38 patients (dropout: 5%) with 72 implants (50 maxillary and 22 mandibular implants, 25 maxillary and 11 mandibular FPDs) were available for follow-up after a mean observation period of 56.2 ± 10.3 months. High cumulative implant survival and success rates (100%) and healthy peri-implant parameters (mean marginal bone resorption: 1.8 ± 0.3 mm; mean pocket depth: 2.5 ± 1.0 mm; Periotest value: -4.5 ± 1.1; and Plaque/Bleeding/Gingival indices of 0 in 70% of sites [with significantly better results in the maxilla than in the mandible]) were achieved. The most frequent required prosthodontic maintenance efforts were maxillary recementation (3/25; 12%) and mandibular rebasing (2/11; 18.2%). A high score for satisfaction was obtained, although slightly better overall results were seen for maxillary than for mandibular FPDs., Conclusion: For all parameters evaluated, these FPDs proved to be a viable treatment procedure for anterior partial edentulism with good clinical and esthetic outcomes.

Purpose: Implant success, peri-implant conditions, and prosthodontic maintenance requirements were evaluated and compared for mandibular overdentures supported by two implants and retained with ball or resilient telescopic crown attachments during a 5-year period., Materials and Methods: Twenty-five patients with an edentulous mandible each received two root-form dental implants in the mandibular interforaminal (canine) region. The type of denture attachment was chosen randomly; 13 patients received ball attachments and 12 patients received resilient telescopic crowns. Implant success and peri-implant conditions (bone resorption, pocket depth, Plaque Index, Gingival Index, Bleeding Index) as well as prosthodontic maintenance and patient satisfaction were evaluated annually during a 5-year follow-up period and compared with respect to the two retention modalities used., Results: Implant success, peri-implant conditions, and subjective patient satisfaction scores did not differ between the two retention modalities used. However, during the 5-year observation period, significantly more postinsertion complications/interventions for maintenance purposes were registered in the ball group (87 interventions, 61.1%) than in the telescopic crown group (53 interventions, 37.9%; P < .01). Differences in prosthodontic maintenance efforts were most significant in the second and third years (P < .05) of the follow-up period but were similar at the end of the study for both anchorage systems., Conclusion: Both ball attachments and resilient telescopic crowns on isolated implants in the atrophic mandible are viable treatment options for implant-supported overdentures. No implant losses, good peri-implant conditions, and general patient satisfaction were noted. Although the frequency of technical complications was initially higher with ball attachments than with resilient telescopic crowns over a 5-year period, similar frequencies of maintenance efforts may be anticipated for both retention modalities.

Purpose: The present study evaluated implant and peri-implant outcomes as well as prosthodontic maintenance efforts for implant/bar-supported mandibular prostheses with different prosthesis anchorage systems., Materials and Methods: Seventy-six patients who received two or four interforaminal implants were assigned to one of three different bar designs and subsequently to different prosthesis supporting systems. Forty-nine patients received implants and a mucosa-supported implant-retained overdenture (OD) with an ovoid bar (two implants; design 1) or multiple ovoid bars (four implants; design 2). Twenty-seven patients received four implants and a rigid implant-supported prosthesis (ISP) with a milled bar (design 3). Implant survival, peri-implant parameters (marginal bone resorption, pocket depth, and plaque, bleeding, gingival, and calculus indices), and postinsertion prosthodontic maintenance were followed over a 5-year period and compared among the different retention modalities. At the most recent follow-up examination, subjective patient satisfaction was additionally evaluated using a simplified scoring system (ranging from 1 = not satisfactory to 5 = excellent)., Results: Implant survival rates (100%) and all peri-implant parameters evaluated showed no differences among the three designs used for implant prosthesis anchorage. Prosthodontic maintenance did not differ between the different ODs (OD design 1: average of 1.04 maintenance visits/year/patient; OD design 2: 1.2 maintenance visits/year/patient), but it was significantly lower for the dentures that were rigidly stabilized with milled bars (ISP: 0.37 maintenance visits/year/patient). A high subjective satisfaction rate (range: 4.5 to 5.0) was registered at the final examination, without any differences among the designs used., Conclusions: Rigid anchorage with milled bars on four-implant prostheses combined with a metal-reinforced framework showed a lower extent of prosthodontic maintenance issues than round bars on two- or four-implant overdentures with resilient denture stabilization. Nevertheless, implants and peri-implant structures were not negatively affected by either resilient or rigid anchorage mechanisms.

Purpose: The aim of this retrospective study was to evaluate the long-term survival and success rates of screw-type root-shaped (Camlog) implants of various diameters and their implant-prosthodontic reconstructions for more than 5 years of clinical use., Materials and Methods: A retrospective study of patients receiving root-shaped screw-type dental implants placed between May 2001 and July 2003 was conducted. The cumulative implant survival and success rates and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index) as well as the prosthodontic maintenance requirements were evaluated., Results: In all, 541 implants (3.8 mm: 237 implants; 4.3 mm: 211 implants, 5/6 mm: 93 implants) were placed and restored for implant prosthodontic rehabilitation in 216 patients (134 women, 82 men; mean age 54.3 +/- 9.1 years). Of the original 216 patients enrolled, 198 (91.6%; 510/541 implants [94.2%]) were available for a follow-up evaluation after 5 to 7 years (mean follow-up, 68.8 +/- 7.4 months). The overall cumulative 5-year survival and success rates were 98.3% and 97.3%, respectively. A failure rate of 3.7% (9/237) was seen for 3.8-mm-diameter implants; the corresponding figures for the 4.3-mm and wide-diameter (5.0/6.0-mm) implants were 1.4% (3/211) and 1.0% (1/93), respectively. For implants classified as successful, the average peri-implant marginal bone resorption value was 1.8 +/- 0.4 mm, with no differences among the different implant diameters evaluated. Peri-implant soft tissue conditions such as plaque, bleeding, and pocket depth were also satisfactory. All prostheses were functional throughout the observation period, with no fractures of implants, abutments, or screws. Abutment screw (4.5%) or isolated crown loosening (9.8%) for single-tooth restorations requiring recementation, retightening of screws, and adaptation of removable prostheses were the most frequent prosthodontic maintenance needs., Conclusion: The root-shaped implants and the associated prosthetic constructions used in this study showed excellent survival and success rates.

Purpose: This retrospective study assessed implant and prosthodontic treatment outcomes of patients suffering from rheumatic disorders such as rheumatoid arthritis (RA) and connective tissue diseases (CTDs)., Materials and Methods: This study included 22 patients (all women) suffering from autoimmune rheumatic disorders such as isolated RA (n = 16), RA with concomitant CTDs (n = 5), or isolated CTDs (n = 1). Overall, 89 implants were placed for rehabilitations such as single-tooth replacement (n = 8), fixed partial dentures (n = 14), complete dentures (n = 5), and overdentures (n = 2), and were evaluated after a mean of 42.6 +/- 25.2 months. The cumulative implant survival and success rates and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, and Calculus Index) were evaluated with a special focus on RA and CTDs. In addition, incidence and type of prosthodontic maintenance were evaluated., Results: A high implant survival rate was noted during follow-up with a cumulative 3-year implant success rate of 96.1%. Patients with RA demonstrated acceptable marginal bone resorption (mean: 2.1 +/- 0.5 mm) and good soft tissue conditions, while CTD patients showed increased bone resorption (mean: 3.1 +/- 0.7 mm). This was especially noted in scleroderma patients, as were major peri-implant soft tissue alterations (Bleeding Index) in patients suffering from Sjogren syndrome., Conclusions: A high implant and prothodontic success rate can be anticipated even for patients suffering from autoimmune rheumatic disorders such as RA and CTDs. A scrupulous maintenance program that includes optimal oral hygiene could assist in ensuring stable long-term results for CTD patients with more vulnerable soft tissue conditions. Int J Prosthodont 2010;23:22-28.

Removable maxillary prostheses (n = 31) rigidly retained on either a one-piece anteriorly located milled bar fixed on four implants located in the anterior maxillary region (group 1, n = 15) or on two bilaterally placed milled bars fixed on six to eight implants located in the posterior maxillary region (group 2, n = 16) were evaluated for prosthodontic maintenance and the calculated bar-generated supporting area. Comparisons of the incidence of prosthodontic maintenance and the supporting area generated by the bars did not differ between groups. Evident advantages were noted for the anterior concept (group 1) with regards to surgical, technical, and prosthodontic aspects, suggesting a preference for this approach versus the more intricate and complex posterior concept (group 2) under particular circumstances and on appropriate indication.

Purpose: The aim of the present study was to evaluate the prosthodontic maintenance required for mandibular overdentures supported by 4 implants and splinted with either a round bar and resilient overdenture anchorage or a milled bar with rigid anchorage over a 5-year period., Materials and Methods: In a randomized prospective trial, 51 edentulous patients received 4 mandibular interforaminal implants to support an overdenture and maxillary complete dentures. For the implant-supported overdentures (IODs), bar architecture and denture stabilization were chosen randomly; 25 patients received round bars (group 1) and resilient anchorage and 26 patients received milled bars (group 2) and rigid anchorage. The prosthodontic maintenance required for the IODs and opposing dentures were evaluated during a 5-year follow-up period and compared between the 2 retention modalities used for IODs., Results: Forty-six patients (22 in group 1, 24 in group 2) were available for a 5-year follow-up (dropout rate: 9.8%). Prosthodontic maintenance efforts were significantly greater (P < .01) with the round bar design (group 1) than with the overdentures stabilized with milled bars (group 2). In group 1, prosthodontic maintenance efforts were more frequent in the early phase of use (1 to 2 years), as compared with an evenly distributed incidence over the 5-year period with the rigid milled bar system. Major prosthetic complications (IOD remaking, bar fracture) were only seen in cases without metal-reinforced frameworks (group 1)., Conclusion: When 4 interforaminal implants are used to anchor mandibular overdentures, the design of the anchorage system will significantly affect prosthodontic maintenance efforts and complication rates. Rigid anchorage using milled bars and a metal-reinforced denture framework required less prosthodontic maintenance, ie, for clip activation/fracture, than resilient denture stabilization using multiple round bars without a rigid denture framework.

Purpose: The aim of this study was to evaluate the use of provisional implants, which can provide patients with provisional fixed partial dentures during the healing time of augmentation procedures and/or during the osseointegration period of definitive implants until delivery of the definitive prosthesis., Materials and Methods: Thirty-one patients were consecutively included in the study. Eighteen patients (group A, primary simultaneous group) were initially treated simultaneously with provisional and definitive implants and provided with 18 interim fixed partial dentures. Thirteen patients (group B) received provisional implants in a staggered procedure. In the first stage of group B patients (augmentation phase), provisional implants were placed to bridge the augmentation phase and for anchoring 13 interim fixed partial dentures. In the second stage (secondary simultaneous group), patients of group B received provisional implants to bridge the osseointegration phase for simultaneously placed definitive implants by further use of 13 interim fixed partial dentures. All patients were followed from provisional implant and definitive implant placement to delivery of the definitive prosthesis. Loss of provisional implants and interim fixed partial dentures was noted, and stability of provisional implants was evaluated using the Periotest device. The procedures of immediate rehabilitation with fixed partial dentures using provisional implants were subjectively rated by patients with regard to satisfaction, treatment period, and acceptance., Results: In 31 patients, 44 provisional fixed partial dentures were supported by 98 provisional implants. No provisional implant loss in group A or group B-second stage was observed. Only 3 (3%) provisional implants were lost in group B-first stage during the augmentation phase. Incidence (90.8% versus 9.2%) and stability (Periotest values: 8.6 +/- 3.9 versus 4.8 +/- 2.7) of provisional implants differed significantly between maxilla and mandible (P < .01). All interim fixed partial dentures (n = 44) remained in place for the intended time period but in 3 cases with provisional implant loss they were shortened. No definitive implant loss (n = 94, survival: 100%) and especially no implant loss in cases of maxillary sinus augmentation was seen. The items rated showed high satisfaction and good acceptance of the intensive surgical and prosthodontic program., Conclusion: This clinical review showed that (1) provisional implants can successfully provide patients with a fixed partial denture for immediate rehabilitation to bridge the osseointegration or augmentation phase, even in cases with an initially compromised bone situation and (2) although treatment is elaborate, the selected patients decided on a fixed interim rehabilitation with provisional implants rather than on a removable solution.

Purpose: The aim of the present retrospective investigation was to evaluate implant-supported maxillary overdentures using either anterior (group 1) or posterior (group 2) maxillary implant placement., Material and Methods: Maxillary overdentures were planned with support by either 4 implants placed in the maxillary anterior region (group 1) or 6 to 8 implants placed in augmented maxillary posterior regions (group 2, bilateral sinus augmentation) and anchored either on an anterior or on 2 bilaterally placed milled bars. Cumulative implant survival rate, peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, and Calculus Index) and the incidence and type of prosthodontic maintenance were assessed and compared for the 2 groups. In addition, the cumulative survival rate for implants placed in grafted regions was compared with that of implants placed in nongrafted regions., Results: Thirty-four patients (16 for group 1 and 18 for group 2) with 179 implants were available for follow-up examination after a mean period of 42.1 +/- 20.1 months. Four initially placed implants failed to osseointegrate and were replaced, but no further losses were seen during the loading period, for a 5-year cumulative implant survival rate of 978%. No differences in implant survival rates were seen between either the group-1 (98.4%) and group-2 (97.4%) concepts or nongrafted (98.0%) and grafted (97.5%) implants. The peri-implant parameters showed a healthy soft tissue, good oral hygiene, and an acceptable degree of peri-implant marginal bone loss. The rigid fixation of all overdentures was associated with a low incidence of prosthodontic maintenance, without any significant differences between the 2 groups., Conclusions: In well-planned overdenture treatment programs, a high survival rate and excellent peri-implant conditions can be achieved for implants placed in the anterior or posterior maxilla. Rigid anchorage of maxillary overdentures either on an extended anterior milled bar or on 2 bilateral posterior milled bars provides for a low incidence of prosthodontic maintenance.

Purpose: The aim of this retrospective study was to present the results of implants and natural teeth used as combined abutments to support maxillary telescopic prostheses., Materials and Methods: Between 1997 and 2004, 22 patients with residual maxillary teeth underwent prosthodontic rehabilitation with supplementary implant placement of implant-tooth-supported telescopic prostheses. A total of 60 supplementary implants (mean: 2.9 implants; SD: 1.6; range: 1 to 5 per patient) were placed in strategic position and connected with 48 natural abutment teeth (mean: 2.2 teeth; SD: 0.9; range: 1 to 4 per patient) using telescopic crowns. The follow-up registration included implant and natural tooth survival rates and peri-implant and periodontal parameters, along with prosthodontic maintenance. Natural tooth abutments were additionally followed to compare their periodontal parameters at baseline to the follow-up examination., Results: After a mean of 38 months (12 to 108 months) no implants or natural tooth abutments were lost (survival rate: 100%). There was no fracture, endodontic treatment, loss, or intrusion of natural teeth used for telescopic abutments. Implant abutments showed high stability and excellent periimplant soft tissue conditions. Natural tooth abutments used for double crowns also showed uneventful progress. A low rate of prosthodontic maintenance was seen, with implant screw abutment loosening as the most severe complication (3 of 60 implants; 5%)., Conclusions: On the basis of this retrospective clinical review, the following conclusions were drawn: (1) successful function over a prolonged period and a minor complication rate of implant-tooth-supported telescopic maxillary dentures may be anticipated, and (2) the great variety of treatment modalities offered by tooth-implant support for telescopic prostheses appears to be useful as a treatment option for the maxilla in elderly patients.

Purpose: The aim of this retrospective study was to evaluate implant survival rate, peri-implant conditions, and prosthodontic maintenance for implant-supported mandibular overdentures rigidly retained with a milled bar., Materials and Methods: Patients with 4 interforaminal implants (cylindric or screw-type) supporting an overdenture on a milled bar treated between 1996 and 2004 were asked to participate in a retrospective study. The cumulative implant survival rate and peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, and calculus presence) were evaluated and compared between cylindric and screw-type implants. The incidence and type of prosthodontic maintenance and subjective patient satisfaction rating were also evaluated., Results: Fifty-eight of 67 patients (87.3%) and 232 implants (76 cylindric, 156 screw-type) were available for follow-up examination after a mean period of 59.2 +/- 26.9 months. The cumulative implant survival rate was 99%, and no differences in peri-implant soft tissue conditions were noted between the different implant types used. The cylindric implants showed more pronounced marginal bone resorption than the screw-type implants (1.9 +/- 0.6 mm vs 2.2 +/- 0.6 mm; P = .02) but the difference was not clinically significant. A low incidence of prosthodontic maintenance evenly distributed throughout the overall follow-up period and a high subjective satisfaction rating by the patients were noted., Conclusion: Interforaminal screw-type and cylindric implants supporting a milled bar for rigid overdenture anchorage were associated with a high survival rate and excellent peri-implant conditions. The incidence of prosthodontic maintenance was low and evenly distributed throughout the follow-up period as a result of rigid denture stabilization by the milled bar. Rigid anchorage of a mandibular overdenture with a milled bar unites the prosthodontic advantages of removable and fixed prostheses. (Clinical Trial) (More than 50 references.)

The aim of this study was to evaluate 4 veneer composites-Signum+EM, Gradia Enamel E3, Sinfony E3, and SR Adoro S1-in a standardized test at 2 different conditions. For each composite, 2 groups of specimens (added to cultures immediately after preparation [ie, fresh] or after 7 days of incubation in cell culture medium) were added to L-929 fibroblast cultures for 72 hours. All composites showed reduced cell numbers compared to glass controls. Fresh specimens of Signum+EM exhibited the least cytotoxicity, followed by Gradia Enamel E3 and Sinfony E3 and then SR Adoro S1. For specimens with 7-day incubation, 3 of the composites (Signum+EM, Sinfony E3, and Gradia Enamel E3) showed similarly low cytotoxicity, while cytotoxic results with SR Adoro S1 were significantly higher. With low in vitro toxicity values in conjunction with good mechanical properties, veneer composites appear to offer an interesting alternative for prosthetic rehabilitation.

Purpose: The aim of this study was to evaluate single-tooth implant-supported restorations placed in conjunction with several methods of maxillary sinus augmentation., Materials and Methods: A retrospective review was conducted of all consecutively treated patients who received single-implant tooth rehabilitation in combination with sinus augmentation. Implant survival rate and peri-implant conditions, such as marginal bone resorption (mm), pocket depth (mm), Plaque and Bleeding Indices, and Periotest values, were compared for the different augmentation procedures., Results: Fifty-one patients were treated with 54 screw-type single implant-supported restorations in the posterior maxilla in combination with isolated sinus floor augmentation. Depending on the residual ridge height and the intended augmentation height, sinus lift elevation was performed either in a 1-stage lateral approach (25 patients, 28 implants), in a 2-stage lateral approach (12 patients, 12 implants), or with the osteotome technique (14 patients, 14 implants). The predominant use of long implants provided for a favorable implant-crown ratio (> 1.0) and produced an overall clinical survival rate of 100% over the observation period (44.5 +/- 22.7 months), with no differences between the augmentation procedures and implant types used. The most frequent site for single-tooth replacement in combination with sinus floor augmentation was the first molar region (61%). Implants with wider diameters (94% 2 4.3 mm) were used in this region. The most frequent intraoperative complication was tearing of the sinus membrane (58%) as a result of the restricted access for the lateral 1- or 2-stage approach, and the most frequent prosthetic complication was crown loosening., Conclusion: On the basis of this retrospective review, the following was observed: (1) Successful function and excellent peri-implant parameters may be anticipated for single implant-supported restorations placed in conjunction with sinus elevation procedures. (2) Clinical and radiographic examinations demonstrated similar conditions for single-tooth restorations despite the use of different surgical approaches to sinus augmentation. (More than 50 references).

Purpose: This study was intended to calculate the augmentation volume for a sinus lift procedure based on cross-sectional computerized tomography (CT) scans for 2 different augmentation heights., Materials and Methods: Based on area calculations of cross-sectional CT scans, the volume of additional bone needed was calculated for 44 sinus lift procedures. The amount of bone volume needed to raise the sinus floor to heights of both 12 and 17 mm was calculated., Results: To achieve a sinus floor height of 12 mm, it was necessary to increase the height by a mean of 7.2+/-2.1 mm (range, 3.0 to 10.5 mm), depending on the residual ridge height; to achieve a height of 17 mm, a mean of 12.4+/-2.0 mm (range, 8.5 to 15.5 mm) was required (P < .01). The calculated augmentation volume for an augmentation height of 12 mm was 1.7+/-.9 cm3; for an augmentation height of 17 mm, the volume required was 3.6+/-1.5 cm3. Increasing the height of the sinus lift by 5 mm, ie, from 12 mm to 17 mm augmentation height, increased the augmentation volume by 100%. A significant correlation was found between augmentation height and the calculated sinus lift augmentation volume (r = 0. 78, P < .01)., Discussion and Conclusion: Detailed preoperative knowledge of sinus lift augmentation volume is helpful as a predictive value in deciding on a donor site for harvesting autogenous bone and on the ratio of bone to bone substitute to use. Calculation of the augmentation size can help determine the surgical approach and thus perioperative treatment and the costs of the surgery for both patients and clinicians.

Purpose: The aim of the present study was to evaluate implant survival, peri-implant conditions, and prosthodontic maintenance requirements for implant-supported mandibular overdentures in atrophic mandibles retained with ball or resilient telescopic crown attachments during a 3-year period., Materials and Methods: Twenty-five patients with edentulous mandibles each received 2 Camlog root-form dental implants in the mandibular interforaminal (canine) region. The denture attachment system was chosen randomly; 13 patients received ball attachments and 12 patients received resilient telescopic crowns. Implant survival, implant mobility (Periotest values), and peri-implant conditions such as bone resorption, pocket depth, Plaque Index, Gingiva Index, Bleeding Index, and Calculus Index values were assessed for each implant. In addition, detailed prosthodontic maintenance was evaluated during the follow-up period and the 2 retention modalities were compared., Results: There were no differences in implant survival, implant mobility (Periotest values), and peri-implant conditions between the 2 retention modalities. During the 3-year period significantly more complications/interventions for maintenance purposes were registered in the ball group (62 interventions) than in the telescopic crown group (26 interventions; P < .01)., Conclusion: The results indicate that both ball attachments and resilient telescopic crowns used on isolated implants in the edentulous mandible are viable treatment options. Implant success and peri-implant conditions did not differ between ball attachments and telescopic crowns used as retention modalities for implant overdentures, but the frequency of technical complications was significantly higher with ball attachments than with resilient telescopic crowns.

Purpose: The aim of this study was to evaluate the sagittal inclination of interforaminal implants, the clinical implant outcome, and the necessary extent of prosthodontic compensation modalities for implant overdentures (IODs)., Materials and Methods: Lateral cephalometric radiographs of 62 patients, each with a mandibular IOD retained by 2 to 4 implants, were analyzed. The sagittal inclination of the longitudinal implant axis of the most anterior implant was analyzed relative to the mandibular and occlusal planes. The angle needed to compensate for the inclination of the mandibular implant to obtain Angle's class I for the prosthesis (the compensation angle) was measured and compared with respect to skeletal class. Peri-implant structures were measured using the Plaque Index and the Gingival Index. The compensation angle was correlated with the mandibular implant inclination, the degree of mandibular atrophy, and the anterior facial height., Results: The most anterior mandibular implants showed a mean retroinclination of 74.3 +/- 9.3 degrees in relation to the mandibular plane; retroinclination was significantly more pronounced in skeletal class II than skeletal classes I and III (P < .05). The compensation angle (26.9 +/- 10.5 degrees) was more significant for skeletal class II than for skeletal classes I and III (P < .01). Sagittal mandibular implant inclination correlated significantly to the compensation angle (r = -0.46; P < .05), mandibular atrophy (r = 0.32; P < .05) and mandibular facial height (r = -0.45; P < .05). Implant survival rate and peri-implant parameters (bone loss, pocket-depth, Plaque and Gingival Indices) of the interforaminal implants were not shown to be influenced by implant retroinclination. Nine patients (2 skeletal class 1, 7 skeletal class II) reported phonetic problems with the IOD because of narrowing of the lingual space but described significant improvement after a median 4.7 months (range, 3 to 12 months)., Discussion and Conclusion: Depending on skeletal class, prosthetic compensatory mechanisms will be operative in the presence of mandibular implant retroinclination for IOD. Knowledge of mandibular inclinations and the compensatory mechanisms may be an essential factor in successful prosthetic rehabilitation and may provide for a homogenous design of the bar construction and easier handling and may also reduce stress on the attachment mechanism.

Purpose: The survival rate of splinted and unsplinted provisional implants for anchoring removable interim overdentures, as well as handling and maintenance of the interim dentures, was evaluated., Materials and Methods: Eighteen edentulous maxillae were provided with 72 provisional implants for anchoring interim overdentures. For 10 patients, 40 unsplinted implants were used with conical copings to retain the provisional prostheses, while for 8 patients 32 implants had a splinted bar architecture for supporting the interim prostheses. Failure rate of provisional implants, as well as handling and behavior of the anchored interim overdentures, was followed until definitive prosthetic restoration and compared between groups., Results: Eighteen (25.0%) of the 72 provisional implants were prematurely lost. The loss rate of unsplinted implants (37.5%) was significantly higher than that of splinted implants (9.3%). Patient handling and maintenance of maxillary interim overdentures during the follow-up period was found to be easier with the splinted bar-retained method than with the unsplinted prosthodontic method., Conclusion: Placement of provisional implants fulfilled the requirements for initiating immediate prosthetic rehabilitation and showed that removable interim overdentures can be adequately stabilized and provide added patient comfort and satisfaction. The results suggest benefits of the splinted retention modality over the unsplinted method because of advantages regarding failure rate, patient handling, and interim denture maintenance.

Purpose: To evaluate wide-diameter (ie, 5.5-mm-wide) Frialit-2 implants used for several forms of prosthetic rehabilitation., Materials and Methods: In this retrospective study, 121 wide implants (74 maxillary, 47 mandibular) were placed in 114 patients (61 female, 53 male, mean age 37.2 +/- 14.9 years). Thirty-six single-tooth restorations, 63 fixed partial dentures (68 implants), 6 removable overdentures (7 implants), and 3 fixed complete dentures (8 implants) were placed. Eighty-seven were placed in the molar regions. The follow-up period for the implants was 12 to 114 months (mean 41.8 +/- 18.5 months). Peri-implant bone loss, pocket depth, Plaque Index values, Bleeding Index values, and Periotest values were evaluated., Results: Overall, 2 maxillary implants were lost, for a cumulative survival rate of 98.3% (97.3% in the maxilla; 100% in the mandible). Mean peri-implant pocket depth (3.4 +/- 1.1 mm), bone resorption (1.4 +/- 1.2 mm), Periotest values (-4.3 +/- 3.1) as well as the Plaque Index and Bleeding Index (grades of 0 in 80% of cases) indicated acceptable results., Discussion: The high survival rate may be attributed to avoidance of the use of short wide-diameter implants, and the primary intention to place wide-diameter implants. Preference of the molar region was a consequence of the peri-implant bone situation in the premolar region, which was frequently inadequate for a 5.5-mm implant., Conclusions: The use of wide-diameter implants can be a viable treatment option and may provide benefits in posterior regions for long-term maintenance of various implant-supported prosthetic rehabilitations. Some anatomic and prosthodontic limitations for the use of wide implants were

Purpose: This study evaluated the status of teeth adjacent to single-tooth implants in the anterior and posterior jaw during a follow-up of more than 3 years., Materials and Methods: Seventy-eight single-tooth implants and 148 adjacent teeth were followed for a mean of 58 months. Implant survival rate, peri-implant structures, and prosthetic complication rates were evaluated. Crowns and periodontal status of adjacent teeth were compared at crown placement and at the last examination. Horizontal distance from the implant edge to adjacent teeth was calculated and compared for anterior and posterior regions. The influence of approximal crestal bone resorption of the adjacent teeth was calculated using multivariate regression analysis., Results: The clinical findings for implants (one loss), peri-implant structures, and prosthetic complication rates (three crown fractures) were excellent. There was a high proportion of intact adjacent teeth in both anterior and posterior regions at crown placement and at the follow-up examination. No adjacent teeth required extraction or endodontic treatment, and only four required restoration. Comparison of the periodontal status at crown placement and at follow-up revealed no differences for plaque and bleeding indices or for pocket depth of adjacent teeth. There was a significant influence of the horizontal distance on approximal bone loss in the closer distance of the anterior region, but not in the posterior region., Conclusion: The crown and periodontal status of teeth adjacent to single-implant restorations was excellent. The approximal bone crest reduction of the adjacent teeth was significantly influenced by the horizontal distance between the implant edge and neighboring tooth.

Purpose: The behavior of provisional implants in edentulous maxillae/mandibles used for anchoring removable interim overdentures was followed for the time of the intended healing of the definitive implants., Materials and Methods: Twenty-eight edentulous arches (19 maxillae, 9 mandibles) were provided with 77 provisional implants (2 to 4 in maxillae; 2 or 3 in mandibles) for anchoring removable interim prostheses (overdentures). The provisional implants were to be maintained until final restoration (6 to 9 months in the maxilla and 3 months in the mandible). The loss rate of provisional implants and handling and behavior of the anchored overdenture were monitored until the definitive prosthetic restoration was placed., Results: Twenty-three (29.8%) of the 77 provisional implants were lost prematurely. The loss rate of maxillary provisional implants (21/58; 36.2%) was significantly higher than that of mandibular implants (2/19; 10.5%) (P < .01). Determination of terminal stability (by means of the Periotest) of the provisional implants showed higher stability in the mandible (+3.8 +/- 2.3) than in the maxilla (+8.6 +/- 3.9) (P < .05). In obvious contrast to mandibular interim overdentures, handling of maxillary interim overdentures was found to improve significantly during the follow-up period (P < .01)., Discussion and Conclusion: With both the low loss rate in the mandible and the higher loss rate seen in the maxilla, placement of provisional implants fulfills the requirements for initiating immediate prosthetic rehabilitation. The removable interim overdenture can be adequately stabilized and provides for added patient comfort and satisfaction as compared to a conventional complete denture. An important aspect of the continued use of provisional implants concerns the expectations placed in these implants by both clinician and patient, which are quite different than those for definitive implants.

Purpose: This study was intended to provide a report of experience and results with Frialit-2 implants used for single-tooth replacement., Materials and Methods: Over a 7-year period (1994-2000), 146 single-tooth implants (84 maxilla, 62 mandible) were placed in 112 patients (67 females, 45 males; 31.2 +/- 16.4 years). The sites included maxillary anterior teeth (n = 38) as well as the mandibular premolars and molars (n = 57). Ninety-three crowns were cemented and 53 crowns were screw mounted (22 with vertical, 31 with horizontal screws) on standard abutments. The follow-up time varied between 3 and 80 months (35.8 +/- 16.5 months)., Results: Two implants (1.4%) were lost, 1 during early loading and the other after 6 years. The most frequent prosthetic complication was isolated crown loosening of cemented crowns requiring recementation of 9 crowns (9.9%). Crowns with vertical screws showed no crown and/or screw loosening. Four crowns (2.8%) were replaced because of ceramic fracture., Discussion: Peri-implant soft tissue condition, bone resorption, and Periotest values indicated satisfactory results. The cumulative implant survival rate during the follow-up period was 97.3%, and that of the crowns 96.4% (total cumulative survival rate 93.7%)., Conclusions: With the low number of abutment screw loosenings (3.5%), the deep internal hexagonal retention compared favorably to external retention methods. The predominant use of long implants (98.4% > or = 13 mm) allowed a favorable implant/crown ratio with the potential for problem-free, long-term results.

Little information exists to define the minimum number of implants required for sufficient anchorage of mandibular overdentures. To date, 2 implants placed in the interforaminal region have been considered the minimum. The aim of this study was to examine whether a single symphyseal implant would suffice for adequate anchorage of a mandibular complete denture in elderly patients (octogenarians), and whether this surgically, prosthetically, and financially simple concept would also satisfy patients needing replacement of the mandibular dentition. Nine patients with a mean age of 82.2 years underwent placement of a single symphyseal endosseous implant and anchorage of a complete denture using a ball attachment. Standardized recall examinations, including patient response and inspections of the peri-implant soft tissue and bone conditions, were carried out at 3- to 6-month intervals for a period of 1 1/2 years. It was found that anchorage with a single implant led to both a significant improvement in patients' subjective satisfaction (P < .01) and a significant reduction in reported symptoms (P < .01). During the observation phase, pocket depth and bone resorption initially increased around implants but stabilized after the sixth month. Denture management (placement and removal) also improved during the recall period (P < .01). The results of this study indicate that oral rehabilitation by mandibular complete dentures anchored on a single implant can be considered an economical therapeutic alternative to a conventional mandibular complete denture for very old (octogenarian) patients.

A variable number of septa, also referred to as Underwood's septa, divide the floor of the maxillary sinus into several recesses and may thus cause various complications during sinus-lift procedures. The incidence of Underwood's septa was evaluated by examining 41 edentulous maxillas. In 13 of these maxillas (31.7% of the cases), sinus floors with at least one septum were observed. Most of the septa were located in the region between the second premolar and the first molar. A possible cause of septal formation could be the variable phases of maxillary sinus pneumatization of the empty alveolar process following tooth extraction.