Maxillary Sinus Augmentation with Anorganic Bovine Bone Mineral of Different Particle Sizes: A Split-Mouth Study with Histomorphometric, Radiographic, and Clinical Analyses.

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.

Efficacy of Labial Split-Thickness Eversion Periosteoplasty for Soft Tissue Management in Posterior Mandibular Horizontal Ridge Augmentation Procedures: A Prospective Clinical Study.

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.

Transsinusoidal lateral nasal floor augmentation for implant placement in the atrophic premaxilla: A within-patient, 5-year, prospective comparative study.

OBJECTIVES: To evaluate the clinical outcome for implants placed with transsinusoidal-lateral nasal cavity augmentation (NA) compared to implants placed in maxillary sinus augmentation (SA). MATERIALS AND METHODS: In 28 atrophic edentulous maxillary regions (14 patients bi-maxillary), a lateral window approach was used to perform transsinusoidal-lateral NA (TSLNA) combined with maxillary SA. After healing period of about 6 months, each patient received bimaxillary one anterior implant located in the pre-maxilla having lateral NA and 2-3 implants in the maxillary posterior region with SA. In a prospective follow-up evaluation, clinical implant outcome (survival/success rates) and peri-implant health (mucositis/peri-implantitis) were assessed and compared between implants placed in TSLNA (n = 28) and SA (n = 58). RESULTS: At the year-1, year-3, and year-5 evaluation, neither patient-based nor implant-based comparisons revealed differences for marginal bone level reduction between implants placed in TSLNA (5-year overall: 1.11 ± 0.26 mm) and SA (5-year overall: 1.07 ± 0.30 mm), although with a significant (p < .001) continuous reduction over the observation time. At the year-5 evaluation, all implants (n = 86) and restorations (n = 14) were still in situ (survival 100%) and showed an implant-based incidence of peri-implant mucositis/peri-implantitis of 14.3%/0% in TSLNA and 6.9%/3.4% in SA corresponding to 21.4%/0% and 28.6%/7.1% for implant-based evaluation. In addition, the implant success rate did not differ between NA and SA at implant- (100%/ 98.8%) and patient-based (100%/97.6%) evaluation. CONCLUSION: The findings obtained show TSLNA as an effective method for implant placement of adequate length and direction in the atrophic premaxilla providing for success rates comparable to those of implants placed in SA.

The influence of different forms of sinus membrane perforation on the prevalence of postoperative complications in lateral window sinus floor elevation: A retrospective study.

BACKGROUND: Maxillary sinus membrane perforation (SMP) during lateral window sinus floor elevation (SFE) might be associated with postoperative complications (PC). OBJECTIVES: To evaluate the prevalence of PC and clinical implant outcome for different forms of SMP with lateral window SFE. MATERIAL AND METHODS: The prevalence of PC such as maxillary sinusitis, graft necrosis and wound infection was retrospectively evaluated for 434 lateral window SFE (334 patients) with 331 SFE (241 patients) without and 103 SFE (93 patients) with SMP. SMP was additionally classified into four subgroups regarding to membrane perforation size (small-moderate [<10 mm] vs. large [>10 mm]) and membrane biotype ([BT] thin vs. thick). Additionally, patient- and surgery-related risk factors affecting PC and the 1-year implant survival rate were evaluated for SFE without and with SMP and subgroups. RESULTS: A significantly higher prevalence including significant odds ratios of PC such as maxillary sinusitis (10/103 [9.7%] vs. 4/331 [1.2%]; p < 0.021; OR: 8.85; p < 0.021) and graft necrosis (7/103[6.8%] vs. 1/103[0.3%]; p < 0.017; OR:7.43; p < 0.017) was found for SFE with than without SMP. The SMP subgroup with large size and thin BT involved significantly (p < 0.005) more PC (15/20[75%]) than all other SMP subgroups (5/20[25%]). For the risk factors evaluated the univariate analysis demonstrated differences of PC for the presence versus absence of SMP (p < 0.001) and for thin versus thick sinus mucosa (p < 0.038; p < 0.006) but not for sex, smoking, sinus septa and surgical stage. In the multivariate risk factors analysis, PC were significantly related to risk factors such as large size with thin BT (OR:18.049; p < 0.007). The 1-year implant survival rate did not differ between SFE without (99.5%) and with SMP (99.1%), regardless of successfully repaired subtype of SMP. CONCLUSION: The synopsis of perforation size and membrane biotype is crucial in differentiating different forms of SMP assessing and anticipating different prevalences of PC in lateral window SFE.

Prevalence, risk factors, and repair mechanism of different forms of sinus membrane perforations in lateral window sinus lift procedure: A retrospective cohort study.

OBJECTIVES: To evaluate prevalences, affecting risk factors and efforts for repair mechanism for different forms of sinus membrane perforations (SMP) during sinus floor elevation (SFE) using the lateral window technique (LWT). MATERIAL AND METHODS: For 334/434 patients, SFE undergoing LWT prevalence of SMP was retrospectively evaluated including a subselection based on membrane perforation size (<10 mm: small-moderate/≥10 mm: large) and biotype (BT; thick BT/thin BT) into four subgroups (SMP1: thick BT/small-moderate; SMP2: thin BT/small-moderate; SMP3: thick BT/large; SMP4: thin BT/large). For the various subgroups, patient- and surgery-related/anatomic risk factors affecting SMP were evaluated and the scope of sinus membrane repair (SSMR) mechanisms rated with 1 (easy) to 5 (complex) was compared. RESULTS: For 103/434 SMP (27.6%) in 93/334 patients (30.8%) the prevalence of various forms of SMP differed significantly (p < 0.001) among the four subgroups. SMP4 with a prevalence of 45.6% (n = 47) was the most frequent type, while SMP3 had low prevalence with 4.85% (n = 5). Small/moderate SMPs with thick (SMP1: n = 26) or thin BT (SMP2: n = 23) were seen in 26.2% and 23.3%, respectively. Univariate analysis showed significant differences between subgroups with large perforations (SMP3/SMP4) and those with small/moderate perforations (SMP1/SMP2) regarding anatomic risk factors such as residual ridge height (p = 0.023) and history of previous oral surgical interventions (OSI; p = 0.026). Most evidently, multivariate analysis showed that induction of large SMP with thin biotype (SMP4) was significantly affected by the presence of sinus septa (p < 0.022, OR: 2.415), reduced residual ridge height (p < 0.001, OR: 1.842), and previous OSI (p < 0.001, OR: 4.545). SSMR differed significantly (p < 0.001) between SMP4 (4.62 ± 0.49) and the subgroups SMP1 (1.11 ± 0.32), SMP2 (1.08 ± 028), and SMP3 (2.2 ± 0.55). CONCLUSION: The most frequently found type of SMP had characteristics of thin biotype and large size associated with risk factors such as sinus septa, reduced residual ridge, and previous surgical interventions and required challenging repair mechanisms assessing clinical impact.

Risk Factor Analysis Affecting Sinus Membrane Perforation During Lateral Window Maxillary Sinus Elevation Surgery.

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.

Clinical Outcome of Implants Placed in Staged Maxillary Sinus Augmentation Using Bovine Bone Mineral Mixed with Autogenous Bone at Three Different Ratios: A 5-Year Prospective Follow-up Study.

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.

Mandibular Full-Arch Fixed Prostheses Supported on 4 Implants with Either Axial Or Tilted Distal Implants: A 3-Year Prospective Study.

PURPOSE: This prospective study evaluated the clinical and radiographic outcome of distally cantilevered 4-implant-supported fixed mandibular prostheses (4-ISFMP) with distal implants either in axial or distally tilted direction. MATERIAL AND METHODS: Forty-one mandibulary edentulous patients received acrylic veneered 4-ISFMP with casted framework. Based on distal implant placement direction patients were assigned to 2 groups: 21 patients with four (2 anterior/2 posterior) axial implants (axial-group I) and 20 patients with 2 anterior axial/2 distal tilted implants (tilted-group II). Patients were prospectively followed for 3 years by annual examinations of implants and prosthetic survival rates including assessment for biological and mechanical complications. Additionally, peri-implant marginal bone resorption [MBR], pocket depth [PD], plaque index [PI], bleeding index [BI] and gingival index [GI], and calculus index [CI] were evaluated at each annual follow-up. RESULTS: 37/41 patients (19 axial-group I, 18 tilted-group II) and 148/164 implants were followed at the 1-, 2-, and 3-year evaluation (dropout rate: 11.8%) presenting no implant and denture loss (100% survival). The overall, MBR at year 1, 2, and 3 was 1.11 ± 0.4 mm, 1.26 ± 0.42 mm, and 1.40 ± 0.41 mm, respectively, representing a significant (p < .001) continuing time depending annual reduction. MBR and PD did not differ between anterior and posterior regions in both groups or for anterior and posterior regions between the groups. PI and CI were significantly (p < .001) higher for implants in anterior regions than for posterior regions in both groups. Moreover, posterior implant regions showed significantly (p < .001) higher PI and CI for axial-group I than for tilted-group II over time. Biological and mechanical complications as well as GI and BI did not differ between the groups over a 3-year follow-up period. CONCLUSION: For clinical implant and prosthesis outcome no statistical significant mean differences were noted for distally cantilevered 4-ISFMP supported by distal implants placed in tilted or axial direction.

Factors affecting peri-implant bone resorption in four Implant supported mandibular full-arch restorations: a 3-year prospective study.

BACKGROUND: Peri-implant marginal bone-level (MBL) alteration represents one of the parameters included in the criteria for determining implant health. OBJECTIVE: Factors affecting peri-implant MBL alteration for 4-implant-supported fixed mandibular prostheses (4-ISFMP) were assessed. MATERIAL & METHODS: A 3-year prospective, cohort study was conducted on 44 mandibularly edentulous patients treated with 4-ISFMP. Peri-implant MBL alteration was evaluated radiographically at the 12-, 24- and 36-month follow-ups considering to patient-related risk factors [age, gender, diabetes mellitus, smoking, cardiovascular disease (CVD), rheumatic disorders (RD)] and implant/prosthesis-related features (implant location, keratinized gingiva, denture cantilever length, prosthesis supporting zone, opposing dentition) as well as to peri-implant biological parameters (plaque-, bleeding-, calculus index). RESULTS: 148/176 implants (37 patients, drop-out: 15%) were followed for 3 years showing significant (p < 0.001) annual differences of MBL alterations over time. The univariate analysis demonstrated differences of MBL alterations for smokers (p = 0.014), for patients with CVD (p = 0.001) and RD (p = 0.011). In the 3-year multivariate analysis, MBL alteration was influenced by time (p < 0.001) and showed relationship with risk factors as smoking (p < 0.002; OR = 18.965), CVD (p < 0.021; OR = 5.172), RD (p < 0.006; OR = 50.171) and plaque-index (p = 0.034; OR = 3.252). CONCLUSIONS: Although peri-implant MBL alteration increased annually, significant odds ratios, were found for patients-related risk factors identifying them potentiating the alterations.

Immediately loaded distally cantilevered fixed mandibular prostheses supported by four implants placed in both in fresh extraction and healed sites: 2-year results from a prospective study.

OBJECTIVES: To evaluate the outcome of immediately loaded distally cantilevered mandibular full-arch prostheses according to the 'all-on-four' concept supported by implants placed in both fresh extraction and healed sites. MATERIAL AND METHODS: A prospective study was conducted in 24 patients with extraction of all remaining mandibular teeth and placement of 4 implants per patient (2 mesial axial and 2 distal tilted) for full-arch mandibular restorations. Implants were inserted in fresh extraction sockets 2.3 ± 1.0 per patient and 1.7 ± 1.0 implants in healed sites. Implants placed in fresh extraction sites (n = 55) were significantly (P <0.01) more deeply inserted than implants (n = 41) placed in healed sites (peri-implant alveolar crest: +1.6 ± 0.8 mm vs +0.6 ± 0.7 mm). Patients received an immediate provisional fixed dental prosthesis and, 3 months later, a definite resin veneered prosthesis with metal framework. At the 12-and 24-month follow-up, patients were evaluated for implants and prosthesis success, for prosthodontic maintenance efforts and patient satisfaction. At both follow-up examinations, peri-implant marginal bone level, implant pocket depth, plaque, bleeding, gingival and calculus indices were evaluated and compared between implants placed in fresh extraction and healed sites. RESULTS: At the 24-month follow-up, no implant failed and all prostheses were stable. There were five fractures of the provisional prosthesis in 5 patients but no fracture of the definite prostheses. For the definite prostheses, 15 acrylic teeth had to be renewed/repaired (in 10 patients) and 18 patients presented the need for the implant-supported prosthesis to be rebased. Peri-implant marginal bone level after 12 and 24 months was -0.18 ± 0.20 mm and -0.40 ± 0.29 mm for all implants (P <0.001) representing bone level differences of 0.35 mm between implants placed in healed and post-extractive sites at both the 1st year (95%-CI:-0.49 to -0.20) and the 2nd year (95%-CI: -0.57 to -0.14) assessment. Plaque (1st year: 1.17 ± 0.48 versus 0.5 ± 0.6; P <0.001; 2nd year: 1.21 ± 0.51 versus 0.55 ± 0.6; P <0.001) and calculus indices (1st year: 0.92 ± 0.28 versus 0.45 ± 0.51; P <0.001; 2nd year: 1.00 ± 0.42 versus 0.5 ± 0.51; P <0.001) were significantly higher for implants placed in fresh extraction than in healed sites. Patients' subjective satisfaction score rating assessed by 5 items was high at the 1- (score: 4.6 ± 0.4) and 2-year evaluation (score: 4.7 ± 0.36). CONCLUSION: Within the limits of this study, immediately loaded full-arch prostheses can be supported by four implants placed simultaneously into healed and fresh extraction sites.

Clinical outcome and peri-implant findings of four-implant-supported distal cantilevered fixed mandibular prostheses: five-year results.

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.

Implant-prosthodontic rehabilitation of anterior partial edentulism: a clinical review.

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.

Comparison of ball and telescopic crown attachments in implant-retained mandibular overdentures: a 5-year prospective study.

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.

Soft tissue development around abutments with a circular macro-groove in healed sites of partially edentulous posterior maxillae and mandibles: a clinical pilot study.

OBJECTIVES: The aim of this study was to evaluate soft tissue development at concave circular macro-grooved titanium abutments in healed sites. MATERIAL AND METHODS: In a split-mouth pilot study 10 patients received two implants each at healed posterior sites in contralateral maxillary or mandibular jaw quadrants. Either circular macro-grooved concave study abutments or conventional convex control abutments were immediately provisionalized and received permanent crowns 3 months postimplantation. Marginal bone level, papilla index, modified plaque and bleeding index were recorded. The esthetic outcome was evaluated with standardized perpendicular pictures according to the Pink Esthetic Score (PES). Statistical analysis included the description of all variables by mean value, standard deviation and range. PES values were compared using the Wilcoxon signed rank test for paired data. RESULTS: Cumulative survival rate for all 20 implants was 100%. At the 1-year follow-up, there was no statistical significant difference of marginal bone levels between sites restored with the study (-0.11 ± 0.77 mm) vs. the control (-0.34 ± 0.53 mm) abutments (P>0.05). Esthetic evaluation (PES) revealed statistically significant differences in scores between the study group [study abutment group] (7.2 ± 2.82, 8 ± 1.89) and the control group [control abutment group] (9.5 ± 1.58, 10.5 ± 1.72) at the time of prosthetic delivery and the 1-year follow-up. Whereas PES scores for mesial papilla at control sites at the 1-year follow-up demonstrated statistically significant higher values, both soft tissue level and soft tissue contour at control sites revealed statistically significantly higher PES values (P<0.05) at time of prosthetic delivery and at 1-year follow-up when compared with study sites. CONCLUSIONS: Concave macro-grooved abutments in healed posterior maxillary and mandibular sites did not exhibit a superior soft tissue development compared with standard convex abutments.

Removable implant-prosthodontic rehabilitation of the edentulous mandible: five-year results of different prosthetic anchorage concepts.

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.

Implant prosthodontic rehabilitation of patients with rheumatic disorders: a case series report.

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.

Gingivomorphometry - esthetic evaluation of the crown-mucogingival complex: a new method for collection and measurement of standardized and reproducible data in oral photography.

OBJECTIVES: A new method is introduced for the esthetic evaluation of the periimplant mucogingival complex through collection of standardized oral photographs and computer-assisted measurement of reproducible data. Using this method, different soft tissue and crown parameters in the dentogingival complex can be measured and the esthetic outcome monitored. MATERIAL AND METHODS: A photographic device for standardized oral photography and a standard protocol for the esthetic evaluation of the crown-mucogingival complex is presented, comprising six soft tissue parameters: (1) mesial and (2) distal papilla areas, (3) mesial and (4) distal papilla heights, (5) soft tissue-crown perimeter, and (6) gingival recession. In order to demonstrate the reproducibility of standardized oral photographs and the accuracy of the measurement of the six parameters, the data obtained in each of two such standardized clinical photographs, taken at 10-14 days intervals, of the anterior maxillary region from 10 patients with no apparent dental disease were compared. For the statistical analysis of the reproducibility of these dependent data the 95% confidence interval and the coefficients of variation were calculated from measurement means and ranges of each of the above parameters, pooled from all 10 patients. RESULTS: Statistical analysis revealed high reproducibility with no significant differences between the range of mean values of all six parameter measurements on the first and second standardized oral photograph of the same patient, respectively. CONCLUSION: Gingivomorphometry on standardized oral photographs can be considered to be an accurate and reproducible method for the evaluation and measurement of different dentogingival and periimplant parameters.

Mechanical stability of immediately loaded implants with various surfaces and designs: a pilot study in dogs.

PURPOSE: Immediate loading is among the most innovative techniques in implant therapy today. This pilot study investigates the biomechanical outcome of various designs and surfaces that claim to shorten implant treatment. MATERIALS AND METHODS: In each quadrant of two mongrel dogs, four different implants were used for immediate loading. The following implants were placed 3 months after tooth extraction: screw with low thread profile and anodic oxidized surface (LPAOS), solid screw with wide thread profile and titanium plasma spray coating (WPTPS), screw with low profile and hybrid design of double-etched and machined surface (LPHES), and screw with two thread profiles and a sandblasted and acid-etched surface (DTSAE). The insertion torque of each implant was above 35 Ncm. Resonance frequency analysis was performed after implant placement and again after sacrifice. Additionally, the removal torque and the amount of embedded titanium particles in the peri-implant bone were measured. RESULTS: All 16 prostheses were functional after a 5-month loading period. The highest mean removal torque values were recorded with WPTPS implants (24.4 Ncm/mm), followed by DTSAE implants (22.3 Ncm/mm) and LPAOS implants (18.7 Ncm/mm); the lowest score was obtained by LPHES (12.0 Ncm/mm). The ISQ values increased between the time of surgery and recall for all systems on average, but a significant positive correlation was found for DTSAE only. Significantly higher amounts of titanium were found in the surrounding bone with WPTPS (0.76%) and LPAOS (0.41%) in comparison with DTSAE (0.10%) and LPHES (0.03%). CONCLUSION: Immediate loading is possible with various designs and surfaces if high primary stability can be achieved during implant placement.

Provisional implants for immediate restoration of partially edentulous jaws: a clinical study.

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.

Computerized tomography-assisted calculation of sinus augmentation volume.

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.