Tooth-implant and implant supported fixed partial dentures: a 10-year report. Effectiveness of three treatment modalities for the edentulous mandible. A five-year randomized clinical trial. An evaluation of the effects of two distal extension removable partial denture designs on tooth stabilization and periodontal health. Influence of clasp design of distal extension removable partial dentures on the periodontium of the abutment teeth. Immediate loading of dental implants supporting fixed partial dentures in the posterior mandible: a randomized controlled split-mouth study--machined versus titanium oxide implant surface. Restoration of partially edentulous patients using dental implants with a microtextured surface: a prospective comparison of delayed and immediate full occlusal loading. A randomized clinical trial of two basic removable partial denture designs. Part II: Comparisons of masticatory scores. Rehabilitation of oral function in head and neck cancer patients after radiotherapy with implant-retained dentures: effects of hyperbaric oxygen therapy. Cemented versus screw-retained implant-supported single-tooth crowns: a 4-year prospective clinical study.
The use of implants for prosthetic rehabilitation of partially edentulous patients is increasing. However, the possibilities of placing implants in the posterior part of the mandible are often limited. The purpose of this longitudinal study with 10 years of follow-up was to evaluate the use of short implants supporting fixed partial dentures (FPD) in the posterior part of the mandible, and to compare implant supported FPDs to tooth-implant supported FPDs.
                The patient material comprised 23 patients with residual mandibular anterior teeth, and each patient received FPDs unilaterally. On one side the FPD was supported by two implants, and on the other side by one implant and one tooth, thus permitting intraindividual comparison. The distribution of the two types of FPDs in each jaw was randomized. Implant success rates, marginal bone changes, and mechanical complications were studied.
                The tooth-implant connection did not demonstrate any negative influences on the overall success rates for the 10-year period, nor were the shorter implants found to be less favorable.
                It is suggested that a prosthetic construction supported by both a tooth and an implant may be recommended as a predictable and reliable treatment alternative in the posterior mandible. Currently, 3 treatment options are available for patients with denture complaints and an edentulous mandible with a height of at least 15 mm: meticulous construction of a new set of dentures (CD), construction of a new set of dentures following preprosthetic surgery to enlarge the denture-bearing area (PPS), and construction of an implant-retained mandibular overdenture (IRO). The aim of this study was to evaluate patient satisfaction and subjective chewing ability of edentulous patients treated with one of these treatment modalities. Ninety edentulous patients (Cawood class IV and V, mean mandibular height 20.7 mm) were randomly assigned to receive 1 of these 3 groups. Denture satisfaction and chewing ability were assessed using questionnaires focusing on denture-related complaints and problems chewing different types of food were assessed before treatment, and 1- and 5-years after treatment. At the 1-year evaluation, significantly better scores were observed in the 2 surgical groups (IRO, PPS) than in the CD group. At 5-year evaluation the "complaints of the lower denture" showed a significantly better score in the IRO group when compared to the PPS and CD groups. No significant differences were observed between the PPS and CD group. From this study it is concluded that both in the short and long term denture satisfaction appears most favourable in the IRO group when compared to the PPS and CD groups. Implant-retained overdentures are therefore a satisfactory treatment modality for edentulous patients with problems with their lower denture, even in cases of not severely resorbed mandibles. A 30-month follow-up study was conducted on 36 patients to evaluate the effects of the lingual plate as a major connector in distally extended removable partial dentures (RPDs) on tooth stabilization. At the same time, the study evaluated the effects of lingual plate-type RPDs and lingual bar-type RPDs on periodontal health. The most striking finding of the study was that, with the exception of gingival recession (GR), periodontal conditions improved with both types of RPDs. At the end of 30 months, there were significant differences in plaque index, GR and tooth mobility (TM) values between treatment groups (P < 0.05). Plaque accumulation was greater in the lingual plate treatment group; however, this did not result in periodontal breakdown. There were no statistically significant differences between treatment groups with respect to pocket depth, gingival index or attachment loss (P > 0.05). Moreover, patients treated with lingual plate-type RPDs demonstrated less TM when compared with patients treated with lingual bar-type RPDs at the end of 30 months follow-up. Overall study findings established that with adequate checks on oral and denture hygiene at regular intervals, patients with RPDs may even experience improved periodontal health. Moreover, the clinical interpretation of decreased TM observed in patients treated with lingual plate-type RPDs may be questionable as the plaque accumulation was greater in the lingual plate treatment group inspite of periodic recalls. Three removable partial denture designs were investigated to determine the effect of minor connector configuration on the periodontal health of abutment teeth. Twenty-five patients wore three different removable partial dentures for 19 weeks each. The first removable partial denture placed a tilting force on the abutment teeth; the second was stress-releasing; and the third collected the least amount of plaque. Plaque accumulation, the condition of the periodontium, migration of the abutment teeth, deformation of the clasp arms, retention of the prosthesis, and patient preferences were assessed. The results demonstrated that the partial denture retentive design did not affect plaque formation. The prosthesis designed to place a tilting force on the abutment teeth appeared to cause the least mobility and migration of the abutments and had the greatest acceptance by the patients. A split-mouth study was conducted to compare dental implants with either machined or titanium oxide (TiO) surfaces immediately loaded with fixed partial dentures in the posterior mandible.
                Ten patients with bilateral partial edentulism in the posterior mandible received 42 implants; 20 on the test (TiO) and 22 on the control (machined) side. The implants were loaded within 24 hours postsurgery. At implant placement the maximum insertion torque (IT) was recorded. Implant stability quotient (ISQ) was also evaluated at baseline (day 0) and 1, 2, 4, 12, 24, and 52 weeks following implant placement. The radiographic bone level (RBL) change was measured on periapical radiographs at baseline and 12 months after loading. Means for the 2 groups were compared by paired t test.
                The overall implant success rate was 95%. No implants were lost in the test group; 2 failed in the control group. The difference between the groups in RBL change after 1 year of function was not statistically significant (P = .224). However, average RBL change for machined implants in distal positions was significantly higher than for TiO surface implants in the same position (post-hoc comparison; P = .048). ISQ and peak IT values did not differ between the groups (P = .414 and P = .762, respectively). The high IT necessary to insert the implants did not seem to affect the RBL change (P = .203).
                No significant difference was observed between machined and TiO implant surface in terms of RBL change or ISQ, although TiO implants may provide a lower RBL change compared to machined implants when utilized in the distal position. Immediate loading of implants using fixed partial dentures in posterior mandible may be considered as a treatment option if implants are inserted with IT > or = 20 Ncm and ISQ > or = 60 into nonaugmented bone and loaded with light centric occlusal contact. The aim of this study was to determine the clinical effectiveness of placing dental implants with microtextured surfaces into full occlusal loading at the time of placement in partially edentulous patients.
                Two demographically similar groups of 14 patients each were treated with a total of 92 Spline Twist Implants (Centerpulse Dental, Carlsbad, CA). Test implants were placed into immediate full occlusal loading, and control implants were restored using a conventional delayed loading procedure. Otherwise, both groups of patients received similar therapy from the same treatment team. Radiographs, periodontal indices, and Periotest values were recorded every 6 months during routine clinical follow-up appointments. The mean loading time for all prostheses was 24 months at the time of this report.
                No implants failed in the test group, and 1 implant failed before loading in the control group. Cumulative implant success was 98.9% for all implants placed (test group = 100%; control group = 92.9%). Periodontal measurements indicated no significant clinical differences between implants placed into immediate full occlusal loading and those loaded via a conventional delayed protocol.
                Immediate full occlusal loading of partial prostheses supported by microtextured implants in partially edentulous patients demonstrated excellent clinical results, with no adverse periodontal effects after 24 months of function. Additional follow-up will provide invaluable information on the long-term effects of this technique.
                Immediate full occlusal loading of partial prostheses supported by microtextured implants can be successfully achieved for 24 months in highly motivated patients with excellent oral hygiene. There is no known data on the functional efficacy of different removable partial denture designs.
                This randomized clinical trial compared the masticatory performance of two commonly used designs in 118 patients who needed a unilateral or bilateral mandibular partial denture.
                One half of the patients received a partial denture with distal occlusal rests and cast circumferential clasps and the other half a partial denture with mesial rests and I-bar cast clasps. The left side, right side, and swallowing threshold masticatory tests were made with peanuts and carrots before treatment and 16 weeks after the prosthesis insertion (baseline) and thereafter at 6, 18, 36, and 60 months.
                Masticatory scores at entry were higher in the circumferential design group, but the only significant (p < 0.05) difference was found in the right side carrot performance. Both groups realized significant improvements (p < 0.001) in all performance scores with partial dentures. Mean improvements of 24.7 with peanuts and 35.8 with carrots in the right side performance scores and 19.0 in the swallowing threshold score with peanuts in the bar design group were significantly higher (p = 0.017) than the respective mean improvements of 15.9, 21.4, and 5.6 in the circumferential design group. However, no significant differences were found between the two groups for any of the 10 performance scores at baseline.
                Despite some performance differences at entry, the mean performance scores for the two groups became similar at baseline and at subsequent intervals. Surgical treatment of malignancies in the oral cavity and subsequent radiotherapy often result in an anatomic and physiological oral condition unfavorable for prosthodontic rehabilitation. The objective of this prospective study was to assess the effect of hyperbaric oxygen therapy on treatment outcome (condition of peri-implant tissues, implant survival, oral functioning and quality of life) of prosthodontic rehabilitation with implant-retained lower dentures in radiated head and neck cancer patients 6 weeks and 1 year after placing the new dentures. The treatment outcome was assessed in a group of 26 head neck cancer patients who were subjected to radiotherapy after tumour surgery. Standardized questionnaires were completed and clinical and radiographic assessments were performed. After randomization, endosseous Brånemark implants were placed in the anterior part of the mandible either under antibiotic prophylaxis (13 patients) or under antibiotic prophylaxis combined with pre and postsurgery hyperbaric oxygen (HBO) treatment (13 patients). In the HBO and non-HBO group eight implants (implant survival 85.2%) and three implants (implant survival 93.9%) were lost, respectively. Peri-implant tissues had a healthy appearance in both groups. Osteoradionecrosis developed in one patient in the HBO group. All patients functioned well with their implant-retained lower denture. The quality of life related to oral functioning and denture satisfaction were improved to a comparable extent in the HBO and non-HBO group. Implant-retained lower dentures can improve the quality of life related to oral functioning and denture satisfaction in head and neck cancer patients. Adjuvant hyperbaric oxygen therapy could not be shown to enhance implant survival in radiated mandibular jaw bone. The purpose of this controlled prospective clinical study was to compare cemented and screw-retained implant-supported single-tooth crowns followed for 4 years following prosthetic rehabilitation with respect to peri-implant marginal bone levels, peri-implant soft tissue parameters, and prosthetic complications.
                Twelve consecutive patients were selected from a patient population attending the Implantology Department at the University of Padova. They all presented with single-tooth bilateral edentulous sites in the canine/premolar/molar region with adequate bone width, similar bone height at the implant sites, and an occlusal scheme that allowed for the establishment of identical occlusal cusp/fossa contacts. Each patient received 2 identical implants (1 in each edentulous site). One was randomly selected to be restored with a cemented implant-supported single-tooth crown, and the other was restored with a screw-retained implant-supported single-tooth crown. Data on peri-implant marginal bone levels and on soft tissue parameters were collected 4 years after implant placement and analyzed to determine whether there was a significant difference with respect to the method of retention (cemented versus screw-retained).
                All patients completed the study. All 24 implants survived, resulting in a cumulative implant success rate of 100%. Statistical analysis revealed no significant differences between the 2 groups with respect to peri-implant marginal bone levels and soft tissue parameters.
                The data obtained with this study suggested that the choice of cementation versus screw retention for single-tooth implant restorations is likely not based on clinical results but seems to be based primarily on the clinician's preference.
                Within the limitations of this study, the results indicate that there was no evidence of different behavior of the peri-implant marginal bone and of the peri-implant soft tissue when cemented or screw-retained single-tooth implant restorations were provided for this patient population.
There is weak evidence that it may be advantageous, for dentists providing a complete denture service, to prescribe prosthetic posterior teeth with cusps to improve patient satisfaction compared to providing cuspless teeth. However, this conclusion may only be made tentatively until further well conducted trials comparing different occlusal schemes for complete dentures are undertaken.