Prognosis of implants and abutment teeth under combined tooth-implant-supported and solely implant-supported double-crown-retained removable dental prostheses.

OBJECTIVE: Objective of this study was to evaluate the incidence of complications in dental implants and abutment teeth used for combined tooth-implant- and solely implant-supported double crown-retained removable dental prostheses (RDPs). MATERIAL AND METHODS: Patients were selected from a prospective clinical study. Seventy-three RDPs retained by 234 implants and 107 abutment teeth were placed in 39 men and 22 women with a mean age of 65 years. Forty-five RDPs were located in the maxilla and 28 in the mandible. Thirty-four RDPs were solely implant-supported and 39 were combined tooth-implant-supported. Kaplan-Meier analysis was used to estimate success defined as survival without severe abutment-related complications, and Cox regression was used to isolate the most relevant prognostic risk factors. RESULTS: After a median observation period of 2.7 years for the RDPs, six implants failed and eleven implants were diagnosed with peri-implantitis. Four abutment teeth were extracted, and three abutment teeth showed severe complications requiring extended interventions. For both abutment teeth and implants, Kaplan-Meier analyses revealed a 5-year probability of success of 85% for solely implant-supported RDPs and 92% for combined tooth-implant-supported RDPs. Multiple Cox regression identified RDP location (P = 0.01), age (P = 0.01), and gender (P = 0.04) as prognostic risk factors for severe implant-related complications. Solely implant-supported RPDs showed a poorer prognosis, but the risk difference did not reach statistical significance. CONCLUSIONS: Preliminary data suggest that the combination of teeth and implants to support double crown-retained RDPs may result in a prognostic advantage. The present findings should be validated in independent studies.

Short-term complications of implant-supported and combined tooth-implant-supported fixed dental prostheses.

OBJECTIVE: The objective of this clinical study was to evaluate survival and incidence of complications for metal-ceramic and all-ceramic implant-supported fixed dental prostheses (FDPs) and tooth-implant-supported FDPs. MATERIAL AND METHODS: One-hundred and sixty-six FDPs placed in 132 patients from a prospective study were selected for this retrospective analysis. Included were 91 conventional implant-supported FDPs with implant support on both extremities, 27 implant-supported cantilever FDPs, and 48 tooth-implant-supported FDPs. All restorations were veneered with ceramic. Twenty-six FDPs had a zirconia framework and 140 had a metal framework. Kaplan-Meier analysis was performed to estimate FDP success defined as complication-free survival and the Cox regression model was used to isolate risk factors for the most frequent complications. RESULTS: Within a median follow-up of 1 year and 2 months, three failures were caused by a failed implant (n = 2) and by extended chipping of the veneer (n = 1). In contrast with this low incidence of failure was a high incidence of complications including chipping (n = 29), loss of retention (n = 35), and abutment fractures (n = 2). Multivariate survival analysis revealed a significantly greater incidence of chipping for males and a tendency to increased incidence of chipping for zirconia-based FDPs. The incidence of loss of retention tended to be less for tooth-implant-supported FDPs, for which semi-permanent cement was the only significant risk factor, with a hazard ratio of almost 5. CONCLUSIONS: As chipping of the ceramic veneer was the most frequent complication leading to substantial aftercare, improvements of ceramic veneers are desirable for zirconia-based and metal-based FDPs.

Influence of bone augmentation procedures on the short-term prognosis of simultaneously placed implants.

OBJECTIVES: The purpose of this study was to investigate the effect of simultaneous bone-augmentation procedures, and their combination, on the survival of dental implants and on the incidence of complications. MATERIAL AND METHODS: Within a retrospective analysis, 958 implants placed in 404 patients (mean age 58.18) were selected from a prospective clinical study. In 304 cases of reduced bone width, bone spreading (n = 217) with hand osteotomes, or bone splitting (n = 15), or guided bone regeneration (n = 72) combined with autogenous bone grafts were also performed. Eighty-eight implants were placed in combination with simultaneous internal sinus floor elevation without using graft material. For 194 additional implants, several augmentation procedures were combined because of extensive bone deficits. Three-hundred and seventy-two conventionally placed implants served as controls. Implant failures and complications were recorded after a mean observation period of 2.1 years (maximum 6.9 years). RESULTS: Seventeen failures and nine additional implant-related complications were observed. After 4 years, Kaplan-Meier curves revealed a probability of survival without complication of 97.5% for conventionally placed implants, and 95.8% for implants placed in combination with a single augmentation technique. If several augmentation techniques were combined, success decreased to 94.1%. Complication-free survival differences between combined augmentation techniques and conventionally placed implants were significant (P = 0.004). Age, gender, and location showed no effect on implant survival. CONCLUSIONS: It can be concluded that simultaneous bone-augmentation techniques slightly reduce short-term prognosis for dental implants. This effect was more pronounced when advanced defects required the combination of several augmentation procedures.

Clinical success rates for polyether crown impressions when mixed dynamically and statically.

The purpose of this study is to compare success rates of dual-viscosity impressions for two types of mixing techniques of the polyether elastomeric impression material. Additionally, influencing parameters on the success rates should be evaluated. The expectation was that there would be no difference between the success rates for the two mixing techniques. Two centres enrolled 290 subjects (727 teeth) into the trial. Patients were randomized for the two types of mixing techniques. One step, dual-viscosity impressions were made with either statically mixed Impregum Soft tray material (SAM) or dynamically mixed Impregum Penta H DuoSoft (DMM). Low viscosity Impregum Garant L DuoSoft was used for both groups. Gingival displacement involved the use of two braided cords. Full-arch trays were used exclusively. Both critical defects and operator errors were assessed for the first impression taken by trained dentists. The primary outcome was impression success. For comparison of the two mixing techniques, the odds ratio for success and the corresponding one-sided 95% confidence interval was calculated by a logistic regression model. To account for the dependence between several teeth within one patient, the method of general estimating equations was used. The overall impression success rate was 35.4%. Both mixing techniques showed equal success rates indicated by an OR of 1.0 and a lower limit of the one-sided 95% confidence interval of 0.71. Using this result to develop the corresponding interval for the difference, it could be shown that the success rate using SAM was at most 8.2% lower than that when using DMM with a probability of 95%. Multivariate logistic regression analysis of other potential influencing factors showed position of finish line (p = 0.008, supra compared to mixed), blood coagulation disorder (p = 0.021) and the level of training of the clinician (student vs dentist, p=0.008) to have an independent influence on the success rate. Dynamic mechanical mixing and the new static mixing of polyether tray material showed nearly equal success rates in the study even though success rates were comparatively low (DMM, 35.3%; SAM, 35.4%).

Efficient prosthodontic treatment in a young patient with long-standing bulimia nervosa: A clinical report.

Time-saving, efficient dental treatment is essential for patients in poor dental condition. This clinical report describes a systematic technique for restoration of the visibly-destroyed dentition of a long-term bulimia nervosa patient, including occlusal vertical dimension increase, with composite resin core foundations and prosthetic rehabilitation with ceramic crowns, in only a few treatment sessions. The efficiency of this procedure is gained from composite resin core restorations that establish the new occlusal vertical dimension (OVD) and replace and form the foundation for the subsequent crown preparation.

Early loading of implants with fixed dental prostheses in edentulous mandibles: 4.5-year clinical results from a prospective study.

AIM: The purpose of this study was to evaluate the survival and success of early-loaded implants placed in the intraforaminal area of the edentulous mandible, and the survival of the implant-supported fixed dental prostheses (FDP). MATERIAL AND METHODS: Thirty-seven patients (18.9% male, mean age 64.5 years) with edentulous lower jaws were treated with implant-supported FDPs in the mandible. One hundred and eighty-five screw-type implants were placed in the intraforaminal area of the symphysis (five implants per patient). Immediately after implant placement, a framework was fabricated and the FDP was manufactured on the framework. Within 2 weeks, the implants were rigidly connected and loaded with the implant-retained FDP. RESULTS: During the 1-8-year observation period (mean 4.5 years), a total of 32 implant-retained complications occurred. Nineteen implants were lost in 10 patients, resulting in a cumulative survival of 89.7%. Nine implants in five patients did not osseointegrate. Although these implants were not removed, because stability within the connective tissue was acceptable and inflammation was absent, they were recorded as unsuccessful. Consequently, the cumulative success declined to 84.9%. Four implants in three patients had clinical signs of periimplantitis (2.2% of all implants). Denture-related complications included one complete failure, when one FDP had to be removed after the last of five implants had been replaced. Furthermore, 10 fractures of the framework occurred in six patients, three FDPs had to be adapted or modified, and the facing of the FDP had to be repaired 16 times in 11 patients. CONCLUSION: Although one-stage early-loaded implants functioned well for most patients with edentulous mandibles, immediate loading is associated with a larger number of implant-related complications than in other studies investigating delayed loading. Because of the substantial prosthetic complications and aftercare, this procedure cannot be generally recommended.

All-ceramic inlay-retained fixed partial dentures: preliminary results from a clinical study.

OBJECTIVES: The objective of this study was to evaluate the clinical performance of zirconia-based all-ceramic fixed partial dentures anchored by inlays. METHODS: A total of thirty FPDs, manufactured using a zirconia frame and veneered with press ceramic, were anchored by use of inlay retainers. All FPDs were designed to replace one missing molar and were adhesively luted by use of one of two different resin cements. Documentation included failures and other complications, plaque accumulation, and aesthetic and functional performance. Statistical analysis was performed using a cox-regression model. RESULTS: During the 12 months observation period a total of thirteen clinically relevant complications occurred-four delaminations of the veneer and six decementations. Three FPDs had to be replaced because of a fracture of the framework. The cement chosen, the location, and the design of the retainer had no statistically significant effect on the occurrence of complications. During the observation period, accumulation of plaque on the abutment teeth was not significantly greater than on reference teeth. Postoperative sensitivity did not differ significantly between the different luting cement groups. The aesthetic and functional performance of the FPDs was acceptable. CONCLUSIONS: Improved adhesion between resin cement and inlay retainer is desirable before general recommendation of all-ceramic inlay-retained FPDs. Use of different luting cements seems to have no effect on the occurrence of complications.

Survival of double-crown-retained dentures either tooth-implant or solely implant-supported: an 8-year retrospective study.

PURPOSE: To compare survival and incidence of complications for solely implant-supported double-crown-retained dentures (DCRDs) and combined tooth-implant-supported DCRDs for restoration of a complete jaw. MATERIALS AND METHODS: Patients were consecutively admitted to treatment at the Department of Prosthodontics, University of Heidelberg, during a time period from 2003 to 2011. Schedule and unscheduled visits were recorded on standardized documentation forms. Age, gender, location of implants, number of abutment teeth, jaw, and antagonist were assessed as possible factors affecting the number of complications per patient. RESULTS: Fifty-five patients with 66 DCRDs on 209 implants and 102 teeth were included. Of these, 30 dentures on 129 implants were solely implant-supported whereas the other 36 were combined tooth-implant-supported. During an observation period of up to 8.3 years (mean 3.4 years; SD 1.9) superstructure survival was 93.3% for the solely implant-supported DCRDs and 100% for the combined tooth-implant-supported DCRDs. Survival without major complications was 86.7% and 83.3%, respectively. Gender and location of both superstructure and implants were statistically associated with a greater number of complications. CONCLUSION: Within the limitations of this exploratory retrospective study, not only solely implant-supported DCRDs but also superstructures combining remaining teeth and implants within DCRDs might be a reliable treatment option for elderly patients. Prospective randomized clinical trials are needed to confirm this, however.

Early loading of implants with fixed dental prostheses in edentulous mandibles: 7.2-year clinical results from a prospective study.

PURPOSE: The purpose of this prospective follow-up study was to evaluate survival and success of early-loaded implants placed in the edentulous mandible and the survival of the fixed dental prostheses (FDPs) after in mean 7.2 years. MATERIALS AND METHODS: Thirty-seven patients (mean age 64.5 years, 18.9% male) received 185 implants in the intraforaminal area of the edentulous mandible (five implants per patient). Within 2 weeks, all implants were early loaded with fixed dental prostheses. The patients were recalled once a year for clinical and radiographic examinations. The 17 patients (79 implants) attending the recall in 2012 were additionally asked for their satisfaction of functional and aesthetic aspects. RESULTS: During a mean observation time of 7.2 years, 20 implants were lost in 11 patients, resulting in implant survival of 89.2%. Eight of all implants (4.3%) had too much marginal bone loss to satisfy the criteria of success. A total of 19 prosthetic complications and aftercare measurements had to be performed between in mean 4.5 to 7.2 years of observation. The survival of the original FDPs decreased to 83.8%. Of the 17 patients attending the recall in 2012, a total 59.5% had a satisfactory oral hygiene. According to the criteria of Albrektsson, the success rate for the remaining 79 implants was 89.9% after in mean 11.7 years. Patient satisfaction for assessment of functional and aesthetic aspects was in median 9 and 8 on the numeric rating scales. CONCLUSION: Long-term observation of in mean 7.2 years showed satisfactory results for both implant and superstructure survival. Prosthetic complications were easy to repair in most cases, but patients' ability for oral hygiene was reduced after the longer observation period. Especially in elderly patients, their attitudes and manual skills should be considered when planning the design of a new superstructure.

Survival and chipping of zirconia-based and metal-ceramic implant-supported single crowns.

PURPOSE: The objective of this retrospective study was to compare the incidence of chipping of implant-supported, all-ceramic, and metal-ceramic single crowns. MATERIAL AND METHODS: One hundred fifty-three patients (51.7% male, mean age 55.0 years) received 232 cemented implant-supported single crowns. One hundred and seventy-nine crowns had a metal framework (gold alloy) and 53 crowns were all-ceramic (zirconia framework and glass-ceramic veneer material). Age, gender, kind of cementation, and location of the restorations were assessed as possible factors affecting chipping. RESULTS: During the observation period of up to 5.8 years (mean 2.1 years; standard deviation 1.4), a total of 13 (24.5%) all-ceramic and 17 (9.5%) metal-ceramic crowns suffered from chipping, a difference that was statistically significant. A total of ten single crowns had to be remade resulting in survival of 86.8% (all-ceramic) and 98.3% (metal-ceramic). The other possible factors did not have a significant effect on the chipping. CONCLUSION: Chipping was found to be more frequent for all-ceramic implant-supported single crowns. If the reasons for the vulnerability of all-ceramic crowns remain unknown, implants with all-ceramic single crowns should generally be recommended with care.

Retrospective comparison of semipermanent and permanent cementation of implant-supported single crowns and FDPs with regard to the incidence of survival and complications.

PURPOSE: To retrospectively compare the fixation modalities semipermanent and permanent for all cemented single crowns and Fixed Dental Prostheses (FDPs) placed at the Department of Prosthodontics in the years 2002 to 2010 with regard to the incidence of survival and complications. MATERIALS AND METHODS: Two hundred forty-one patients (48.5% male, mean age 57.3 years) received 166 FDPs and 232 single crowns. A total of 50.6% of the FDPs and 54.7% of the single crowns were fixed using semipermanent cements. Aside from fixation, age, gender, type, location, and material of the suprastructures were assessed as possible factors affecting complications, namely de-cementation, chipping, framework, or abutment fracture. RESULTS: During an observation period of up to 6.6 years (mean 2.24 years; standard deviation 1.38), the survival rates were 96.4% and 100% for FDPs (semipermanent/permanent cementation), and 98.4% and 92.4% for single crowns (semipermanent/permanent). The success rates achieved, counting every complication, for the FDPs were 61.9% and 70.7% (semipermanent/permanent) and for single crowns were 75.6% and 77.1% (semipermanent/permanent). The cement used had a significant effect on loss of retention of the FDPs (p = .006), but no significant effect on the retention of the single crowns. Cementation procedure exhibited no significant impact on chipping for both FDPs and single crowns. The frequency of framework or abutment fractures was too low for further statistical analyses. CONCLUSION: Both semipermanent and permanent cementation of FDPs and single crowns resulted in high survival rates. Within the limitations of the study design, because of the amount of chairside aftercare required, implant-borne FDPs could be recommended for permanent cementation.