Clinical Longevity of Obturators in Patients with Jaw Defects: a Retrospective Cohort Study.

OBJECTIVES: The primary objective of the present retrospective clinical study was to determine the survival time of obturators while analyzing possible influencing factors. MATERIALS AND METHODS: This retrospective clinical cohort study analyzed the influence of various clinical factors on the survival probability of obturators and their follow-up outcomes using Kaplan‒Meier analysis. RESULTS: A total of 76 patients with 115 obturators were included in the study (47 men and 29 women, mean age 58.1 ± 18.1 years). The mean observation time was 3.0 ± 4.5 years (maximum 26.3 years). A total of 40.9% (47) of all obturators observed had to be replaced. The survival rate after 5 years was 79.5% for telescopic-crown-retained tooth-supported obturators, 86.9% for telescopic-crown-retained implant-supported obturators, 58.8% for removable full denture obturators, 22.1% for clasp-retained obturators and 0.0% for splints. The type of attachment, attendance at a regular follow-up and defect cause significantly influenced the survival of the obturators (p < .05). CONCLUSIONS: The findings obtained in this study support the recommendation of using implant-supported obturators. Telescopic-crown attachments, either tooth- or implant-supported, seem to be favorable in terms of survival time. Attendance at a strict follow-up program seems to have a major influence on the longevity of the obturators. CLINICAL RELEVANCE: The use of implant-supported obturators to cover permanent oral and maxillofacial defects is highly recommended. Additionally, the use of telescopic-crown attachments seems to be favorable in terms of survival time. Clasp-retained obturators and surgical splints should be used primarily for temporary restorations due to their shorter survival times.

Clinical performance of different types of dental prosthesis in patients with head and neck tumors-a retrospective cohort study.

OBJECTIVES: To investigate how different types of dental prosthesis perform in patients with head and neck tumors. MATERIALS AND METHODS: In this retrospective clinical cohort study, the impact of different patient-related factors was analyzed as influencing factors on the survival probability of dental prosthesis using Kaplan-Meier estimate. For analysis, the dental prosthesis was divided into groups: group 1 (fixed dental prosthesis), group 2 (removable dental prosthesis), group 3 (implant-supported dental prosthesis), and group 4 (prostheses anchored using wrought wire clasps and obturators). The incidental aftercare measures were also evaluated. RESULTS: Two hundred seventy-nine restorations were observed (mean observation: 2.7 ± 3.0 years, max.14.8 years) out of which 49 (17.6%) had to be replaced during the observation. After 5 years, 100% of group 1 restorations, 79.9% of group 2 restorations, 91.4% of group 3 restorations, and 30% of group 4 restorations were still functional. Four hundred eighty-eight dental implants were observed, of which 77 (15.8%) failed. CONCLUSIONS: Groups 1, 2, and 3 restorations showed good survival times after 5 years in function, whereas group 4 presented the worst survival times. Group 2 restorations showed the highest amount of necessary aftercare measures. CLINICAL RELEVANCE: The current investigation shows that groups 1, 2, and 3 restorations should be preferred in the prosthetic treatment planning of patients with head and neck tumors. A treatment with group 4 restorations should only be considered if no other prosthetic treatment is possible or as temporary treatment.

Survival of Double-Crown-Retained Implant-and-Tooth- Supported Removable Partial Dentures: A ≥ 5-Year Clinical Follow-up Study.

PURPOSE: To assess the survival of double-crown-retained implant-and-tooth-supported removable partial dentures (DCR-ITSRPDs), evaluate abutment survival, and identify first aftercare measures. MATERIALS AND METHODS: The influence of various factors on the survival of the DCR-ITSRPDs and the abutments were observed in this retrospective and clinical follow-up study using the Kaplan-Meier estimate. In addition, the first-required aftercare measure for each prosthesis was evaluated. RESULTS: In total, 47 DCR-ITSRPDs were investigated (mean observation: 4.3 ± 3.8 years; max: 14.3 years), 3 of which (6.4%) had to be replaced. The survival probability for DCR-ITSRPDs was 100% at 5 years and 75% at 10 years. A total of 297 abutments (120 natural teeth and 177 dental implants) were observed, 22 of which (7.4%; 6 teeth and 16 implants) failed. The survival probability for teeth was 90.2% at the 5- and 10-year mark; for dental implants, it was 90.4% at 5 years and 76.3% at 10 years. CONCLUSIONS: DCR-ITSRPDs are a successful and durable treatment option for patients with substantially reduced residual dentitions. Both prostheses and abutments show good survival times after 5 and 10 years in function. The patient-associated factors tested showed no influence on the survival of DCR-ITSRPDs and abutments. Peri-implant infection was the decisive factor for abutment loss; therefore, regular dental prophylaxis and examinations are of major importance.

Which Patient-Related Factors Influence the Outcome of Telescopic-Retained Removable Implant-Supported Dental Prostheses in Edentulous Patients?

PURPOSE: To survey the clinical performance of telescopic-retained removable implant-supported dental prostheses (TR-RISDPs) in edentulous patients, as well as incidental maintenance measures and technical complications. MATERIALS AND METHODS: In this retrospective analysis, the former presence of oral cancer, prosthesis location (maxilla or mandible), and participation in a follow-up program were analyzed as possible factors with an influence on survival and maintenance treatments of the TR-RISDPs and dental implants using Kaplan-Meier estimates. RESULTS: A total of 86 TR-RISDPs (mean follow-up: 4.62 ± 3.24 years; maximum 13.8 years) and 465 implants (mean follow-up: 5.67 ± 3.59 years; maximum 16.5 years) were observed. Six (6.9%) of the TR-RISDPs had to be remade, and 11 (2.3%) implants failed. Regular attendance in the follow-up program showed significantly higher survival times and fewer maintenance treatments for the TRRISDPs (P < .05). Implants in patients with former oral cancer showed significantly lower survival times (P < .001). CONCLUSIONS: TR-RISDPs in edentulous patients show excellent clinical outcomes. Regular check-ups are decisive for success.

Survival time of post and cores after recementation: A 16-year retrospective study with special focus on loss of retention.

OBJECTIVES: Numerous studies investigating the survival time of post and cores have found that loss of retention is the most common cause of failure Nevertheless, investigations focusing on decementation, survival after recementation, and the influencing parameters in a large number of patients with long follow-up periods are lacking. Therefore, the aim of this short communication article is the survival analysis of post and cores after recementation and repeated loss of retention. MATERIALS AND METHODS: During the observation period (2004-2020), 653 patients received 953 post and cores. From these, 112 post and cores which suffered loss of retention were selected. The patient files were analysed for the following parameters: Type of covering prosthetic restoration, location, type of tooth, luting material, post and core material, bone attachment and therapist. The survival time until loss of retention or repeated decementations after recementation was documented. Survival probability was assessed using Kaplan-Meier and Cox regression analyses. RESULTS: The average time until decementation was 13.33 years. The cumulative decementation rate was 11.8%, while in 42.0% of the cases, post and cores showed multiple losses of retention. A significant influence (Kaplan-Meier analysis) was recorded for the type of covering prosthetic restoration, type of tooth, luting material, post and core material and bone attachment. The multifactorial survival analysis (Cox regression) showed a significant influence of patient's age and the type of covering prosthetic restoration. CONCLUSIONS: Once decementation occurs, recementation neither guarantees definitive fit nor necessarily predetermines repeated decementations. CLINICAL SIGNIFICANCE: Post and cores should be avoided under primary crown-retained removable partial dentures (RPD). If this treatment is inevitable, a continuous follow-up is necessary to check the denture for proper fit to the tissues to prevent overloading on the post and core.

Clinical Outcomes of Implant-Supported Dental Prostheses: A Retrospective Analysis Considering Patient-Related Factors.

PURPOSE: To investigate the clinical performance of implant-supported dental prostheses (ISDPs), this retrospective clinical study observed influencing factors on survival of the prostheses and necessary maintenance treatments during the observation time and complications of the dental implants. MATERIALS AND METHODS: Patients who were provided either with fixed implant-supported dental prostheses (FISDPs) or telescopic-retained removable implant-supported dental prostheses (TR-RISDPs) were included in this retrospective clinical study. Potential influencing factors on the survival probability of the prostheses were observed using Kaplan-Meier analysis: patient sex, type of prosthesis, location, dentition in opposing arch, participation in follow-up visits, and whether the patient had a previous history of oral cancer. The type and number of maintenance treatments and complications of dental implants were also analyzed. RESULTS: A collective of 473 patients who were provided with either FISDPs (n = 320) or TR-RISDPs (n = 153) and 1,499 implants were included in the study. 6.6% of the prostheses (24 FISDPs and 7 TR-RISDPs) had to be replaced, and 6.3% of the implants (n = 45) were lost. The calculated 5-year survival probabilities were 87.4% for FISDPs and 95.5% for TR-RISDPs. FISDPs in patients who also had ISDPs in the opposing arch showed the lowest survival probabilities (P < .05). TR-RISDPs in patients who regularly attended follow-up visits showed the highest survival rates (P < .05). Maintenance treatments had to be performed at an earlier stage for patients with TR-RISDPs, and especially for TR-RISDPs located in the mandible (P < .05). CONCLUSION: FISDPs and TR-RISDPs showed good survival rates in this study. However, when planning FISDPs, the dentition in the opposing arch should be considered to prevent possible failure. TR-RISDPs indicate a higher need for aftercare measures, especially in the early years of function. Regular attendance of follow-up visits is still a decisive factor for success.

Wear and Fracture Strength of New Ceramic Resins for Chairside Milling.

PURPOSE: The purpose of this in vitro study was to evaluate wear and fracture strength of chairside-milled new ceramic resins after artificial aging in a chewing simulator. MATERIALS AND METHODS: Two ceramic resins (Lava Ultimate and Vita Enamic) and two conventional ceramics (IPS Empress CAD and Celtra Duo) were tested. For analysis of wear, baseline and follow-up scans of the specimens were made, the scans were superimposed, and the wear was calculated. To determine fracture strength, the specimens were loaded until they fractured. RESULTS: Lava Ultimate showed the highest wear, caused the lowest wear of the opposing dentition, and showed statistically significantly higher fracture strength than conventional ceramics after cyclic loading. CONCLUSION: New ceramic resins for chairside milling are a good alternative to conventional ceramics.

Nonprecious Alloy vs Precious Alloy Telescopic Crown-Retained Removable Partial Dentures: Survival and Maintenance Needs.

PURPOSE: The purpose of this retrospective clinical study was to evaluate the clinical outcomes of nonprecious alloy (NPA) vs precious alloy (PA) telescopic crown-retained removable partial dentures (TRPDs), the factors influencing survival, and the type and number of maintenance procedures required during the observation period. MATERIALS AND METHODS: This retrospective clinical study is based on 462 patients with a total of 572 TRPDs on a total of 1,946 abutment teeth. The following parameters were analyzed with Kaplan-Meier analysis: sex; alloy type; denture location; number and distribution of abutment teeth (Kennedy Class); vitality of abutment teeth; dentition in the opposing arch; and participation in follow-up visits. RESULTS: The mean observation period was 3.87 ± 3.15 years (2.99 ± 2.52 years for NPATRPDs and 5.36 ± 3.53 years for PA-TRPDs; maximum 11.01 years). During the observation period, 4.2% (n = 24) of the TRPDs ceased functioning and 8.3% (n = 161) of the abutment teeth had to be removed. The calculated 5- to 10-year survival probabilities were 96.1% and 84.0%, respectively, for the TRPDs. The number of abutment teeth was the only parameter that significantly (P < .05) impacted this probability, whereas the vitality of the abutment teeth and the type of alloy significantly (P < .05) impacted the survival probability of the abutment teeth. NPA-TRPDs needed significantly earlier initial treatment than PA-TRPDs (P < .05). CONCLUSION: The type of alloy seems to have no impact on TRPD survival, but seems to have an influence on the survival of the abutment teeth. There are also differences in maintenance between NPA- and PA-TRPDs.