A clinical evaluation of conical crown retained dentures

Double-crown-retained removable dentures: Types and clinical application

A 55-year-old man wearing maxillary and mandibular clasp-retained removable partial dentures (RPDs) sought improvement in retention, support, mastication efficiency, and esthetics. Three prosthodontic treatment options were provided to the patient, who selected maxillary and mandibular conical crown-retained removable partial dentures (CCRPDs) without strategic implants. Oral health-related quality of life (OHRQoL) and satisfaction of the patient were evaluated before treatment and 2 weeks and 1 year after inserting the CCRPDs. The patient reported better retention, support, stability, mastication efficiency, esthetics, and an improved OHRQoL after CCRPD placement than before treatment. These improvements were maintained after 1 year.

Survival and success of tooth-implant-supported and solely implant-supported double-crown-retained overdentures: A prospective study over a period of up to 11 years

OBJECTIVES

To investigate the long-term performance, over a period of up to 11 years, of tooth-implant-supported and solely implant-supported double-crown-retained overdentures (DCRDs) for complete restoration of the jaw.

MATERIALS AND METHODS

Between 2002 and 2015, patients were consecutively enrolled in the study at Heidelberg University Hospital's Department of Prosthodontics. Scheduled and unscheduled visits were both documented on standardized forms. Kaplan-Meier curves were used to evaluate survival and success of the DCRDs. Mixed effects Cox regression was used to identify the potential effects of age, sex, jaw, location of implants, and the number of abutment teeth on the success of the DCRDs.

RESULTS

One hundred and thirty-nine DCRDs were placed in 126 participants (mean age: 65.6 ± 9.1 years; 76 [60.3%] men). The mean follow-up period was 4.2 years. Fifty-three (38%) DCRDs were solely implant-supported (213 implants) and 86 (62%) were tooth-implant-supported (239 teeth and 199 implants). Cumulative five-year survival was 96.2% in the implant-supported group and 97.7% in the tooth-implant-supported group. Simultaneous consideration of failures and severe complications revealed cumulative five-year success of 88.2% for implant-supported DCRDs and 81.9% for tooth-implant-supported DCRDs, with no significant difference between the two types of restoration. Cox regression analysis revealed a greater risk of major complications (hazard ratio: 4.87, p = .04) for maxillary DCRDs than for mandibular DCRDs.

CONCLUSIONS

Although the study design has limitations, the results show that tooth-implant-supported and solely implant-supported DCRDs are both recommendable treatment options. After a mean follow-up of 4.2 years, survival and success were high. However, minor complications were common and required much aftercare.

CLINICAL TRIAL REGISTRATION

This study started in 2005 and was approved by the local review board of the University of Heidelberg. In 2005, clinical trial registration was not yet common. For this reason, the study was not registered.

Telescopic Denture

Aim:

This article explains the concept of telescopic denture.

Procedure:

It describes the different types of telescopic attachment (or double crown), and provides an overview of the advantages and the disadvantages of this type of prosthodontic treatment.

Conclusion:

The indications and the clinical applications of telescopic denture are discussed.

Overdenture Prostheses with Metal Copings: A Retrospective Analysis of Survival and Prosthodontic Complications

PURPOSE

To retrospectively evaluate complications associated with overdentures and abutment teeth restored with metal copings, including post-procedural and prosthetic problems; also to analyze the frequency and influencing factors associated with these problems.

MATERIALS AND METHODS

A total of 80 subjects (48 females, 32 males, mean age 62 years) wearing root-supported overdentures were enrolled in the study. All participants were thoroughly examined by a single examiner, and appropriate maintenance care was performed. The 80 subjects had 270 abutments, which were endodontically treated teeth. All 80 subjects were carefully interviewed, inspected, and evaluated for post-procedural and clinical problems with their overdentures for an observation period of up to 5 years.

RESULTS

Of the post-procedural problems evaluated, the most common problems were gingival inflammation (69%) and root caries (36%) because of poor oral hygiene (41%) and loss of metal copings (34%), followed by overdenture base fracture over abutment teeth (34%). Other post-procedural problems reported were loss of overdenture stability (23%), incidence of overdenture repair (20%), poor retention (18%), incidental finding of root fragments (unplanned) in the jaws (15%), and up to two grade net change in the mobility of overdenture abutments (8%). All prostheses were in use at the time of data collection and observation up to 5 years.

CONCLUSIONS

Overdenture therapy was satisfactory; however, post-procedural and prosthetic complications and aftercare maintenance must not be underestimated.

Prognosis of double crown-retained removable dental prostheses compared with clasp-retained removable dental prostheses: A retrospective study

PURPOSE

The present study compared the clinical prognosis of double crown-retained removable dental prostheses (D-DRPs) with that of clasp-retained removable dental prostheses (C-RDPs).

METHODS

Clinical records of 201 patients who had received 52 D-RDPs with 144 abutment teeth (D-teeth) and 199 C-RDPs with 399 abutment teeth (C-teeth) at the Prosthetic Dentistry Clinic in Hokkaido University Hospital between April 2005 and June 2015 were analyzed. Survival and complication probabilities of the two types of prostheses and abutment teeth were evaluated using the Kaplan-Meier method and compared using the log-rank test. Cox regression analysis was used to determine the impact of covariates on abutment teeth survival and complications such as gender, age, type of retainer, Eichner classification, jaw, type of tooth, endodontic therapy performed, type of edentulous space, and presence of opposing teeth.

RESULTS

Statistical analysis showed no significant differences between the two types of prostheses in terms of prostheses survival, prostheses complication, and abutment teeth survival. However, a significant difference was observed for complications of abutment teeth. Decementation was the most frequent cause of failure, which occurred in 76.9% of D-teeth and 28.3% of C-teeth. Patient's age, jaw, endodontic therapy performed, and type of edentulous space affected the survival of abutment teeth, whereas the type of retainer and edentulous space affected complications of abutment teeth.

CONCLUSION

The prognosis of both types of prostheses was considered to be acceptable. Although D-RDP had lower complication-free rates for abutment teeth, most of the observed complications were decementation, which was considered to be reparable.

Ensuring Maintenance of Oral Hygiene in Persons with Special Needs

Patients with special needs often must rely on inadequately trained caregivers for oral health maintenance. Consequently, full compliance is often not achieved. It is crucial that dentists carefully consider restorative materials and restoration design to maximize durability and facilitate cleansing in these challenging circumstances. This article discusses materials selection, prosthetic design, and oral hygiene techniques for caregivers to ensure longevity and maintenance of oral health in the special needs population.

Retention force of plastic clips on implant bars: a randomized controlled trial

OBJECTIVES

Retention of overdentures is important for patients' satisfaction. The study tested whether the clinical performance of retentive clips made of poly-ether-ether-ketone (PEEK) is superior to those made of poly-oxy-methylene (POM).

METHODS

A total of 30 patients received complete dentures with round bars (SFI-Bar) on two implants in a chairside technique. Two types of clip matrices (PEEK/POM) were used in a split-mouth technique. Retention forces were measured separately for both materials at baseline when the dentures were inserted and after 1, 3 and 6 months. The measurement was performed extraorally and intraorally by using a measuring stylus equipped, respectively, with an opposing matrix or bar part. Simultaneously, at each point in time the patient and the dentist judged the retention either to be good, or to be too high or too low. Statistical analysis involved performance of global non-parametric testing of dependence of retention force on time and material was performed with Brunner-Langer model; non-parametric 95% confidence intervals (CIs) were calculated.

RESULTS

At baseline the median force for POM matrices was 6.89N (95% CI: 6.50-8.21) and for PEEK matrices 7.17N (95% CI: 6.97-7.93). After 6 months, the retention of POM decreased to 5.53N (95% CI: 4.81-7.00) and of PEEK to 6.42N (95% CI: 5.15-7.51). The retention force changed significantly over time (P = 0.004) without differences between POM and PEEK (P = 0.135). No significant alteration of the retention force over time was measured at the bar (P = 0.289). Retention was estimated to be good with 90% at baseline and with 80% after 6 months, equally by patients and dentist.

CONCLUSIONS

POM as well as PEEK material fulfills the requirements of retentive clips on round bars.

Prognosis for Abutment Teeth of Removable Dentures: A Retrospective Study

PURPOSE

This retrospective study evaluates the clinical success of conical crown-retained removable dentures.

MATERIALS AND METHODS

Ninety-seven patients were treated with 97 dentures at the University of Frankfurt, Department of Prosthodontics, between 1993 and 2000. The average observation period was 4.9 +/- 2.8 years. The dentures were supported by 445 natural abutment teeth. To evaluate the long-term success of the restorations, the variables abutment loss, tooth mobility, mean probing depths, and radiological bone loss were used. Data were obtained by one clinical examiner at baseline, by systematic evaluation of patient records, and at clinical re-examinations. Survival-time methods were used to analyze time-to-event data. Specifically, the Cox model with frailty term was applied to account for correlations between intra-patient survival data. Thirty abutment teeth had to be extracted during the observation period.

RESULTS

Statistical analysis showed no significant effects of the variables tooth mobility (p= 0.42), mean probing depths (p= 0.23), and radiological bone loss (p= 0.59) on the time to tooth extraction. For the non-extracted abutment teeth significant changes during time for the variables tooth mobility (p < 0.0001) and radiological bone loss (p= 0.0240) were observed.

CONCLUSION

Removable partial dentures retained by conical crowns have a favorable clinical prognosis.

Telescopic crowns as attachments for implant supported restorations: a case series

The use of dental implants to support mandibular or maxillary overdentures is a widely used treatment modality. Advantages are an increase in retention, an increase in chewing ability, and easy access for oral hygiene procedures. While telescopic and conical crowns have been used for decades to connect natural teeth to overdentures, not many cases have been reported in the literature of telescopic crowns placed on implants to support overdentures. This article describes 7 patients with overdentures supported by telescopic crowns who received 65 implants (ITI Straumann). The cases presented in this report have been in function for up to 4.5 years. During that time no adverse events were reported. The use of telescopic crowns as attachments for implant-supported overdentures may be a viable treatment option.

Parameters affecting retentive force of conus crowns

The aim of this study was to determine the values of the retentive forces of the telescopic crowns. At the first step of the study, the samples having different heights and angles were compared in relation to retentive force. At the second step, the samples were subjected to removal procedures having a pre-determined speed, force and number. The obtained retention values were compared. Ninety dies were prepared in order to measure the retention of the conus crowns. The removal tests were performed with the insertion/separation device. The speed of the test device was 100 cm min(-1) providing the placement of the pieces with 5 kgf in 100, 200, 300, 500, 1000, 5000 and 10 000 cycles. The mean of the retention values of the changes of the angles were found to be statistically different (P < 0.01). According to the results of the variant analysis, the differences in the changes of the height were statistically significant (P < 0.01). The differences between the changes of the number of procedures of all groups were statistically significant (P < 0.01). The number of procedures, height and angle interactions were statistically insignificant (P = 0.758). According to the results of this study, the effect of the angle and height factors in terms of retention among the groups were not independent of each other. In equal angles, as the height increased, increased retention measurements were obtained. In more acute angles, the increase in retention was more obvious. It was also found that an accessory device was necessary to maintain retention capabilities after a long-term use.

Restoration of the partially edentulous mouth--a comparison of overdentures, removable partial dentures, fixed partial dentures and implant treatment

OBJECTIVES

Loss of posterior teeth may result in the loss of neuromuscular stability of the mandible, reduced masticatory efficiency, loss of vertical dimension of occlusion and poor aesthetics. Prosthetic rehabilitation should aim at restoring the vertical dimension and increasing the occlusal contact area in the premolar/molar region. Overdentures are particularly indicated in patients with a severe loss of periodontal attachment, uncertain periodontal prognosis and complicated functional or aesthetic conditions. Removable partial dentures are particularly indicated in Kennedy Class I cases when there is need for a simple and economic solution. Placement of a removable partial denture with occlusal overlays is a simple way to restore occlusal face height. Cross-arch cantilevered fixed partial dentures are primarily indicated for stabilization of periodontally weakened abutments. Short unilateral or bilateral bridges are a solution in patients who refuse removable appliances and who cannot afford more extensive rehabilitation with fixed prosthodontics. Rehabilitation with a fixed partial denture supported by means of osseointegrated implants is the optimal solution in Kennedy Class II cases provided that the bone conditions are appropriate. For any prosthetic treatment, a definite recall system should be established depending on the patient's degree of cooperation, caries susceptibility, periodontal status and the rate of residual ridge resorption. This is essential in order to obtain a satisfactory prognosis. In a patient with poor oral hygiene, the best solution, with regard to the prognosis of the remaining teeth, is to abstain from any prosthetic treatment.

METHODS

This manuscript reviews the current literature to identify treatment options for the Kennedy Class I and II partially edentulous patient.

A 25 year longitudinal study of patients treated with removable partial dentures

A 25 year longitudinal study was carried out on a number of patients fitted with removable partial dentures (RPDs) in 1969. Before the prosthetic treatment all patients were given oral hygiene motivation and instructions in order to create a high level of co-operation. The RPDs, most of which were lower bilateral distal extension dentures, were carefully planned and designed. During the first 10 years the patients were examined in our clinic at yearly intervals at which time encouragement and reinstruction regarding oral hygiene were given and various treatment procedures were performed as required. After the initial 10 years the patients were advised, for practical reasons, to continue to have yearly controls on their own initiative. Of the initial 30 patients from 1969, 23 were still alive in 1994, all of whom were examined. In five of those 23 the original RPD situation had changed more or less due mainly to general illness contracted and/or change to other therapies. In the remaining 18 patients wearing in total 20 RPDs, 13 (65%) of the original RPDs were still functioning. Seven RPDs were new with principally the same design as the original ones. Among these 18 patients the number of lost teeth, the number of new DF surfaces and the increased number of endodontically treated teeth were few. No apparent changes took place regarding the periodontal condition during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)