A prospective 10-year study of metal ceramic single crowns and fixed dental prosthesis retainers in private practice settings

STATEMENT OF PROBLEM

Metal ceramic restorations are widely used in prosthodontics, but long-term data on their clinical performance in private practice settings based on prospective trials are sparse.

PURPOSE

This clinical trial was designed to provide realistic long-term survival rates for different outcomes related to tooth loss, crown loss, and metal ceramic defect.

MATERIAL AND METHODS

Ninety-five participants were provided with 190 noble metal ceramic single crowns and 138 participants with 276 fixed dental prosthesis retainer crowns on vital posterior teeth. Follow-up examinations were scheduled 2 weeks after insertion, annually up to 8 years, and after 10 years. Kaplan-Meier survival analyses, Mantel-Cox logrank tests, and Cox regression analyses were conducted.

RESULTS

Because of variations in the time of the last examinations, the maximum observation period was 12.1 years. For the primary outcome 'loss of crown or tooth', the Kaplan-Meier survival rate was 94.3% ±1.8% (standard error) at 8.0 years (last outcome event) for single crowns and 94.4% ±1.5% at 11.0 years for fixed dental prosthesis retainer crowns. The difference between the survival functions was not significant (P>.05). For the secondary outcome 'metal ceramic defect', the survival rate was 88.8% ±3.2% at 11.0 years for single crowns and 81.7% ±3.5% at 11.0 years for fixed dental prosthesis retainer crowns. In Cox regression models, the only significant covariates for the outcome event 'metal ceramic defect' were bruxism in the medical history (single crowns) and signs and symptoms of bruxism (fixed dental prosthesis retainer crowns) with hazard ratios of 3.065 (95% CI 1.063 - 8.832) and 2.554 (95% CI 1.307 - 4.992).

CONCLUSIONS

Metal ceramic crowns provided in private practice settings show good longevity. Bruxism appears to indicate a risk for metal ceramic defects.

Rehabilitation of the edentulous maxilla complicated by combination syndrome with an implant overdenture: a case report

The treatment of the edentulous jaws with complete dentures is determined individually and often is unpredictable. Implant-assisted overdentures are a significant improvement over conventional complete dentures in terms of patient comfort and function. Combination syndrome refers to a dramatic exaggeration of maxillary alveolar resorption leading to a more complicated rehabilitation. This article reviews how the edentulous maxilla can be rehabilitated with an implant-assisted overdenture. A case report is presented which utilizes a computer-aided design/computer-aided manufactured milled titanium connecting bar to retain a chrome-cobalt based, precision attachment, palateless prosthesis.

Upper and lower full arch dental reconstruction with implant supported overdentures: a case study

STATEMENT OF PROBLEM

In clinical situations where implant placement in the maxilla is prohibited due to the lack of available bone, more invasive techniques such as autogenous bone grafting and sinus augmentation are often off-putting to patients due to the added expense, risk and morbidity. Purpose of treatment: The intention of this treatment was to dentally restore a patient with a severely resorbed edentulous maxilla, without the use of any grafting techniques.

METHODS

Under local anaesthetic, five implants were placed in the patient's maxilla using the combined techniques of alveolar ridge-splitting and a Summer's lift. The crest of the alveolus was dissected bilaterally with a fine rotary disc. A combination of osteotomes and bone spreaders were then used to create the individual osteotomies. In the most distal site on the right side, the floor of the maxillary sinus was tapped up to facilitate implant placement. All implants were submerged under the gum for six months to allow them to ossteointegrate. Restorative stages were then completed.

RESULTS

At six months, all five maxillary implants had successfully integrated. The maxilla also showed marked expansion where the alveolus had been dissected and bone had healed between the separated buccal and palatal plates. The final restoration was a metal-framed overdenture attached to a milled titanium bar supported on five implants.

CONCLUSION

In this single case study, a patient's atrophic, edentulous maxilla was successfully restored without grafting techniques. The overdenture has been in trouble-free function for two years.

Managing dislodged locator from a titanium alloy implant bar in an implant-supported bar overdenture: a clinical report

An implant-supported prosthesis is a successful treatment option for edentulous patients. This article reports on a case that has not been documented in the literature involving complications in a maxillary implant-supported bar overdenture, followed by the management of the complications.

Using a fiber-reinforced composite fixed partial denture to restore a missing posterior tooth: a case report

With the advent of new adhesive technologies, fiber-reinforced composite fixed partial dentures (FRC-FPDs) have become an inexpensive, esthetic and useful restorative option for patients missing a single tooth. This article describes a case involving an inlay-retained FRC-FPD with a prefabricated fiber-reinforced pontic substructure. In addition, a 6-year follow-up is presented. The FRC-FPD fully restored the single missing molar with simple and conservative intracoronal preparations in the proximal teeth and was deemed clinically acceptable after the evaluation period. The clinical procedures to build a FRC-FPD with a prefabricated fiber-reinforced pontic substructure typically are finished by the clinician in 1 or 2 visits without laboratory assistance, making it a viable alternative for patients who cannot afford implant-based treatment or a conventional metal-ceramic FPD.

Prosthetic rehabilitation interventions in adolescents with fixed bridges: a 5-year observational study

AIM

The aim of this work is to verify the rate of success and failure causes of 32 FRC-FPD (Fiber Reinforced Composite Fixed Partial Dentures) placed on 30 adolescents with dental agenesis, over a follow-up period of 5 years.

MATERIALS AND METHODS

Our study sample involved 30 subjects (10 males and 20 females) aged between 13 and 17 years who have been rehabilitated with FRC Maryland bridges to treat agenesis of maxillary incisors (for a total of 32 FRC-FPD). The observational study spans 5 years following the general rules coded by the modified United States Public Health Service (USPHS) system.

RESULTS

After 5 years of follow-up of a sample of 32 FRC-FPD bridges, 30 were still in effective use (so 2 were excluded). All the bridges were FRC, replacing a missing lateral incisor, and had a double wing retention. All requirements of stability, peripheral seal and morphology preservation were well satisfied. The two failed bridges had a structural failure after about two years from placement.

DISCUSSION AND CONCLUSION

In adolescents our orientation about the edentulous rehabilitation is towards solutions that, when possible, provide an acceptable aesthetic and functional restoration with fixed partial dentures, or removable dentures in cases of severe oligodontia. Obviously, techniques involving the placement of dental implants before the end of skeletal growth were never adopted. In our study FRC bridges showed a great functional performance and good compliance from young patients. Considering the positive cost-benefit ratio and the reversibility of the treatment in case of failure, such interventions can be considered a highly reliable early rehabilitation. Further studies are necessary to verify the maintenance requirements tested for longer periods.

Quantitative evaluation and comparison of stress transmission characteristics of bar-clip and short coping overdenture attachments under dynamic loading: a photoelastic stress analysis

STATEMENT OF PROBLEM

When two canine abutment teeth are used to support an overdenture prosthesis, optimal stress distribution to minimize forces to abutments is desired.

PURPOSE

This study used photoelastic stress analysis to compare the stress patterns generated around canine abutments using two different overdenture retainer designs.

MATERIALS AND METHODS

Two canine abutments were anchored in the photoelastic mandible and overdentures were fabricated using two different overdenture attachments. The fitting surface of dentures were lined with resilient layer of light bodied silicon rubberbase impression material to simulate oral mucosa. The attachments used were Bar-Clip and Short coping type. Verticalload of 5 to 50 lb was applied by jaw simulator. Resultant stress fringes were photographed and evaluated quantitatively.

RESULTS

Bar-Clip type of attachment transmitted more amount of stress than short coping type transmitted. There was gross difference in magnitude of stresses between two types of retainers.

CONCLUSION

As the retentivity of the attachment increased there was more stress concentration around the abutments.

Unilateral bounded saddles: a clinical case report on the use of a two part sectional removable partial denture

An increasing proportion of the adult population is partially dentate. Dental implants, being fixed and conservative of tooth tissue could be the ideal treatment of choice however cost, systemic and localfactors may limit their use. An alternative treatment modality is therefore required fo rpatients who are not suitable candidates for dental implants, conventional removable partial dentures or bridges. This case report illustrates the use of a sectional removable partial denture to restore a unilateral bounded saddle using a Hader bar connector.

Fabrication of an implant-supported overdenture using CAD/CAM technology: a clinical report

This case report describes a new method for the fabrication of implant-supported overdentures that are rigidly retained by custom tapered abutments milled from commercially pure titanium using CAD/CAM technology. The dentition of a 60-year-old woman was restored with six implants in the edentulous maxilla. An implant-supported overdenture retained by custom tapered abutments was fabricated using CAD/CAM technology. Screw-retained abutments were designed and milled with a taper of 6 degrees. The reinforcing metallic denture base with integrated secondary crowns, exactly fitting on the tapered abutments, was fabricated from the same data set. The secondary structures could be seated tensionfree on the six abutments, creating friction in the final position. No clinical complications were observed at the 12-month follow-up examination, and the patient remained satisfied with the function and esthetics of the restoration. This case demonstrates the practicality of a fully CAD/CAM fabrication of an implant-supported overdenture retained by friction only. Controlled clinical studies are needed to evaluate the long-term performance of this type of restoration.

Retention systems for implant-retained overdentures

There have been demographic and cultural changes in the past few decades with regards to edentulism. Conventional mucosa-borne dentures can be poorly accepted by some patients. Implant overdentures have a useful role to play in the treatment of some of these patients. Some form of attachment mechanism between the implants and the prosthesis is normally required. This paper updates the reader on the different types of attachment systems and bars available.

CLINICAL RELEVANCE

It is important that dentists and technicians are able to understand the advantages and disadvantages of different attachment types for overdentures, in order to select the most appropriate technique for each patient.

Fabrication of maxillary overdenture supported by custom waxed and cast locator abutments: case report

The fabrication of a maxillary overdenture supported and retained by custom waxed and cast locator attachments will be described. These angulated abutments were made necessary by a lack of maxillary bone due to advanced periodontal problems that contributed to the loss of all of the maxillary and mandibular teeth; thus, the maxillary anterior implants were placed in a labially or facially inclined position, which necessitated placement of labially inclined implant bodies. This article describes a method for correcting this angulation to create a more vertical path of placement and to allow the facially inclined implants to be used for an overdenture retentive device.

Effect of various fixation parameters on strain development of screw- and cement-retained implant-supported restorations

OBJECTIVE

The objective of this study was to quantify the potential effects of screw- and cement-retention on strain development of implant-supported fixed dental prostheses (FDPs).

METHOD AND MATERIALS

A total of 20 single crowns and 70 three-unit FDPs were fabricated to fit an in vitro model situation with two implants. Using strain gauges attached to the model material adjacent to the implants, strain development of the restorations during fixation was recorded while the parameters cement type (provisional and definitive cement), cementation force (10 N and 100 N), and tightening torque (5 Ncm, 10 Ncm, and 15 Ncm) were varied. MANOVA with Pillai's trace was used for pairwise comparisons between groups (α = .05).

RESULTS

Mean absolute strain development ranged from 5.11 µm/m for to 27.26 µm/m for single crowns and from 16.46 µm/m to 689.04 µm/m for multi-unit restorations. Screw-retained single crowns exhibited significantly smaller strain development as compared to cement-retained single crowns (P = .009). The type of cement used seemed to have no effect on strain development of an FDP regardless of the cementation force applied (P = .064 and P = .605). An increase in tightening torque for screw-retained FDPs also had no effect on resulting strain development (P values ranging from .692 to .807). Nonuniform results were found when comparing screw- and cementretention as the retention mechanism for FDPs.

CONCLUSION

Strain development seems to depend predominantly on the accuracy achieved during the fabrication process whereas the retention mechanisms themselves as well as their potential parameters only have a minor effect.

Coffee straw can replace Hader bar for bar retained overdentures--a clinical report

Bar attachment system provides retention and support for the overdenture. Retention of a mandibular denture can be achieved by an implant-retained or natural tooth-retained bar and stud attachment in the anterior segment of the mandible. A simple and cost effective treatment for more complex implant overdenture is the concept of conventional tooth-retained overdentures. The authors present a clinical report of a patient treated with a mandibular tooth-borne overdenture with a bar. The bar was fabricated using a coffee straw.

The retentive forces of the locator attachment system at different angulations

The change of retentive force of three types of Locator inserts when the implant analogue was positioned perpendicular to horizontal, 5 degrees and 10 degrees to perpendicular after 4,200 cycles in vitro was measured using an EnduraTech fatigue testing machine lubricated with artificial saliva. The more rapid decrease in retention occurred up to three months and stabilized after one year of simulated use. The Locator inserts provided more retention when the analogue was placed at 5 degrees to perpendicular compared to 0 degrees and 10 degrees after 9 months of simulated clinical use. After 2 years of simulated clinical use, there was a reduction in retention for all the three inserts of between 70% and 80%.

Immediate rehabilitation of the edentulous mandible using Ankylos SynCone telescopic copings and intraoral welding: a pilot study

The aim of this prospective study was to assess the suitability of immediate rehabilitation of the edentulous mandible using SynCone copings and the intraoral welding technique. Patients with an edentulous mandible were fitted with a removable restoration supported by an intraorally welded titanium bar. Copings were connected to their respective SynCone 5-degree abutments and then welded to a titanium bar using an intraoral welding unit. This framework was used to support the definitive restoration, which was delivered on the day of implant placement. Restoration success and survival, implant success, and biologic or technical complications were assessed immediately after surgery and at 6 and 12 months. Twenty-two patients were consecutively treated with 88 immediately loaded implants. No acrylic resin fractures or radiographically detectable alterations of the welded frameworks were present in the 22 restorations delivered. One implant (1.1%) failed 1 month after surgery; all remaining implants (98.9%) were clinically stable at the 12-month follow-up. Within its limitations, this pilot study demonstrated that it is possible to successfully rehabilitate the edentulous mandible on the day of surgery with a definitive restoration supported by an intraorally welded titanium framework and SynCone 5-degree abutments.

Patient attendance in a recall program after prosthodontic rehabilitation: a 5-year follow-up

PURPOSE

This study evaluated the recall attendance and maintenance for a patient population after prosthodontic treatment in undergraduate student courses.

MATERIALS AND METHODS

Four hundred ninety-three patients who received fixed restorations (FRs; crowns or fixed partial dentures) or removable partial dentures (RPDs; conical crown-retained or precision attachment-retained dental prostheses) were included in a recall program. The number of patients attending regularly scheduled follow-up visits every 6 months was recorded. On the basis of the complexity of the performed treatment, all follow-up interventions were assigned to the categories minimal, moderate, or extensive.

RESULTS

After 60 months, a cumulative follow-up attendance rate between 63% (RPD) and 74% (FR) was evident and not gender related. Altogether, 399 patients (193 FR, 206 RPD) regularly attended the follow-up visits. Between 61.9% (RPD) and 93.8% (FR) of these patients did not need any extensive treatment; however, only 19.2% (RPD) to 85.6% (FR) did not need any moderate or extensive treatment between follow-up visits.

CONCLUSIONS

Patients treated with FRs showed a higher recall attendance than patients treated with RPDs. Further, patients with RPDs needed more extensive and moderate treatments than patients with FRs. This difference should be taken into consideration during prosthetic planning and patient consultation.

Provision of a swing lock denture for a patient with Gorlin Goltz syndrome

Swinglock dentures are used relatively infrequently but in cases of compromised anatomy or where the pattern of tooth loss is unfavourable, they provide a useful removable partial denture design option. The aim of this article is to provide a clear summary of the clinical and technical considerations necessary when providing a Swinglock denture.

A custom-milled titanium complete-arch mandibular framework and a maxillary complete denture fabricated in 3 appointments: a dental technique

BACKGROUND

When restoring multiple implants in the completely edentulous mandible, fabrication of a passive-fitting framework using traditional casting procedures is difficult. The introduction of computer-aided design and manufacturing techniques for fabricating custom 1-piece titanium frameworks simplifies this challenge and reduces time spent by the restorative dentist.

PURPOSE

The aim of this case presentation is to explain how to fabricate a milled titanium framework using Procera technique step by step.

MATERIALS AND METHODS

A 79-year-old woman with an edentulous maxilla and mandible received a maxillary complete denture in 3 appointments by duplicating her existing complete denture, and a mandibular screw-retained fixed dental prosthesis using a milled titanium framework. The patient did not have any problems regarding her implants and restorations in a year of service.

CONCLUSION

This clinical report presents a complete oral rehabilitation, in which a custom-milled titanium complete-arch mandibular framework was fabricated with an overdenture, and a maxillary complete denture was fabricated using a denture duplication technique in 3 appointments.

Randomized clinical trial on single retainer all-ceramic resin-bonded fixed partial dentures: Influence of the bonding system after up to 55 months

OBJECTIVES

This study evaluated the clinical outcome of all-ceramic resin-bonded fixed partial dentures (RBFPDs) with a cantilevered single-retainer design.

METHODS

Thirty anterior zirconia ceramic RBFPDs were inserted using either a phosphate monomer containing resin (Panavia 21 TC; N=16) or an adhesive bonding system with a phosphoric acid acrylate primer (Multilink-Automix with Metal/Zirconia primer; N=14).

RESULTS

During a mean observation time of 41.7 months one debonding occurred in each group. Both RBFPDs could be rebonded successfully resulting in a three-year survival rate of 100%.

CONCLUSION

Independent of the bonding system cantilevered zirconia ceramic RBFPDs showed promising results during the first three years.

CLINICAL SIGNIFICANCE

Single-retainer zirconia ceramic RBFPD present an alternative treatment option offering good aesthetics, a minimal invasive preparation, a high biocompatibility and can even be used to treat juvenile patients who do not yet come into consideration for implant placement. No significant influence of the bonding system used was detected so far.

Implant-supported full-mouth reconstruction Malo Implant Bridge

This article describes the clinical techniques and laboratory procedures for fabricating a predictable Malo Implant Bridge involving application of an occlusal screw-retained implant superstructure on the basis of the All-on-4 concept. The Malo Implant Bridge features a removable occlusal screw-retained superstructure; fabrication of the framework with a computer-aided design/computer-aided manufacturing system allowing accurate adaptation; and use of the final tooth position model with guide temporary crowns allowing easy porcelain build-up and satisfying the patient's esthetic concerns.

Implant-retained overdentures: a review

Implant-retained overdentures represent a treatment option for many patients unable to tolerate conventional dentures. They may be specifically indicated in patients with altered anatomy, neuromuscular disorders, a pronounced gag reflex or severe residual ridge resorption. This article discusses the different ways in which implant overdentures can be retained, outlines some of the clinical stages involved in planning and providing these prostheses, and highlights long-term maintenance requirements associated with implant-retained overdentures.

CLINICAL RELEVANCE

Patients with implant-retained overdentures are likely to present in general dental practice. Practitioners should be aware of issues associated with the design, treatment planning and maintenance of these prostheses.