Evaluating the clinical behavior of veneered zirconia in comparison with monolithic zirconia complete arch implant-supported prostheses: A systematic review and meta-analysis

STATEMENT OF PROBLEM

Because the use of zirconia in dentistry is relatively new, the number of published studies on the subject is scarce, even though material selection is an important factor in clinical performance. Therefore, a systematic assessment of the impact of the prosthetic material, framework design, veneering material, and manufacturing process is required.

PURPOSE

The purpose of this systematic review and meta-analysis was to investigate the survival and success rates of feldspathic porcelain veneered zirconia (VZir) in comparison with monolithic zirconia (MZir) complete arch implant-supported prostheses (CAISPs). A secondary objective was to assess the influence of the type of loading, the presence or absence of a cantilever, the type of zirconia used, the location, and the opposing arch on complications rates and patient satisfaction.

MATERIAL AND METHODS

An electronic search of the MEDLINE database (via PubMed), Scopus, Science Direct, Cochrane Library, and OpenGrey was carried out. The criteria described in the preferred reporting items for systematic reviews and meta-analyses statement were used. The search was restricted from January 2000 to January 2022.

RESULTS

The systematic search resulted in 20 articles that met the established criteria. In total, 751 patients (VZir=302; MZir=449) with 3038 CAISPs (VZir=368; MZir=2670) were analyzed. Higher prosthetic survival and success rates were found in MZir compared with VZir CAISPs (100% and 95.45%, respectively). The meta-analysis found significantly fewer complications related to MZir (9.4% [4.8%-14.1%]) compared with VZir (33.7% [17.5%-49.9%]).

CONCLUSIONS

Based on the findings of this systematic review, MZir CAISPs had higher survival and success rates than VZir CAISPs, with significantly fewer prosthetic complications. The influence of factors such as the type of functional loading, the presence of a cantilever, the material used in the prosthodontic workflow, the location of the CAISP, and the type of antagonist arch on the performance of Zir CAISPs remains unclear.

Prosthetic complications and survival rates of metal-acrylic implant fixed complete dental prostheses: A retrospective study up to 10 years

STATEMENT OF PROBLEM

Long-term data are sparse on the use of metal-acrylic resin implant-supported fixed complete dentures.

PURPOSE

The purpose of this retrospective clinical study was to assess the prosthetic survival and complication rate in patients treated with metal-acrylic resin implant-supported fixed complete dentures (ma-IFCDs).

MATERIALS AND METHODS

The patient record system at the Dental College of Georgia was searched from 2006 to 2020 to identify all patients treated with ma-IFCDs by the graduate prosthodontic and general practice residents during this time. Variables collected were date of delivery of the prosthesis, arch treated (maxilla, mandible), date of the last visit, status of the opposing arch (complete arch fixed implant-supported prosthesis, complete denture, removable implant-supported overdenture, teeth and removable partial denture, teeth and implants, teeth only), date of replacement, and reason for replacement. Reasons for replacement were grouped as fracture of the framework, implant loss, patient-related concerns, catastrophic acrylic resin fracture (judged to be beyond predictable repair by the clinician), and extensive occlusal wear (judged to have worn to the point of requiring replacement).

RESULTS

A total of 84 arches in 55 patients who met the inclusion criteria were identified from the electronic health review. Of the 84 complete arch prostheses, 43 were maxillary and 41 were mandibular. The median follow-up time was 2.8 years (interquartile range [IQR] 0.95, 4.65). A total of 31 of the 84 arches were identified as having failed, requiring replacement. The most frequent reason for replacement was catastrophic fracture of the acrylic resin (61%), followed by excessive occlusal wear (19%). It was found that 13% of the failures were associated with patient-related concerns, and 7% with the loss of an implant. Survival rates were analyzed based on the opposing arch. The combined survival rate (Kaplan-Meier, log-normal modeling) for ma-IFCDs was 54% at 5 years (95% confidence interval [CI] 42%, 66%) and 32% at 10 years (95% CI 20%, 47%).

CONCLUSIONS

Mid- to long-term survival rates for ma-IFCDs are concerningly low. The findings suggest that the status of the opposing arch plays a role in the survival rate of ma-IFCDs. The most common complication was catastrophic fracture of the acrylic resin superstructure, followed by wear of the acrylic resin denture teeth.

Clinical performance of full-arch implant-supported fixed restorations made of monolithic zirconia luted to a titanium bar: A retrospective study with a mean follow-up of 16 months

OBJECTIVES

This retrospective case series aimed to evaluate the short-term clinical advantages and limitations of full-arch implant-supported restorations made of monolithic zirconia suprastructures passively luted to titanium bar infrastructures and to report the rate of complications within a minimum of 1-year follow-up.

MATERIALS AND METHODS

This study included 31 patients (19 men and 12 women) requiring full-arch implant-supported prostheses in the upper or lower jaw. The patients were treated using an entirely digital approach from implant planning and guided implant placement to prosthetic construction planning, design, and fabrication. Full-arch implant-supported monolithic zirconia suprastructures luted to prism-shaped titanium bars were used in all the cases. All the restorations were evaluated for biological and technical complications during fixed control appointments.

RESULTS

No implant failures or serviceable prosthetic complications were reported, and the prosthetic survival rate was 100%, with a follow-up duration ranging from 12 months to 20 months. In two cases, a fracture line was observed in the zirconia suprastructures, although it did not require any intervention.

CONCLUSIONS

After a 16-month mean follow-up period, the monolithic zirconia implant-supported full-arch fixed dental prostheses demonstrated no biological or technical complications. Further clinical studies with long-term results are required to confirm these reported outcomes.

CLINICAL SIGNIFICANCE

CAD-/CAM-milled monolithic zirconia structures passively luted to titanium bar infrastructures are a viable treatment option for full-arch restorations over implants, demonstrating 100% survival and success rates in the present study. The outcomes of this short-term retrospective study indicated high success in function, aesthetics, phonetics, and the ability to maintain flawless hygiene. However, the long-term results of restorations produced using the proposed technique should be considered before recommending this approach for routine clinical use.

The Use of Zirconia for Implant-Supported Fixed Complete Dental Prostheses: A Narrative Review

The success of implant-supported fixed complete dental prostheses (ISFCDPs) depends on multiple factors: some are related to the fixtures, such as fixture material, surface characteristics, positioning, and type of connection to prosthetic components; others are related to the prostheses, such as design and materials used. Zirconia is a material widely used in fixed prosthodontics, whether on natural teeth or on implants, with excellent results over time. Regarding the use of zirconia for ISFCDPs, the 2018 ITI Consensus Report stated that "implant-supported monolithic zirconia prostheses may be a future option with more supporting evidence". Since CAD/CAM technology and zirconia are being continuously innovated to achieve better results and performances over time, a narrative review of the literature seems necessary to focus research efforts towards effective and durable solutions for implant-supported, full-arch rehabilitations. The objective of the present narrative review was to search the literature for studies regarding the clinical performance of zirconia-based ISFCDPs. According to the results of this review, the use of zirconia for ISFCDPs showed good clinical outcomes, with high survival rates ranging from 88% to 100% and prosthetic complications that were restorable by the clinicians in most cases.

Survival rates, patient satisfaction, and prosthetic complications of implant fixed complete dental prostheses: a 12-month prospective study

PURPOSE

To determine the survival rate, incidence of prosthetic complications, and patient satisfaction of implant fixed complete dental prostheses (IFCDPs) after a mean observation period of 1.4 years.

MATERIALS AND METHODS

Twenty-eight (28) eligible participants were recruited according to specific inclusion and exclusion criteria. The definitive metal-acrylic resin IFCDPs consisted of titanium bars veneered with acrylic resin and acrylic denture teeth. Prosthodontic complications, divided into major and minor, were monitored. Parameters such as gender, jaw location, bruxism, and occlusal scheme were evaluated. Moreover, a questionnaire was administered throughout the study to assess patient satisfaction. Poisson regression as well as repeated measures ANOVA were used for statistical analysis.

RESULTS

Fourteen (14) males and 14 females were enrolled and followed-up at 3, 6, and 12 months. All IFCDPs survived (100% survival rate). The most frequent minor complication was the loss of material used to close the screw access hole (20% out of total complications). The most frequent major complication was chipping of the acrylic denture teeth (77.14% out of total complications). Gender (p = 0.008) and bruxism (p = 0.030) were significant predictors for the total major complications (major wear and major chipping) while occlusal scheme was a significant predictor for major chipping events (p = 0.030).

CONCLUSIONS

While IFCDPs demonstrated high prosthetic survival rates, they also exhibited a high number of chipping events of the acrylic veneering material, especially in males, bruxers, and individuals with canine guidance occlusion. However, the occurrence of these prosthetic complications did not negatively affect patient satisfaction.

Oral and Periodontal Risk Factors of Prosthetic Success for 3-Unit Natural Tooth-Supported Bridges versus Implant-Supported Fixed Dental Prostheses

The goals of this research are: (1) to compare the survival and prosthetic success of metal-ceramic 3-unit tooth- versus implant-supported fixed dental prostheses; (2) to evaluate the influence of several risk factors on the prosthetic success of tooth- and implant-supported fixed dental prostheses (FPDs). A total of 68 patients with posterior short edentulous spaces (mean age 61.00 ± 1.325 years), were divided into two groups: 3-unit tooth-supported FPDs (40 patients; 52 FPD; mean follow-up 10.27 ± 0.496 years) and 3-unit implant-supported FPDs (28 patients; 32 FPD; mean follow-up 8.656 ± 0.718 years). Pearson-chi tests were used to highlight the risk factors for the prosthetic success of tooth- and implant-supported FPDs and multivariate analysis was used to determine significant risk predictors for the prosthetic success of the tooth-supported FPDs. The survival rates of 3-unit tooth- versus implant-supported FPDs were 100% and 87.5%, respectively, while the prosthetic success was 69.25% and 68.75%, respectively. The prosthetic success of tooth-supported FPDs was significantly higher for patients older than 60 years (83.3%) vs. 40-60 years old (57.1%) (p = 0.041). Periodontal disease history decreased the prosthetic success of tooth- versus implant-supported FPDs when compared with the absence of periodontal history (45.5% vs. 86.7%, p = 0.001; 33.3% vs. 90%, p = 0.002). The prosthetic success of 3-unit tooth- vs. implant-supported FPDs was not significantly influenced by gender, location, smoking, or oral hygiene in our study. In conclusion, similar rates of prosthetic success were recorded for both types of FPDs. In our study, prosthetic success of tooth- versus implant-supported FPDs was not significantly influenced by gender, location, smoking, or oral hygiene; however, history of periodontal disease is a significant negative predictor of success in both groups when compared with patients without periodontal history.

Modification of denture teeth for improved occlusal stability of a maxillary removable complete denture opposed by a mandibular implant-supported fixed complete denture: A clinical report

Wear of artificial teeth is the most common complication associated with an implant-supported fixed complete denture (ISFCD). This wear alters the occlusal scheme, with loss of eccentric occlusal balance and vertical dimension of occlusion (VDO). This clinical report describes the fabrication of a new maxillary removable complete denture opposing an existing ISFCD with occlusal modifications. Both prostheses received splinted zirconia crowns cemented with composite resin cement.

Strategic Use of CAD-CAM Interim Restoration for the Recovery of the Vertical Dimension of Occlusion in the Posterior Partially Edentulous Jaw

Occlusal contact loss occasionally occurs following the placement of implant-supported fixed dental prostheses in the posterior region. This complication is caused by the change in the vertical dimension of occlusion after the recovery of mastication. The change is probably related to the prosthesis sinking phenomenon and previous mandibular dislocation. The use of interim prostheses could help re-establish the vertical dimension of occlusion. The definitive prostheses can then be accurately fabricated using digital techniques in the newly established vertical dimension. In this case report, we introduce a protocol incorporating a computer-aided design and computer-aided manufacturing (CAD-CAM) interim prosthesis and digital techniques to minimize the occurrence of unexpected initial occlusal changes in the prosthetic treatment of implant-supported prostheses in the posterior region.

Ceramic Materials and Technologies Applied to Digital Works in Implant-Supported Restorative Dentistry

Computer-aided design and manufacturing technology has been closely associated with implant-supported restoration. The digital system employed for prosthodontic restorations comprises data acquisition, processing, and manufacturing using subtractive or additive methods. As digital implantology has developed, optical scanning, computer-based digital algorithms, fabricating techniques, and numerical control skills have all rapidly improved in terms of their accuracy, which has resulted in the development of new ceramic materials with advanced esthetics and durability for clinical application. This study reviews the application of digital technology in implant-supported dental restoration and explores two globally utilized ceramic restorative materials: Yttria-stabilized tetragonal zirconia polycrystalline and lithium disilicate glass ceramics.

Survival rates and prosthetic complications of implant fixed complete dental prostheses: An up to 5-year retrospective study

STATEMENT OF PROBLEM

Implant fixed complete dental prostheses (IFCDPs) are widely used in the rehabilitation of completely edentulous patients, yet limited information is available on the relationship between prosthetic complications and patient-associated and prosthesis-associated risk factors.

PURPOSE

The purpose of this retrospective study was to assess the prosthetic complication and survival rates of IFCDPs after a mean observational period of 3.5 years.

MATERIAL AND METHODS

Eligible participants were identified by an electronic health record review. The study consisted of a review of the dental record and a single-visit study appointment when a comprehensive examination was performed, including a review of the medical and dental history, clinical and radiographic examination, intraoral photographs, patient satisfaction questionnaire, and occlusal analysis. Prosthodontic parameters and risk factors were assessed, including time with the prosthesis in place, bruxism, occlusal device use, prosthesis material, number of implants, cantilever length, and mode of prosthesis retention. Association between these prosthodontic parameters and risk factors and the observed prosthetic complications was assessed.

RESULTS

A total of 37 participants (mean age 62.35 ±10.39 years) with 48 IFCDPs were included. Thirty-eight prostheses were metal-acrylic resin (MR group), whereas 10 were metal-ceramic (MC group). Five of the 48 prostheses failed during the follow-up period, a cumulative prosthesis survival rate of 88%. Minor complications were more frequent than major complications. The most frequent minor complication was loss of screw access hole material (5.18%/year), whereas the most frequently observed major complication was major wear of the prosthetic material (5.85%/year). A significant association was found between not wearing an occlusal device and minor chipping, loss of access hole material, and framework fracture. Minor chipping was significantly associated with bruxism, whereas the opposing dentition significantly affected the total number of prosthetic complications.

CONCLUSIONS

High survival rates were observed with both MR and MC IFCDPs. No significant difference was found between MR and MC groups in terms of patient satisfaction, as well as total number of prosthetic complications.

Making the Best Clinical Decisions for Patients: The Pros-CAT ProtocolTM

The Pros-CAT protocol critical appraisal method uses accepted strategies to identify and summarize best evidence to support patient care through evidence-based analysis that includes assessing the patient; developing a concise clinical question; conducting a literature search to identify pertinent research; critically appraising the identified literature for validity, reliability, and applicability to the patient situation; synthesizing the literature into a meaningful conclusion using an organized method; and applying that synthesis to the patient's need. The Pros-CAT protocol is applicable for practicing clinicians, dental students, postgraduate students, and residents. The Pros-CAT index compares evidence strength for patient applicability.

Guided Nitinol-Retained (Smileloc) Single-Tooth Dental Restorations

Nitinol metal alloy that changes shape according to temperature has been in clinical use at select clinics worldwide for the past 2 years and is now released for general use. The Smileloc Abutment and nitinol sleeve enable "cementless," "screwless," crown fastening that saves time and cost with the prospect of replacement of much of the present, sometimes troublesome, anthropic, soon to be anachronistic, technology.

Management of Biotechnical Complications Associated with a Full-Arch Implant Restoration Using Digital and Conventional Workflows: A Clinical Report

Full-arch implant-supported restorations using a metal-acrylic resin design have had a high success rate but are also associated with frequent technical complications including framework misfit due to casting errors, debonding of denture teeth, and fracture of the acrylic from the metal framework. This clinical report describes a case of maxillary and mandibular full-arch implant-supported rehabilitation associated with technical and biological complications and use of digital technology for fabricating monolithic restorations. The use of a bio-functional try-in and its subsequent use as a conversion prosthesis for fabricating a master cast is described. The use of the patient's existing metal bar to fabricate a retread type prosthesis is also described along with using digital technology for fabricating a new metal bar and a monolithic type of restoration. The integration of digital and conventional workflows to obtain an increased level of accuracy and simplicity is also discussed.

[Efficacy of probiotic application in the treatment and prevention of peri-implant mucositis]

The aim of this study was to evaluate the effectiveness of probiotics in the treatment and prevention of peri-implant complications. Clinical, immunological and microbiological studies were conducted before, 1 and 6 months after the periodontal treatment in 42 patients (120 implants) with peri-implant mucositis. The use of probiotics in the treatment of peri-implant mucositis led to a significant and more pronounced improvement in oral health state in terms of an increased functional activity of the salivary glands, local immunity factors and microbiocenosis.