Complications Associated with Metal Resin Fixed Complete Dentures Based on Implant Distribution.

PURPOSE: To compare prevalence and type of complications associated with metal resin fixed complete dentures based on implant distribution. MATERIALS AND METHODS: This retrospective study included data collected for a period of 12 years for patients treated with maxillary and mandibular implant-supported fixed complete dentures at Loma Linda University School of Dentistry. In total, 223 patient's charts were reviewed which included 100 maxillary and 123 mandibular fixed complete dentures. Implant distribution and prevalence of complications associated with each implant-supported fixed complete denture were documented. Tooth delamination, the most common complication associated with fixed complete dentures, was compared between 2 implant distribution groups in each arch. Covariates including age, sex, opposing arch, cantilever occluding units, and number of implants were evaluated to determine their association with tooth delamination. Data and hypotheses were statistically analyzed using descriptive statistics along with logistic regression model. All tests of hypotheses were considered statistically significant at an alpha level of 0.05. RESULTS: In the maxillary arch, some effect of the prevalence of tooth delamination was seen for the group that had implants placed posterior to canine eminence but it was not statistically significant. Denture tooth delamination had the highest prevalence among complications irrespective of implant distribution. Significant denture tooth delamination was seen for patients with opposing fixed complete dentures in comparison to patients with removable opposing arch prostheses. CONCLUSIONS: Implant distribution is not a significant factor related to metal resin fixed complete dentures. Opposing fixed complete dentures have a significantly higher association with denture tooth delamination.

Implant rehabilitation of edentulous jaws with predominantly monolithic zirconia compared to metal-acrylic prostheses: a 2-year retrospective clinical study.

Limited data are available on the clinical outcomes of patients with edentulism treated with predominantly monolithic zirconia fixed complete dentures (FCDs) compared to traditional restoration materials. The purpose of this study was to analyze the differences in terms of complications and failures of definitive full-arch implant rehabilitations made in metal-acrylic versus those made in monolithic zirconia with porcelain veneering limited to non-functional areas. This retrospective clinical study included 50 patients treated between January 2015 and December 2018, with 222 implants inserted in fifty edentulous jaws. All patients were treated with immediately loaded full-arch fixed prostheses (22 maxillary; 28 mandibular) each supported by four to six implants (two/four axial, two distally tilted). All 25 zirconia prostheses were predominantly monolithic with ceramic veneering limited to non-functional areas. The primary outcome measures were prosthetic success of the definitive restoration and implant survival. The secondary outcome measures were full mouth plaque score, full mouth bleeding score, peri-implant probing depths and periimplant keratinized tissue. All implants and prostheses analyzed had a minimum of 2 years of followup. No chipping of the veneered facial porcelain or other technical complication was observed over the study period achieving a prosthesis survival and success rate of 100%. No implants were lost, achieving a 100% survival rate. Bleeding on probing was positive in 33% and 13% of probing sites for metal-acrylic prosthesis and zirconia prosthesis, respectively (p = 0.0445). Plaque index was positive in 76% and 53% of probing sites for metal-acrylic prosthesis and zirconia prosthesis, respectively (p = 0.0491). Mean probing depth was 1.74mm (SD 0.89mm) for the 106 implants supporting metal-acrylic prosthesis and 1.52mm (SD 0.63mm) for the 116 implants supporting zirconia prosthesis (p=0.0412). No other statistically significant differences were found between the two groups. The results of this retrospective evaluation showed that predominantly monolithic zirconia is a feasible alternative to the conventional metal framework acrylic for full arch implant-supported prosthesis. The restauration material did not influence the failure rate and complication risk of both prosthesis and implants.

Digital workflow for implant-supported fixed complete dentures based on backwards planning in an edentulous patient.

AIM: This case report describes a digital workflow for prosthetically driven surgical planning, implant placement, and the fabrication of two screw-retained, complete-arch, implant-supported dentures in an edentulous patient. The purpose of this case report is to present and discuss the digital steps in the workflow, especially the scanning technique to obtain the centric relation, through a clinical case. The limitations of the workflow are also discussed. MATERIALS AND METHODS: Static computer-aided implant surgery (s-CAIS) was planned three-dimensionally, based on cone beam computed tomography, intraoral optical scanning, and digital bite registration. Using s-CAIS, four and six implants were placed in the edentulous mandible and maxilla, respectively. The final screw-retained complete-arch monolithic zirconia restorations were manufactured based on a digital workflow, using the pre-existing modified radiologic guide for the digital maxillomandibular record. CONCLUSIONS: The evolution of digital processing methods allows for design, processing, and fabrication of implant-supported fixed complete dentures using a surgical, prosthetic, and technical workflow based on 3D restorative backward planning. A digital prosthetic setup and CAD/CAM can be used for the fabrication of intraoral try-ins that serve as a model for the final monolithic zirconia superstructure.

Interdisciplinary management of nonsyndromic tooth agenesis in the digital age.

BACKGROUND AND OVERVIEW: Tooth agenesis is the most common congenital condition affecting the oral cavity. This condition can involve single or multiple missing teeth. Severe forms of tooth agenesis are best managed by a team of specialists, as they can be daunting for a single provider. CASE DESCRIPTION: As the goal of most patients is to replace missing teeth to improve cosmesis and function, a prosthodontist or restorative dentist plays a major role in the team's effort. Although diagnostic skills and careful planning are still the mainstay of this treatment, digital technology and modern materials can greatly facilitate implementation of the treatment plan. The authors present a case of a patient with nonsyndromic oligodontia who had a deficient occlusal vertical dimension that was treated by means of an interdisciplinary approach. The management included a combination of orthodontics, fixed and removable prosthodontics, and oral surgery. CONCLUSIONS AND PRACTICAL IMPLICATIONS: When treating patients with complex congenital tooth anomalies, the prosthodontist or restoring dentist is well positioned to take the lead and orchestrate treatment of the patient.

Digital Versus Conventional Full-Arch Implant Impressions: A Prospective Study on 16 Edentulous Maxillae.

PURPOSE: A prospective clinical study to compare for the first time the accuracy of digital and conventional maxillary implant impressions for completely edentulous patients. MATERIALS AND METHODS: Sixteen patients received maxillary implant supported fixed complete dentures. After the verification of the conventional final casts, the casts were scanned with a desktop (extraoral) scanner. Intraoral full-arch digital scans were also obtained with scan bodies and STL files. Extraoral and intraoral scans were superimposed and analyzed with reverse engineering software. The primary outcome measure was the assessment of accuracy between scans of the verified conventional casts and digital full-arch impressions. The secondary outcome was the effect of the implant number on the 3D accuracy of impressions with Spearman's rank correlation coefficient. RESULTS: The 3D deviations between virtual casts from intraoral full-arch digital scans and digitized final stone casts generated from conventional implant impressions were found to be 162 ± 77 µm. In the 4-implant group, 5-implant group, and 6-implant group the 3D deviations were found to be 139 ± 56 µm, 146 ± 90 µm, and 185 ± 81 µm, respectively. There was a positive correlation between increased implant number and 3D-deviations, but there was no statistically significant difference (p = 0.191). CONCLUSIONS: The 3D accuracy of full-arch digital implant scans lies within previously reported clinically acceptable threshold. Full-arch digital scans and a complete digital workflow in the fabrication of maxillary fixed complete dentures may be clinically feasible.

The influence of prosthetic material on implant and prosthetic survival of implant-supported fixed complete dentures: a systematic review and meta-analysis.

PURPOSE: Evaluating the impact of the prosthetic material on implant- and prosthetic survival of implant-supported fixed complete dentures. STUDY SELECTION: Electronic and hand searches were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to identify clinical studies including at least 10 patients restored with implant-supported dentures. The primary outcome was to evaluate the implant survival rate according to the applied restorative materials. The prosthetic survival rate was evaluated as secondary outcomes. RESULTS: Forty-one of 2254 studies were finally selected. A statistically significant difference (p = 0.0337) was found between implant survival rates in the main restorative groups (metal-ceramic:97%(95%CI [0.96;0.98]), all-ceramic:99%(95%CI [0.98;1.00]), metal-resin:97%(95%CI [0.96;0.98])). Prosthetic survival rates were: (metal-ceramic:95%(95%CI [0.89;0.97]), all-ceramic:97%(95%CI [0.92;0.99]), metal-resin:97%(95%CI [0.95;0.98]), with no statistically significant difference (p = 0.3796) between the groups. Chipping incidence rates were as follows: metal-ceramic:8%(95%CI[0.03;0.20]), all-ceramic:15%(95%CI [0.06;0.32]), and metal-resin:22%(95%CI [0.13;0.33]). Five types of exact restorative materials were identified (porcelain-fused-to-non-precious alloy, porcelain-fused-to-zirconia, precious-metal-acrylic-resin, non-precious-metal-acrylic resin, and PMMA). Again, implant survival rates were statistically significantly influenced by the applied restorative materials (p = 0.0126), whereas, no significant differences were reported regarding prosthetic survival rate. CONCLUSIONS: Prosthetic material selection seems to have no clinically relevant influence on implant- and prosthetic survival rate in implant-supported fixed complete dentures. Due to the high chipping rate, quantifying prosthetic survival alone does not seem to be a reliable tool for evaluating the outcome of the restorations and providing recommendations. These results, along with the obvious lack of evidence, suggest that clinicians must exercise caution whenever porcelain-fused-to-zirconia or metal-resin restorations are considered.

Retrospective 2- to 7-Year Follow-Up Study of 20 Double Full-Arch Implant-Supported Monolithic Zirconia Fixed Prostheses: Measurements and Recommendations for Optimal Design.

PURPOSE: To measure the extension of cantilever lengths, thicknesses, and heights of zirconia prostheses in the lingual and facial areas of the distal screw access openings, and to evaluate the clinical performance regarding chipping or fracture of the distal cantilevered sections of double full-arch CAD/CAM screw-retained, stained, monolithic zirconia, gingival-colored ceramic implant-supported fixed prostheses (MZ-FPs). MATERIALS AND METHODS: Ten edentulous patients were provided with a total of 20 CAD/CAM double full-arch MZ-FPs. The zirconia thicknesses around distal screw access openings at three different levels (crown height space, screw access opening lengths, and dimensions of the cantilevered segments) were measured in the resin prototypes. Patients were evaluated clinically (visually) without magnification, with intraoral digital photography, and radiologically by the author, approximately every 6 months. Ten patients with 20 MZ-FPs were evaluated. Twenty resin prototypes with 35 cantilevered segments (15 maxillary, 20 mandibular) were measured. The lingual and facial thicknesses of the resin frameworks and the crown height spaces of 35 distal access openings were measured. RESULTS: The average extension of the maxillary cantilever segments was 7.72 mm; the mandibular cantilever average was 13.72 mm. The average crown height space for maxillary prostheses was 13.27 mm, for the mandibular prostheses it was 11.89 mm. Zirconia thickness around distal screw access openings at the middle of the crowns, margins and middle of the gingival areas (buccal side of maxillary prostheses) was 4.29, 3.79, and 3.87 mm, respectively. On the lingual sides the thicknesses were 3.13, 2.85, and 3.15 mm, respectively. For mandibular prostheses the thicknesses were 3.56, 3.08, and 3.15 mm, respectively, on the buccal sides, and 2.07, 2.00, and 2.99 mm, respectively, on the lingual sides. No implant failure or changes in the occlusal surface, chipping of the cuspid or incisal edges, or prosthesis distal extension fractures were observed during follow-up periods ranging from 2 to 7 years. The survival rate was 100% for implants and prostheses. In one of the patients, chipping of the pink ceramic was noted in the maxillary prosthesis 36 months after placement. CONCLUSIONS: The results of this study indicated that full-arch MZ-FPs without cutback, or with partial digital cutback and veneering ceramic, were a therapeutic option. Recommendations regarding the thickness of zirconia at the level of the distal screw access openings, the crown height spaces, and the lengths of the cantilever segments were recorded. Additional in vitro and clinical studies will be required for more scientific analysis of the criteria for design of this type of prosthesis to minimize prosthetic complications. Long-term and multicenter studies are needed to corroborate the findings discussed in this report.

Technique of Framework Cemented on Prepared Abutments to Obtain Passive Fit at Fixed Complete Denture: A 2-Year Follow-Up Report

The passive fit of implant-supported dentures is fundamental to the rehabilitation success due the absence of the periodontal ligament in osseointegrated implants. Many techniques to obtain passive fit have been reported in the literature, some inaccessible for the clinicians and dental laboratories. This case report presents a technique to fabricate fixed complete dentures aiming at obtain passive fit with reduced time and cost, but without demerit for the aesthetics, function and longevity. A 40-year-old woman was referred for treatment presenting some teeth in the maxilla and an edentulous mandible, reporting eating problems related to instability and little retention of the mandibular complete denture. Treatment based on the reverse planning was performed to guide the rehabilitation with a complete mandibular fixed complete denture and maxillary occlusal plane adjustment. The framework of the fixed complete denture was manufactured luting a cast metal bar above the prepared titanium cylinder abutments using resin cement. The aim of this technique was to obtain a fixed complete denture with passive fit presenting positive esthetic and functional outcomes after 2 years of follow-up.

A adaptação passiva de próteses implantossuportadas é fundamental para o sucesso da reabilitação devido à inexistência de ligamento periodontal em implantes osseointegrados. Inúmeras técnicas de confecção da infraestrutura destas próteses tem sido relatadas na literatura, algumas inacessíveis para os clínicos e laboratórios de prótese. Este relato de caso apresenta uma técnica para confecção de próteses totais fixas visando obtenção de adaptação passiva com tempo e custo reduzido, porém sem demérito à estética, função e longevidade. Uma paciente de 40 anos se apresentou para tratamento apresentando alguns dentes na maxila e mandíbula edêntula, relatando dificuldades na mastigação relacionados a instabilidade e falta de retenção da prótese total inferior. Foi realizado um planejamento reverso para orientar a reabilitação com prótese total mandibular fixa e adequação do plano oclusal da maxila. A infraestrutura da prótese total fixa foi confeccionada pela cimentação de uma barra metálica em cilindros de titânio preparados com cimento resinoso. O objetivo desta técnica foi obter uma prótese total fixa com adaptação passiva apresentando resultados positivos em termos de estética e função após 2 anos de acompanhamento.

Systematic review of short- (5-10 years) and long-term (10 years or more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants.

OBJECTIVES: The aim of this systematic review was to investigate the short-term (5-10 year mean follow-up) and long-term (10 year or more) survival and success of fixed full arch dental hybrid prosthesis and supporting dental implants. METHODS: Studies reporting interventions with full-arch fixed dental hybrid prostheses were identified by searching PubMed/Medline (NCBI), Web of Science (Thomson Reuters), the Cochrane Register of Controlled Clinical Trials (EBSCO), and Dentistry and Oral Sciences Source (DOSS; EBSCO) from the earliest available dates through July 17, 2013. Through a series of review process by two examiners, potentially qualifying studies were identified and assessed with respect to the inclusion criteria. RESULTS: A total of 18 studies were included for the quality assessment and the systematic review. Within the limitation of available studies, high short-term survival rates of full arch fixed dental hybrid prostheses (93.3-100%) and supporting implants (87.89-100%) were found. However, the availability of studies investigating long-term outcomes seemed scarce. Furthermore, the included studies were subjected to potential sources of bias (i.e. publication, reporting, attrition bias). CONCLUSIONS: Despite seemingly high short-term survival, long-term survival of implant supported full arch fixed dental hybrid prosthesis could not be determined due to limited availability of true long-term studies. Although it may be a valuable option for a patient with a completely edentulous ridge(s), the strategic removal of teeth with satisfactory prognosis for the sake of delivering an implant supported full-arch dental hybrid prosthesis should be avoided.