Full‐Arch Implant‐Supported Fixed Dental Prosthesis Retained by a Combination of Galvano‐Telescopic Copings and Screws: A Clinical Report

Full‐arch screw‐retained implant‐supported fixed dental prostheses have a high long‐term success rate and are considered the gold standard by many clinicians. However, accurate fabrication of a passive fit long‐span prosthesis can be challenging. A novel intraoral adhesion method using galvano‐telescopic copings was proposed as a way of improving prosthetic fit for edentulous patients. This report describes the treatment of a 74‐year‐old female with a full‐arch implant‐supported dental prosthesis, supported by a combination of galvano‐telescopic copings and screws to prevent retention loss. Four years have passed since this superstructure was placed, during this time she exhibited a good clinical course with no inflammation noted in surrounding tissues. Treatment with an implant‐supported fixed dental prosthesis, retained by a combination of galvano‐telescopic copings and screws, can be a useful alternative treatment for edentulous patients.     

Prospective 10‐Year Cohort Study Based on a Randomized,Controlled Trial (RCT) on Implant‐Supported Full‐Arch Maxillary Prostheses. Part II: Prosthetic Outcomes and Maintenance

Background: Long‐term follow‐up studies (i.e., over 5 years), focusing on prosthetic outcomes and maintenance of implant‐supported reconstructions in the edentulous maxilla, are scarce in the literature. Purpose: The purpose of this study was to evaluate and report 10‐year data on outcomes and maintenance of screw‐retained implant‐supported full‐arch casted titanium‐resin prostheses in the edentulous maxilla. Materials and Methods: In the randomized control trial cohort of 24 patients, the outcome and maintenance of 23 bridges were registered. Results: One patient dropped out of the study prior to the 10‐year control. Of the 23 remaining patients, 21 still had their original frameworks; one framework fractured after 8 years and one was remade after 7 years to create better support for the acrylic. The remaining 23 prostheses showed criteria of success, survival, and failure in 9, 82, and 9%, respectively. Tightening of two assembly screws was necessary in one patient. No detrimental effects were seen because of long cantilever extensions or opposing dentition. A total of 4.7 resin‐related complications per prosthesis were observed; tooth fracture was the most common prosthetic complication. There was an indication of greater prevention in the number of resin‐related complications with the use of lingual gold onlay compared with a resilient mouth guard, 0.71 and 1.67, respectively per bridge. The bridges were removed and reinserted 0.83 times per patient. No abutment or abutment screw fractures were registered. Conclusion: Fracture or wear of the reconstruction materials were considered predictable risks when using resin‐based suprastructure materials. Status of opposing dentition and length of cantilevers did not confer additional risk. The use of a lingual gold onlay indicated prevention of resin‐related complications. Future research should focus on the suprastructure materials to predict better overall treatment results of implant‐supported full‐arch bridges in the edentulous maxilla.     

A Technique for Retrofitting a Metal Ceramic Crown to an Attachment‐Retained Removable Partial Denture: A Clinical Report

In dental applications, precision attachments have been used to retain removable partial dentures (RPDs) for several decades. Various types of extracoronal attachments are commonly used in combination with fixed partial dentures and RPDs to achieve retention and stability. Fracture of the framework, fracture of the roots or teeth, and irretrievable decrease of retention are common reasons for a failed attachment‐retained RPD. Another complication of metal ceramic crowns with precision attachment is decementation of the crowns. When fixed components of the attachment‐retained RPD fail, the traditional treatment approach requires remaking both the fixed and removable components of the attachment‐retained RPD. This technique describes retrofitting of a metal ceramic crown to a resilient attachment‐retained RPD.     

Fabrication of a Fractured Mandibular Bar‐Retained Implant Overdenture Without Implant‐Level Impression Making: A Clinical Report

The most frequent mechanical complications of bar‐retained implant overdentures (IODs) are fracture of the dentures, loosening of the bar screws, and the need to reactivate the retentive clips. When a bar‐retained IOD with an acrylic resin base fractures, the existing bar attachment should be removed to fabricate a new overdenture. So far, no method has been previously described for remaking a fractured mandibular bar‐retained IOD without removing the existing bar attachment. This article describes fabrication of a fractured mandibular bar‐retained IOD with distally placed ball attachments using attachment transfer analogs. The described technique allows the patient to use the existing overdenture temporarily until the new overdenture is delivered.     

Three‐Dimensional Image Correlation Analyses for Strains Generated by Cement and Screw‐Retained Implant Prostheses

Purpose: This study aimed to measure and compare strains generated by splinted implant crowns retained by cement or screws for two implants with applied load. Materials and Methods: A stereolithic resin model was printed using computed tomography data from a patient missing all mandibular molar teeth. Two 4 × 6 mm implants were consecutively placed in the left side. One set of splinted cement and screw‐retained crowns were made to fit the two implants. Image correlation technique was used for full‐field measurement of strains using an image correlation software and two synchronized high‐resolution digital cameras. A random dot pattern was applied to the model surface. Cameras recorded changes in random dot patterns as prostheses were loaded up to 400 N in vertical and oblique directions using a universal testing machine. Testing was repeated three times for cement and screw‐retained prostheses. An image correlation algorithm used the dot pattern to define correlation areas or virtual strain gauge boxes. Three‐dimensional coordinates of gauge box centers were determined for each recorded photograph and used to calculate strains. Strain distribution data were compared for major, minor, and von Mises strains for each loading condition, as well as peak and average strains for the field of view using an analysis of variance (α = 0.05). Results: Patterns and magnitudes of strain for cement‐ and screw‐retained splinted crowns were similar under vertical loading. Neither peak nor mean strains were significantly different for the two retention methods. For oblique loading, peak strains were lower for the screw‐retained crowns; however, there were no statistically significant differences between the two groups when strains were averaged throughout the entire field of view. Conclusions: Cement retention did not improve the magnitude of transferred strains for splinted implant crowns using either loading condition.     

Porcelain Fracture Resistance of Screw‐Retained,Cement‐Retained,and Screw‐Cement‐Retained Implant‐Supported Metal Ceramic Posterior Crowns

Purpose: The purpose of this in vitro study was to compare the porcelain fracture resistance between screw‐retained, cement‐retained, and combined screw‐ and cement‐retained metal–ceramic (MC) implant‐supported posterior single crowns; and to investigate the effect of offsetting the occlusal screw‐access opening on porcelain fracture resistance of screw‐retained and cement‐retained MC implant‐supported posterior single crowns. Materials and Methods: Forty standardized MC molar‐shaped restorations were fabricated. The 40 restorations were divided into four groups (SRC, SRO, CRP, and CSC) of 10 specimens each. Group SRC: screw‐retained, screw‐access hole placed in the center of the occlusal surface; Group SRO: screw‐retained, screw access hole placed 1 mm offset from the center of the occlusal surface toward the buccal cusp; Group CRP: cement‐retained, zinc phosphate cement was used; Group CSC: cement‐retained with a screw‐access hole in the center of the occlusal surface. The screw‐retained restorations and abutments were directly attached to 3i implant fixtures embedded in acrylic resin blocks. Subsequently, all test specimens were thermocycled and vertically loaded in a universal testing machine at a crosshead speed of 2 mm/min until fracture. Mean values of load at fracture (in N) were calculated in each group and compared with a one‐way ANOVA and Tukey's Studentized test (α= 0.05). Results: Mean values of loads required to fracture the restorations were as follows (N): Group SRC: 1721 ± 593; Group SRO: 1885 ± 491; Group CRP: 3707 ± 1086; Group CSC: 1700 ± 526. Groups SRC, SRO, and CSC required a significantly lower force to fracture the porcelain than did the CRP group (p < 0.05). Conclusion: The cement‐retained restorations showed significantly higher mean fracture loads than the restorations having screw‐access openings in their occlusal surface. The position of the screw‐access hole within the occlusal surface did not significantly affect the porcelain fracture resistance.     

A Prosthesis Retention System for Full‐Arch,Fixed, Implant‐Supported Prosthesis

Full‐arch, fixed, implant‐supported prostheses can be designed to be cement‐ or screw‐retained. Both retention mechanisms have a few inherent disadvantages. A fixed attachment system has been introduced to circumvent the disadvantages of both screw and cement retention. This system eliminates the screw access holes and the use of cement. The number of intraoral procedures required is also reduced. The purpose of this article is to report a case using the Locator F‐Tx Attachment System to facilitate fabrication of an esthetic, clinician‐retrievable, full‐arch implant‐supported fixed dental prosthesis.     

A Systematic Review of the Clinical Performance of Tooth‐Retained and Implant‐Retained Double Crown Prostheses with a Follow‐Up of ≥3 Years

Purpose: The objective of this review was to systematically screen the literature for data related to the survival and complication rates observed with dental or implant double crown abutments and removable prostheses under functional loading for at least 3 years. Materials and Methods: A systematic review of the dental literature from January 1966 to December 2009 was performed in electronic databases (PubMed and Embase) as well as by an extensive hand search to investigate the clinical outcomes of double crown reconstructions. Results: From the total of 2412 titles retrieved from the search, 65 were selected for full‐text review. Subsequently, 17 papers were included for data extraction. An estimation of the cumulative survival and complication rates was not feasible due to the lack of detailed information. Tooth survival rates for telescopic abutment teeth ranged from 82.5% to 96.5% after an observation period of 3.4 to 6 years, and for tooth‐supported double crown retained dentures from 66.7% to 98.6% after an observation period of 6 to 10 years. The survival rates of implants were between 97.9% and 100% and for telescopic‐retained removable dental prostheses with two mandibular implants, 100% after 3.0 and 10.4 years. The major biological complications affecting the tooth abutments were gingival inflammation, periodontal disease, and caries. The most frequent technical complications were loss of cementation and loss of facings. Conclusions: The main findings of this review are: (I) double crown tooth abutments and dentures demonstrated a wide range of survival rates. (II) Implant‐supported mandibular overdentures demonstrated a favorable long‐term prognosis. (III) A greater need for prosthetic maintenance is required for both tooth‐supported and implant‐supported reconstructions. (IV) Future areas of research would involve designing appropriate longitudinal studies for comparisons of survival and complication rates of different reconstruction designs.     

Rehabilitation of a Bilateral Maxillectomy Patient with a Free Fibula Osteocutaneous Flap and with an Implant‐Retained Obturator: A Clinical Report

A 47‐year‐old man underwent surgical resection and reconstruction with a fibula osteocutaneous flap. After the surgery, a surgical obturator was placed and adjusted. After flap healing, a conventional obturator was fabricated with polymethyl methacrylate resin and retained by the anatomical undercuts around the reconstructed fibula bone flap and the posterior part of the defect. As the defect shape changed with time, a second conventional obturator was fabricated and fitted. No further recurrence of myoepithelioma was observed for 2 years, and the patient was satisfied with the obturator during mastication and speech; however, despite having no major complaints, the patient found it difficult to chew on the right side, and the obturator was displaced slightly downward when the mouth was opened wide and shifted when chewing hard and sticky food. Thus, an implant‐retained obturator was suggested to provide better retention and stability. Four dental implants were therefore placed into the fibula bone, although one did not osseointegrate because either primary stability was insufficient or overload was affected in the nonloaded implant environment and was replaced. After fitting custom abutments with a magnet, an implant‐retained obturator was placed, and the patient was satisfied with the outcome. During 3 years of follow‐up, no issues were noted with the implant bodies, abutments, obturator, or reconstructed site. The conventional obturator was displaced slightly downward when the patient opened his mouth wide, and it shifted when chewing hard and sticky food because there was limited fibula bone at the reconstruction site and more available posteriorly. For better retention and stability, the implant‐retained obturator was fabricated with a custom abutment and magnetic retention. The patient was satisfied with the results, as improved implant retention increased the stability of the prosthesis. This clinical report describes the rehabilitation of a bilateral maxillectomy patient with a free fibula osteocutaneous flap and an implant‐retained obturator. The patient's oral functions were improved when the prosthesis was stabilized by means of dental implants and custom abutments.     

Screw retained vs. cement retained implant‐supported fixed dental prosthesis

A fixed dental prosthesis can be secured to an endosseous implant via cementation (using a provisional or definitive cement) on an implant abutment that is screw retained to the implant or directly in the implant via screw retention. The clinical decision as to which retention system best suits the individual patient depends on several factors. The aim of this review is to present a detailed overview of the factors potentially influencing whether to choose screw retention or cement retention. These factors include the individual indication, advantages and disadvantages of the different retention mechanisms, the retention provided, retrievability, provisionalization, esthetics and clinical performance, including failures and complications. The results of recently published systematic reviews on this topic are discussed and an overview is provided. A decision tree is presented to facilitate the clinical selection of the retention type. This overview concludes that the choice of retention type (screw retained or cement retained) might not influence the overall survival of the implant‐supported fixed dental prosthesis, but may be responsible for the development of certain complications. The decision may depend on technical feasibility and on weighing the pros and cons.     

Cement Selection for Cement‐Retained Implant‐Supported Prostheses: A Literature Review

Cement‐retained implant‐supported prostheses are widely used for restoring missing teeth; however, they show some complications in comparison to screw‐retained restorations, such as difficulty in retrieving the restoration and biocompatibility of cement. Therefore, the practitioner should consider several important aspects when using this type of restoration. In this regard, one major concern is appropriate cement selection, with considerations including cement biologic compatibility, methods for limiting the excess cement, ease of removing the excess cement, radiographic view of the cement, and also the possibility of future retrieval of the prosthesis. The aim of this review article was to address most aspects related to this type of prosthesis in terms of cementation.     

Non‐Radiological Method for Fabrication of a Screw‐Channel Drilling Guide in Cement‐Retained Implant Restorations Using Intraoral Digital Scanning and Imaging Superimposition: A Clinical Report

The difficulty of retrieving the abutment screw is a major disadvantage of cement‐retained implant restorations. Conventional methods for locating the screw‐access hole are based largely on radiography or manual labor, which limits accuracy and clinical feasibility. This clinical report describes a non‐radiological method for fabricating an accurate drilling guide for location of the screw channel using intraoral optical scanning, 3D superimposition, and computer‐aided design and computer‐aided manufacturing (CAD/CAM) technologies. The present technique not only improves the guide fabrication process and the accuracy of screw‐channel drilling, but also has wide indications for implant restorations.     

Three Tumor Patients with Total Maxillectomy Rehabilitated with Implant‐Supported Frameworks and Maxillary Obturators: A Follow‐Up Report

Background: Few reports are available on treatment using implant‐supported frameworks with maxillary obturators after total maxillectomy on tumor patients. Purpose: To describe, evaluate, and report the clinical and radiographic performance of implant‐supported frameworks and maxillary obturators after maxillectomy during the first years of function. Materials and Methods: Three patients with cancer in the maxillary region treated by total maxillectomy were rehabilitated. Seventeen dental and two craniofacial implants were installed, and the patients each received implant‐supported, screw‐retained, three‐unit frameworks with a U‐shaped bar and obturators retained by four magnetic attachments. Clinical and radiographic data were collected up to 7 years of follow‐up. Results: The frequency of complications was low. Two craniofacial implants and one dental implant were loose and removed at abutment connection. No implants were lost after framework connection, and the mean marginal bone loss was small. Conclusion: Within the limitations of this report, dental implants are useful for rehabilitation of total maxillectomy patients, and a three‐unit, screw‐retained, implant‐supported framework with maxillary obturator retained by magnetic attachment is a successful treatment concept for this patient group.     

Immediate Loading of Two Implants with a Mandibular Implant‐Retained Overdenture: A New Treatment Protocol

Purpose: The aim of this study was to present the clinical outcomes of the immediate loading of two bar‐splinted implants retaining a mandibular overdenture. Materials and Methods: In a clinical trial, 124 edentulous patients were treated according to a new treatment concept, which involves the immediate loading of two bar‐splinted SLActive implants with an implant‐retained mandibular overdenture. The new conventional mandibular denture is used as a template for implant positioning and as an impression tray, and for mounting the retention clip by the dental laboratory. At the same day the implants are placed, the conventional denture is converted into an implant‐retained overdenture. During the healing and evaluation period, resonance frequency analysis (RFA) was undertaken to assess the effect of loading on implant stability and survival. Results: The survival rate of the implants was 98.8% during the evaluation period (12–40 months). Only 3 of the 248 implants were lost. During the healing (osseointegration) phase, the implant‐stability quotient increased significantly (p = .0001). During the evaluation period, four patients (3%) needed a relining of their mandibular overdenture, whereas 13 patients (11%) needed relining of the maxillary denture. Conclusions: Two interconnected implants can be successfully loaded by a mandibular overdenture at the same day of implant placement with a high survival rate of the implants. Only a few patients needed additional relining of the overdenture. Repeated RFA measurements can be useful in gauging implant stability and survival.     

A Novel Approach for Converting a Mandibular Complete Denture to a Fixed Interim,Screw‐Retained Implant Prostheses: A Case Report

For most of the last century, conventional complete dentures have been the standard of care and the most common treatment for edentulous patients. Technological advancements in fabrication techniques may significantly reduce the number of office visits required to fabricate complete dentures. Immediate occlusal loading with mandibular full arch prostheses has been extensively researched and is now one of the standards of care for edentulous patients. A clinical technique for converting a mandibular immediate complete denture to an interim full arch, screw‐retained fixed prosthesis with novel implant restorative components for immediate loading on four implants is described.     

Six‐Year Survival of a Mini Dental Implant‐Retained Overdenture in a Child with Ectodermal Dysplasia

Patients with ectodermal dysplasia (ED) experience several problems caused by abnormal development and functioning of the head and neck region. In addition to developmental nasal cartilage abnormalities and absence of sweat glands, hair, and eyebrows, edentulism or developmental disorders of teeth (cone‐shaped teeth) are commonly observed in these types of patients. ED is also characterized by underdeveloped alveolar ridges, a decreased occlusal vertical dimension, reduced salivary secretion, and dry oral mucosa, which make prosthetic rehabilitation difficult. Few studies of intraosseous dental implant‐retained prostheses have described adverse effects on craniofacial growth and esthetic and functional disadvantages, while some researchers have described the advantages of this treatment option as an alternative option in these cases. Due to the associated alveolar bone deficiency, dental mini‐implant therapy may be a treatment option for these patients; however, there are isolated cases in the literature regarding the rehabilitation of ED patients with mini‐implant‐supported overdentures. This clinical report describes the rehabilitation of a 6‐year‐old child with ED using a maxillary removable partial prosthesis and a mini‐implant‐retained mandibular overdenture. The clinical and radiographic findings of this prosthetic rehabilitation during the 6‐year follow‐up are also presented.     

The Digital One‐Abutment/One‐Time Concept. A Clinical Report

The digital fabrication of dental restorations on implants has become a standard procedure during the last decade. Avoiding changing abutments during prosthetic treatment has been shown to be superior to the traditional protocol. The presented concept for implant‐supported single crowns describes a digital approach without a physical model from implant placement to final delivery in two appointments. A 54‐year‐old man was provided with a single‐tooth implant on his left mandibular first molar. Before wound closure, the implant position was captured digitally with an intraoral scanning device. After bone healing at the time of second‐stage surgery the final screw‐retained crown fabricated without a physical model was inserted. Soft tissue healing took place at the definitive restoration, avoiding abutment changes or changes of the healing cap. These led to stable soft tissues with a minimum of surgery. The benefits of digital fabrication and the unique way to scan the implant right after placement give an additional value that would not be achieved by analog techniques. In addition to financial benefits it represents a biologically advantageous, one‐abutment/one‐time approach with customized screw‐retained, full‐contour crowns or cemented crowns on custom abutments.     

Fracture Resistance of Three Ceramic Inlay‐Retained Fixed Partial Denture Designs. An In Vitro Comparative Study

Purpose: The fracture resistance of ceramic inlay‐retained fixed partial dentures (CIRFPDs) was studied. Materials and Methods: Thirty CIRFPDs were constructed using ice zircon milled ceramic material. Specimens were divided into three groups, 10 specimens each, according to the abutment preparation: inlay‐shaped (occluso‐proximal inlay + proximal box), tub‐shaped (occluso‐proximal inlay), and proximal box‐shaped preparations. Each group was then subdivided into two subgroups of five specimens each, according to the span of the edentulous area representing a missing premolar or molar. All specimens were subjected to a fracture resistance test. Results: CIRFPDs with inlay‐shaped retainers showed the highest fracture resistance values for missing premolars and molars. CIRFPDs with box‐shaped retainers showed lower fracture resistance values. Statistical analysis revealed a significant difference between the three tested CIRFPD designs. There was a statistically significant difference between CIRFPDs constructed for the replacement of molars and those constructed for the replacement of premolars. The CIRFPD constructed for the replacement of molars gave lower fracture resistance values with the three tested designs. All the fracture resistance values obtained in this study were superior to the assumed maximum mastication forces. Failure mode was delamination and chipping of the veneering material. Conclusions: There was a statistically significant difference between the three designs of CIRPFDs tested. There was a statistically significant difference between CIRFPDs constructed for the replacement of molars than those constructed for the replacement of premolars. The CIRFPDs constructed for the replacement of molars gave lower fracture resistance values with the three tested designs. All fracture resistance values obtained in this study were superior to the assumed maximum mastication forces.     

Care and Aftercare Related to Implant‐Retained Dental Crowns in the Maxillary Aesthetic Region: A 5‐Year Prospective Randomized Clinical Trial

Aim: To prospectively assess surgical and prosthetic care and aftercare related to the placement of implant‐retained dental crowns after local bone augmentation in patients missing one tooth in the maxillary aesthetic region. Methods: Ninety‐three patients were randomly allocated to one of three local augmentation groups: (1) chin bone; (2) chin bone covered by a Bio‐Gide® membrane (Geistlich, Wolhusen, Switzerland); and (3) Bio‐Oss® covered by a Bio‐Gide® membrane. After local augmentation, implant placement (ITI) and fabrication of an implant‐retained dental crown (cemented metal‐ceramic dental crown) was performed. Prosthetic and surgical care and aftercare was scored from the first visit until 5 years after the augmentation of the implant region. Results: The need for care and aftercare was comparable between the local augmentation groups. Three implants were lost (5‐year implant survival rate: 96.7%). Surgical aftercare was needed in 9% of patients and consisted of care related to peri‐implant tissue problems. Prosthetic aftercare was needed more often: all patients needed periodic routine inspections; 63% needed supplemental oral hygiene support; and 16% needed additional prosthetic care, mainly consisting of fabricating new crowns (12%). Conclusion: Placing an implant in the maxillary esthetic region after local bone augmentation is a safe and reliable treatment option not needing much specific aftercare other than periodic preventive routine inspections, routine oral hygiene care, and fabrication of a new crown in one out of every eight to nine patients in 5 years. The method used for augmentation was irrespective of the patients' need for aftercare.     

The cross‐pin retained implant supported restoration: a study of gasket placement and leakage

Background: Advantages of cross‐pin retained implant supported restorations (ISRs) include predictable retrieval and predictable retention. Unlike direct to fixture (DTF) or cement retained restorations, the prosthetic design of a cross‐pinned restoration retains gaps at the interfaces between the crown, abutment and cross‐pin screw. These spaces permit leakage into the suprastructure and gasket placement has been recommended to prevent this leakage. Methods: Five different gaskets were assessed for their ability to prevent leakage into a cross‐pinned ISR. The gaskets tested were: cement admixture on the cross‐pin screw; cement admixture on the inner surface of the coping and the cross‐pin screw; cement admixture on the inner surface of the coping only; cement admixture placed 1 mm from the margin of the coping and a filler placed in the abutment chimney. Results: Only gaskets which sealed both the cross‐pin screw interface and the abutment‐crown interface prevented leakage. A filler placed in the abutment chimney prevented leakage into this space but did not prevent fluid accumulating between the coping and abutment. Conservative placement of cement at the margin of the coping failed to prevent leakage. Conclusions: Cement gaskets may effectively prevent leakage into a cross‐pinned ISR. However, the use of a cement as a gasket has to be weighed against the issue of predictable retrieval, cement extrusion and incomplete seating.