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Nederlands Tijdschrift Voor... Jul 2018Restorative dentists are faced with a dilemma: they needs to be aware of the most recent developments in order to be able to offer state-of-the-art care but they also... (Review)
Review
Restorative dentists are faced with a dilemma: they needs to be aware of the most recent developments in order to be able to offer state-of-the-art care but they also have to be able to identify which of the many innovations are superfluous. In this doctoral dissertation the focus was on the role of digital production and procedures in restorative dentistry, and in oral implantology in particular. The variety of studies performed revealed that patients prefer to have impressions taken digitally rather than with dental impression putty and that digital impressions can be taken more quickly. Modern restorative materials are often made of ceramics, such as the white and aesthetically appealing zirconium dioxide (3Y-TZP). It was revealed that zirconia when used as abutment material for implant-born restorations showed no signs of degradation after 1 year of clinical use and was more or less as strong as it had been in the beginning. Milled composite resin crowns, however, that were cemented to them did not adhere well to the ceramic.
Topics: Dental Implant-Abutment Design; Dental Implants; Dental Materials; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Humans
PubMed: 30015816
DOI: 10.5177/ntvt.2018.07/08.18135 -
The International Journal of Oral &... 2018Implant-retained mandibular overdentures are a proven treatment modality for edentulous patients. Low-profile stud attachments may allow divergence between the abutments...
PURPOSE
Implant-retained mandibular overdentures are a proven treatment modality for edentulous patients. Low-profile stud attachments may allow divergence between the abutments up to 40 degrees. The purpose of this study was to investigate load transfer characteristics of various locations and nylon male configurations of low-profile stud attachment-retained overdentures.
MATERIALS AND METHODS
Three tapered dental implants were placed into three photoelastic mandibular models. The center implants were placed vertically onto the midline, and the distal implants were inclined 20 degrees corresponding to centralized implants. Three different distances (11, 18, and 25 mm) between the centralized and the distal implants were set on the models. Low-profile stud attachment (Locator)-retained mandibular overdentures were fabricated for each photoelastic model. Five different nylon male configurations of this stud attachment were established. The load transfer characteristics of the configurations were tested using a circular polariscope.
RESULTS
The observed stress levels for the tested configurations were moderate except for group 25C (photoelastic model with 25-mm interimplant distances and clear nylon male), which illustrated a high stress level. For the 11-mm photoelastic model, little or no discernible stress was noted around the dental implants for group 11R (red nylon male), group 11G (green nylon male), and configurations of clear and red or green nylon males (group 11CR [clear and red nylon males] and group 11CG [clear and green nylon males]).
CONCLUSION
The applied loads were distributed to the supported dental implants and denture-bearing areas for tested designs. Equitable load distribution and less stress may be gathered using nylon males for angulated implants (red and green) when dental implants are placed inclined.
Topics: Dental Implants; Dental Materials; Dental Prosthesis, Implant-Supported; Dental Stress Analysis; Denture Design; Denture Retention; Denture, Overlay; Humans; Mandible; Mouth, Edentulous; Stress, Mechanical
PubMed: 30024990
DOI: 10.11607/jomi.6207 -
The International Journal of... 2015The degree of misfit between a prosthesis and its supporting implants is a major concern in screw-retained prostheses because it can lead to screw loosening or...
The degree of misfit between a prosthesis and its supporting implants is a major concern in screw-retained prostheses because it can lead to screw loosening or mechanical failure of implant components. On the other hand, the difficulty of removing subgingival excess cement and the irretrievability of the superstructure are major drawbacks to cement-retained prostheses. A newly designed screw- and cement-retained prosthesis (SCRP) may solve these problems with its passivity, retrievability, and ease in the complete removal of excess cement, giving it the advantages of both screw-retained and cement-retained prostheses. This prosthetic system is mainly composed of a cement-retained framework with screw holes on the occlusal surface and specially designed cementable abutments for multiunit prostheses. The principle and structure of the SCRP system is described in this article.
Topics: Cementation; Dental Abutments; Dental Cements; Dental Implant-Abutment Design; Dental Implants; Dental Marginal Adaptation; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Humans
PubMed: 26523721
DOI: 10.11607/ijp.4236 -
Implant Dentistry Apr 2017Implant-supported prosthetic rehabilitations are in constant augmentation in everyday dental practice. This is largely due to increasing demand from patients for fixed... (Review)
Review
PURPOSE
Implant-supported prosthetic rehabilitations are in constant augmentation in everyday dental practice. This is largely due to increasing demand from patients for fixed or implant-stabilized prosthesis, although they are frequently reticent to complex preimplant bone augmentation surgeries, whenever bone volume is lacking. Narrow-diameter implants (NDI; ≤3.5 mm) have been developed to offer relatively simple implant solutions in challenging bone-deficient sites. However, concerns regarding their mechanical properties have been raised. Special titanium-zirconium material (Ti-Zr), with superior mechanical resistance, compared with pure titanium alloys has been introduced into the market. The purpose of this systematic review was to determine the available data on clinical performance of Ti-Zr NDI.
MATERIALS AND METHODS
A literature search of all available clinical articles dealing with Ti-Zr NDI has been carried out. After including only prospective clinical trials, 14 papers were retrieved for thorough reviewing.
CONCLUSION
Short-term results from preliminary clinical reports are quite promising, although the number of published studies and the follow-up periods are still insufficient to determine the real benefit of this hybrid material compared with titanium, especially when using NDI.
Topics: Alloys; Animals; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis, Implant-Supported; Humans
PubMed: 28114266
DOI: 10.1097/ID.0000000000000557 -
The International Journal of Oral &... 2020To evaluate and compare the effects of two restorative materials with different stiffness on peri-implant bone microstrain and implant micromovements during occlusal...
PURPOSE
To evaluate and compare the effects of two restorative materials with different stiffness on peri-implant bone microstrain and implant micromovements during occlusal loading in implant-supported single and adjacent splinted crowns.
MATERIALS AND METHODS
Two 3 × 10-mm implants were inserted into the tibia of four rabbits. During the osseointegration process, prosthetic restorations were performed. Before suturing the flap, each implant's position and direction were obtained by fastening two splinted transfer abutments, onto which implant analogs were placed and fastened; the splinted transfer abutments were subsequently unfastened. Splinted transfer abutment/analog complexes were cast using type IV plaster to obtain eight different working models. Two single mandibular premolar crowns of monolithic zirconia and acrylate polymer composite were generated using CAD/CAM technology, and 16 adjacent splinted crowns (eight of each material) with the same design were also generated. After 6 weeks of implant osseointegration, the animals were sacrificed. Tibial sections with the implants were extracted, and prosthetic restorations (performed during implant osseointegration) were fastened to the implants. Static loading tests were performed with 100-N force application and an inclination of 6 degrees over the central fossa of the premolars. Implant micromovement was measured using an image analysis technique. Bone microstrain was quantified using two strain gauges placed on the crestal bone around the implants. Data were analyzed using two-way analysis of variance.
RESULTS
The mean implant micromovement values were lower for monolithic zirconia single and splinted crowns (61.5 ± 26.3 μm and 57.7 ± 8.8 μm, respectively) than for acrylate polymer composite-based single and splinted crowns (78.9 ± 37.3 μm and 59.61 ± 11.5 μm, respectively). No significant differences between the materials were noted. Bone microstrain around the implants was lower for splinted crowns (303.7 ± 281.3 με for acrylate polymer composite; 312.4 ± 226.8 με for monolithic zirconia) than for single crowns (539.7 ± 8.8 με for acrylate polymer composite; 574.6 ± 271.9 με for monolithic zirconia).
CONCLUSION
Using restorative materials of different stiffness did not significantly affect the micromovement of already-osseointegrated implants supporting single or splinted crowns. Independent of material stiffness, single crowns transfer significantly more microstrain than splinted crowns.
Topics: Animals; Computer-Aided Design; Crowns; Dental Abutments; Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported; Osseointegration; Rabbits; Tibia
PubMed: 33270053
DOI: 10.11607/jomi.8094 -
The International Journal of Oral &... 2021To assess the impact of abutment angulation on loosening torque, torque loss, and percentage of torque loss in the prosthesis and abutment screws after aging of the...
PURPOSE
To assess the impact of abutment angulation on loosening torque, torque loss, and percentage of torque loss in the prosthesis and abutment screws after aging of the implant-supported prosthesis.
MATERIALS AND METHODS
Fifty epoxy maxillary casts with missing central, lateral, and canine teeth were used, and each cast received two implants. All casts were divided into five groups (n = 10): (1) both implants received straight abutments (0-0); (2) the central implant received a straight abutment and the canine implant received a 17.5-degree angled abutment (0-17.5); (3) the central implant received a straight abutment and the canine implant received a 35-degree angled abutment (0-35); (4) both implants received 17.5-degree angled abutments (17.5-17.5); and (5) both implants received 35-degree angled abutments (35-35). For each cast, a three-unit zirconia restoration was fabricated, and a torque meter was utilized to tighten the abutment screw (25 Ncm) and prosthesis screw (18 Ncm). The reverse torque value was recorded for each screw. All restorations were subjected to 3,500 thermal cycles between 5°C and 55°C and load cycled for 150,000 cycles with 50-N load. After the loosening torque was measured for each screw, the torque loss and percentage of torque loss were calculated.
RESULTS
There was a statistically significant difference in the torque loss of the central prosthesis screw (P < .001) and canine prosthesis screw (P < .001) between study groups. The 35-35 group showed the highest percentage of torque loss, while the 0-0 group showed the lowest value. A significant difference was found regarding the torque loss of the central abutment screw (P < .001) and canine abutment screw (P < .001). The abutment screws of the 35-35 group showed the highest percentage of torque loss, while the 0-0 groups showed the lowest percentage of torque loss.
CONCLUSION
Screw loosening of the prosthesis and abutment screws increases with increasing abutment angulation after aging. In the same fixed prosthesis, the torque loss in the prosthesis and abutment screws was higher in canine screws employing different angled abutments.
Topics: Bone Screws; Dental Abutments; Dental Implant-Abutment Design; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Dental Stress Analysis; Humans; Torque
PubMed: 34411211
DOI: 10.11607/jomi.8647 -
British Dental Journal Mar 2023
Topics: Humans; Dental Implants; Dental Implantation, Endosseous; Head and Neck Neoplasms; Dental Restoration Failure; Dental Prosthesis, Implant-Supported
PubMed: 36899241
DOI: 10.1038/s41415-023-5638-7 -
British Dental Journal Mar 2017Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those...
Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those that are edentate. This article aims to inform the reader of a variety of retention systems that are available to retain an implant overdenture and to understand how these systems work, their advantages and disadvantages and to outline some of the clinical and treatment planning considerations involved in selecting the most appropriate retention system for patients.
Topics: Dental Prosthesis Design; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Denture, Overlay; Humans
PubMed: 28281622
DOI: 10.1038/sj.bdj.2017.215 -
The Journal of Prosthetic Dentistry May 2021The metal-acrylic resin implant-supported fixed complete dental prosthesis (IFCDP) is a reliable restorative option. However, clinical complications and laboratory...
The metal-acrylic resin implant-supported fixed complete dental prosthesis (IFCDP) is a reliable restorative option. However, clinical complications and laboratory fabrication concerns are associated with these restorations. Maintenance and repair lead to increased chair time, but recently introduced computer-aided design and computer-aided manufacturing (CAD-CAM) materials and technology can improve efficiency and mitigate complications. In this clinical report, the existing design principles and CAD-CAM materials were combined to fabricate a metal-acrylic resin IFCDP that minimized individual tooth fracture and facilitated efficient resurfacing of worn surfaces.
Topics: Acrylic Resins; Computer-Aided Design; Dental Implants; Dental Prosthesis Design; Dental Prosthesis, Implant-Supported
PubMed: 32576372
DOI: 10.1016/j.prosdent.2020.04.006 -
The Journal of Oral Implantology Oct 2017There is controversy in the literature regarding the indicated retentive mechanism for implant-supported crowns. When adjacent implants are restored, the restoration can...
There is controversy in the literature regarding the indicated retentive mechanism for implant-supported crowns. When adjacent implants are restored, the restoration can be screw retained, cement retained, or a combination of cement and screw retained. Adjacent implant-supported crowns can be restored as individual implant supported crowns or can be splinted. A classification system is proposed when adjacent implants are restored. The classification system describes currently available options to restore adjacent implants. Six types of prosthetic design options are proposed as Class I through Class VI. In Class I design, individual cement-retained crowns are made. In Class II, individual screw-retained crowns are fabricated. Class III involves fabrication of individual screw-retrievable/cement-retained crowns. Class IV prosthetic design involves splinted cement-retained implant crowns. Class V prosthetic design involves splinted screw-retained crowns, and Class VI involves splinted screw-retrievable/cement-retained implant supported crowns.
Topics: Cementation; Crowns; Dental Implants; Dental Prosthesis Design; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported
PubMed: 28628355
DOI: 10.1563/aaid-joi-D-17-00078