Search results for "abutment"
showing 10 items of 85 documents
Fracture resistance and the mode of failure produced in metal-free crowns cemented onto zirconia abutments in dental implants.
2019
The purpose of the investigation was to analyze fracture resistance and mode of failure of zirconium oxide (zirconia) abutments placed on dental implants bearing crowns of different esthetic materials: zirconia, lithium disilicate (LDS), and nano-ceramic resin, for replacing single teeth in the anterior sector. Eighty implant-abutment-crown units were divided into four groups: Group T-MC (control): 20 metal-ceramic crowns cemented onto titanium abutments; Group Z-Z: 20 zirconia crowns on zirconia abutments; Group Z-LD: 20 lithium disilicate crowns on zirconia abutments; and Group Z-NCR: 20 nano-ceramic resin crowns on zirconia abutments. Specimens underwent a fatiguing process (dynamic load…
Implant-supported metal-ceramic and resin-modified ceramic crowns: A 5-year prospective clinical study.
2018
Abstract Statement of problem Because of market demand for innovation, new restoration materials have been introduced without adequate testing; clinical failure may be the consequence, and clinical studies are needed. Purpose The purpose of this clinical study was to evaluate the biological and mechanical clinical behavior of implant-supported resin-modified ceramic crowns compared with that of metal-ceramic crowns. Material and methods Forty-two participants aged between 35 and 65 years received single implants in posterior edentulous sites. After the osseointegration period, half of the implants (selected randomly) (n=25) were restored with metal-ceramic crowns (MC group) and the other ha…
Vulnerability of a Damaged Bridge Abutment in a Seismic Area
2018
The case of the abutment of a motorway urban viaduct damaged by human intervention is presented. Built in the 1960s, it lies in a critical seismic area and the human-induced damage involved the elements of the abutment foundation. The structure is geometrically complex and the evaluations of its structural safety were carried out by applying Italian codes from different times: those concerning the time of construction, those of a recent past (1996), and those of the present (2008), inspired by Eurocodes. A comparison between the safety checks performed and the requirements of all these codes is presented and discussed, especially regarding safety coefficients after the damage was done. Two …
The influence of platform switching in dental implants. A literature review.
2010
Introduction: The platform switching concept involves the reduction of the restoration abutment diameter with respect to the diameter of the dental implant. In 1991, dental implants of 5 and 6 mm diameter platforms were introduced. However, matching-diameter prosthetic abutments were not available. These implants were restored with “standard”-diameter prosthetic components (4,1 mm). Long-term follow up around these wide-platforms showed higher levels of bone preservation. In time, it has been called platform switching. The first case report applying this concept was indexed in MedLine in 2005. Materials and Methods: The aim of this article is to carry out a literature review of articles whi…
Tooth-implant connection in removable denture.
2016
When the patient cannot be rehabilitated with a fixed denture, or when he does not succeed in adapting to a traditional removable denture, a possible alternative solution consists in the use of a limited number of implants, placed in strategic positions in the arches of the patient, and subsequently connected to their residual teeth. The aim of this review is to evaluate the progress made on connections between teeth and implants in removable denture, to analyze their advantages and disadvantages and to compare the survival rate, both of the teeth and of the implants used as abutments, present in the various studies taken into examination, with the aim of being able to evaluate the effectiv…
Impact of abutment geometry on early implant marginal bone loss. A double‐blind, randomized, 6‐month clinical trial
2022
Objectives The objective of this study was to analyze the impact of the abutment width on early marginal bone loss (MBL). Material and Methods A balanced, randomized, double-blind clinical trial with two parallel experimental arms was conducted without a control group. The arms were “cylindrical” abutment and “concave” abutment. Eighty hexagonal internal connection implants, each with a diameter of 4 × 10 mm, were placed in healed mature bone. The main variable was the peri-implant tissue stability, which was measured as MBL at 8 weeks and 6 months. Results The final sample consisted of 77 implants that were placed in 25 patients. 38 (49.4%) were placed using the cylindrical abutment, and t…
Survival rates of a lithium disilicate-based core ceramic for three-unit esthetic fixed partial dentures: a 10-year prospective study.
2013
Purpose The aim of this prospective study was to evaluate the clinical efficacy and long-term survival rate of three-unit fixed partial dentures (FPDs) made from lithium disilicate-based core ceramic. Materials and methods Twenty-one three-unit FPDs were placed in 19 patients to replace single lost teeth in the esthetic area, following a study protocol that took clinical, esthetic, and radiologic aspects into consideration. Each case was reviewed at 1 week following placement, at 6 months, and then annually for 10 years. Statistical analysis was performed using Kaplan-Meier survival analysis. Results Out of the 19 patients, 14.3% presented reversible postoperative sensitivity. Recession was…
Support of removable partial dentures in situations with a unilaterally missing canine and a curved edentulous ridge.
1997
The load and movement of abutments and removable partial dentures were examined in situations with a unilaterally missing canine and a curved edentulous ridge. These measurements were performed on a model adapted to intraoral conditions. In this simulation, removable partial dentures supported by incisors may result in failure. Spring rest support results in significantly reduced articulation vertically and horizontally when compared with solid rest support and avoids periodontal overloading.
Mechanical resistance of zirconium implant abutments: A review of the literature
2010
The increase of aesthetic demands, together with the successful outcome of current implants, has renewed interest in the search for new materials with enough mechanical properties and better aesthetic qualities than the materials customarily used in implanto-prosthetic rehabilitation. Among these materials, zirconium has been used in different types of implants, including prosthetic abutments. The aim of the present review is to analyse current scientific evidence supporting the use of this material for the above mentioned purposes. We carried out the review of the literature published in the last ten years (2000 through 2010) of in vitro trials of dynamic and static loading of zirconium ab…
Comparative fracture behavior of monolithic and veneered zirconia posterior fixed dental prostheses
2017
The purpose of this study was to evaluate and to compare the fracture load and the fracture pattern of monolithic and veneered zirconia posterior fixed dental prostheses (FDPs). Twenty standardized steel dies were prepared to receive posterior 3-unit FDPs. Specimens were randomly divided into 2 groups (n=10): (1) Lava Zirconia, and (2) Lava Plus. All FDPs were cemented using glass ionomer cement and subjected to thermal and mechanical cycling at 5-55ºC with a 30-s dwell time for 120,000 masticatory cycles. All specimens were subjected to a three-point bending test until fracture. Data were statistically analyzed using Student's t test, paired t-test and Weibull statistics (α=0.05). No diffe…