Discrepancies in marginal and internal fits for different metal and alumina infrastructures cemented on implant abutments

Abstract

Cemented crowns are increasingly being used on dental implants instead of on screw-retained prostheses because of the reliability of internal Morse taper implant-abutment connections. However, there is a lack of information on the fit of metal ceramic and premachined alumina infrastructures. Therefore, the aim of this study was to evaluate the marginal and internal fits of different metal and alumina infrastructures cemented on universal post abutments. A total of 45 abutments (6 mm in height and 3.3 mm in diameter) were divided into five groups on the basis of their infrastructure material: cobalt-chromium (CoCr), nickel-chromium (NiCr), nickel-chromium-molybdenum-titanium (NiCrMoTi), gold (Au), and premachined alumina. The alumina group showed marginal overextension, and the Au group showed the highest discrepancy in marginal fit among the metal alloys. The CoCr and alumina groups showed the lowest discrepancies in internal fit. In conclusion, the alumina cylinders exhibited the best internal fit, despite their horizontal overextension. Among the metal alloys, CoCr exhibited the best fit at critical regions, such as the cervical and occlusal areas.

Marginal and Internal Adaptation of Zirconia Crowns: A Comparative Study of Assessment Methods

“…It has been reported that a 100-120-μm-thick cement layer is considered clinically acceptable for good long-term clinical prognosis of the indirect restoration (7,8). Poor internal adaptation can lead to lack of restoration retention and poor resistance form for the tooth-restoration complex (9,10). Therefore, the study of factors that affect marginal and internal adaptation of indirect restorations is critically important in restorative dentistry.…”

Simplifying the Treatment of Bone Atrophy in the Posterior Regions: Combination of Zygomatic and Wide-Short Implants—A Case Report with 2 Years of Follow-Up

“…However, this system also has some disadvantages. It demands greater accuracy in the preparation of the surgical bed and larger surgical care and there is less versatility with respect to prosthetic components for external hexagon connections [28]. …”

Fatigue Behavior of Different CAD/CAM Materials for Monolithic, Implant‐Supported Molar Crowns

“…For G3, the crowns were cleaned with isopropanol in an ultrasonic bath for 5 minutes, and an adhesive was applied (Scotchbond Universal; 3M ESPE). Next, all crowns were cemented (RelyX Ultimate; 3M ESPE) under a 50‐N constant load using a universal test machine (EMIC DL2000; Instron, Norwood, MA) . The excess cement was removed, and crowns were light‐cured for 30 seconds (Valo Cordless; Ultradent, South Jordan, UT).…”

“…Next, all crowns were cemented (RelyX Ultimate; 3M ESPE) under a 50-N constant load using a universal test machine (EMIC DL2000; Instron, Norwood, MA). 16 The excess cement was removed, and crowns were light-cured for 30 seconds (Valo Cordless; Ultradent, South Jordan, UT). After 10 minutes, all crowns were immersed in deionized water for 7 days prior to thermal and mechanical cycling.…”

“…Cemented crowns are increasingly being used in dental implants instead of screw-retained prostheses because the reliability of the Morse taper implant-abutment connection prevents screw-loosening issues. 16 One common abutment for a cemented prosthesis is the universal post, for which only a few components are necessary to restore single, edentulous spaces in the anterior and posterior regions. 17 However, CAD/CAM monolithic crowns cemented onto universal post abutments are subjected to cyclic occlusal loading under wet conditions that can lead to fractures and debonding.…”