An in vitro evaluation of the strength of an internal conical interface compared to a butt joint interface in implant design

Abstract

Dental implants are subject to large and highly complex loads of varying magnitude, duration and vector. Bridge performance is closely related to load transmission both at the bone to implant interface and between components within the implant-abutment-bridge cylinder complex. The design of the interface between components within this complex may have a profound influence on the long term function of the implant supported prosthesis. An in vitro evaluation of implants 3.5 mm in diameter, utilizing an internal conical interface has demonstrated increased resistance to bending moments at the fixture-abutment interface (P = 0.00010) and at the abutment-bridge cylinder interface (P < 0.01), when compared to a standard 3.75 mm implant with a hex mediated, butt joint interface. The relatively small values for coefficient of variance measured in both systems would confirm that whilst the size of data is small, it is nonetheless a reliable indication of the relative strength of these implant designs.

Retrieval of a fractured abutment screw thread from an implant: a case report

“…12,13 The absence of form lock and friction, as found in internal-taper designs, results in lack of protection against the bending forces in the system implicated in screw loosening. 14,15 Causes of screw loosen ing or fracture have been identifi ed as inadequate tightening, adverse occlusal forces, and fatigue character and yield ing strength of the screw material. 16,17 Additionally, the surface of a new metal screw has microscopic surface imperfec tions in the form of high spots, grooves, and irregularities, such that when initial torque is applied only the high spots in the system will be in contact.…”

Influence of surface treatment of yttria-stabilized tetragonal zirconia polycrystal with hot isostatic pressing on cyclic fatigue strength

“…Given that the ceramic implant will be subjected to a humid environment and mastication in the oral cavity, cyclic fatigue tests are essential in assuring their success. Some recent studies have used cyclic loading to determine the durability of such implants under clinical conditions 17) rather than the static loading conventionally used 18,19) . Grinding, sandblasting, or acid-etching should be used to enhance osseointegration when zirconia is used for the implant body.…”

The titanium PV I endosteal implant from beta-titanium alloy Ti 38Nb 6Ta

“…This corresponds to similar threads used in the AstraTech system of the implants [15][16][17] . The abutment, fully and accurately fitting the fixture is another positive feature of the implant construction.…”