Effects of Taper Angle and Sealant Agents on Bacterial Leakage Along the Implant-Abutment Interface: An In Vitro Study Under Loaded Conditions

Abstract

Differences in taper angles in the internal conical connections had no significant effect on leaked bacterial counts or the frequency of bacterial contamination under dynamic loading. The application of 2% chlorhexidine gel or a silicone sealant can reduce the leaked bacterial counts and reduce the frequency of bacterial leakage.

Study of the Effect of GapSeal on Microgap and Microleakage in Internal Hex Connection After Cyclic Loading

“…The results of studies that used bacteria to measure microleakage are more consistent with reality compared to the use of methylene blue. (6,11) In the present study, the size of microgap was 0.99±0.39 µm in the GapSeal group and 3.04±0.54 µm in the control group. Bacteria ranged in size from 0.2 to 5 µm.…”

“…The shape of the abutment-implant junction and dynamic loading can increase micromovement and create a pumping effect, affecting leakage of bacteria and liquids. (7,11,19) in some previous studies, the amount of leakage has been studied statically. In 2011, Lorenzoni et al showed that microleakage and gap at the implant-abutment interface were present in two types of hexagonal implants; however, the samples were not cyclically loaded.…”

“…In 2018, Ozdiler et al showed that sealants (silicone sealant and chlorhexidine), unlike the taper angle, reduce bacterial leakage at the conical internal implant-abutment interface under dynamic loading with a 50-N force and 500,000 cycles. (11) In the present study, the specimens were loaded with more cycles and higher forces in the physiological range (200,000 to 1,200,000 cycles, 15 to 160 N); the results were consistent with the results of the study by Ozdiler et al (11) Nayak et al (2014) evaluated the sealing ability of O-ring polysilicon and GapSeal to prevent microleakage between the fixture and abutment in static conditions and showed that the use of GapSeal at the inner surface of the fixture before torqueing reduced the microleakage rate. (8) The c-clamp was used to fasten the abutment screw without mounting the fixture, whereas in the present study, the fixtures were mounted in molds containing acrylic resin, which were more similar to the fixture inserted in the patient's jaw.…”

“…(8) In 2018, Ozdiler et al showed that sealants, contrary to different taper angles of conical implants, reduce bacterial leakage at the internal conical implant-abutment interface under a dynamic load of 50 N and 500,000 cycles. (11) In the present study, the specimens underwent cyclic loading with more force compared to previous studies in the physiological range (200,000 to 1,200,000 cycles, 15 to 160 N), evaluating the effect of GapSeal equivalent to 48 months of chew-ing force inside the mouth. (11) In this study, the effect of GapSeal and its control group on preventing liquid leakage and microgaps in internal hexagon connection after dynamic loading with a 100-N force and 1,200,000 cycles was investigated.…”

“…(8)(9)(10) Various studies have shown fluid flow and bacterial accumulation around the implant-abutment junction regardless of the type of connection (external or internal); gaps of up to 49 µm have been reported. (11)(12)(13)(14)(15)(16)(17) Studies have shown a lower rate of microgap and leakage with internal implant-abutment connection compared to the external ones. (9) The effect of sealants on microgap and microleakage reduction between fixtures and abutments in internal connections under dynamic loading has been limitedly studied.…”