Showing 6 results for Dental Leakage
A Zarbakhsh, A Mazaheri Tehrani, F Shamshirgar, H Khosroshahi,
Volume 3, Issue 3 (8-2018)
Abstract
Background and Aim: The mismatch of the implant-abutment connection can produce instant stress and microleakage which result in mechanical and biological complications. This study aimed to investigate the influence of GapSeal® as a sealing material on the extent of microgap and microleakage at the external hexagon implant platform following cyclic loading.
Materials and Methods: Sixteen implants with an external-hexagon connection (BioHorizons External dental implant) were employed in this in-vitro experimental study. All implant-abutment sets were assigned to two groups and were molded in acrylic resins. GapSeal® was injected into the implants in the experimental (test) group. Then, implant assemblies were tightened with the torque of 30 N/cm, and 1200,000 loading cycles with the force of 100 N and the frequency of 1 Hz were applied. Every sample was immersed in a methylene blue dye to evaluate microleakage. Microgap was measured in six regions randomly using a scanning electron microscope (SEM). The data were entered into SPSS 22 and were analyzed using t-test.
Results: The mean±SD microgap was 0.87±0.35 µm and 3.43±1.61 µm in the test and control groups, respectively. Methylene blue dye was observed in all of the specimens of the control group, while no liquid was seen in the test group. A significant statistical difference was found between the groups regarding the microgap and microleakage (P<0.0001).
Conclusion: Application of GapSeal® reduced the dimension of the microgap and decreased microleakage at the implant-abutment interface.
Sh Naser Mostofy, E Jalalian, N Valaie, Z Mohtashamrad, A Haeri, T Bitaraf,
Volume 4, Issue 3 (9-2019)
Abstract
Background and Aim: Formation of microgaps between the fixture and abutment surfaces is still one of the major problems that may lead to mechanical and biological failure and inflammation around the implant. In this study, the effect of GapSeal on the prevention of liquid leakage and microgap in internal hex connection was investigated.
Materials and Methods: In this experimental study, sixteen internal hex implants (BioHorizons) were used in two groups. All implant-abutment assemblies were mounted in acrylic molds. GapSeal was inserted into the implants in the case group. All specimens were given a torque of 30 Ncm. Then, 1,200,000 cycles with a 100-N force and frequency of 1 Hz were applied to all samples. The samples were immersed in a methylene blue solution for microleakage evaluation. Microgap was randomly measured at six areas using scanning electron microscopy (SEM). Data were analyzed by SPSS 22 software using t-test.
Results: The size of microgap was 3.04±0.54 µm in the control group and 0.99±0.39 µm in the case group, which was three times larger in the control group; the t-test showed that this difference was significant (P<0.000). In the control group, all samples (100%) showed leakage in the internal hex connection while in the case group, none of the samples (0%) showed leakage; Fischer's exact test showed that the difference was statistically significant (P<0.0001).
Conclusion: According to the results of this study, it can be concluded that GapSeal reduces microgap and microleakage in the case group compared to the control group.
Sh Naser Mostofy, A Zarbakhsh, Mm Alaei, T Bitaraf,
Volume 5, Issue 3 (8-2020)
Abstract
Background and Aim: Oral bacteria can proliferate in the implant-abutment interface (IAI) and cause inflammation in the peri-implant tissues and adjacent bone. This study aimed to assess the effect of zirconia and titanium abutments on the microleakage of the IAI under oblique cyclic loading conditions.
Materials and Methods: In this in-vitro study, 12 implant-abutment assemblies with zirconia and titanium abutments, in two groups of six, were vertically mounted inside resin blocks modified with autopolymerizing polyester base. The specimens were subjected to 75N oblique cyclic loading at an angle of 30±2° to the longitudinal axis of the implant at a frequency of 1 Hz at 500,000 cycles, which is equivalent to 20 months of human masticatory force. Fuchsine solution was used to evaluate the microleakage. To examine the penetration of fuchsine into the IAI, the fixtures were cut from the middle using a cutting machine. Then, the amount of fuchsine penetration in each of the samples was measured with a stereomicroscope at ×75 magnification at three points in each semicircle (cut implant), and the average of these six points was recorded as microleakage (µm). T-test was used to compare the microleakage after load with the significance level set at 0.05.
Results: The microleakage rate after cyclic loading was 66.08±11.66 µm in zirconia abutments and 39.17±10.65 µm in titanium abutments, which was significantly higher with zirconia abutments (P=0.002).
Conclusion: Microleakage after oblique cyclic loading varies depending on the type of abutment. Titanium abutments showed significantly less microleakage than zirconia abutments.
N Naseri, A Babasafari, E Jalalian, A Mazaheri, A Zarbakhsh,
Volume 6, Issue 4 (9-2021)
Abstract
Background and Aim: This study assessed the effects of cyclic loading on screw loosening, vertical misfit, and microleakage at the fixture-angulated abutment interface.
Materials and Methods: This in vitro study evaluated 12 implants in two groups (n=6). The implants were mounted in self-cure acrylic resin. The abutment screw was torqued to 30 N/cm by a digital torque-meter and re-torqued after 5 min. Six points at the fixture-abutment interface were inspected under a stereomicroscope (x75 magnification), and the distance between the two reference points was measured. Six implant-abutment assemblies then underwent cyclic loading (75 N, 1 Hz, 500,000 cycles) while the remaining six (control group) were stored at room temperature. The distance was measured again at the same 6 points after cyclic loading. Vertical misfit was calculated by subtracting the before and after values. The torque loss was measured by a digital torque-meter. The assemblies were then immersed in fuchsine and incubated at 37°C for 24 h. Next, the abutment was unscrewed and the fixtures were cut in half. The penetration depth of fuchsine was measured at 3 points of each fixture half under a stereomicroscope at x75 magnification, and the mean of the six measurements (entire fixture) was reported as the microleakage score of each sample. Data were analyzed using t-test.
Results: Cyclic loading significantly increased the misfit (P=0.001) and microleakage (P=0.01), and decreased the detorque value (P=0.04). No case of screw loosening was noted in any group.
Conclusion: Cyclic loading significantly increases the vertical misfit, microleakage, and torque loss.
Arezu Babasafari, Ezatollah Jalalian, Arash Zarbakhsh, Abdolkarim Rostamian, Shaghayegh Golalipour, Sotoudeh Khorshidi,
Volume 8, Issue 3 (8-2023)
Abstract
Background and Aim: This study aimed to assess the effect of horizontal cantilever on microgap and microleakage at the implant-straight abutment interface in cement-retained crowns.
Materials and Methods: In this experimental study, 12 implant-abutment assemblies and 12 cement-retained crowns were evaluated. The implant fixtures were bone-level, and had 10 mm length and 4 mm diameter. Straight titanium abutments had 7 mm length, 4 mm diameter, and 1 mm gingival height with Morse-Taper connection. Two groups were evaluated: 6 cement-retained crowns with a horizontal cantilever (test group) and 6 cement-retained crows without a horizontal cantilever (case group). The assemblies underwent load cycling in a chewing simulator. Cyclic load (75 N) with 1 Hz frequency was applied along the longitudinal axis of each specimen to the triangular ridge between the mesiobuccal and mesiolingual cusps of the crown. The amount of microgap before and after cyclic loading, and the microleakage score after immersion in fuchsine were evaluated under a light microscope. Data were compared by t-test (alpha=0.05).
Results: The change in microgap after cyclic loading compared with before was not significant in the control group (P=0.724). However, in the case group, the amount of microgap significantly increased after cyclic loading compared with before (P=0.000). Microleakage in the case group was significantly greater than that in the control group (P=0.019).
Conclusion: Horizontal cantilever caused horizontal microgap and increased the microleakage at the implant-straight abutment interface. |
Yashar Rezaei, Anahita Ahmad Pour Zabarjad, Katayoun Katebi, Sasan Bagheri Maleki,
Volume 9, Issue 4 (12-2024)
Abstract
Background and Aim: Application of disinfectants in pits and fissures is a commonly used method to lower the cariogenic bacterial count in teeth. This study compared the effect of applying chlorhexidine on microleakage of pit and fissure sealant therapy using two adhesive systems.
Materials and Methods: In this in vitro study, 60 extracted molar teeth were randomly assigned to four groups (n=15): control group 1 (etch-and-rinse adhesive), control group 2 (self-etch adhesive), group 3 (etch-and-rinse adhesive and 0.2% chlorhexidine), and group 4 (self-etch adhesive and 0.2% chlorhexidine). After applying the sealant and subjecting the teeth to thermocycling, the teeth were immersed in 5% methylene blue solution. The teeth were sectioned into four parts and the dye penetration depth was measured under a stereomicroscope. Data were analyzed by the Mann–Whitney and Kruskal–Wallis tests using SPSS 24 (alpha=0.05).
Results: Microleakage was significantly lower in the self-etch adhesive system compared to the etch-and-rinse system in the control groups (P<0.05). For the etch-and-rinse adhesive, there was no significant difference in microleakage between the two groups with chlorhexidine (1.67±1.11) and without chlorhexidine (1.33±0.81) (P>0.05). Similarly, in the self-etch adhesive, microleakage did not significantly differ between groups with chlorhexidine (1.07±0.45) and without chlorhexidine (1.07±0.70) (P>0.05). The interaction effect of adhesive type and chlorhexidine on microleakage was not significant (P=0.428).
Conclusion: Application of chlorhexidine with both self-etch and etch-and-rinse adhesive systems did not significantly affect the microleakage of fissure sealant therapy. Chlorhexidine may be used under fissure sealants for its antimicrobial effects without increasing microleakage.
