Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

scholarly journals Influence of Orthodontic Anchor Screw Anchorage Method on the Stability of Artificial Bone: An In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3205 ◽  
Author(s):  
Seen-Young Kang ◽  
Ji-Min Yu ◽  
Hyoung-Sik Kim ◽  
Jun-Seok Lee ◽  
Chan-Mi Yeon ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Automatic Device ◽  
Insertion Torque ◽  
Artificial Bone ◽  
Artificial Bones ◽  
Significant Difference ◽  
The Mean ◽  
The Stability ◽  
Torque Values

This study aims to compare the torque values for various lengths of the titanium-based orthodontic anchor screw (OAS), different anchorage methods and varying artificial bone densities after predrilling. Furthermore, the effects of these parameters on bone stability are evaluated. A total of 144 OASs were prepared with a diameter of 1.6 mm and heights of 6, 8 and 10 mm. Artificial bones were selected according to their density, corresponding to Grades 50, 40 and 30. Torque values for the automatic device and manual anchorage methods exhibited a statistically significant difference for the same-sized OAS, according to the bone density of the artificial bones (p < 0.05). However, when insertion torque was at the maximum rotations, there was no significant difference in the torque values for the Grade 30 artificial bone (p > 0.05). When the torque values of both anchorage methods were statistically compared with the mean difference for each group, the results of the manual anchorage method were significantly higher than those of the automatic device anchorage method (p < 0.05). A statistically significant difference was observed in the bone stability resulting from different OAS anchorage methods and artificial bone lengths. These findings suggest that the automatic anchorage method should be used when fixing the OAS.

scholarly journals In Vitro Evaluation of Manual Torque Values Applied to Implant-Abutment Complex by Different Clinicians and Abutment Screw Loosening

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Onur Dincer Kose ◽  
Burcin Karataslı ◽  
Sabit Demircan ◽  
Taha Emre Kose ◽  
Erhan Cene ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Optical Microscope ◽  
Control Group ◽  
Screw Loosening ◽  
Loading Test ◽  
Torque Wrench ◽  
Implant Abutment ◽  
Torque Values ◽  
Abutment Screw

Preload is applied to screws manually or using a torque wrench in dental implant systems, and the preload applied must be appropriate for the purpose. The aim of this study was to assess screw loosening and bending/torsional moments applied by clinicians of various specialties following application of manual tightening torque to combinations of implants and abutments. Ten-millimeter implants of 3.7 and 4.1 mm diameters and standard or solid abutments were used. Each group contained five implant-abutment combinations. The control and experimental groups comprised 20 and 160 specimens, respectively. Implants in the experimental group were tightened by dentists of different specialties. Torsional and bending moments during tightening were measured using a strain gauge. Control group and implants with preload values close to the ideal preload were subjected to a dynamic loading test at 150 N, 15 Hz, and 85,000 cycles. The implants that deformed in this test were examined using an optical microscope to assess deformities. Manual tightening did not yield the manufacturer-recommended preload values. Dynamic loading testing suggested early screw loosening/fracture in samples with insufficient preload.

scholarly journals Experimental Investigation of the Influence of Chlorhexidine Gel on the Implant-Abutment-Connection

2020 ◽  
Author(s):  
Lisa Mandlbauer ◽  
Vasilios Alevizakos ◽  
Ahmed Othman ◽  
Marcus Stoetzer ◽  
Constantin von See
Keyword(s):  
Testing Machine ◽  
In Vitro Study ◽  
Control Group ◽  
Removal Torque ◽  
Significance Level ◽  
Saliva Substitute ◽  
Group 3 ◽  
Group 2 ◽  
Chlorhexidine Gel

Abstract Background The aim of this study was to determine the effect of chlorhexidine gel on removal torque of abutment prosthesis screws in vitro. Methods 60 implants (BEGO Semados ® S/RI 4.1, BEGO Implant Systems GmbH & Co. KG, Bremen, Germany) were embedded in acrylic resin for study set-up. The abutments (S/RI 4.1 SUB-TEC WI, BEGO Implant Systems GmbH & Co. KG, Bremen, Germany) were fixed with prothesis screws with 25 Ncm on the implants and were loaded for 10.000 cycles with 250N in a static material testing machine. The implemented study consisted of three groups (n=20). Group 1 (control group) were loaded under dry conditions. Group 2 was filled with a saliva substitute only (Sialin-Sigma solution, Sigmapharm Arzneimittel GmbH, Vienna, Austria), group 3 was filled with a saliva substitute and additional with chlorhexidine gel (Chlorhexamed 1% GEL, GlaxoSmithKline Consumer Healthcare GmbH & Co. KG, München, Germany). Statistical analysis was performed using ANOVA (significance level p<0.05). Results The control group showed the smallest range of removal torque (19.85 Ncm ± 1.42 Ncm) while group 2 showed 20.32 Ncm ± 2.61 Ncm and in group 3 was 19.74 Ncm ± 2.96 Ncm. No significant differences between the three groups were evaluated. Conclusions Within the limits of this in-vitro study, it can be concluded that the application of chlorhexidine gel did not show any significant effect on the removal torque on abutment screws after loading.

Dynamic and static load performance of dental biomaterial systems with conical implant-abutment connections

2020 ◽  
Vol 31 (5) ◽  
pp. 319-328
Author(s):  
Mehmet Can Basgil ◽  
Cem Kurtoglu ◽  
Koray Soygun ◽  
Yunus Uslan ◽  
Teyfik Demi̇r
Keyword(s):  
Dynamic Loading ◽  
Fracture Strength ◽  
Static Loading ◽  
Sem Analysis ◽  
Control Group ◽  
Compression Load ◽  
Implant Abutment ◽  
The Stability ◽  
Implant System

BACKGROUND: The stability of the implant-abutment interface is an important factor that influences load distribution on the marginal bone. OBJECTIVE: In this study, three dental implants with the same connection were subjected to different dynamic loading cycles. The fracture strengths and the horizontal compatibility of implants were assessed. METHODS: Eighty four implant specimens were embedded in a polyacetal cylinder as simulated bone loss of 3 mm from the implant platform. Three of the implants were used to determine the endurance limit. The other specimens were subdivided into four subgroups (n = 6): three for dynamic + static loading, and one for static loading (control group). The tests were performed by applying a compression load. The dynamic loading experiments included three different cycles with endurance upper limit loads at a frequency of 10 Hz. RESULTS: The differences between the fracture strength values of the implant brands were found to be statistically significant. However, there were no meaningful differences between the fracture strength values of implants of the same brand. The specimens of the DTI implant system had the lowest strength (647.9 ± 41.5 N) and the SEM analysis indicated that the Implantium implant system had the shortest horizontal gaps. CONCLUSIONS: There was a negative correlation between the fracture strengths and size of the microgaps. The importance of these in vitro results needs to be validated by clinical trials because the loads in the mouth can be applied from various angles.

Comparative Study to Evaluate the Surface Detail Reproduction of Dental Stone after Immersion in Various Different Disinfectant Solutions, Under Stereomicroscope 10 X Magnification –An In-Vitro Study

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya
Keyword(s):  
Sodium Hypochlorite ◽  
In Vitro Study ◽  
Control Group ◽  
Immersion Method ◽  
Significant Difference ◽  
Surface Irregularities ◽  
Disinfectant Solution ◽  
Surface Detail ◽  
Group B

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde

scholarly journals Pomegranate Peel Extract Is a Potential Alternative Therapeutic for Giardiasis

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 705
Author(s):  
Asmaa M. El-Kady ◽  
Iman A. M. Abdel-Rahman ◽  
Samer S. Fouad ◽  
Khaled S. Allemailem ◽  
Taghrid Istivan ◽  
...  
Keyword(s):  
Diarrheal Disease ◽  
Apoptotic Cell ◽  
In Vitro Study ◽  
Ethanolic Extract ◽  
Control Group ◽  
Pomegranate Peel ◽  
Pomegranate Peel Extract ◽  
Multiple Drugs ◽  
Peel Extract

Giardiasis is a major diarrheal disease affecting approximately 2.5 million children annually in developing countries. Several studies have reported the resistance of Giardia lamblia (G. lamblia) to multiple drugs. Therefore, identifying an effective drug for giardiasis is a necessity. This study examined the antiparasitic effect of Punica granatum (pomegranate) and evaluated its therapeutic efficacy in rats infected with G. lamblia. In vitro study showed high efficacy of pomegranate peel ethanolic extract in killing G. lamblia cysts as demonstrated by eosin vital staining. We showed that treating infected rats with pomegranate extract resulted in a marked reduction in the mean number of G. lamblia cysts and trophozoites in feces and intestine respectively. Interestingly, the number of G. lamblia trophozoites and cysts were significantly lower in the pomegranate extract-treated group compared to the metronidazole-positive control group. Moreover, pomegranate extract treatment significantly induced nitric oxide (NO) and reduced serum IL-6 and TNF-α, compared to infected untreated rats. Histological and scanning electron microscopy (SEM) examination of the jejunum and duodenum of pomegranate extract-treated animals confirmed the antiparasitic effect of the extract, and demonstrated the restoration of villi structure with reduction of villi atrophy, decreased infiltration of lymphocytes, and protection of intestinal cells from apoptotic cell death. In conclusion, our data show that the pomegranate peel extract is effective in controlling G. lamblia infections, which suggests that it could be a viable treatment option for giardiasis.

scholarly journals Potential of different fluoride gels to prevent erosive tooth wear caused by gastroesophageal reflux

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Philipp Körner ◽  
Luca Georgis ◽  
Daniel B. Wiedemeier ◽  
Thomas Attin ◽  
Florian J. Wegehaupt
Keyword(s):  
Gastroesophageal Reflux ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Wear ◽  
Control Group ◽  
Erosive Tooth Wear ◽  
Custom Made ◽  
Post Hoc ◽  
Bovine Enamel

Abstract Background This in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear. Methods Surface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1–5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2–5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test. Results The overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047). Conclusions After 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.

scholarly journals Time Efficiency of Digitally and Conventionally Produced Single-Unit Restorations

2021 ◽  
Vol 9 (6) ◽  
pp. 62
Author(s):  
Sofia Stromeyer ◽  
Daniel Wiedemeier ◽  
Albert Mehl ◽  
Andreas Ender
Keyword(s):  
Single Unit ◽  
Operating Time ◽  
In Vitro Study ◽  
Working Time ◽  
Control Group ◽  
Similar Amount ◽  
Scan Design ◽  
Time Efficiency ◽  
Dental Professional

The purpose of this in vitro study was to compare the time efficiency of digital chairside and labside workflows with a conventional workflow for single-unit restorations. The time efficiency in this specific sense was defined as the time, which has to be spent in a dental office by a dental professional performing the relevant steps. A model with interchangeable teeth on position 36 was created. These teeth were differently prepared, responding to several clinical situations to perform single-unit restorations. Different manufacturing techniques were used: For the digital workflows, CEREC Omnicam (CER) and Trios 3 (TN/TI) were used. The conventional workflow, using a dual-arch tray impression technique, served as the control group. For the labside workflow (_L) and the conventional impression procedure (CO), the time necessary for the impressions and temporary restorations was recorded and served as operating time. The chairside workflow time was divided by the time for the entire workflow (_C) including scan, design, milling and finishing the milled restoration, and in the actual working time (_CW) leaving out the chairside milling of the restoration. Labside workflow time ranged from 9 min 27 s (CER_L) to 12 min 41 s (TI_L). Entire chairside time ranged from 43 min 35 s (CER_C) to 58 min 43 s (TI_C). Pure chairside working time ranged from 15 min 21 s (CER_CW) to 23 min 17 s (TI_CW). Conventional workflow time was 10 min 39 s (CO) on average. The digital labside workflow and the conventional workflow require a similar amount of time. The digital chairside workflow is more time consuming.

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