scholarly journals The Effect of Undersized Drilling on the Coronal Surface Roughness of Microthreaded Implants: An In Vitro Study

2020 ◽  
Vol 10 (15) ◽  
pp. 5231 ◽  
Author(s):  
Omer Cohen ◽  
Ofer Moses ◽  
Talia Gurevich ◽  
Roni Kolerman ◽  
Alina Becker ◽  
...  

This in-vitro study assessed the effect of an underdrilling implant placement protocol on the insertion torque, implant surface temperature and surface roughness (Sa) topography of the cervical microthreads of implants. Three groups of 25 implants (3.75 mm × 10 mm) were placed in osteotomies prepared in an artificial bone disc with final diameters of 3.65 mm according to the manufacturer’s instructions and in osteotomies prepared in accordance with an underdrilling protocol with final drill diameters of 3.2 and 2.8 mm (groups D3.65, D3.2, D2.8, respectively). Implants were inserted at a constant rate of 30 rpm. The surface temperature of the implants was measured with a thermal camera and temperature amplitude (Temp-Amp) was calculated by subtracting the room temperature from the measured implant surface temperature. Upon implant retrieval, coronal surface topography was assessed using a Nanofocus µsurf explorer and compared to a set of 25 new implants (control group). The differences between groups were compared using one-way ANOVA (p < 0.05). Significantly higher insertion torque, surface temperature values and significantly smaller average Sa values were measured in the implants inserted in undersized preparations. The highest temperature, insertion torque and Temp-Amp values and the largest decrease in Sa were measured in the D2.8 group. The lowest values were measured in the D3.65 group.


2013 ◽  
Vol 07 (S 01) ◽  
pp. S083-S088 ◽  
Author(s):  
Murat Tozlu ◽  
Didem Nalbantgil ◽  
Fulya Ozdemir

ABSTRACT Objective: An appliance was designed to increase the cortical bone surface contact area of miniscrew implants (MSIs). The purpose of this in vitro study was to evaluate the effects of this appliance on the anchorage force resistance and the stability of orthodontic MSIs. Materials and Methods: A total of 48 MSIs were placed into bone specimens prepared from the ilium of bovines. Half were placed with the newly designed apparatus and half were placed conventionally. All the specimens were subjected to tangential force loading perpendicular to the MSI with lateral displacement of 0.6 mm, using an Instron Universal Testing machine. The maximum removal torque of each tested specimen was also recorded. Both study and control groups were divided into two subgroups based on whether they had thin and thick cortical bone. Results: The test group had statistically higher force anchorage resistance and maximum insertion torque values than the control group (p < 0.001). The results were found to be more significant in cases in which the cortical bone was thin (p < 0.001). Conclusions: Within the limits of this in vitro study, the present findings suggest that the newly designed apparatus might have a favorable effect on MSI stability in patients presenting with thin cortical bone. Clinical studies are necessary to confirm the results that were observed in vitro.



2019 ◽  
Vol 30 (S19) ◽  
pp. 76-76
Author(s):  
Ofer Moses ◽  
Yariv Shimon ◽  
Talia Gurevich ◽  
Rachel Sarig ◽  
Zeev Ormianer


2016 ◽  
Vol 28 (7) ◽  
pp. e16-e20 ◽  
Author(s):  
Carlo Cafiero ◽  
Marco Aglietta ◽  
Vincenzo Iorio-Siciliano ◽  
Giovanni E. Salvi ◽  
Andrea Blasi ◽  
...  


2020 ◽  
Vol 11 (2) ◽  
pp. 196-201
Author(s):  
Fatih Oznurhan ◽  
Ceren Ozturk

Aim: To compare the surface roughness, microtensile bond strength (µTBS), and flexural strength of polypropylene (PP) fibers reinforced glass ionomer cements (GICs). Materials and Methods: A comparative in vitro study was designed to test the PP fiber reinforced GIC, which was formed when 0.5–1 mm length PP fibers were added into the powder of conventional GIC. Four groups were prepared (Group 1: control, Group 2: 1 wt% PP fiber, Group 3: 3 wt% PP fiber, and Group 4: 5 wt% PP fiber) to evaluate flexural strength, surface roughness values, and µTBS. A total of 10 samples with 25 × 2.5 × 5 mm dimensions were prepared for each group to test flexural strength. Disk-shaped specimens ( n = 10) of 2 mm thickness and 10 mm diameter were used to test surface roughness. A total of 24 human primary molar teeth were used to evaluate µTBS, and 12 sticks were obtained for each group. The fractured surface analyses of samples from µTBS was performed using scanning electron microscope. The data obtained from the experiments were recorded and analyzed with one-way analyses of variance technique, and the normality was tested using the Shapiro–Wilk technique. A significance level of .05 was used. Results: In flexural strength tests, Group 3 (3 wt% PP fiber) showed significantly increased values ( p < .05) when compared with other groups. Group 4 (5 wt% PP) showed significantly highest values in surface roughness tests ( p < .05). No significant differences were seen between the groups ( p > .05) according to µTBS results. More PP fibers were seen in fractured surfaces, when PP ratio increases. Conclusion: It was observed that increased PP fiber percentage showed increased surface roughness, and 3 wt% PP fiber gave optimal values for fracture toughness. Incorporation of PP fiber to GIC does not affect the bonding to primary tooth dentine.





2014 ◽  
Vol 60 (5) ◽  
pp. 200-203
Author(s):  
Andreea Borş ◽  
Cristina Molnar-Varlam ◽  
Melinda Székely

Abstract Objective: The aim of this in vitro study was to evaluate the influence of erosive conditions on the wear resistance of aesthetic direct restorative materials. Methods: Six dental filling materials were tested: two composites (Filtek Z550 and X-tra fil), two compomers (Dyract Extra and Twinky Star) and two glass ionomers (Ketac Molar and Fuji II LC). Twenty disks (10mm×2mm) of each material were prepared (n=120) and kept in artificial saliva at 37˚C for 24 hours. Specimens were cycled in acidic soft drink (Coca-Cola) 5×/day, for 5’, over 30 days. Initial surface roughness ISR (Ra-μm) and final surface roughness FSR were measured using a profilometer. The wear rate was calculated as difference of final minus the initial roughness (ΔSR=FSR-ISR). For statistical analysis t-test and one-way ANOVA test were used by GraphPad Prism version 5.03 statistical software. The level of significance was set at p<0.05. Results: The erosive wear rates (mean±SD, μm) after exposure to acidic beverage were: 0.30±0.03 (Ketac Molar), 0.28±0.04 (Fuji II LC), 0.27±0.00 (Filtek Z550), 0.23±0.01 (X-tra fil), 0.20±0.00 (Twinky Star) and 0.14±0.01 Dyract Extra, respectively. There were significant differences between the tested materials (p<0.05). Conclusions: Dental filling materials had different behaviour under the same erosive condition, however all investigated aesthetic restorative materials showed surface degradation. These findings suggest that erosive wear resistance of tooth coloured restoratives could influence their longevity in intraoral acidic conditions. Acknowledgements: The study was supported by the Internal Research Grant no. 5/30.01.2013 of the University of Medicine and Pharmacy of Tirgu Mureş.



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