scholarly journals In Vitro Effect of Drilling Speed on the Primary Stability of Narrow Diameter Implants with Varying Thread Designs Placed in Different Qualities of Simulated Bone

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1350
Author(s):  
Georgios E. Romanos ◽  
Daniel J. Bastardi ◽  
Rachel Moore ◽  
Apoorv Kakar ◽  
Yaro Herin ◽  
...  

It is hypothesized that there is no statistically significant impact of drilling speed (DS) on the primary stability (PS) of narrow-diameter implants (NDIs) with varying thread designs placed in dense and soft simulated bone. The aim of this in vitro study was to evaluate the impact of DS on the PS of NDIs with varying thread designs placed in dense and soft simulated bone. Two hundred and forty osteotomies for placement of various implant macro-designs were divided into three groups (80 implants per group): Group A (NobelActive, 3.0/11.5 mm); Group B (Astra OsseoSpeed-EV, 3.0/11 mm); and Group C (Eztetic-Zimmer, 3.1/11.5 mm) implants. These implants were placed in artificial dense and soft simulated bone using DSs of 800 and 2000 revolutions per minute (RPM). Resonance frequency analysis (RFA) and implant stability quotient (ISQ) were assessed. Group comparisons were performed using the one-way analysis of variance with Tukey’s post hoc tests. Level of significance was set at P < 0.05. In groups A and B, there was no difference in the ISQ for NDIs inserted in dense bone at 800 and 2000 RPM. In Group C, ISQ was significantly higher for NDIs placed in dense bone at 800 PRM compared to 2000 RPM (P < 0.05). In Group A, ISQ values were significantly higher for NDIs inserted in soft bone at 2000 RPM as compared to those inserted at 800 RPM (P < 0.05). For NDIs, a lower drilling speed in dense artificial simulated bone and a higher drilling speed in soft artificial simulated bone is associated with high primary stability.

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Xiao-yu Liu ◽  
Hai-feng Shi ◽  
Jie Zheng ◽  
Ku-lin Li ◽  
Xiao-xi Zhao ◽  
...  

Objective. The objective of this study was to investigate the impact of left atrial (LA) size for the ablation of atrial fibrillation (AF) using remote magnetic navigation (RMN). Methods. A total of 165 patients with AF who underwent catheter ablation using RMN were included. The patients were divided into two groups based on LA diameter. Eighty-three patients had small LA (diameter <40 mm; Group A), and 82 patients had a large LA (diameter ≥40 mm; Group B). Results. During mapping and ablation, X-ray time (37.0 (99.0) s vs. 12 (30.1) s, P<0.001) and X-ray dose (1.4 (2.7) gy·cm2 vs. 0.7 (2.1) gy·cm2, P=0.013) were significantly higher in Group A. No serious complications occurred in any of the patients. There was no statistical difference in the rate of first anatomical attempt of pulmonary vein isolation between the two groups (71.1% vs. 57.3%, P=0.065). However, compared with Group B, the rate of sinus rhythm was higher (77.1% vs. 58.5%, P<0.001) during the follow-up period. More patients in Group A required a sheath adjustment (47/83 vs. 21/82, P<0.001), presumably due to less magnets positioned outside of the sheath. In vitro experiments with the RMN catheter demonstrated that only one magnet exposed created the sheath affects which influenced the flexibility of the catheter. Conclusions. AF ablation using RMN is safe and effective in both small and large LA patients. Patients with small LA may pose a greater difficulty when using RMN which may be attributed to the fewer magnets beyond the sheath. As a result, the exposure of radiation was increased. This study found that having at least two magnets of the catheter positioned outside of the sheath can ensure an appropriate flexibility of the catheter.


2019 ◽  
Vol 17 (1) ◽  
pp. 228080001881601
Author(s):  
Filiberto Mastrangelo ◽  
Isabella Perraro ◽  
Sabrina Mattia ◽  
Giuseppe Troiano ◽  
Khrystyna Zhurakivska ◽  
...  

Introduction: The technique of sealing is a widely accepted procedure for prevention of caries. The aim of our in vitro study was to compare the effect of two different curing units (traditional LED source and innovative laser diode lamp) on the integrity of fissure sealant material and its interface with tooth enamel. Materials and methods: Sixty healthy third molars were randomly assigned to two groups. In group A were teeth intended for polymerization by LED B lamp, and group B comprised teeth to be polymerized by an innovative laser diode. Both groups were treated with the traditional sealing technique, subjected to a metallization process, and analyzed by scanning electron microscope. Results: Micro-gaps between the sealant and the enamel were found in specimens in both A (43%) and B (40%) groups ( p=0.793), and sealant shrinkage was seen. Significant differences between the groups emerged in the percentage of perimetric micro-erosion sites (80% vs. 100%, p=0.010) and the presence of holes and micro-bubbles on the sealant surface (21% vs. 63%, p=0.001). Conclusions: Although macroscopic clinical polymerization occurred with both instruments, the microscopic evaluation showed significant differences between the studied groups in terms of perimetric micro-erosion sites and micro-bubbles, which were higher in laser-cured samples.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1833 ◽  
Author(s):  
Rafael Delgado-Ruiz ◽  
Ana Nicolas Silvente ◽  
Georgios Romanos

Implant connections must resist surgical and prosthetic procedures without deformation. This study evaluated the deformation of different internal connections (IC) of narrow dental implants (NDI) after their insertion in artificial dense bone. Thirty NDI, with different IC geometries, Group A (internal hexagon), Group B (tri-channeled), and Group C (four-channeled), with the same length and similar narrow diameters, were inserted in type II density bone blocks. Drilling protocols for dense bone from each implant manufacturer were followed. The Insertion torque (IT), connection length, vertex angles, and wall deformations were analyzed before and after the insertion of the implants. ANOVA (Analysis of Variance) and Tukey post-test were used for statistical comparisons. IT values were higher for Group A, surface damage, and titanium particles were observed in the IC in all the groups. Angle deformations between 5 and 70 degrees were present in all the groups, and the walls of Group B connection were the most affected by deformations (p < 0.05). Within the limitations of this experiment, it can be concluded that narrow diameter implants will suffer deformation of the implant connection and will also experience surface damage and titanium particle release when inserted in type II bone density.


2017 ◽  
Vol 05 (01) ◽  
pp. 039-046 ◽  
Author(s):  
Monica Sharma ◽  
Ajay Bansal ◽  
Sunny Panthi ◽  
Shefali Malik ◽  
Atulya Sharma

Abstract Purpose: The purpose of this in vitro study was to evaluate marginal fit of cobalt- chromium (Co-Cr) copings fabricated by direct metal laser sintering system (DMLS) and conventional lost-wax technique (LW). Materials and method: Forty tooth preparations were carried out over extracted mandibular molars. They were divided into two groups A and B of 20 each. For group A Co-Cr copings were fabricated by direct metal laser sintering (DMLS) and for group B by lost wax technique (LW). Glass –ionomer cement (GIC) was used to tack the copings over their preparations. Marginal fit was then evaluated directly under the stereomicroscope. Results: The mean marginal gap of group A was 27.9 ± 2.4 μm and group B was 40.4 ±6 μm. Statistical analysis using t - test showed highly significant difference (P>.05) between the marginal mean of the DMLS (group A) compared to LW (group B). Conclusion: The DMLS copings demonstrated superior marginal fit compared to that of conventional Co-Cr casted copings.


2018 ◽  
Vol 9 (4) ◽  
pp. 254-260 ◽  
Author(s):  
Gholam Ali Gholami ◽  
Milad Karamlou ◽  
Reza Fekrazad ◽  
Farzin Ghanavati ◽  
Neda Hakimiha ◽  
...  

Introduction: Several techniques such as using citric acid, plastic curettes, ultrasonic devices, and lasers have been suggested for debridement of contaminated implant surfaces. This comparative investigation aimed to assess and compare the effects of Er, Cr: YSGG laser and super-saturated citric acid on the debridement of contaminated dental implant surfaces. Methods: In this in-vitro study, 12 contaminated failed implants were collected and randomly divided into 2 groups (6 in group A, and 6 in group B). Also, one implant was considered as the control. The implants were horizontally sectioned into coronal and apical portions and subsequently irradiated by Er, Cr: YSGG laser in coronal and citric acid in apical in group A and the opposite in group B. In order to evaluate the effect of water spray on the laser section, half the laser portion of the implants was irradiated using water, while the other half was irradiated without water with an irradiation time of 1 minute. Results: Results revealed that calculus and plaque removal was greater in the laser part of both groups (with and without water) compared to citric acid parts and the correlation between calculus removal and surface roughness were statistically significant. Furthermore, the surface roughness in the citric acid parts was significantly higher than in laser parts. Water spray during irradiation had a very small influence on understudy factors. Conclusion: Based on the results of this study, the Er, Cr: YSGG laser was more effective in calculus removal and caused less surface roughness compared with citric acid application.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Basawaraj Biradar ◽  
Sudharani Biradar ◽  
Arvind MS

Objectives. The objective of this in vitro study was to investigate whether weight gain or loss in the three different composites occurs due to water absorption when they are stored in water.Methods. The composite restorative materials selected for this study included a microfine hybrid (Synergy) and two nanofilled composite restorative materials (Ceram X and Filtek Supreme Ultra). Twenty specimens of each material were fabricated of each composite material. Group A: Filtek Supreme Ultra, Group B: Synergy, Group C: Ceram X. Then all the specimens were stored in 10 ml Distilled water containing test tubes and placed in incubator at 37°C for six weeks. The weight changes of these specimens were measured daily for the first week and later once a week for next five weeks by using an electrical analytical balance.Results.The data was analyzed by one-way analysis of variance and Student'sttest. All groups showed maximum amount of water absorption in the first week than gradual decrease in the water absorption from the second to the sixth week, as compared to the first week and there is no statistically significant difference between the groups tested.Conclusion. All the composite restorative material absorbs some amount of water. The water absorption of the composite may decrease the physical and mechanical properties of the composites; hence it is necessary to consider the type of the material before starting the treatment.


2017 ◽  
Vol 8 (3) ◽  
pp. 83-89
Author(s):  
Johnny Holanda De Gauw ◽  
Lara Maria Melo Costa ◽  
Rodrigo Neves Silva ◽  
Natanael Barbosa Santos ◽  
Maria Dânia Holanda Tenorio

Objective: This study aimed to evaluate the effect of ferrous sulfate (FS) on demineralized and non-demineralized human deciduous teeth. Additionally, it was evaluated the penetration extent of FS and its remineralizing effect on the enamel of deciduous teeth using Polarized Light Microscopy (PLM). Method: The sample comprised 44 human deciduous teeth. The 44 crowns were divided randomly into four groups: group A (FS after demineralization), group B (FS without demineralization), group C (only demineralization), and group D (control group). FS at 0.45 mol/L-1 was used daily (15 days) and demineralization was done by pH cycling (7 days). Then, three longitudinal slices of the crowns were photographed using PLM. The degree of penetration of the lesion or stain was measured in micrometers, as well as the distance between the external enamel surface and the core of lesion. Results: Group A showed a dark stain on the outer surface of enamel larger than the group B. It is suggested, a remineralizing effect when comparing groups, A and C. The mean depth and standard deviation for groups A, B, and C were 4.27µm (±1.49), 3.72 µm (±1.68) and 5.00 µm (±1.84), respectively. No dark stains were observed in group D. Conclusion: FS stained the demineralized and non-demineralized human deciduous teeth. However, dark stains in the non-demineralized teeth were smaller or absent, than in the demineralized teeth. Therefore, FS may have a protective effect against demineralization.


2011 ◽  
Vol 35 (3) ◽  
pp. 277-282 ◽  
Author(s):  
TR Chaitra ◽  
VV Subba Reddy ◽  
GM Devarasa ◽  
TL Ravishankar

Objective: Preventive procedures using pit and fissure sealants are one of the important aspects of pediatric dental practice. The objectives of this in vitro study were to comparatively evaluate microleakage and resin tag penetration of a flowable resin used as a sealant on molars after preparation with Conventional, Enameloplasty and Fissurotomy techniques. Method: A total of 48 teeth were divided into 3 groups (n-16). Group A(CST),Group B (EST),and Group C (FT). Following the fissure preparation sealant was applied as per manufacturer's instructions. 8 samples in each group were used for Microleakage and Resin tag analysis. Microleakage analysis was done under Stereomicroscope after Methylene blue dye immersion by using scoring system. The resin tag analysis was done by measuring the length of resin tags on scanning electron microscope (SEM) images consisting of 10μm scale taken under optical zoom of 2000 X. Results: Significantly lesser microleakage score (P&lt;0.01) and longer resin tag penetration (P&lt;0.001) observed in EST(mean score 0.5±0.53) & (12.19±1.93μm) when compared to CST(mean score 1.75±0.89) & (5.96±1.84μm)and FT (mean score 1.5±0.53) & (6.76±1.82μm) which showed more microleakage and short resin tags. No statistical significance between CST and FT was found. Conclusion: EST has proven to be an excellent method for preparation of pits and fissures when Flowable composite is used as a sealant because of its lesser microleakage and longer resin tag penetration.


2002 ◽  
Vol 26 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Ana Beatriz Alonso Chevitarese ◽  
Orlando Chevitarese ◽  
Ivete Pomarico Ribeiro de Souza ◽  
Roberto Braga de Carvalho Vianna

The aim of this study was to evaluate the influence of prophylaxis on the sealants microleakage in 30 premolars divided into: Group A, Group B and Group C. The teeth were analyzed using the optical microscope (OM) and at scanning electron microscope (SEM). There was a statitical significant difference among the groups regarding the presence of microleakage, but not with the presence of tags.


2020 ◽  
Vol 7 (10) ◽  
pp. 2041
Author(s):  
Neha Thilak ◽  
Sundeep K. Hedge ◽  
Sham S. Bhat

Background: The aim of the study is to compare the erosive potential of three different commonly used pediatric syrups on deciduous teeth enamel. The objectives of the study were to assess the endogeneous pH and titratable acidity of mefenamic acid syrup (meftal P), cetrizine syrup (alerid) and multivitamin syrup (zincovit) and to evaluate the microhardness of the enamel after successive immersion cycles in each of the syrups.Methods: 40 non carious deciduous teeth were included for the study The samples were then randomly allocated into 4 groups (10 in each group): Group A- mefenemic acid syrup (meftal P), Group B- cetrizine syrup (alerid), group C- multivitamin syrup (zincovit) and group D- control (distilled water). The samples were then subjected to the immersion cycles in the syrups. Assessment of enamel surface microhardness was done using Vickers hardness tester at 7th day and 14th day. The pH and titrable acidity of the syrups were also assessed. One way analysis of variance (ANOVA) and post hoc tests were used for the statistical analysis.Results: Out of the test groups, group C showed the lowest pH of around 4.2 and exhibited the largest titrable acidity (22.8 ml) compared with 21 ml in group A and 15.5 ml in group B. At the end of 14th day, group A had microhardness of about 293.43.84±6.34, group B had 299.930±6.85, group C had 313.380±6.23 and group D had 334.190±5.51.Conclusions: All the pediatric liquid medications assessed in the study, meftal P, alerid and zincovit showed acidic pH, high titrable acidities and all the syrups showed loss of microhardness after exposure to the syrups for 14 days. Loss of microhardness was highest for meftal P followed by alerid and least for zincovit.


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