scholarly journals Deformation of the Internal Connection of Narrow Implants after Insertion in Dense Bone: An in Vitro Study

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.

2021 ◽  
Vol 9 (8) ◽  
pp. 97
Author(s):  
Andreas Greuling ◽  
Johanna Maria Emke ◽  
Michael Eisenburger

Objectives: The purpose of this in vitro study was to compare the abrasion behaviour of different charcoal toothpastes when brushing with electric toothbrushes on human enamel. Materials and Methods: A self-designed brushing machine was built using six commercially available electric toothbrushes in abrasion chambers. Each chamber was constantly supplied with a toothpaste–water mix. Pieces of human enamel, which were embedded in PMMA, were brushed for 4 h. Before and after brushing, profilometer measurements were performed in order to determine the substance loss due to brushing. Results: The following calculated mean removal values (mean ± SD) were found: (4.6 ± 0.6) µm (Group C: Splat Blackwood), (3.2 ± 0.9) µm (Group D: Curaprox Black is White), (2.3 ± 0.7) µm (Group B: Sensodyne Pro Schmelz), (1.7 ± 0.6) µm (Group A: Water), (1.4 ± 0.6) µm (Group E: Prokudent Black Brilliant). A post hoc Tukey HSD test (p = 0.05) showed that the results for Group A/B/E, Group B/D and Group C each lie within subsets that differ statistically significantly from the other subsets. Conclusions: Within the limitations of this in vitro study, it can be stated that some charcoal toothpastes lead to significantly higher abrasion on human enamel, when brushing with electric brushes. Clinical Relevance: As low-abrasion toothpaste is generally advisable, and some charcoal toothpastes should be viewed critically with regard to their abrasive properties.


Author(s):  
Teresa Al Haddad ◽  
Elie Khoury ◽  
Nada Farhat Mchayleh

Abstract Objectives The aim of the present in vitro study is to compare the remineralization brushing effect of three toothpastes and Aloe vera (AV) gel. Materials and Methods Forty sound extracted teeth were placed in a demineralizing solution for 4 days and randomly assigned to four groups: group A: 1,450-ppm fluoride toothpaste; group B: AV nonfluoridated toothpaste; group C: AV 1,000-ppm fluoridated toothpaste; and group D: AV gel. A 3-minute pH cycling was performed twice a day for each group for 12 days. Specimens were analyzed before and after by scanning electron microscope—energy dispersive X-ray. Statistical analysis The outcomes were analyzed by Kolmogorov–Smirnov’s tests, repeated-measures analyses of variance followed by univariate analyses, and Bonferroni’s multiple comparisons tests to compare the calcium-to-phosphorus (Ca:P) ratio within time among toothpaste groups. Results Following remineralization, the Ca:P ratio increased in all groups. The difference of the Ca:P ratio was not significant between groups C, D, and A. The mean ratio was significantly lower in group B (p-value = 0.026). Conclusions The AV gel demonstrated a remineralization capacity equal to that of the 1,450-ppm fluoride toothpaste. In contrast, fluoride-free AV toothpaste showed a lower remineralization efficiency. Further studies are required to understand its mechanism.


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.


2010 ◽  
Vol 22 (1) ◽  
pp. 325
Author(s):  
M. E. Dell'Aquila ◽  
B. Ambruosi ◽  
R. Guastamacchia ◽  
F. Binetti ◽  
E. Ciani ◽  
...  

Juvenile in vitro embryo transfer (JIVET) reduces the generation interval and increases the rate of genetic gain. The developmental competence of in vitro-produced embryos is strictly related to oocyte quality. Oxidative stress in the oocyte is an emerging problem in reproductive in vitro technologies, due to the gas atmosphere used to incubate oocytes and the lack of physiological defense mechanisms available in the female reproductive tract. The major source of reactive oxygen species (ROS) is represented by mitochondria where ROS are produced during oxidative phosphorylation. The aim of the present study was to analyze mitochondria and ROS in ovine prepubertal oocytes before and after IVM in order to clarify their suitability in JIVET programs. Cumulus-oocyte complexes from the ovaries of 38 slaughtered prepubertal (less than 8 months of age) lambs of the Comisana breed were analyzed at retrieval (group A) or after IVM (group B; Ambruosi et al. 2009 Theriogenology 71, 1093-1104). After cumulus cell removal, all oocytes underwent nuclear chromatin, mitochondria and ROS evaluation by confocal analysis of fluorescence distribution and intensity. Hoechst 33258 and Mitotracker Orange CMTM Ros (Molecular Probes Inc., Eugene, OR) were used to label nuclear chromatin and mitochondria (Ambruosi et al. 2009) and 2′,7′-dichloro-dihydro-fluorescein diacetate was used for ROS labelling (Hashimoto et al. 2000 Mol. Reprod. Dev. 57, 353-360). Out of 65 oocytes from group A, 38 oocytes with regular size (>130 μm in diameter), morphology and nuclear chromatin at the GV stage were selected for analysis. One-hundred-thirty-eight oocytes underwent IVM (group B). Nuclear maturation rate (metaphase II with 1st polar body extruded) was 54%, 75/138. All MII oocytes were used for analysis. Significantly higher rate of oocytes from group B showed heterogeneous (large aggregates, clusters, pericortical, perinuclear) mitochondrial (mt) distribution pattern than oocytes from group A (55%, 41/75 v. 29%, 11/38, respectively; P < 0.05) which showed uniform distribution of small mt aggregates. Fluorescent intensity of mt labeling did not differ between groups (43.05 ± 16.15 v. 45.89 ± 10.36, for group A and B respectively; NS). In most of the oocytes from both groups, intracellular ROS were distributed in small or large aggregates (35/38, 92% and 62/75, 83%). No statistical difference was observed for intracellular ROS levels between oocytes from group A (66.36 ± 13.2) and group B (72.84 ± 20.63; NS). The culture conditions used in this study provided normal mt distribution and intracellular ROS levels. Qualitative and quantitative evaluation of mitochondria and intracellular ROS could be useful to improve in vitro culture methods in ovine prepubertal oocytes.


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.


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