scholarly journals Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Rene Franzen ◽  
Nasrin Kianimanesh ◽  
Rudolf Marx ◽  
Asma Ahmed ◽  
Norbert Gutknecht
Keyword(s):  
Surface Treatment ◽  
Laser Irradiation ◽  
Fracture Strength ◽  
High Speed ◽  
Structural Integrity ◽  
Control Group ◽  
Mean Values ◽  
Four Point Bending ◽  
Significant Difference ◽  
Hand Piece

Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm2), and Er,Cr:YSGG (2.78 μm, 7.8 J/cm2) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as82.0±27.3 MPa for the control group (n=10),104.5±26.3 MPa for high speed drill treatment (n=10),96.1±28.1 MPa for Er,Cr:YSGG laser irradiation (n=20), and89.1±36.3 MPa for Er:YAG laser irradiation (n=18). Independent Student’st-tests showed no significant difference between each two groups (p>0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment.

Maximum Temperature Through a Yttrium Stabilized Zirconia Ceramic After Er,Cr:YSGG Laser Irradiation

2020 ◽  
Vol 02 ◽  
Author(s):  
Laurel Stringer ◽  
Sarah Malley ◽  
Darrell M. Hutto ◽  
Jason A. Griggs ◽  
Susana M. Salazar Marocho
Keyword(s):  
High Speed ◽  
Potential Method ◽  
Maximum Temperature ◽  
Zirconia Ceramic ◽  
Tooth Pulp ◽  
Control Group ◽  
Stabilized Zirconia ◽  
Significant Difference ◽  
Power Setting ◽  
Group A

Background: The most common approach to remove yttria stabilized zirconia (YSZ) fixed-dental prostheses (FDPs) is by means of diamond burs attached to a high-speed handpiece. This process is time-consuming and destructive. The use of lasers over mechanical instrumentation for removal of FDPs can lead to efficient and predictable restoration retrievability. However, the heat produced might damage the tooth pulp (>42˚C). Objective: The purpose of this study was to determine the maximum temperature (T) reached during the use of different settings of the erbium, chromium:yttrium-scandium-gallium-garnet Er,Cr:YSGG laser through a YSZ ceramic. Methods: YSZ slices (1 mm thick) were assigned into 7 groups. For the control group, a diamond bur was used to cut a 1 mm groove into the YSZ slices. For the 6 experimental groups, the laser was operated at a constant combination of 33% water and 66% air during 30 s with two different power settings (W) at three frequencies (PPS), as follows (W/PPS): 2.5/20, 2.5/30, 2.5/45, 4.5/20, 4.5/30, 4.5/45. The T through the YSZ slice was recorded in degrees Celsius by using a digital thermometer with a K thermocouple. Results: The median T of the control group was 26.5˚C. The use of 4.5 W resulted in the median T (˚C) of 44.2 at 20 PPS, 53.3 at 30 PPS, and 58.9 at 45 PPS, while 2.5 W showed 34.6, 31.6, and 25.0 at 20, 30, and 45 PPS, respectively. KruskalWallis one-way ANOVA showed that within each power setting, the T was similar. The high power and lowest frequency (4.5/20) showed no significant difference from the 2.5 W settings and the control group. Conclusion: The lower power setting (2.5 W) is a potential method for the use of the Er,Cr:YSGG laser to debond YSZ structures. The higher power (4.5 W) with high frequencies (30 and 45 PPS) is unsuitable.

scholarly journals Assessment of the Tissue Response to Modification of the Surface of Dental Implants with Carboxyethylphosphonic Acid and Basic Fibroblastic Growth Factor Immobilization (Fgf-2): An Experimental Study on Minipigs

Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 358
Author(s):  
Javier Aragoneses ◽  
Ana Suárez ◽  
Nansi López-Valverde ◽  
Francisco Martínez-Martínez ◽  
Juan Manuel Aragoneses
Keyword(s):  
Surface Treatment ◽  
Test Group ◽  
Mean Value ◽  
Control Group ◽  
P Value ◽  
Implant Surface ◽  
Bone Contact ◽  
Bone Implant ◽  
Significant Difference ◽  
The Mean

The aim of this study was to evaluate the effect of implant surface treatment with carboxyethylphosphonic acid and fibroblast growth factor 2 on the bone–implant interface during the osseointegration period in vivo using an animal model. The present research was carried out in six minipigs, in whose left tibia implants were inserted as follows: eight implants with a standard surface treatment, for the control group, and eight implants with a surface treatment of carboxyethylphosphonic acid and immobilization of FGF-2, for the test group. At 4 weeks after the insertion of the implants, the animals were sacrificed for the histomorphometric analysis of the samples. The means of the results for the implant–bone contact variable (BIC) were 46.39 ± 17.49% for the test group and 34.00 ± 9.92% for the control group; the difference was not statistically significant. For the corrected implant–bone contact variable (BICc), the mean value of the test group was 60.48 ± 18.11%, and that for the control group, 43.08 ± 10.77%; the difference was statistically significant (p-value = 0.035). The new bone formation (BV/TV) showed average results of 27.28 ± 3.88% for the test group and 26.63 ± 7.90% for the control group, meaning that the differences were not statistically significant (p-value = 0.839). Regarding the bone density at the interthread level (BAI/TA), the mean value of the test group was 32.27 ± 6.70%, and that of the control group was 32.91 ± 7.76%, with a p-value of 0.863, while for the peri-implant density (BAP/TA), the mean value of the test group was 44.96 ± 7.55%, and that for the control group was 44.80 ± 8.68%, without a significant difference between the groups. The current research only found a significant difference for the bone–implant contact at the cortical level; therefore, it could be considered that FGF-2 acts on the mineralization of bone tissue. The application of carboxyethylphosphonic acid on the surface of implants can be considered a promising alternative as a biomimetic coating for the immobilization of FGF-2. Despite no differences in the new bone formation around the implants or in the interthread or peri-implant bone density being detected, the biofunctionalization of the implant surface with FGF-2 accelerates the mineralization of the bone–implant interface at the cortical level, thereby reducing the osseointegration period.

scholarly journals Impact of cleaning regimes on dental water unit contamination

2011 ◽  
Vol 9 (4) ◽  
pp. 647-652 ◽  
Author(s):  
Soad A. Abdallah ◽  
Ahmed I. Khalil
Keyword(s):  
High Speed ◽  
Tap Water ◽  
Daily Basis ◽  
Dental Chair ◽  
Dental Clinics ◽  
Significant Difference ◽  
Before And After ◽  
Hand Piece ◽  
Viable Bacteria ◽  
Dental Unit Waterlines

Microorganisms that have been identified in dental unit waterlines (DUWLs) are of concern because they can cause infections, especially in immunocompromised patients. This study aimed to assess the incidence of microbial contamination in DUWLs before and after intervention to reduce contamination, and to investigate the presence of coliforms, Escherichia coli and Pseudomonas aeruginosa. Water samples were collected aseptically from the waterlines. The high-speed hand-piece and dental chair units were served by one distillation apparatus, which was fed by the potable tap water of four dental clinics. Different interventions were used: chlorination, flushing before clinics and between patients, draining at the end of the day, and freshly distilled water on a daily basis. There was a significant difference between the level of contamination in the high-speed hand-piece (1.5–2.7 log CFU/ml) and dental chair unit water (2.0–3.5 log CFU/ml). Coliforms (0.9%) E. coli (0.9%) and Pseudomonas (1.8%) were detected during 2008. This study indicates the need to monitor water quality regularly and prevent stagnation in DUWLs to reduce the number of viable bacteria to <100 CFU/ml. We recommend flushing the DUWL for 2 min before the first patient and for 10–20 s between patients, flushing the dental unit at the end of the day and draining it overnight to reduce the development of biofilms, and chlorination of the DUWLs.

scholarly journals The Effect of Smoking on the Lipid Profile of Inhabitant Smokers of Hasilpur, District Bahawalpur, Pakistan

2020 ◽  
Vol 10 (2) ◽  
pp. 82-86
Author(s):  
Mushtaq Hussain Lashari ◽  
Sumbel Sumera ◽  
Umer Farooq ◽  
Zia Ur Rehman ◽  
Nuzhat Sial ◽  
...  
Keyword(s):  
Lipid Profile ◽  
Serum Triglyceride ◽  
Mean Value ◽  
Heavy Smoker ◽  
Control Group ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Control Light ◽  
Heavy Smokers

Background: Health problem are culturally associated with smoking in developing countries. Many hazardous chemicals are taken up by direct or passive smoking causing lipid peroxidation resulting in oxidative stress. Objectives: To estimate the occurrence of smoking and its effects on the lipid profile in populations of Hasilpur, Pakistan. Methodology: The current study was conducted from April - August 2014. Out of 247 apparently healthy subjects of both genders (male=220; female=27), 134 were smokers and 113 were non-smokers. In order to analyze lipid profile, blood samples were collected in early morning hours from the selected members who were asked to fast all night. By using Chem-100 chemistry analyzer, cholesterol, triglyceride, HDL, LDL and VLDL were analyzed. Results: The overall prevalence of smokers was 54.25%. The results showed 60.9% prevalence in males and 0% in females. The mean value of serum triglyceride in control, light smokers and heavy smokers was 147.4±11.7mg/dl, 190.8±41.4 and 205.3±29.7mg/dl, respectively. The results of cholesterol in control, light smokers and heavy smokers were 147.38±7.99mg/dl, 136.8 ±12. 8mg/dl and 173.44±8.63mg/dl, respectively. There was a considerable distinction in the mean level of serum triglyceride and cholesterol between the control group, light smokers and heavy smoker groups (P<00.5). The mean value of HDL of control, light smokers and heavy smokers was 30.93±1.30mg/dl, 31.10±2.45 and 34.58±1.55mg/dl, respectively. The mean values of LDL and VLDL of control, light smokers and heavy smokers were 110.46±3.63mg/dl, 106.00±4.52mg/dl, 117.19±3.48mg/dl and 33.54±3.11mg/dl, 49±9.02mg/dl, 41.06±5.34mg/dl, respectively. There was significant difference in the mean level of HDL, LDL and VLDL between the control group, light smokers and heavy smoker groups (P<0.05). Conclusion: This study concluded that smoking is the reasons of variation in the lipid profile. Elevated period of smoking and the number of smoked cigarettes/day reason the alteration in serum lipid levels and is probably related with increased danger for coronary artery disease.

scholarly journals Evaluation of effect of local exogenous application of Myrrh oil on healing of wound incisions of facial skin (Histochemical, Histological and Histomorphometrical study in rabbits)

2019 ◽  
Vol 31 (4) ◽  
Author(s):  
Nawar Bahjet Kamil ◽  
Nada M. Al-Ghaban
Keyword(s):  
Healing Process ◽  
Inflammatory Cells ◽  
Control Group ◽  
Facial Skin ◽  
Histological Findings ◽  
Control Groups ◽  
Mean Values ◽  
Significant Difference ◽  
The Right ◽  
New Zealand Rabbits

Aim of the study: Is to evaluate the effect of myrrh oil local application on the healing process of skin wounds histologically , histomorphometrically and , histochemically. Materials and methods:Twenty male white New Zealand rabbits were used in this study. An incisional wounds with full thickness depth and of 2 cm length were done on both sides of the cheek skin of each rabbit. The left sided incisions (the control group) were irrigated with distilled water (10µL). The right sided incisions (the experimental groups) were treated with myrrh oil (10µL). Each group was subdivided into 4 subgroups according to the healing interval into 1,3,7 and 14 days(5 rabbits for each group). Results: Histological findings of our current study showed a highly significant difference between the experimental and the control groups in count of the inflammatory cells which showed that mean values increased with time for the control and the experimental groups. The histomorphometrical findings had shown that the thickness of the epithelium was nearly completed at about 7 days for the experimental groups and at about 14 days for the control. The blood vessels count was recorded to have a highly significant difference between the groups at days 1 and 3 only. The histochemical findings had shown that the collagen fibers remodeling had recorded a highly significant difference between the control and the experimental groups at days 7 and 14. Conclusion: The current study had revealed that myrrh oil accelerates wounds healing in rabbits. Key word:Wound healing , Myrrh oil, Masson’s Trichrome staining.

Difference of Hamstring Activity Between Bilateral and Unilateral Nordic Hamstring Exercises With a Sloped Platform

2021 ◽  
pp. 1-6
Author(s):  
Toshiaki Soga ◽  
Taspol Keerasomboon ◽  
Kei Akiyama ◽  
Norikazu Hirose
Keyword(s):  
High Speed ◽  
Biceps Femoris ◽  
Break Point ◽  
Hamstring Injury ◽  
Emg Activity ◽  
Maximum Voluntary Isometric Contraction ◽  
Mean Values ◽  
Significant Difference ◽  
Long Head ◽  
Control Study

Context: This study aimed to examine the differences in electromyographic (EMG) activity of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles, break-point angle (BPA), and the angle at peak BFlh EMG activity between bilateral and unilateral Nordic hamstring exercise (NHE) on a sloped platform. Design: This study was designed as a case-control study. Methods: Fourteen men participated in the study. The participants initially performed maximum voluntary isometric contraction (MVIC) on the prone leg curl to normalize the peak hamstring EMG amplitude as the %MVIC. Then, participants were randomized to perform the following 3 variations of NHE: bilateral (N40) or unilateral (N40U) NHE with a platform angle of 40°, and unilateral NHE with a platform angle of 50° (N50U). The EMG activities of the BFlh and ST and the knee flexion angle during the NHE variations were recorded to calculate the EMG activity of the BFlh and ST in terms of the %MVIC, the angle at peak BFlh EMG, and BPA. Results: The BFlh %MVIC was significantly higher in N40U (P < .05) and N50U (P < .05) than in N40. A significant difference in BFlh %MVIC and ST %MVIC was observed between N40U (P < .05) and N50U (P < .05). The mean values of BPA and the angle at peak BFlh EMG were <30° for all NHE variations. Conclusions: In the late swing phase of high-speed running, BFlh showed higher EMG activity; thus, unilateral NHE may be a specific hamstring exercise for hamstring injury prevention.

scholarly journals Evaluation of Effect by Different Surface Treatment Agents on Retention of Custom Made Cast Metal Post and Prefabricated Glass Fibre Post-A Comparative Study

2015 ◽  
Vol 03 (01) ◽  
pp. 007-011
Author(s):  
Sunny Panthi ◽  
Kusum Dutta ◽  
Gaurav Singla ◽  
Keyword(s):  
Surface Treatment ◽  
Ethyl Alcohol ◽  
Glass Fibre ◽  
Control Group ◽  
Sand Blasting ◽  
Cast Metal ◽  
Custom Made ◽  
Significant Difference ◽  
Glass Fibre Posts ◽  
Metal Post

AbstractPosts are widely used for restoring endodontically treated teeth with insufficient coronal tooth structure. Custom made cast metal post and core systems have a long history of successful use due to their superior physical properties. Prefabricated post systems have recently become more popular because they can provide satisfactory results, while saving time and reducing costs. Materials and Method: Post spaces were prepared in 60 extracted caries free teeth, and divided into two main groups of 30 teeth each for cast metal and glass fibre posts. These groups were further divided into 3 subgroups of 10 specimens each I) Control group without any surface treatment, II) Specimens treated with 57% ethanol, III) Specimens air abraded with 50um air borne alumina particles. Teeth were mounted in acrylic blocks prepared from a specially fabricated metal device. Posts were luted in the prepared post spaces with glass ionomer luting cement. Retentive strength was tested by Universal testing machine at 2mm/min crosshead speed. Results: Sand blasting of cast metal posts showed more significant improvement in retention compared to both control group and ethyl alcohol treated groups. In case of glass fibre posts, sand blasting significantly improved its retention compared to control group but no significant difference was observed between control and ethyl alcohol treated groups. There was also no significant difference between ethyl alcohol treated and sand blasted group. Conclusion: It was concluded that, sand blasting is an effective method to improve retention of both cast metal and glass fibre posts.

scholarly journals Effect of whitening dentifrices on the surface roughness of a nanohybrid composite resin

2016 ◽  
Vol 10 (02) ◽  
pp. 170-175 ◽  
Author(s):  
Gabriela Migliorin da Rosa ◽  
Luciana Mendonça da Silva ◽  
Márcio de Menezes ◽  
Hugo Felipe do Vale ◽  
Diego Ferreira Regalado ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Composite Resin ◽  
Wilcoxon Test ◽  
Control Group ◽  
Mean Values ◽  
Short Period ◽  
Significant Difference ◽  
Before And After ◽  
Nanohybrid Composite ◽  
One Way Anova

ABSTRACT Objectives: The present study verified the influence of whitening dentifrices on the surface roughness of a nanohybrid composite resin. Materials and Methods: Thirty-two specimens were prepared with Filtek™ Z350 XT (3M/ESPE) and randomly divided into four groups (n = 08) that were subjected to brushing simulation equivalent to the period of 1 month. The groups assessed were a control group with distilled water (G1), Colgate Total 12 Professional Clean (G2), Sensodyne Extra Whitener Extra Fresh (G3), and Colgate Luminous White (G4). A sequence of 90 cycles was performed for all the samples. The initial roughness of each group was analyzed by the Surface Roughness Tester (TR 200-TIME Group Inc., CA, USA). After the brushing period, the final roughness was measured, and the results were statistically analyzed using nonparametric Kruskal–Wallis and Dunn tests for intergroup roughness comparison in the time factor. For intragroup and “Δ Final − Initial” comparisons, the Wilcoxon test and (one-way) ANOVA were, respectively, performed (α = 0.05). Results: The roughness mean values before and after brushing showed no statistically significant difference when the different dentifrices were used. None of the dentifrices analyzed increased significantly the nanohybrid composite resin surface roughness in a 1 month of tooth brushing simulation. Conclusions: These results suggest that no hazardous effect on the roughness of nanohybrid composite resin can be expected when whitening dentifrices are used for a short period. Similar studies should be conducted to analyze other esthetic composite materials.

Influence of Different Restoration Techniques on Fracture Resistance of Root-filled Teeth: In Vitro Investigation

2018 ◽  
Vol 43 (2) ◽  
pp. 162-169 ◽  
Author(s):  
ME Hshad ◽  
EE Dalkılıç ◽  
GC Ozturk ◽  
I Dogruer ◽  
F Koray
Keyword(s):  
Fracture Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Compressive Force ◽  
Control Group ◽  
Hybrid Resin ◽  
Flowable Composite ◽  
In Vitro Investigation ◽  
Significant Difference

SUMMARY Objective: The purpose of this study was to determine the fracture strength of endodontically treated mandibular premolar teeth restored with composites and different reinforcement techniques. Methods and Materials: Forty-eight freshly extracted human mandibular premolar teeth were randomly divided into four groups: group IN, group CR, group FRC, and group PRF. Group IN consisted of teeth with intact crowns and served as the control group. In the other three groups, endodontic treatment was performed and standard mesio-occluso-distal (MOD) cavities were prepared. Then cavities were restored with hybrid resin composite only, flowable composite and hybrid resin composite, and Ribbond, flowable composite and hybrid resin composite in groups CR, FRC and PRF, respectively. All of the teeth were subjected to fracture by means of a universal testing machine, and compressive force was applied with a modified stainless-steel ball at a crosshead speed at 0.5 mm/min. Results: The highest values were observed in group IN, while the lowest values were determined in group CR. There was not any statistically significant difference between group CR and group FCR (p&gt;0.05). When groups CR, FCR, and PRF were compared, group PRF showed significantly better fracture strength than did groups CR and FCR (p&lt;0.05). It was determined that there was not any significant difference between group IN and group PRF (p&gt;0.05). Conclusions: Polyethylene ribbon fiber considerably increases the fracture strength of mandibular premolar teeth with MOD cavities restored with composite.

CD59 Deficient Granulocytes in High Risk Groups of Myelodysplastic Syndromes (MDS).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4717-4717
Author(s):  
Georgia Kaiafa ◽  
Vasiliki Tsavdaridou ◽  
Athanasios Papadopoulos ◽  
Christos Savopoulos ◽  
Apostolos Hatzitolios ◽  
...  
Keyword(s):  
Normal Subjects ◽  
Risk Groups ◽  
Mean Value ◽  
Control Group ◽  
Refractory Anaemia ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Group B ◽  
Pnh Clone

Abstract Background: Blood cells are deficient in membrane-bound glycosyl-phosphatidylinositol (GPI)-anchored proteins in paroxysmal nocturnal hemoglobinuria (PNH) because of an acquired disorder of the pluripotent stem cell. CD55 and CD59 antigens are the most common GPI-anchored proteins that are used for the diagnosis of the presence of PNH clone. The association of MDS with PNH is rather controversial. There are few published individual cases of PNH arrived from a previous MDS or MDS following PNH. Aim: Recent studies have demonstrated the existence of PNH clone in some MDS patients. These studies were performed mostly on erythrocytes and to the best of our knowledge they are only 4. Granulocytes appear to be more sensitive markers of PNH clone existence than erythrocytes and therefore we investigate the expression of PNH clone on granulocytes of patients with MDS. Material-Methods: A total number of 95 patients 25–80 yrs old with MDS {A:19 with refractory anaemia (RA), B:9 with refractory anaemia with ring sideroblasts (RARS), C:17 with refractory anaemia with excess blasts (RAEB), D: 12 with refractory anaemia with excess blasts in transformation (RAEB-t) and E: 19 with chronic myelomonocytic leukemia (CMLL)} and 19 healthy donors were included in our study. The presence of GPI-anchored proteins (CD55, CD59)-deficient granulocytes was examined by flow cytometry. For the detection of the PNH clone the commercial kit by Beckman Coulter (cellquant CD55/CD59) was used. Statistical analysis was made by ANOVA, while Robust test was performed because there was no homogeneity of variances by ANOVA. Results: Table 1 shows the percentages of CD55 and CD59 deficient granulocytes in the 5 groups of pts with MDS comparing with the control group. a) Although the mean values of CD55 deficient granulocytes in the groups RAEB, RAEB-t and CMLL were higher enough than those of the normal subjects, there were no statistically significant differences (p>0.10) in the comparison of the mean values of CD55 deficient granulocytes between each group of patients with the control group. b) On the contrary there was a very statistically significant difference in the comparison of the mean value of CD59 deficient granulocytes between the three last groups (C, D and E) of pts with the control group (p< 0.086, p< 0.001 and p<0.001 respectively). The percentages of CD55 and CD59 deficient granulocytes in the 5 groups of patients with MDS and in the control group CD55 CD55 CD59 CD59 Groups N Mean Value Std deviation Mean Value Std deviation A (RA) 19 2.89 2.79 2.91 2.85 B (RARS) 9 1.05 1.14 3.89 3.63 C (RAEB) 17 4.78 4.76 11.75 6.06 D (RAEB-t) 12 4.23 2.85 23.76 8.53 E (CMLL) 19 6.01 4.97 38.26 16.18 Control 19 3.67 2.89 3.67 2.89 Total 95 4.00 3.87 14.44 16.39 Conclusions: There are relatively large CD59 negative subpopulations (mean values 11.75–38.26%) of granulocytes in the last three groups (RAEB, RAEB-t, CMLL) of MDS patients. On the contrary the two low risk forms (RA, RARS) revealed no such populations. Non-expression of CD59 antigen on granulocytes is a more sensitive marker than that of CD55 antigen for the presence of a possible PNH clone in MDS patients.

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