scholarly journals Two-Body Wear of Occlusal Splint Materials Against Different Antagonists

2020 ◽  
Author(s):  
Kubra Yildiz Domanic ◽  
Yilmaz Umut Aslan ◽  
Yasemin Ozkan

Abstract Background: This study aimed to demonstrate that the material of the occlusal splint can be chosen according to the needs of individual patients and contribute to the knowledge of the wear rate of these materials.Methods: In this study four occlusal splints materials (Sr Ivocap Heat Cured, Valplast, SR Ivocap Elastomer and Eclipse were selected. As antagonist materials natural tooth enamel, inCoris TZI and IPS e.max Press ceramic materials were used. Each wear test was performed using a chewing simulator (n=16; test load: 50 N; number of cycles: 10,000, 20,000 and 30,000; continuous rinsing with water at 30°C for the wet condition).Results: There was a statistically significant effect of the difference in materials on the amount of wear (p < 0.001). Furthermore, there was a statistically significant difference among the mean values of all materials (p > 0.001). The highest mean value was obtained with Eclipse (0,318 mm3), and the lowest mean value was obtained with Valplast (0,134 mm3).Conclusion: Our study found differences in the in vitro wear rate among various occlusal splint materials.

2021 ◽  
Author(s):  
Elzbieta Klimuszko ◽  
Karolina Orywal ◽  
Barbara Mroczko ◽  
Teresa Sierpinska

Abstract Objective of the study was to assess the potential role of zinc and copper in the process of severe enamel wear. Methods: Three groups of dental enamel samples were analyzed: 50 from subjects with worn dentition, 20 from healthy volunteers in vivo and 15 healthy teeth cut longitudinally into seven layers in vitro. The amounts of Ca, Mg and Zn in the enamel bioptates were established using atomic absorption spectroscopy with an air/acetylene flame after acid biopsy technique had been applied. The concentration of Cu was established using an electrothermic method with argon gas on the AA spectrometer. Results : Mean values of calcium (Ca) and magnesium (Mg) did not differ between all the analyzed specimens. The mean value of zinc amount was very high in the samples obtained from worn teeth comparing to the healthy teeth. Statistically significant difference was confirmed between mean value of zinc amount in severe worn dentition and all the layers in vitro and in vivo. Strong positive relationships between magnesium and zinc contents have been shown at some depths. Significant difference was registered between the amount of copper in the severely worn dentitions compared to the superficial layer of the healthy teeth in vitro and in vivo. Conclusion: It was found that zinc amount was considerably different when comparing worn dentition and healthy teeth. It appears that zinc metabolism may play an important role in enamel formation and may influence the enamel resistance to wear after tooth eruption.


Author(s):  
Yuko Komuro ◽  
Yuji Ohta

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.


2021 ◽  
Vol 8 (3) ◽  
pp. 147-152
Author(s):  
Mosmi Lomi ◽  
Jonathan Daniel M

Determining gender is one of the most important procedure in forensics. Teeth are made of the most enduring mineralized tissues in the body, as such, they have an extraordinary resistance to putrefaction and the effects of external agents (physical, thermal, mechanical, chemical or biological) which makes them invaluable material for anthropological, genetic, odontologic and forensic examinations.i)To assess the degree of sexual dimorphism in maxillary canine using maxillary canine index, maxillary first molar and central incisor using mesiodistal (MD) and buccolingual/buccopalatal (BL) dimensions of the crown. ii) To determine the accuracy of maxillary canine index, first molar and central incisor dimensions (mesiodistal and buccolingual/buccopalatal) in determining sex.This study consisted of total 30 participants (males=15, females=15) of age group ranging from 20 to 35 yrs. Measurement of dimensions of selected teeth were performed on maxillary cast using digital Vernier caliper, resolution 0.01mm. Data thus obtained were analyzed statistically.The mean values of all the measurements in males were greater than females. There was statistical significant difference in mean value of bucco-lingual width of molar, mesiodistal width of canine (on left side, right side and average) and the inter-canine distance between males and females. The buccolingual width of molar showed the highest % of sexual dimorphism (5.33%) and the mesiodistal width of molar showed the least % of dimorphism (0.7%). Bucco-lingual width of molar posed the highest prediction accuracy for gender determination. We conclude that buccolingual width of maxillary first molar can be used to predict the gender when only teeth of maxillary arch are available for forensic examination.


2020 ◽  
Vol 10 (2) ◽  
pp. 82-86
Author(s):  
Mushtaq Hussain Lashari ◽  
Sumbel Sumera ◽  
Umer Farooq ◽  
Zia Ur Rehman ◽  
Nuzhat Sial ◽  
...  

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.


2021 ◽  
Vol 12 (47) ◽  
pp. 113-125
Author(s):  
Nathalia Silveira Finck ◽  
Juliana da Mota Paiva ◽  
Rafael Dario Werneck ◽  
Mariana Itaborai Moreira Freitas ◽  
Priscilla Santos Guimarães

This study aimed to present a literature review with data obtained in vitro and in vivo on metal free partial fixed protheses (PFP) in the posterior region, considering the following variables: ceramic material to be used; prosthesis extension; survival or longevity; main failures found, and comparison with the longevity of conventional metaloceramic PFP. A bibliographical survey was carried out using the databases: United States National Library of Medicine (PubMed) and Scientific Electronic Library Online (Sciello) for articles in English and Portuguese from 1998 to 2019. Articles should meet the inclusion criteria, which were articles that contained information that enabled the calculation of PFPs survival and success, articles with a minimum observation period of 3 years, articles that identified the reason of failures, and studies reported since 1998. Sixteen studies met the inclusion criteria and were evaluated comparatively. The survival rate of the PFP’s varies depending on the ceramic material used and the prostheses extension, no significant difference was observed in the relation between the ceramic material used and the connectors size; however, the greater the extension of the prosthesis, the higher must be the connector size. It was concluded that ceramic materials based on zirconia are the ones that have the longest survival. In addition, the main reasons that lead to decreased survival of PFP’s are secondary caries and connector fracture, however, more studies are needed to determine safely which materials and the extent of PFP’s are the most indicated.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Francesca Cattoni ◽  
Giulia Teté ◽  
Alessandro Mauro Calloni ◽  
Fabio Manazza ◽  
Giorgio Gastaldi ◽  
...  

Abstract Background Aesthetic porcelain veneers proved to be a long-term reliable prosthetic solution, ensuring minimal invasiveness. The use of veneers requires an adhesive cementation technique, so maintaining as much enamel as possible is to ensure lasting success. A diagnostic mock-up is a key tool that allows a preview of the outcome of the aesthetic restoration: it is obtainable both in an analog and digital way. With the recent developments in impression technology and the ever so fast growing use of CAD-CAM technologies it is useful to understand the pros and cons of either one of these techniques (analog and digital) in order to identify the easier and more convenient workflow in aesthetic dentistry. Methods After taking pictures and impressions of the dental arcs of a patient in need of aesthetic rehabilitation, 52 resin models were produced and a digital drawing of the smile was outlined. Both an analog and a digital wax-up were obtained from two of the 52 models: the latter was obtained using digital impressions and a dedicated software. The analog wax-up was then used to produce 25 matrices that have later been used to mould 25 resin mock-ups using a traditional moulding protocol (Control Group - CG). The digital wax-up was used to mill 25 PMMA mock-ups. Each mock-up, both milled and moulded (total 50), was then laid on the other 50 resin models as a digital impression of it was taken. The STL. files of the milled mock-ups were compared with the 3D CAD wax-up made using a specific software. The STL. files of the analog printed mock-ups were compared with the traditional wax-up design. A statistical analysis was carried out to evaluate the difference between the groups. Results The statistical analysis showed a significant difference (P > 0.01) between the mean value of the distance between the points of the overlapping STL. meshes in GC (0.0468 mm) and in TG (Test Group - TG) (0,0109 mm). Conclusions The study showed a difference in accuracy between traditional moulded and milled mock-ups compared to their original wax-up. The data analysis reports that the digital method allows for greater accuracy. Within the limitations of this study, a fully digital workflow is to considered more reliable when it come to creating an esthetic mockup: the digital procedure has been shown to be more accurate than the one made manually which is much more operator dependent and it brings an increase to the chance of error, and that could ultimately affect the final result.


2018 ◽  
Vol 6 (11) ◽  
pp. 2168-2172
Author(s):  
Shady M. El Naggar ◽  
Mohamed I. Seif El Nasr ◽  
Hassan M. Sakr ◽  
Sherihan M. Eissa ◽  
Asmaa N. Elboraey ◽  
...  

BACKGROUND: A gap still exists between in vitro and clinical studies concerning the biocompatibility of the material in the oral environment and their potential to cause immunological undesirable side effects. The uses of glass fibres to improve the mechanical properties of acrylic resin denture base polymers are well documented in vitro. AIM: The present study aimed to evaluate the effect of denture base reinforcement using light-cured E- glass fibres mesh on the level of salivary immunoglobulin A (S-IgA) in patients wearing complete dentures. MATERIAL AND METHODS: Fourteen completely edentulous patients, in need of complete dentures, participated in the study. The patients were divided into two groups (n = 7) according to the treatment protocol. In the first group, patients received conventional heat-cured acrylic resin dentures. In the second group, the mandibular dentures were reinforced using light cured resin impregnated E glass fibres mesh. In both groups, salivary samples were collected using passive drool technique. The level IgA was assessed by enzyme-linked immunosorbent assay (ELISA) technique at different time intervals. Statistical analysis was carried out using one-way ANOVA followed by Tukey`s post-hoc test and independent t-test. The significant level was set at P ≤ 0.05. RESULTS: Acrylic resin dentures and reinforced ones demonstrated an increase in the mean values of IgA level at the end of the follow-up intervals. And this increase was statistically significant (P ≤ 0.05). Although, the reinforced dentures revealed higher mean values, there was no statistically significant difference between the two groups (P > 0.05) CONCLUSIONS: Within the limitations of the present study, the following could be concluded: (1) the insertion of complete dentures induced changes in the level of IgA; and (2) denture base reinforcement using light cured resin impregnated E-glass fibres mesh had a similar effect to that of heat cured acrylic resin on the level of IgA.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Miao Zhou ◽  
Hui Zhou ◽  
Shu-yi Li ◽  
Yuan-ming Geng

Abstract Purpose Implant location is performed after placement to verify that the safety of neighboring anatomic structure and the realizability of prosthetic plan. Routine postoperative location is based on radiological scanning and raises the concerns on radiation exposure and inconveniency in practice. In the present study a location method based on surface scanning was introduced and the accuracy of this method was assessed in vitro. Material and methods A total of 40 implants were placed in 10 resin mandible models. The models were scanned with intraoral scanner (IS group) and extraoral scanner (ES group). The implant position was located with fusing the images of surface scanning and cone beam computerized tomography (CBCT) after implant placement. Deviations were measured between positions located by surface scanner and postoperative CBCT with the parameters: central deviation at apex (cda), central deviation at hex (cdh), horizontal deviation at apex (hda), horizontal deviation at hex (hdh), vertical deviation at apex (vda), vertical deviation at hex (vdh) and angular deviation (ad). Results In IS group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.27 mm, 0.23 mm, 0.12 mm, 0.10 mm, 0.21 mm, 0.19 mm and 0.72°, respectively. In ES group, the mean value of cda, cdh, hda, hdh, vda, vdh and ad was 0.28 mm, 0.25 mm 0.14 mm, 0.11 mm, 0.22 mm, 0.20 mm and 0.68°, respectively. The implant deviations in IS and ES groups were of no significant difference for any of the measurements. Conclusions Dental implant can be located via surface scanner with acceptable accuracy for postoperative verification. Further clinical investigation is needed to assess the feasibility of the method.


2017 ◽  
Vol 8 (2) ◽  
pp. 61-67
Author(s):  
Harsha K Bhadarka ◽  
Nayana H Patel ◽  
Kruti B Patel ◽  
Nilofar R Sodagar ◽  
Yuvraj D Jadeja ◽  
...  

ABSTRACT Aim In recent past, many studies had come up with the combination of time-lapse (TL) imaging of embryo morphokinetics as a noninvasive means for improving embryo selection and in vitro fertilization (IVF) success. The primary objective of the study was to find out if there is significant variation in morphokinetics of embryos with different implantation potential and also to study the effect of sperm freezing on time points of embryogenesis events in embryos with implantation potential. Materials and methods Kinetic data and cycle outcomes were analyzed retrospectively in 142 patients who had undergone IVF/intracytoplasmic sperm injection (ICSI) cycles using semen with normal parameters and embryo transfer (ET) on day 3. For the surety of specificity of morphokinetics, only cases with single ET cycles were included in the study. Timing of specific events, from the point of ICSI, was determined using TL imaging. Kinetic markers like time to syngamy (t-pnf), t2, time to two cells (c), 3c (t3), 4c (t4), 5c (t5), 8c (t8), tMor, CC2, CC3, t5–t2, t5–t4, s1, s2, and s3 were calculated. The cleavage synchronicity from the 2–8 cell stage (CS2–8), from 4 to 8 cell stage (CS4–8), and from 2 to 4 cell stage (CS2–4) were calculated as defined elsewhere. Deoxyribonucleic acid replication time ratio (DR) was also included in the comparison. Analysis of variance test was used for comparison of the mean timing of cell division and cell cycle intervals. Results Morphokinetics t-pnf, t2, t8, CC2, S2, S3, CS2–8, CS4–8, and CS2–4 differed significantly between embryos with and without implantation potential, when embryos were developed using fresh semen, while t3, t4, t5, CC2, S2, t5–t2, CS2–4, and DR differed significantly between the embryos with and without implantation potential when frozen semen was used. No significant difference was found in mean value of any of the above-stated parameters when comparison was done between implanted embryos fertilized by either fresh or cryopreserved sperm. Conclusion Many morphokinetics parameters of embryogene­sis vary significantly between embryos with different ability to implant; therefore, the criteria developed in our IVF lab can be useful for selection of suitable embryo even at day 3 of development with more chances of implantation. Clinical significance Study indicates necessity of development of individualized selection model based on morphokinetics for every IVF lab and also confirms freezing as an important tool for fertility preservation of males as it does not affect events of embryogenesis. How to cite this article Bhadarka HK, Patel NH, Patel KB, Sodagar NR, Jadeja YD, Patel NH, Patel MN, Patel AV, Patel DH, Patel JS. Study of Morphokinetics in Day 3 Embryo with Implantation Potential and Effect of Sperm Cryopreservation on Embryogenesis. Int J Infertil Fetal Med 2017;8(2):61-67.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4717-4717
Author(s):  
Georgia Kaiafa ◽  
Vasiliki Tsavdaridou ◽  
Athanasios Papadopoulos ◽  
Christos Savopoulos ◽  
Apostolos Hatzitolios ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document