scholarly journals Comparison between Acetal Resin and Cobalt-Chromium Removable Partial Denture Clasp Retention: An in vitro Study

2013 ◽  
Vol 3 (2) ◽  
pp. 50-56
Author(s):  
Tarek Mohamed ◽  
Osama Abdulmoneam Baraka ◽  
Magdy Mostafa Badawy
Keyword(s):  
Tensile Load ◽  
In Vitro Study ◽  
Horizontal Plate ◽  
Cobalt Chromium ◽  
Removable Partial Denture ◽  
Partial Denture ◽  
Group Iii ◽  
Group I ◽  
Molar Teeth

ABSTRACT Statement of problem The retention qualities of acetal resin clasps are questionable. Purpose To asses the initial retention and after cycling for 1,200 cycles of acetal resin clasps as compared to cobalt-chromium clasps. Materials and methods Extracted maxillary first premolars and molars were collected. Each tooth was embedded in acrylic block up to the cementoenamel junction. On each block, partial denture model consisted of Akers clasp, minor connector, cobalt-chromium horizontal plate representing the denture base, and a vertical arm on the horizontal plate was constructed. Models were divided into four groups (five each). Group I had acetal resin clasps on premolars. Group II had cobalt-chromium clasps on premolars. Group III had acetal resin clasps on molars. Group IV had cobalt-chromium clasps on molars. Akers clasps were designed to utilize 0.01 inch undercut. Each model was connected to the universal testing machine through the vertical arm. The model was placed in artificial saliva and a tensile load was applied to measure the initial retention. Then retention was measured after cycling for 200, 400, 600, 800, 1,000 and 1,200 cycles. One-way analysis of variance followed by Duncan's multiple range test was used to test the effect of groups and cycling on tensile load required for clasp dislodgment. Results Groups I and III showed no change in retention on cycling up to 1,200 cycles. Group I showed significantly higher retention than group III. Groups II and IV showed significant reduction in retention upon cycling more than 800 cycles. In spite of this reduction in retention, it is still higher than that in groups I and III. Conclusion Cobalt-chromium clasps showed higher retention than acetal resin clasps despite the deformation encountered in the former. Acetal resin clasps showed more retention qualities on premolar teeth than that on molar teeth. Clinical implications Acetal resin clasps can be used to retain Kennedy's class III partial denture. However, when used on molar teeth, it is recommended to increase the thickness of the retentive clasp arm or to use a deeper undercut. How to cite this article Mohamed T, Baraka OA, Badawy MM. Comparison between Acetal Resin and Cobalt-Chromium Removable Partial Denture Clasp Retention: An in vitro Study. Int J Prosthodont Restor Dent 2013;3(2):50-56.

scholarly journals EVALUATION OF ACETAL RESIN AND COBALT–CHROMIUM CLASP DEFORMATION AND FATIGUE RESISTANCE IN REMOVABLE PARTIAL DENTURE CLASPS AN IN-VITRO STUDY

2017 ◽  
Vol 63 (4) ◽  
pp. 2459-2464
Author(s):  
Mohamed Helal ◽  
Ibrahem Abd El Rahman ◽  
Hassan Sakar ◽  
Amr Gomaa ◽  
Mohamed Abbas
Keyword(s):  
Fatigue Resistance ◽  
In Vitro Study ◽  
Vitro Study ◽  
Cobalt Chromium ◽  
Removable Partial Denture ◽  
Partial Denture

scholarly journals Effect of different cleansers on the weight and ion release of removable partial denture: an in vitro study

2011 ◽  
Vol 19 (5) ◽  
pp. 483-487 ◽  
Author(s):  
Daniela N.B. Felipucci ◽  
Letícia R. Davi ◽  
Helena F.O. Paranhos ◽  
Osvaldo L. Bezzon ◽  
Rodrigo F. Silva ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Ion Release ◽  
Removable Partial Denture ◽  
Partial Denture

scholarly journals Assessment of shear bond strength of brackets bonded by direct and indirect techniques: an in vitro study

2012 ◽  
Vol 17 (4) ◽  
pp. 1-7 ◽  
Author(s):  
Roberto Hideo Shimizu ◽  
Karlos Giovani Grando ◽  
Isabela Almeida Shimizu ◽  
Augusto Ricardo Andriguetto ◽  
Ana Cláudia Moreira Melo ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
In Vitro Study ◽  
Adhesive System ◽  
Vitro Study ◽  
Group Iii ◽  
Indirect Bonding ◽  
Group I ◽  
Group Ii

OBJECTIVE: This in vitro study was designed to evaluate the shear bond strength (SBS) of orthodontic metal brackets bonded by direct and indirect techniques. METHODS: Thirty healthy human maxillary premolar teeth were used. The teeth were divided into three groups of 10 teeth each: Group I - indirect bonding with SondhiTM Rapid-Set system (3M/Unitek), Group II - indirect bonding with TransbondTM XT adhesive system (3M/Unitek) and Group III - direct bonding with TransbondTM XT adhesive system (3M/Unitek). After bonding and obtaining the specimens for the study, the specimens were subjected to SBS testing in a universal testing machine (Emic, model DL-500). The Kolmogorov-Smirnov test was applied to ascertain that the data had a normal distribution and the Bartlett test to check whether there was homogeneity of variance. One-factor analysis of variance was performed and, subsequently, Tukey's test for paired means. A 5% significance level was adopted. RESULTS: The results of Group I were 67.6 (N) and 5.9 (MPa); Group II, 68.9 (N) and 6.1 (MPa) and Group III (control), 92.5 (N) and 8.1 (MPa). CONCLUSION: It can therefore be concluded that the means for Group III were significantly higher compared with Groups I and II in both Newton (N) and Megapascal (MPa) values. The means attained by the indirect bonding technique used in Groups I and II, however, exhibited no statistically significant differences.

scholarly journals The Effect of Flowable Composite Lining Thickness with Various Curing Techniques on Microleakage in Class II Composite Restorations: An in vitro Study

2013 ◽  
Vol 14 (1) ◽  
pp. 56-60 ◽  
Author(s):  
S Nagalaxmi Reddy ◽  
DN Jayashankar ◽  
Mohanthomas Nainan
Keyword(s):  
In Vitro Study ◽  
Class Ii ◽  
Group Iv ◽  
Group V ◽  
Group Iii ◽  
Flowable Composite ◽  
Composite Restorations ◽  
Group I ◽  
Composite Lining

ABSTRACT Aim Aim of this study was to compare class II composite restoration using flowable composites as lining with various thickness and curing techniques by evaluating cervical marginal microleakage. Materials and methods Fifty intact molars, each prepared with two box-only class II cavities, were randomly divided into five groups: Group I, P60 filling alone; group II, ultrathin flowable composite lining (0.5-1mm) cocured with overlying composite; group III, thin lining (1-1.5) cocured with overlying composite; group IV, ultrathin lining (0.5-1 mm) precured and group V, thin lining (1-1.5) precured. The teeth were then thermocycled for 1500 cycles (between 5 and 60 °C) and immersed in dye for 24 hours. Cervical microleakage was measured as the extent of dye penetration. Results Cocured specimens (groups II and III) showed least microleakage and control specimens (group I) showed maximum microleakage. On comparison of curing techniques, cocured specimens (groups II and III) showed less microleakage than precured (groups IV and V). On comparison of lining thickness and type of curing, group IV showed less microleakage than group V. Groups II and III were statistically not significant. Conclusion It was concluded from the results that ultrathin cocured flowable composite lining specimens improved the marginal sealing with decreased microleakage. Clinical significance In this study, the application of additional flowable composite lining with various thicknesses presented different influences in marginal quality of class II box only composite restorations. A new technique applying an ultrathin flowable composite lining with cocuring technique improved the marginal sealing with decreased microleakage. Restorations with thin lining presented reduced marginal integrity after thermocycling. How to cite this article Reddy SN, Jayashankar DN, Nainan M, Shivanna V. The Effect of Flowable Composite Lining Thickness with Various Curing Techniques on Microleakage in Class II Composite Restorations: An in vitro Study. J Contemp Dent Pract 2013;14(1):56-60.

Comparison of antibacterial efficacy of herbal extracts of aloe vera leaves and mushroom against streptococcus mutansand lactobacillus - an in vitro study

2017 ◽  
Vol 9 (1) ◽  
pp. 23-29
Author(s):  
Bijo Kurian
Keyword(s):  
Antimicrobial Activity ◽  
Streptococcus Mutans ◽  
Aloe Vera ◽  
In Vitro Study ◽  
Herbal Extracts ◽  
Zone Of Inhibition ◽  
Group Iii ◽  
Mushroom Extract ◽  
Group I

BACKGROUND AND OBJECTIVES: This study evaluated and compared the antimicrobial efficacy and minimal inhibitory concentration (MIC) of chlorhexidine 0.12% and extracts of aloe vera and mushroom against Streptococcus mutans and lactobacillus. MATERIALS & METHODOLOGY: The agar disc diffusion and broth micro dilution method was used to check the antimicrobial activity of 0.12% chlorhexidine and aqueous extracts of two medicinal plants. The test samples were divided as follows- Streptococcus mutans, group I: chlorhexidine, group II: Aloe vera and group III: Mushroom. Lactobacillus, Group I: chlorhexidine, group II: Aloe vera extract and group III: Mushroom extract. The zone of inhibition and MIC values were tabulated and the data was statistically analyzed using ANOVA and Bonferroni post- hoc tests. RESULTS: Chlorhexidine shows maximum antibacterial action against Streptococcus mutans and lactobacillus followed by mushroom extract and aloe veraextracts with the zone of inhibition of (20.3mm/ 24.13), (17.03/ 16.05), (14.09/14.26) respectively. Both the extracts had MIC value of 80µg/ ml and chlorhexidine was 40µg/ml. CONCLUSION: Within the limitations of this in- vitro study, it can be concluded that all the herbal extracts tested in this study demonstrated antibacterial activity against MS and lactobacillus. Chlorhexidine showed maximum antibacterial action against Streptococcus mutans and lactobacillus followed by mushroom extract and then aloe veraextracts with the zone of inhibition of (20.3mm/24.13), (17.03/ 16.05), (14.09/14.26) respectively. Herbal products have potent antimicrobial activity that can be looked at as an alternative to chlorhexidine. However, further in vitro and long-term in vivo studies are recommended to confirm and correlate the findings of this study clinically.

scholarly journals Comparative study of some mechanical properties of cobalt chromium and polyether ether ketone thermoplastic removable partial denture clasps: an In-vitro Study

2020 ◽  
Vol 23 (3) ◽  
Author(s):  
Rady El-Baz ◽  
Mostafa Fayad ◽  
Mohamed Abas ◽  
Ahmed Shoieb ◽  
Mohammed Gad ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Testing Machine ◽  
Mean Value ◽  
Cobalt Chromium ◽  
Thermoplastic Resin ◽  
Removable Partial Denture ◽  
Partial Denture ◽  
Polyether Ether Ketone ◽  
Group I ◽  
Ether Ketone

Objective: was to evaluate the retentive force, fatigue resistance and deformity of clasps made from two materials cobalt chromium and poly ether et her ketone (PEEK). Material and Methods: sixteen models were fabricated, each one having lower 1st molar. Models were divided into two groups according to materials, group I (GI) for cobalt chromium (Co-Cr) and group II (GII) for PEEK. Each testing models and its clasps were mounted inside universal testing machine, the retention was measured by applying withdrawal force to it by this machine at 5 mm/min. The Fatigue resistance is measured by the reduction in retention through repeated insertion and removal cycles using robot a chewing simulator. Removal and insertion cycling of clasps was carried out for 360, 730, 1080, 1,440,2,116 and 2,880 cycles (corresponding to 3,6,9,12, 18 and 24 months of simulated clinical use of a RPD) to simulate the fatigue resistance test. Deformity was measured before and after each cycling using a digital micrometer. Statistical analysis was done by 2-way-ANOVA test to detect significance effects of each variable. Results: Retention and fatigue resistance, after 360,730, 1080, 1,440,2,116 and 2,880 cycles totally the difference between Co-Cr and PEEK groups was statistically non-significant (P = 0.0980>0.05) where (Co-Cr > PEEK). Deformation results, regardless to evaluation time, Co-Cr group recorded statistically significant higher deformation mean value than PEEK group (P = 0.008<0.05). Regardless to material group, deformation mean value changed non significantly by time (P = 0.2882> 0.05). Conclusion: PEEK clasps (1.0 mm in cross section diameter) engage 0.50 mm undercut provide sufficient retention nearly similar that of Co-Cr clasps.KeywordsFlexible clasps; Polyether ether ketone, PEEK; Thermoplastic resin; Partial denture.

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