Ιατρικά Άρθρα: Prosthodontics

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Τρίτη 8 Ιανουαρίου 2019

Prosthodontics

Questionnaires in prosthodontic research
N Gopi Chander

The Journal of Indian Prosthodontic Society 2019 19(1):1-2

Efficacy of prostheses bonding using silane incorporated to universal adhesives or applied separately: A systematic review
Laercio Almeida De Melo, Ilnara De Souza Moura, Erika Oliveira De Almeida, Amilcar Chagas Freitas Junior, Tasiana Guedes De Souza Dias, Fabíola Pessoa Pereira Leite

The Journal of Indian Prosthodontic Society 2019 19(1):3-8

Currently, the long-term success of esthetic rehabilitation with ceramics is required. Hence, professional knowledge about the most indicated dental material for each clinical situation as well as its usage protocol is essential. The aim of this systematic review of clinical and laboratorial studies was to compare the bond strength of prostheses using silane incorporated to universal adhesives or applied separately. The literature search in databases “Cochrane Library,” “MEDLINE,” “Web of Science,” “Scopus,” “LILACS,” “Scielo,” and “Google Scholar” was based on the keywords “Silane;” “Silanes;” “Silane coupling agent;” “Universal adhesive;” and “Universal adhesives.” A total of five articles were included in this review. In general, the studies showed better results for ceramic etching with hydrofluoric acid and application of silane separately to the universal adhesive. As a conclusion, the treatment with pure silane or as an additional pretreatment with universal adhesives improved the bond strength of glass ceramics. Hence, higher shear bond strength can be achieved, resulting in treatment longevity.

A study of change in occlusal contacts and force dynamics after fixed prosthetic treatment and after equilibration – Using Tekscan III
Reddy Chaithanya, Suresh Sajjan, A V Rama Raju

The Journal of Indian Prosthodontic Society 2019 19(1):9-19

Aim: A study has been undertaken to evaluate the changes in occlusal force dynamics after conventional prosthetic rehabilitation. Materials and Methods: In Phase I, the preprosthetic phase, force distribution of 50% ± 10% on either sides of arch in maximum intercuspation and disclusion time (DT) <1 s during mandibular excursions was attained in all patients using Tekscan before starting prosthetic treatment. Conventional procedures to replace missing tooth by fixed dental prosthesis were carried out. Occlusal corrections were performed using articulating paper to the satisfaction of operator and patient. In Phase II, postprosthetic phase, 1 week after cementation of the fixed partial dentures, the occlusal force dynamics were rerecorded and evaluated using Tekscan. Any corrections required were done to restore the equilibrium. Occlusal perception of patient before and after equilibration was recorded by means of a standard questionnaire both in pre- and postprosthetic phase. Twenty patients requiring replacement of a single posterior missing tooth were selected. The obtained values were statistically analyzed using Student's t-test. Results: Subsequent to rehabilitation, the right–left balance of occlusal load was lost and DT was significantly increased. However, the subjective evaluation revealed no significant decline in occlusal comfort. Conclusion: Null hypothesis was rejected. Operator's assessment of articulating paper marks and patient's occlusal perception is not reliable in restoring occlusal equilibrium.

Prosthetic treatment need and associated life course determinants in partially edentulous adults of age 18–35 years in Udupi taluk: A cross-sectional study
Kriti Sharma, Shashidhar Acharya, Deepak Kumar Singhal, Nishu Singla

The Journal of Indian Prosthodontic Society 2019 19(1):20-25

Aim: The aims of this study were to assess the prevalence of use and need for dental prostheses and to associate need with the life course determinants in young adults of age 18–35 years in Udupi taluk, Karnataka, India. Materials and Methods: It was a cross-sectional survey conducted on a total of 580 individuals those attended dental screening camps organized at random locations. A self-administered questionnaire was administered to participants to assess their life course determinants such as socioeconomic, behavioral, and psychological circumstances followed by an oral examination to assess their prosthetic status (WHO, 1997). Bivariate analysis followed by multivariate logistic regression analysis was carried out to determine the adjusted odds ratios (ORs) with 95% confidence interval (CI) for independent variables and the outcome. Results: The need and use of dental prostheses was observed in 38% and 2.2% of young adults, respectively. Adjusted multivariable analysis revealed that life course determinants such as parental rearing style (OR = 7.66 [95% CI: 3.88–15.14]) and interaction between expenditure at 10 years of age and economic hardships at 10 years of age (OR = 9.63 [95% CI: 3.12–29.72] and OR = 6.43 [95% CI: 1.89–21.88]) were significantly associated with the need for prostheses. Conclusion: The need for dental prostheses in the young adults can be related to socioeconomic and psychosocial circumstances during childhood, and thus the concept of life course approach has been highlighted.

An in vitro comparison of the effect of various surface treatments on the tensile bond strength of three different luting cement to zirconia copings
BL Bhavana, PL Rupesh, Bharat Kataraki

The Journal of Indian Prosthodontic Society 2019 19(1):26-32

Aim: The aim of this study was to evaluate and compare the tensile bond strength of zirconia copings subjected to three different surface treatment methods and cemented with three different luting agents. Materials and Methods: Seventy-two extracted maxillary premolar teeth were prepared to receive zirconia copings milled using computer-aided design/computer-aided manufacturing technology, which were divided into 9 groups of 8 specimens each. Three surface treatment protocols such as hydrofluoric acid etch treatment, air abrasion with 110-μm aluminum oxide (Al2O3), and tribochemical silica coating (Rocatec) treatment were carried out, and copings were cemented with three luting agents such as resin-modified glass ionomer cement (RelyX luting 2), 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) resin cement (Panavia F 2.0) and 4-methacryloxyethyl trimellitic acid (4-META) resin cement (G-Cem). Tensile bond strength of the copings was tested in a universal testing machine. Zirconia copings fabricated on the prepared extracted tooth. After the three surface treatments and cementing the zirconia crowns with three luting agents tensile bond strength is tested. The mean and standard deviations (SD) were calculated for the nine groups using one-way ANOVA, followed by Tukey–Kramer post hoc using the SPSS software. Results: The ANOVA test showed that the measured mean bond strength values were 4.22 MPa (tribochemicalsilica coating and MDP resin), 2.71 MPa (air abrasion and MDP resin), 2.61 MPa (tribochemical treatment with META), and 0.66 MPa (RelyX with air abrasion). According to the pairwise comparison of Tukey's honestly significant difference test, significant differences were exhibited among all the groups (P < 0.05). Conclusion: Tribochemical silica coating in combination with 10-MDP and 4-META adhesive resins provided the maximum bonding for zirconia copings.

Comparative evaluation of the effect of electrolyzed oxidizing water on surface detail reproduction, dimensional stability and Surface texture of poly vinyl siloxane impressions
AS Mahalakshmi, Vidhya Jeyapalan, Vallabh Mahadevan, Chitra Shankar Krishnan, NS Azhagarasan, Hariharan Ramakrishnan

The Journal of Indian Prosthodontic Society 2019 19(1):33-41

Aim: The aim of this in vitro study was to comparatively evaluate the effect of chemical disinfectants on the surface detail reproduction, dimensional stability and surface texture of polyvinyl siloxane (PVS) impressions. Materials and Methods: The impressions were then divided into five groups (fifteen samples per group) and subjected to a ten minutes immersion with 2% glutaraldehyde (Group I), 1% sodium hypochlorite (Group II), freshly prepared electrolyzed oxidizing water (EOW) with different pH values - acidic (Group III), alkali (Group IV) and neutral (Group V). The samples were examined pre and post-immersion under visual observation for surface detail reproduction, travelling microscope for measurement of dimensional stability and surface profilometer (3D) for evaluation of surface texture. A standardized master die was fabricated and seventy-five PVS test samples were made. The samples were subjected to immersion disinfection and studied for surface detail reproduction, dimensional stability and surface texture. Post-hoc test, paired t test and ANOVA were used to analyze dimensional stability statistically both within and between the test groups. Results: The surface detail reproduction was satisfactory with both pre and post-immersion test samples. A statistically significant dimensional change was observed post-immersion in Groups II, III and V test samples and a statistically insignificant dimensional change was observed in Groups I and IV test samples. There was a negligible change in surface texture post-immersion in Groups I, III, IV and V test samples with a slight increase in surface roughness post-immersion in Group II samples. Conclusion: In this study, all the test disinfectants produced satisfactory surface detail reproduction on Polyvinyl siloxane impressions. 2% glutaraldehyde and electrolyzed oxidizing water (alkali) have resulted in statistically insignificant dimensional change, while 1% sodium hypochlorite, electrolyzed oxidizing water (acidic) and electrolyzed oxidizing water (neutral) have resulted in statistically significant dimensional changes. All the test disinfectants except 1% sodium hypochlorite showed a reduction in surface roughness (Ra) values.

Effect of cigarette smoke on the surface roughness of two different denture base materials: An in vitro study
Girendra Singh, Abhinav Agarwal, Manesh Lahori

The Journal of Indian Prosthodontic Society 2019 19(1):42-48

Aim: This study aimed to evaluate the effect of cigarette smoke on the surface roughness of two commercially available denture base materials. Materials and Methods: A total numbers of 40 specimens were fabricated from two commercially available denture base materials: heat-cured polymethylmethacrylate and flexible denture base materials (20 for each). The specimens for each type were divided into four subgroups: subgroup I, heat-cured denture base material specimens (control group); subgroup II, flexible denture base material (control group); subgroup III, heat-cured denture base material specimen exposed to cigarette smoking group; and subgroup IV, flexible denture base material specimens exposed to cigarette smoking. The control groups were used for immersion in distilled water, and the smoke test groups were used for exposure to cigarette smoking. The smoke test group specimens were exposed to smoking in a custom-made smoking chamber using six cigarettes for each specimen. The surface roughness was measured using a profilometer, and the measurements were considered as the difference between the initial and final roughness measured before and after smoking. Paired t test and independent t-test were used to interpret differences in initial and final roughness values within and between groups respectively. Results: Paired t-test showed a significant difference between initial surface roughness and final surface roughness within each subgroup. Conclusion: The surface roughness of the specimens fabricated from the flexible denture base material was found to be more compared to heat-cured denture base specimens after exposure to cigarette smoke.

Retention and patient satisfaction with bar-clip, ball and socket and kerator attachments in mandibular implant overdenture treatment: An in vivo study
Nitish Varshney, Sumit Aggarwal, Shalabh Kumar, SP Singh

The Journal of Indian Prosthodontic Society 2019 19(1):49-57

Aim: The aim of this in vivo study was to evaluate and compare the retention and patient satisfaction in implant supported mandibular overdenture with three different attachment system. Materials and Methods: After evaluation of prosthetic space, fifteen edentulous subjects received two implants in the inter-foramina region of the mandible and were divided into 3 groups with 5 subjects each, delayed loading protocol was followed in all the patients. The retention force and satisfaction level with the attachments at baseline and after 6 months was measured in a standardised way using retentive device and VAS questionnaire. The study was based on evaluation of retention and patient satisfaction. 15 subjects were included in the study. The results obtained were statistically analyzed using one-way ANOVA test, and multiple comparisons were carried out using the Bonferroni tests. Results: At the end of six months, the retention force and satisfaction level was higher in Group 3 (Kerator attachment) as compared to Group 1 (ball and socket attachment) and Group 2 (bar and clip attachment) and patient satisfaction was equal in groups 1, 2 and 3 but the total number of interventions is significantly higher in the attachment bar. Analysis of variance with repeated measures showed significant differences in retention force among the three attachment types. Conclusion: (1) Group 3 (kerator attachment) exhibit higher retentive capacities than Group 1 (ball and socket attachment) and Group 2 (bar and clip attachment). (2) patient satisfaction was higher in Group 3 (Kerator attachment) in compare to Group 1 (ball and socket attachment) and Group 2 (bar and clip attachment).

An in vitro study to compare the influence of different all-ceramic systems on the polymerization of dual-cure resin cement
Anindita Majumder, TK Giri, S Mukherjee

The Journal of Indian Prosthodontic Society 2019 19(1):58-65

Aim: The aim of the study is to compare the effect of composition of three different all-ceramic systems on the polymerization of dual-cure resin cement, using different curing cycles and evaluated immediately within 15 min and after 24 h. Materials and Methods: Resin cement disc samples were fabricated by polymerization through three different all-ceramic disc, namely: lithium disilicate discs – IPS e.max (Group B), leucitereinforced discs – IPS Empress (Group C), zirconia discs – Cercon (Group D), and without an intervening ceramic disc, as control (Group A). A total of 80 resin cement disc samples were fabricated for fur groups (n=20). Each group further consisted of two subgroups (n = 10), t10 and t20 according to two different exposure times of 10 and 20 s, respectively. Each of the 80 resin disc samples was evaluated for their degree of polymerization achieved, by measuring the microhardness(Vickers hardness number) of the samples immediately within 15 min and after 24 h, giving us a total of 160 readings. Oneway analysis of variance test, ttest, and paired ttest were used for multiple group comparisons followed by Tukey's post hoc for groupwise comparison. Results: Direct activation of the resin cement samples of control (Group A) showed statistically significant higher mean microhardness values followed by Groups C then B and D, both immediately and after 24 h. The mean microhardness for immediate post-activation was always inferior to the 24 h post-activation test. For both 10 and 20 s curing cycle, there was a significant increase in the microhardness of the resin cement discs cured for 20 s through the different ceramics. Conclusion: Ceramic composition affected the polymerization of dual cured resin cement. Doubling the light irradiation time or curing cycle significantly increased mean microhardness value. Greater degree of conversion leading to an increase in hardness was observed when the resin cement discs were evaluated after 24 h.

A spirometric and cephalometric comparative evaluation of mandibular advancement devices and occlusal jig
Shaily Ujjwal, Pragati Kaurani, U Narendra Padiyar, Sudhir Meena, Devendra Pal Singh, Hemant Kr Sharma

The Journal of Indian Prosthodontic Society 2019 19(1):66-73

Aim: Aim of the current study was to evaluate the effect of occlusal jig with increased vertical dimension and mandibular advancement device on the oropharangeal volume in completely edentulous patients using spirometry and cephalometry. Materials and Methods: The current study included includes 30 completely edentulous patient according to inclusion criteria. They were each subjected to cephalometric and spirometric analysis wearing CCD, OJ & MAD. Results obtained were subjected to following statistical analysis, one-way ANOVA test, unpaired t-test, and Dunnett's test. Result: Both OJ & MAD brings about significant change in oropharangeal volume hence both the devices are effective treatment of choice for OSA, while greater increase was observed in oropharangealvolume of OJ as compared to MAD. Spirometric analysis shows insignificant changes in the oropharangeal volume caused by MAD while OJ causes small but significant change in oropharangeal volume (PIFR]. Conclusion: Within the limitation of the study, it can be concluded that, on cephalometric & spirometric evaluation, OJ shows greater increase in oropharangeal volume when compared to MAD in completely edentulous patient.