scholarly journals Influence of Different Plaque Control Methods and Hydrothermal Aging on Structural Properties of Monolithic Zirconia

2021 ◽  
Vol 22 (3) ◽  
pp. 291-300
Author(s):  
Habibe Öztürk Ulusoy ◽  
Çağatay Aktaş
Keyword(s):  
Structural Properties ◽  
Control Methods ◽  
Hydrothermal Aging ◽  
Monolithic Zirconia ◽  
Plaque Control

Monitoring the efficacy of plaque control methods

1995 ◽  
Vol 8 (1) ◽  
pp. 24-41 ◽  
Author(s):  
Frank A. Scannapieco
Keyword(s):  
Control Methods ◽  
Plaque Control

scholarly journals Effect of Hydrothermal Aging and Beverages on Color Stability of Lithium Disilicate and Zirconia Based Ceramics

Medicina ◽  
2019 ◽  
Vol 55 (11) ◽  
pp. 749 ◽  
Author(s):  
Satheesh B. Haralur ◽  
Noura Raqe S. Alqahtani ◽  
Fatimah Alhassan Mujayri
Keyword(s):  
Green Tea ◽  
In Vitro Study ◽  
Color Stability ◽  
Lithium Disilicate ◽  
Color Difference ◽  
Hydrothermal Aging ◽  
Monolithic Zirconia ◽  
Post Hoc ◽  
Coloring Agents

Background and aim: All-ceramic prosthesis is widely used in modern dental practice because of its improved physico-mechanical and optical properties. These restorations are exposed to coloring agents from various nutrition and beverages in the oral cavity. Long-term color stability is critical for the success of these restorative materials. The purpose of this in vitro study was to assess the effect of common beverages and mouthwash on the color stability of lithium disilicate (LD), monolithic zirconia (MZ) and bilayer zirconia (BZ) surfaces. Material and methods: Thirty disc-shaped specimens from each material were fabricated; each group was subdivided (n = 10) according to coffee, green tea and chlorhexidine immersion solutions. The baseline color of ceramic discs was recorded according to the CIE L*a*b* system with a portable spectrophotometer. The second measurement was recorded after 3000 thermocycling and immersion in coloring agents for 7 days. The mean color difference was calculated and data were compared with Kruskal-Wallis and Mann-Whitney post hoc tests (0.05). Results: ΔE values for LD with the immersion of coffee, tea, and Chlorhexidine gluconate (CHG) were 1.78, 2.241 and 1.58, respectively. Corresponding ΔE values for MZ were 5.60, 5.19, and 4.86; marginally higher than the clinically acceptable level of 3.5. Meanwhile, BZ showed better color stability compared to MZ with ΔE values of 4.22, 2.11 and 1.43. Conclusion: Among the ceramics evaluated, LD ceramic was found to be more color stable, while MZ ceramics displayed a higher susceptibility to discoloration. MZ and BZ ceramic colors were significantly altered with coffee immersion, while LD ceramics were more affected by green tea.

Translucency of Monolithic Zirconia after Hydrothermal Aging: A Review of In Vitro Studies

2020 ◽  
Vol 29 (6) ◽  
pp. 489-500 ◽  
Author(s):  
Katerina Papageorgiou‐Kyrana ◽  
Maria Fasoula ◽  
Eleana Kontonasaki
Keyword(s):  
In Vitro Studies ◽  
Hydrothermal Aging ◽  
Monolithic Zirconia

scholarly journals Fracture Load and Phase Transformation of Monolithic Zirconia Crowns Submitted to Different Aging Protocols

2016 ◽  
Vol 41 (5) ◽  
pp. E118-E130 ◽  
Author(s):  
ETP Bergamo ◽  
WJ da Silva ◽  
PF Cesar ◽  
AA Del Bel Cury
Keyword(s):  
Phase Transformation ◽  
Thermal Fatigue ◽  
Structural Reliability ◽  
Contact Point ◽  
Testing Machine ◽  
Fracture Load ◽  
Hydrothermal Aging ◽  
High Fracture ◽  
Zirconia Crowns ◽  
Monolithic Zirconia

SUMMARY Monolithic zirconia crowns have many favorable properties and may potentially be used to solve dental problems such as chipping. However, monolithic zirconia crown resistance can be affected by its phase transformation when subjected to low temperatures, humidity, and stress. This study evaluated the fracture load and phase transformation of monolithic zirconia crowns submitted to different thermal and mechanical aging tests. Seventy monolithic zirconia crowns were randomly divided into the following five groups: control, no treatment; hydrothermal aging at 122°C, two bar for one hour; thermal fatigue, 104 cycles between 5°C and 55°C, dwell time, 30 seconds; and mechanical fatigue, 106 cycles with a load of 70 N, sliding of 1.5 mm at 1.4 Hz; and combination of mechanical plus thermal fatigue. Fracture load was measured with a universal testing machine. Surface changes and fracture mode and origin were examined with a scanning electron microscope. Monoclinic phase content was evaluated by x-ray diffraction. The fracture load was analyzed using one-way analysis of variance at a level of 5%, and Weibull distribution was performed. No statistically significant differences were observed in the mean fracture load and characteristic fracture load among the groups (p>0.05). The Weibull modulus ranged from 6.2 to 16.6. The failure mode was similar for all groups with the crack origin located at the contact point of the indenter. Phase transformation was shown at different surfaces of the crown in all groups (1.9% to 8.9%). In conclusion, monolithic zirconia crowns possess high fracture load, structural reliability, and low phase transformation.

scholarly journals A Comparative Study of Knowledge and Practices about Plaque Control Methods Among Medical and Dental Students of Gandhara University Peshawar

2014 ◽  
Vol 1 (1) ◽  
pp. 32-38
Author(s):  
Gul Sanga Nizam ◽  
Shariq Ahmad ◽  
Babar Ahad ◽  
Saira Bano ◽  
Saira Afridi
Keyword(s):  
Oral Health ◽  
Medical Students ◽  
Dental Caries ◽  
Oral Cavity ◽  
Dental Students ◽  
Control Methods ◽  
Positive Role ◽  
Dental Attendance ◽  
Plaque Control ◽  
Medical And Dental Students

Back ground:Plaque control methods are one of the most important tools in promoting and improving oral health of an individual. Plaque can lead to the most prevalent oral diseases that are dental caries and gingivitis2.The available data on prevalence of dental caries show that Pakistan is a low caries country whereasthere is persistently high level of periodontal diseases3. Improvement of oral health by healthcare professional is a vital aspect of preventive dentistry 1.Objectives:The aim of the study was to assess and compare the knowledge and practices of medical and dental students of Gandhara University Peshawar about plaque control methods.Materials and methods:In a cross sectional study a total of 386 students were surveyed by using self administered structured questionnaires which covered student’s knowledge about plaque control methods, dental attendance and smoking. A total of 265 students responded with fully filled questionnaires out of which 121 were filled by medical students and 144 by dental students.Results:Almost 79.8% Dental students knew about plaque out of which 78(54.1%) students thought that iscaused by not cleaning the oral cavity and 65(45.1%) thought that it leads to dental caries. One hundred and thirty nine (96.5%) students clean their teeth out of which 93(64.5%) clean their teeth twice a day with a tooth brush. One hundred and eighteen (81.9%) have visited a dentist before out of which only 49(41.5%) went for regular checkup. Sixteen (11.1%) students smoke.Almost 61.1% Medical students knew about plaque out of which 41(33.8%) students thought that it is caused by not cleaning the oral cavity and 37(30.5%) students thought that it leads to dental caries.One hundred and fourteen (94.2%) students clean their teeth out of which 69(57%) clean their teethtwice a day with a tooth brush. Sixty nine (57%) students have visited a dentist before out of which only 26(37.6%) students went for regular checkup. Twenty nine (23.9%) students smoke.Conclusions:It is concluded that there is a marked difference between the knowledge and practices among themedical and dental students, and there is a need to enhance the knowledge of medical studentregarding dental attendance. Both need more awareness regarding plaque control methods to have a positive role in the oral health education of their patients and the community.Key words: Plaque control, dental attendance, tooth brushing, smoking

Control of Specific Plaque Bacteria

1994 ◽  
Vol 8 (2) ◽  
pp. 285-290 ◽  
Author(s):  
R.R.B. Russell
Keyword(s):  
Dental Caries ◽  
Virulence Factors ◽  
Preventive Measures ◽  
Periodontal Diseases ◽  
Bacterial Species ◽  
Control Methods ◽  
Synthetic Analogues ◽  
Molecular Studies ◽  
Plaque Control ◽  
Functional Inactivation

The Specific Plaque Hypothesis posits that particular bacteria are of unique importance in the etiology of dental caries and periodontal diseases, and a logical conclusion is that these bacteria should be the targets for our 'magic bullets' in devising plaque-control methods. This paper considers the development of preventive measures based on understanding of the significance of particular bacterial species and the properties of those bacteria. Knowledge of the importance of specific organisms as mediators of disease and molecular studies on the properties of potential virulence factors may reveal potential targets for inhibition, blocking by synthetic analogues, or functional inactivation by antibodies.

scholarly journals Effect of Different Coloring Procedures on the Aging Behavior of Dental Monolithic Zirconia

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Check Agingu ◽  
Neng-wu Jiang ◽  
Hui Cheng ◽  
Hao Yu
Keyword(s):  
Phase Transformation ◽  
Flexural Strength ◽  
Monoclinic Phase ◽  
Irregular Surface ◽  
Aging Behavior ◽  
Hydrothermal Aging ◽  
Transformation Zone ◽  
Aging Conditions ◽  
Monolithic Zirconia ◽  
Subsurface Microstructure

Objective. This study aimed to investigate the effect of different coloring procedures on the aging behavior of dental monolithic zirconia. Methods. Two types of translucent zirconia (SuperfectZir HTS, Aidite; Katana HT, Kuraray) were tested. Bar-shaped specimens with dimensions of 22 × 4 × 2 mm were prepared from uncolored and precolored blocks. Before being sintered, specimens made from uncolored blocks were colored by dipping them into a coloring liquid, whereas the precolored specimens were not treated. The specimens were then divided into 4 subgroups (n = 13) according to the aging conditions (no aging, 134°C/0.2 MPa for 5 h, 134°C/0.2 MPa for 10 h, and 134°C/0.2 MPa for 20 h). The flexural strength of the specimens was tested with the 4-point flexure. The crystalline phase composition of the specimens was analyzed by XRD. The subsurface microstructure of the fractured specimens was examined by using a SEM. The data were statistically analyzed using 3-way ANOVA and Tukey’s test (α = 0.05). Results. Significant differences were found in the flexural strength between the two zirconia materials tested (P<0.001). Aging and coloring procedures showed no significant effect on the flexural strength of the zirconia. Aging and coloring procedures significantly affected the t→m transformation of the zirconia. The monoclinic phase increased with the aging time. After aging, the precolored specimens showed a significantly higher t→m transformation than the specimens that were dipped in the coloring liquids. After aging for 20 h, the depth of the transformed zone with an irregular surface was approximately 6 µm for SuperfectZir HTS, whereas no detectable transformation zone was observed for Katana HT. Conclusion. Aging and coloring procedures had no significant effects on the flexural strength of the zirconia tested. The coloring procedure had a significant effect on the phase transformation of the zirconia subjected to hydrothermal aging.

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