Effect of protective coating agents on microleakage and flexural strength of glass ionomer cement and zirconomer. an in vitro study

PURPOSE

The objective of this study was to assess the microleakage and flexural strength of glass ionomer cement (GIC) and modified GIC (Zirconomer) when coated with protective coating agents such as COAT-IT and G-COAT plus.

METHODS

Sixty tooth specimens were grouped into two groups based on the type of restorations (GIC (n = 30) and Zirconomer (n = 30)). The samples were further divided into three subgroups (n = 10) based on the protective coating agent (Petroleum jelly, G-COAT Plus, or COAT IT) applied. This study evaluated the microleakage at the occlusal and cervical margins of class V restoration after being subjected to dye penetration and sectioning. Each specimen was viewed under a 40 × microscope and was given scores based on the depth of dye penetration. They were statistically analyzed using the Kruskal-Wallis test and compared within the groups using the Mann- Whitney Test. In addition, flexural strength was assessed using standardized cuboid (25 × 2 × 2 mm) specimens of restorative materials with and without protective coating agents. The mean flexural strength data of all the subgroups were statistically evaluated using a one-way analysis of variance (ANOVA) and compared within the subgroups using the student t test.

RESULTS

A statistically significant difference was found when occlusal margin microleakage scores were evaluated with G-COAT Plus demonstrating the lowest occlusal margin microleakage when applied over GIC restoration. The increasing order of occlusal margin microleakage scores is as follows: GIC with G-COAT Plus, Zirconomer with COAT-IT, GIC with COAT-IT, GIC, Zirconomer with G-COAT Plus, and Zirconomer. However, the cervical margin microleakage scores revealed no significant difference. While flexural strength was found to be highest for the GIC group coated with G-COAT Plus, it was observed that there was a significant improvement in the flexural strength of both GIC and Zirconomer when coated with either of the protective coating agents.

CONCLUSION

Within the limitations of this in vitro study, it was observed that the application of protective coating agents can significantly reduce the potential microleakage and improve the flexural strength of the restorative material especially when zirconia-reinforced GIC is the restorative material.

Clinical patterns of diffuse parenchymal lung disease in Kuwait: a prospective study

OBJECTIVE

To report our experience of the clinicopathological patterns of diffuse parenchymal lung disease (DPLD).

SUBJECTS AND METHODS

Over a 4-year period, 75 patients (41 males, 34 females), aged 13-76 years, who were referred to Mubarak Al-Kabeer and the Chest Diseases Hospitals, Kuwait with a diagnosis of diffuse lung disease, were included in the study. After a comprehensive history and physical examination, further investigations were done, including hematological and immunological profiles, sputum and bronchoalveolar lavage fluid examination, chest radiograph, high resolution computed tomography (HRCT), pulmonary function test and lung biopsy.

RESULTS

Of the 75 patients 60 (80%) were over 40 years of age. The duration of symptoms in 34 patients (45%) was less than 6 months and longer than 1 year in 28 (37.7%) patients. Twenty-five of the patients were cigarette smokers. The mean forced lung capacity (FVC), total lung capacity and diffusing capacity for carbon monoxide were less than 60% of the predicted values in most patients. There was a significant difference in mean FVC value between smokers and nonsmokers (p < 0.05). The HRCT findings were at an advanced stage in 65 patients, with additional honeycombing in 21 of the 65 patients. Idiopathic pulmonary fibrosis was the most common cause of DPLD, occurring in 52 patients, followed by sarcoidosis and collagen vascular diseases.

CONCLUSION

DPLD was observed predominantly in middle aged and elderly patients, due probably to increasing industrialization in the country. The role of cigarette smoking as a contributory factor remains unclear.

Clinicopathological and therapeutic patterns of idiopathic pulmonary fibrosis in Kuwait: a prospective study

Though common, the exact incidence and clinical pattern of idiopathic pulmonary fibrosis (IPF) in Gulf countries are not known. The results of a four-year prospective study undertaken in two tertiary hospitals in Kuwait are presented. The mean age at diagnosis of the 52 patients studied was 55.40 +/- 11.87 years. Thirty-two (61.5%) patients were male and 22 (42.3%) were smokers. The mean duration of symptoms at diagnosis was 2.1 +/- 0.92 years. Digital clubbing was found in 34 (65%) patients. The mean FVC, TLC and TLCO were 57%, 64.4% and 55% of predicted normal, respectively. The FVC value showed a significant difference between smokers and non-smokers (p < 0.05). HRCT findings were abnormal in all patients. Typical histological and high-resolution computed tomography findings of usual interstitial pneumonia, desquamative interstitial pneumonia and non-specific interstitial pneumonia were observed. This study revealed that IPF is prevalent in Kuwait, with patterns showing some similarities to those established elsewhere. The response to treatment was not encouraging, especially in the usual interstitial pneumonia subtype.