Transmission of radiant light energy through the sides of fiber posts.

OBJECTIVES: Resin cements are light polymerized, but the light may not reach all areas of root canals. The purpose of this study was to determine the best predictor of transmitted light radiant exposure (TLRE) from posts' sides. MATERIALS AND METHODS: Fiber posts were placed in a custom-made apparatus and advanced by 1-mm increments. The LED curing probe tip was activated for 40 s on the coronal end of the post. The TLRE was measured with an LED radiometer detector positioned on the side of the post exposed by an opening in the apparatus. Hierarchical multiple linear regression analysis was performed. RESULTS: Post system explained an additional 23.62% of the variation in TRLE. Adding actual post diameter explained an additional 62.64% of the variation in TRLE. While adding post length explained an additional 0.67%. Changing post system from FiberKleer to Postec Plus will decrease the mean value of TRLE by 4.90 units on average. Also, a one-unit increase of actual post diameter and length will decrease the value of TRLE by 44.96 and 0.44 units respectively. The TLRE ranged from 46 to 290 mJ/cm2 , which was between 0.73% and 6.63% of the original emanating light. CONCLUSIONS: The changes in post system, posts' diameter and length can be used to predict the unit changes in TLRE on the side of a translucent fiber post. Emanating radiant exposure from the side of the post was lower than 6.63% of the exposure entering the post. CLINICAL RELEVANCE: Fiber post diameter and length and post system can influence light radiant exposure transmitted from posts' sides, transmitting minimal radiant exposure, which can be increased by increasing curing duration.

Effects of COVID-19 lockdown on the mental health of dental students: A longitudinal study.

OBJECTIVES: Many countries have enforced lockdowns on their populations due to the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to assess the effects of the lockdown on dental students. METHODS: A longitudinal, repeated cross-sectional study was conducted to evaluate psychological problems experienced by dental students during the COVID-19 lockdown in Saudi Arabia. The dental students were selected from different universities using 2-stage cluster sampling. The validated Arabic version of the 21-item depression, anxiety, and stress scale questionnaire was distributed at the beginning and end of the lockdown. Mann-Whitney U and Kruskal-Wallis tests were used as appropriate. Chi-square test was used to compare the proportions between the sociodemographic data, and logistic regression analysis was used to identify variables associated with the students' responses. RESULTS: A total of 1287 respondents participated in this study (695 first-survey respondents, 592 second-survey respondents). There were longitudinally significant differences in the students' mental health outcomes based on gender, university, class year, and survey time during the COVID-19 lockdown. The lockdown increased the likelihood of female, single, and junior students experiencing stress. The students who lived alone recorded a high chance of elevated levels of depression, anxiety, and stress, which showed a significant longitudinal reduction during the lockdown. Moreover, the lockdown increased the likelihood of mental health problems among the students staying in households of two persons or two-five persons. CONCLUSIONS: This study indicates the importance of considering the detrimental mental health consequences on dental students in the event of future pandemics.

A randomized clinical trial of dentin hypersensitivity reduction over one month after a single topical application of comparable materials.

Dentinal hypersensitivity (DH) is a condition that causes patient discomfort. To evaluate the clinical efficacy of Gluma, fluoride varnish and Tetric N-Bond self-etch system in relieving DH immediately and over 30 days following a single topical application. The present randomized clinical trial was conducted on 55 patients with an age range 20-49 years. 70 teeth in total were incorporated and randomly assigned to the three groups. Parameters examined were: Tactile, air blast, and cold stimuli. VAS was used to assess tactile stimulus whereas the Schiff Cold Scale for air blast and cold stimuli. DH was evaluated immediately, at two weeks and 1 month follow up. Gluma showed a statistically significant reduction in DH scores over other materials. It was concluded that Gluma have statistically significant results over other materials in relieving DH immediately and over 30 days following a single topical application.Trial Registration: Clinical Trials.gov Identifier: NCT04351412, King Abdulaziz University Protocol Record 129-09-19. Registered 17 April 2020 - Retrospectively registered. http://ClinicalTrials.gov/NCT04351412 .

Healing of Periapical Lesions After Surgical Endodontic Retreatment: A Systematic Review.

BACKGROUND: Surgical root canal retreatment is required when peri-radicular pathosis associated with endodontically treated teeth cannot be treated by non-surgical root canal therapy (retreatment), or when retreatment was ineffective, not feasible or contraindicated. Endodontic failures maybe happen when irritants remain within the confines of the root canal, or when an extra-radicular infection cannot be eradicated by orthograde root canal treatment. Following enhanced microsurgical techniques in the last years, the success rates of surgical root canal retreatment have improved considerably. OBJECTIVE: The aim of this systematic review is to gather updated data in regard to the surgical root canal (retrograde) retreatment to heal the periapical lesions. MATERIALS AND METHODS: The electronic databases PubMed and Google Scholar were searched in this review using specific inclusion and exclusion criteria. The search was performed in June 2019 and updated in November 2019. Among 3900 studies, 10 studies satisfied the eligibility criteria and were included in the review to be analyzed. RESULTS: The 10 studies showed the importance of surgical root canal retreatment as a treatment option in removing infections within the root canal system and its efficiency in periapical tissue healing. These studies investigated different aspects of healing of periapical lesion after surgical (retrograde) retreatment including success rates, follow-up duration, and updated studies in surgical (retrograde) retreatment. CONCLUSIONS: Surgical root canal (retrograde) retreatment demonstrates its efficiency in reducing the period needed for healing of the periapical lesions in short-term follow-up compared to conventional orthograde retreatment.