Library AJCD

Introduction:

Material and Methods: An electronic search was done between July 2000 and July 2021 in French and English in the following electronic databases: Google Scholar, Cochrane, Scopus, Altavista, Medline. A manual search was performed on the following top most-cited endodontic journals: Journal of Endodontics, International Endodontic Journal, Journal of the American Dental Association, and Dental Traumatology. This research was done according to the PICO model using several specific keywords and search equations. Two investigators selected the responses, which met the selection criteria. We included in this review only randomized trials, cohorts, case controls, original prospective and retrospective human studies. We excluded clinical case reports, opinion pieces, studies in temporary teeth and animal studies.

Results: We identified an initial total of 3132 bibliographic references on the databases consulted. After critical reading and elimination of irrelevant articles, we definitively retained that 19 publications were interested in the analysis of the factors influencing the removal of fractured endodontic instruments, 3 articles were interested in the removal of separated fragments in depending on the location of the fragment, 5 reviews were interested in the removal of fragments depending on the degree of the curvature of canal, 2 publications reported results in the length of the fragment, 9 articles were interested in the analysis of the removal of fractured instruments from the root canal according to the technique and instrument used.

Conclusions: The location of the fractured instruments and the shape of the root canal influence the success of fragments removal from root canals. Ultrasonics under an operating microscope is an effective method for the removal of these fractured instruments. Certain clinical recommendations have been made to facilitate the removal of fractured instruments.

Keys word : Fractured instrument; Instrument removal; Operating microscope; Ultrasonics; Endodontics; Systematic review.

Introduction: Covid-19 is a disease caused by a virus from the Coronaviridae family, SARS-CoV-2. This infectious disease is a zoonosis, the origin of which is still debated (1)..

Objective: The general objective of this study was to evaluate dental practice during the coronavirus disease pandemic in oral health structures in Conakry.

Material and methods: This was a descriptive cross-sectional study of the nursing staff of public dental structures in Conakry which took place from March 1 to April 06, 2021. A total of eleven (11) services were surveyed.

Results: systematic hand washing and wearing of masks were measures taken by all departments to avoid nosocomial contamination of covid19.
During the study, there was a drop in patient attendance of 21.67% in the departments surveyed compared to the two previous years.
The decline in patient attendance was the difficulty most cited by respondents with 56.52%.

Conclusion: the current pandemic due to the coronavirus has a strong impact on the functioning of Guinean health structures in general and public dental structures in particular.

Key words: Covid-19, dental structures, Conakry.

Objectives: The aim of this study was to evaluate the chemical behavior of universal adhesive on human enamel and dentin under different modes of adhesive application.

Methods: To evaluate the modifications on enamel or dentin, samples of human teeth were used in the form of fine powders in order to increase the available reactive surfaces. The study examined the pH changes, the acid strength and concentration when the universal adhesive is mixed with an etched and no etched powders of enamel and dentin. The mineral loss was quantified by atomic spectroscopy and thermogravimetric analysis.

Results: The pH values increase regularly depending on the time of contact, confirming the buffering action of dental tissues. This increase is more marked for the no etched enamel and dentin, statistically different from that obtained with the etched tissues (ANOVA with p<0.05). The dosage of calcium made on the solutions obtained after the various times of contact shows that there is a significant difference when the adhesive was tested on the etched or no etched enamel (averages of absorbance 0.55/0.72). On dentin, no difference was demonstrated p?0.05 (averages of absorbance 0.41/0.44) (ANOVA and Duncan test). Also, thermogravimetric analysis demonstrates different results for the enamel according to the protocol of use of the adhesive and identical results for the dentin.

Conclusion: We conclude that the universal adhesive used with two protocols (etch-and-rinse mode or self-etch mode) do not show a difference when applied on the dentin while on enamel a difference appears.

Clinical Relevance: Our study has shown the effectiveness of the universal adhesive tested on enamel and dentin etched or not. The choice of the collage strategy depends on the clinical situation.

Keywords: Universal adhesive system, Chemical bonding, Calcium release