In order to evaluate the accuracy of RayPex5 apex locator in measuring root canal working length in clinical practice and to analyze the possible factor resulting in deviation, the working length of total 211 root canals were measured by handing method and electronic method respectively. The exact working length of those root canals were determined by X-ray method. The accuracy rate of electronic method and handing method was 96.21% and 78.2% respectively, with significant difference(P<0.001). The accuracy rate of front teeth group and molar group measured by electronic method was 100% and 92.5% respectively, with significant difference(P<0.05), while the apical paradentitis group and the apical non-paradentitis group, the front teeth group and the premolar group, and the premolar group and the molar group didn' t differ from each other, respectively. The study showed that the accuracy rate of electronic method was high for determining root canal working length, and Raypex 5 apex locator could define apical seat to measure root canal working length accurately.

Objective: To investigate the correlation between the presence of a crown (CR) or a proximal restoration (PR) and furcation involvement (FI) on molars. Methods: Data were collected from 237 teeth in 44 patients who had restored and non-restored molars with or without FI.The clinical examinations were conducted on the molars including CR,PR,FI, mobility(MO), endodontic treatment(EN) and probe of periodontal attachment level(PAL). Results: Molars with CR or PR had a significantly highter percentage of FI (P0.05) when compared to molars without restorations. Conclusion: The molars with crowns or restorations involving the proximal tooth surfaces have a highter prevalence of FI and more periodontal attachment lose than molars without restorations.

OBJECTIVETo detect and analyze two important genes, comE and luxS, in quorum sensing signal pathway from Streptococcus oralis (S. oralis).

METHODSThe total genomic DNA of S. oralis NH521 (a clinically isolated strain) was firstly extracted. The comE and luxS genes were then amplified by polymerase chain reaction (PCR) and further sequenced. The obtained sequences were compared with related sequences in GenBank.

RESULTSTarget bands of both comE and luxS genes were detected by electrophoresis. The obtained gene sequences were similar to the corresponding sequences from another S. oralis strain (luxS, 95.0%; comE, 99.6%); however, comparing to gene sequences of another species Streptococcus mutans, comE was more divergent (12.7%) than luxS gene (74.1%).

CONCLUSIONThis study successfully amplified and sequenced comE and luxS genes from S. oralis NH521 strain. The luxS gene accumulated more mutations than comE gene did between two S. oralis strains, but comE gene is more divergent than luxS gene between two Streptococcus species.

Bacterial Proteins ; Carbon-Sulfur Lyases ; Polymerase Chain Reaction ; Quorum Sensing ; Signal Transduction ; Streptococcus mutans ; Streptococcus oralis

The dental operative microscope has been widely employed in the field of dentistry, particularly in endodontics and operative dentistry, resulting in significant advancements in the effectiveness of root canal therapy, endodontic surgery, and dental restoration. However, the improper use of this microscope continues to be common in clinical settings, primarily due to operators' insufficient understanding and proficiency in both the features and established operating procedures of this equipment. In October 2019, Professor Jingping Liang, Vice Chairman of the Society of Cariology and Endodontology, Chinese Stomatological Association, organized a consensus meeting with Chinese experts in endodontics and operative dentistry. The objective of this meeting was to establish a standard operation procedure for the dental operative microscope. Subsequently, a consensus was reached and officially issued. Over the span of about four years, the content of this consensus has been further developed and improved through practical experience.
Humans ; Dentistry, Operative ; Consensus ; Endodontics ; Root Canal Therapy ; Dental Care