Preliminary molecular analysis of bacterial composition in periapical lesions with primary endodontic infections of deciduous teeth

Background The bacterial composition of periapical lesions in deciduous teeth has not been well documented.This study was designed to explore the bacterial compositions,especially the dominant bacteria in periapical lesions using 16S rRNA sequencing.Methods Tissue samples were collected from 11 periapical lesions in deciduous teeth with primary endodontic infections.DNA was extracted from each sample and analyzed using 16S rRNA cloning and sequencing for the identification of bacteria.Results All DNA samples were positive for 16S rRNA gene PCR.One hundred and fifty-one phylotypes from 810 clones were identified to eight phyla,and each sample contained an average of 25.9 phylotypes.In addition,59 phylotypes were detected in more than two samples,and Fusobacterium （F.） nucleatum （8/11）,Dialister （D.） invisus （8/11）,Campylobacter （C.） gracilis （7/11）,Escherichia （E.） coil DH1 （6/11）,Aggregatibacter （A.） segnis （6/11）,and Streptococcus （S.） mitis （6/11） were the most prevalent species.Furthermore,45 as-yet-uncultivated phylotypes were also identified.Conclusions Chronic periapical lesions in deciduous teeth contained polymicrobial infections.F.nucleatum,D.invisus,C.gracilis,E.coli DH1,A.segnis,and S.mitis were the most prevalent species detected by 16S rRNA sequencing.

A randomized retrospective clinical study on the choice between endodontic surgery and immediate implantation

Background:Periapical endodontic surgery(PES)for root amputation and tooth replacement by immediate implant placement are two possible treatment options for bone lesions in the root apex of a tooth that has previously undergone endodontic treatment.Treatment methods are performed when the effectiveness of orthograde canal revision is questionable or when such treatment cannot be performed.The effectiveness of these methods varies from study to study.Objective:clinical evaluation of the efficacy of periapical endodontic surgery for root amputation and immediate implant placement with simultaneous tooth extraction in the proximate and long-term treatment.Materials and methods:The study included 183 patients between the ages of 24 and 63.Patients were divided into 2 groups;group I-endodontic surgery was performed to resect the apex of the tooth root(108 patients)and group II-an operation to install an implant with simultaneous tooth extraction(75 patients).In group I,in 36 cases,PES was performed in the area of the first molars and premolars,and 72 cases in the area of incisors and canines.In group II,75 patients received 231 implants.Results:In all 108 patients of group I in the postoperative period and within 1 month,the wounds healed without complications.In none of the 36 operated premolars and molars,there was no definitive elimination of the radiographic bone loss(Rude grade 2 and 3)after 12 months.In the area of incisors and canines,complete healing was observed only in 37.5%of cases(I class according to Rud).In group II,out of 184 implants installed immediately after tooth extraction,one was removed one month after implantation.In other cases,all implants were successfully integrated with the subsequent fabrication of prosthetic construction.Conclusion:The complex“implant(installed in the socket of the tooth immediately after its removal)-bone-soft tissues-prosthetic construction”is stable over time in terms of functional and aesthetic parameters,preservation of bone tissue,and mucous membrane.