Intentional tooth replantation (ITR) is an advanced treatment modality and the procedure of last resort for preserving teeth with inaccessible endodontic or resorptive lesions. ITR is defined as the deliberate extraction of a tooth; evaluation of the root surface, endodontic manipulation, and repair; and placement of the tooth back into its original socket. Case reports, case series, cohort studies, and randomized controlled trials have demonstrated the efficacy of ITR in the retention of natural teeth that are untreatable or difficult to manage with root canal treatment or endodontic microsurgery. However, variations in clinical protocols for ITR exist due to the empirical nature of the original protocols and rapid advancements in the field of oral biology and dental materials. This heterogeneity in protocols may cause confusion among dental practitioners; therefore, guidelines and considerations for ITR should be explicated. This expert consensus discusses the biological foundation of ITR, the available clinical protocols and current status of ITR in treating teeth with refractory apical periodontitis or anatomical aberration, and the main complications of this treatment, aiming to refine the clinical management of ITR in accordance with the progress of basic research and clinical studies; the findings suggest that ITR may become a more consistent evidence-based option in dental treatment.
Humans ; Tooth Replantation/methods* ; Consensus ; Periapical Periodontitis/surgery*

Instrument separation is a critical complication during root canal therapy, impacting treatment success and long-term tooth preservation. The etiology of instrument separation is multifactorial, involving the intricate anatomy of the root canal system, instrument-related factors, and instrumentation techniques. Instrument separation can hinder thorough cleaning, shaping, and obturation of the root canal, posing challenges to successful treatment outcomes. Although retrieval of separated instrument is often feasible, it carries risks including perforation, excessive removal of tooth structure and root fractures. Effective management of separated instruments requires a comprehensive understanding of the contributing factors, meticulous preoperative assessment, and precise evaluation of the retrieval difficulty. The application of appropriate retrieval techniques is essential to minimize complications and optimize clinical outcomes. The current manuscript provides a framework for understanding the causes, risk factors, and clinical management principles of instrument separation. By integrating effective strategies, endodontists can enhance decision-making, improve endodontic treatment success and ensure the preservation of natural dentition.
Humans ; Root Canal Therapy/adverse effects* ; Consensus ; Root Canal Preparation/adverse effects*

Objective To induce the the 17th condon antonymous mutagenesis of salivary histatin 5(HRP5) cDNA,express the mutant and hrp5 in Pichia pastoris,and to study the effects of mutation on expression.Methods According to the Pichia pastoris' codon bias,two pairs of primers(H1 and H2,H3 and H4) were designed.H1 and H2,H3 and H4 have complementary 3' end,and the EcoR I site was added to the 5' end of H1 and H3,Sal I site to H2,H4.The cDNA of hrp5 and hrp5' was generated with PCR by H1 and H2,H3 and H4,respectively.The secrete vector pPICZ?-A,hrp5 and hrp5' were digested with EcoR I +Sal I,linkede by T4 DNA ligase and transformed to E.coli TOP10 comptetent cell,positive colonies were screened on LB plates with Zeocin.The recombinant plasmids pPICZ?-A-hrp5 and pPICZ?-A-hrp5' identified by digestion and DNA sequencing were amplified largely,linearized by Sac I and transformed to GS115 comptetent cell by electroporation,positive colonies were screened on YEPD plates with Zeocin,the recombinant GS115 were confirmed by PCR,cultured and induced expression by methanol.The amount and anticandidal activity of the expressed products was compared with synthetic HRP5.Results Both hrp5 and hrp5' were integrated into the genome of GS115 and expressed successfully,the anticandidal activity of the recombinant HRP5 and HRP5' was identical with synthetic HRP5,the amount of expressed HRP5 and HRP5' was 4?mol/L and 5?mol/L,respectively.Conclusion Both the recombinant HRP5 and HRP5' showed better anticandidal activity.The amount of expressed prodcts increased 25% by substituting Asn for Lys17 without changing anticandidal activity.