Cliclinical observation of one-visit root canal therapy root separation crown lengthening surgery and combined post-and-core crown to the residual root or crown of the mandibular first molar

Objective To observe the effect of root canal therapy surgical peridontal therapy and combined post-and-core crown to the residual root or crown of the mandibular first molar.Methods One-visit root canal therapy root separation crown lengthening surgery and combined post-and-core crown were ordinally done to the residual root or crown of the sixty-eight mandibular first molar.Results A two-years flow up of all the patients,but two cases were lost 4 cases were fail.The results showed a successful rate of 93.94%.Conclusion To do our best to conserve the residual root or crown of the mandibular first molar.The effect of ordinal therapy is very good.