Clinical Observation Of Glass Fiber Post And Pure Titanium Cast Post-and-core For Repairing The Residual Crowns And Roots Of Premolars

Background: In the clinical diagnosis and treatment works,due to dental caries or injury,dental defects are very common.Dental defects manifested as normal tooth shape,occlusal relationship and adjacency relationship change.Dental defects may influence normal chewing function and pronunciation,even cause tempormandibular diseases.After it affects people's facial appearance,it will give people a certain psychological burden,make people feel depressd in daily life and work.So we must take some measures to repair them.With the popularization of root canal therapy and the continuous development of prosthodontics,the residual crowns and roots of large area defects can be retained by the method of post-and-core crown.Not only restoring normal anatomical morphology of teeth,but also we can minimize the loss of tooth proprioceptor and bone resorption caused by tooth extraction farthest and ensure the patient's chewing efficiency.The teeth which need to make post-and-core crown are all pulp necrosis,as the pulp loses its vitality,the teeth become brittle.And the anatomical morphology of premolar has its particularity.The diameter is narrow between mesial surface and distal surface,and some root canals are curved and irregular,easier to broken than healthy teeth after restoration,so it is more prudent to use the post-and-core crown restoration.With the development of oral materials,there are more and more options for us to choose,including metal material,porcelain material and fiber reinforced resin composite.Different materials bring more choice to clinicians,at the same time,they also bring more challenges.When we do post-and-core crown clinically,how to design and select material types properly,avoid root fracture by stress concentration when the restoration bears the bite force,increase teeth resistance and prolong useful life of the restoration,improve repair success rate,it is a problem that oral doctors must face and think seriously.Objective: In order to analyze and compare the clinical effects of glass fiber post and pure titanium cast post-and-core for repairing the residual crowns and roots of premolars.Materials and methods: One hundred patients(45 males and 55 females)with residual crown and residual root of premolars were selected from Second hospital of Dalian Medical University and Dental hospital of Dalian Medical University from September2015 to February 2017,aging from 18 to 60.The patients were randomly divided into two groups,with 50 cases in each group,and the glass fiber posts composite resin pile core and pure titanium cast post-and-core were repaired respectively.Finally,both groups completed crown restoration with cobalt-chromium metal-ceramic crowns.The follow-up period was 12-24 months,according to the following indicators for evaluation: Success: patients don't have symptoms,the chewing function is normal,the restoration is integrated,closed,without loose or fall off,percussion without discomfort,the gingiva is normal without periodontal pocket.In X-ray examination,there is no root fracture,no progression of periapical lesions or lesions,no resorption of alveolar bone.Failure: patients have self-conscious symptom,cannot exercise chewing function,the restoration is broken,not closed,loose or fall off,percussion discomfort,swollen gums with deep periodontal pocket.In X-ray examination,there is root fracture,progression of periapical lesions or lesions,resorption of alveolar bone,accord with one of them is failure.The success rate of the two groups was calculated and statistical software SPSS22.0 was used to test the success rate of the two groups(?=0.05).In combination with the statistical results,the clinical effects of glass fiber post and pure titanium cast post-and-core were analyzed and compared.Results: The patient is reviewed after 12 to 24 months,one of the 50 cases of the glass fiber post was broken in the post,and one of them was loose and falled off,the restorations of the other 48 cases were firm and had good function.Four of the 50 cases of the pure titanium cast post-and-core falled off,four cases had root fracture,and two cases had gum inflammation,and the other 40 cases were firm and had good function.The repair success rate of glass fiber post group(96%)was higher than that of pure titanium cast post-and-core(80%),the difference between the two groups was statistically significant(P<0.05).Conclusion: Comparing with pure titanium cast post-and-core,the elastic modulus of glass fiber post is close to the dentin,and it has good adhesion with dentin.When combining with composite resin,the clinical operation is simple and the patients have fewer visits,and it has higher success rate when repairing the residual crowns and roots of premolars,which is worthy of promotion and application.Pure titanium cast post-and-core has good physical and mechanical properties,good biocompatibility.Although the production is complicated,the clinical operation is inconvenient,as long as the inspection and analysis are careful before repairing,the design is reasonable,the clinical operation and repair system is precise and normative,we can also get good repair success rate.