Pontic制作纤维桩的弯曲强度和弯曲模量的研究

目的:检测Pontic制作纤维桩的弯曲强度和弯曲模量,为Pontic制作纤维桩的临床应用提供理论基础。方法:在Instron-8841万能实验机上用三点弯曲的方法,在Pontic制作的纤维桩的中央加载,直至试样断裂,记录最大载荷值。同时用玻璃纤维预成根管桩、氧化锆预成根管桩、Ni-Cr合金铸造根管桩、不锈钢预成根管桩和钛合金预成根管桩进行对比实验。结果:Pontic制作的纤维桩的弯曲强度为(600±10)MPa,弯曲模量为(18±1.2)Gpa;Pontic制作纤维桩的弯曲强度与玻璃纤维预成桩的弯曲强度无统计学差异(P>0.05)。结论:Pontic制作的纤维桩弯曲强度能够达到临床应用要求。

Fate of root shell after pontic/socket shield techniques,is it better to extract the whole tooth?

A series of changes occur in the remaining alveolar process after whole tooth extraction.The basic question is,why do the bony walls(especially the labial/buccal)get resorbed immediately after the tooth is removed?This could be because,with cementum of the concerned tooth and its periodontal ligament,the supporting bundle bone is dependent on the presence of the tooth.This loss can be compensated using numerous techniques,such as socket grafting using various biomaterials to preserve the alveolar bone and buccal grafting with guided tissue regeneration to increase the thickness of buccal bone or placement of implant immediately.However,none of these techniques prevent the modelling of the alveolar bone post-extraction.Few studies have demonstrated that preservation of the roots in the alveolar process maintains the bone volume and facilitates vertical bone growth.A histological study in animals and humans has shown that the retained root shell does not pose any interference in the osseointegration of the implant(if placed simultaneously).Although various names have been proposed to describe the concept of retaining full or part of the root to prevent the resorption of the ridge,socket-shield and pontic-shield are the two most commonly used terms worldwide.The extraction of the whole tooth might be the choice of therapy when socket-shield or pontic-shield is not possible due to anatomical variations,infections,or lack of clinical expertise.Irrespective of the size,when a whole root or a root fragment(is left in situ),it is the dentist’s ethical duty to advise/inform the patient and ensure repeated clinical and radiographic follow-up.The present study aimed to highlight the current status of these techniques,their benefits,and possible complications and address whether the paradigm of the teeth extraction methods should be altered.

Influence of pontic design of anterior fixed dental prosthesis on speech: A clinical case study

BACKGROUND The pontic design of fixed dental prostheses(FDPs)is strongly associated with the phonetic function,and the phonetic function of anterior FDPs with different pontic designs remains understudied.AIM To investigate the immediate and short-term influence of pontic design of anterior FDPs on Chinese speech in a clinical case using objective acoustic analysis.METHODS Two FDPs with two types of pontic design(saddle pontic and modified ridge lap pontic)were fabricated for one patient with maxillary anterior teeth missing.The acoustic analysis of patient’s articulation was conducted immediately after wearing the FDPs and 1 wk after wearing these FDPs.RESULTS The effect of FDP on Chinese vowels(/a/,/o/,/e/,/i/,/u/,and/ü/)was insignificant,because the recovery of vowel distortion occurred within 1 wk for both FDPs.Three(/f/,/s/,and/sh/)of eight Chinese fricative consonants were found to have obvious distortions,and the/s/sound distortion last for more than 1 wk for the patient wearing FDP with modified ridge lap pontic design.CONCLUSION The influence of anterior FDP on articulation of Chinese vowels is insignificant,while the articulation of Chinese fricative consonants is more susceptible.When fabricating anterior FDPs for patients with speech related professions,saddle pontic design can be an alternative option compared with modified ridge lap pontic design.

Application of Laser Technology in Fixed Prosthodontics <br/>—A Review of the Literature

Introducing laser light in prosthetic dentistry opens a new era on the treatment modules with new impact in the quality of prosthodontics treatments, with hope of overcoming some of the drawbacks posed by the conventional methods of fixed prosthodontics procedures. Laser techniques cause less pain than traditional methods and eliminate the noise of instrumentals that some fearful patients who have long term neglected care and those have complex medical histories and required more specialized care, could use the advantage of laser in their treatment plan. The aim of the articles review is to highlight the current and emerging application of laser in fixed prosthodontics treatment to be used in conjunction or as replacement for traditional methods based on the research that support the indication described.