[Preliminary study of Simplant software in mandibular molar implantation].

Purpose: The purpose of the study was to investigate the clinical effect and implementation method of mandibular molar implantation using a CT machine combined with Simplant software so as to provide a safer and more reliable method for preoperative preparation of mandibular molar implantation.

Methods: CT/cone-beam CT (CBCT) examinations were applied among 10 cases selected into the study. The Simplant software was used to measure the distances between implantation point center and superior wall of inferior alveolar nerve canal (H1), buccolingual diameter (H2), mesiodistal diameter (H3), ginginal thickness(H4) and occlusal distance (H5).

[Effect of topical fluoride application on young permanent teeth enamel demineralized by juice drinks].

Purpose: To observe the capability of enamel surface resisting juice drinks erosion and the remineralization process of etched enamel after topical fluoride application on young permanent teeth enamel.

Methods: The change of surface microhardness(SMH) of young permanent teeth enamel fluoride which was immersed in orange juice in advance and then applied on its etched part was evaluated.The change of SMH of young permanent teeth enamel treated by 0.

[An experimental study on young permanent teeth enamel demineralization by different kinds of soft drinks].

Purpose: To compare the young permanent teeth enamel demineralization after immersion in different kinds of soft drinks; to compare the degree of enamel demineralization caused by the different immersion time and frequency of beverages.

Methods: The change of young permanent teeth enamel surface microhardness was measured by a leitzs microhardness tester. The change of calcium and phosphate in the different drinks after immersion of the enamel was analyzed by Roche Biochemical analyzer.

[The study of cytotoxicity of different intracanal medications and cell rehabilitation on human periodontal ligament fibroblasts].

Purpose: To determine the cytotoxicity and reversibility of cytotoxicity of 5 intracanal medications in various concentrations with human periodontal ligament fibroblasts (HPLFs), with the aim to provide a comprehensive reliable scientific evidence for making a good choice of these intracanal medications in clinical practice.

Methods: The experimental medications included formocresol (FC), camphorated paramonochlorophenol(CP), metronidazole, calcium hydroxide and traditional Chinese medicine. HPLFs were obtained from healthy premolars extracted for orthodontic reasons.

[Comparison of the clinical efficacy of self-etching bond system and composite resin in repair of dental defects].

Purpose: To compare the efficacy of self-etching bond system and composite resin in repair of dental defects.

Methods: 201 teeth were randomly divided into two groups. 101 teeth in the experimental group were treated with CLEARFIL self-etching bond and AP-X to repair dental defects, while 100 teeth in the control group were treated with Durafill bond and Charisma.