RESUMEN
PURPOSE: To analyze the accuracy of implant position in simple cases by freehand. METHODS: Ninety-seven implants of 68 patients from 3 surgeons were selected.After operation,the deviations of implant position at shoulder apex and angle were measured using cone-beam CT(CBCT).The mean of three parameters were calculated with SPSS 22.0 software package, and the differences were analyzed between three surgeons,three operation areas,free-end missing and non free-end missing. RESULTS: The deviations of 97 implants were (0.76±0.57)mmï¼(1.41±0.90)mmï¼(4.76±3.68)° at shoulder, apex and angle.The deviation of shoulder apex and angle between three surgeons was significantly different(P<0.05). The deviations between left and right group were not significantly different (P>0.05); the deviations between anterior group and left group were significantly different(P<0.05); the deviations between anterior group and right group were not significantly different(P>0.05). The deviation of shoulder between free-end missing area and non free-end missing area was significantly different(P<0.05),other parameters between the two groups were not significantly different(P>0.05). CONCLUSIONS: The deviation of implant placement between surgical guide and mental guide were similar in simple cases. The experience of surgeon was important during freehand implant placement. The deviations were lower when missing tooth is in anterior area than in posterior area, whereas the same at shoulder in non free-end missing area than in free-end missing area.
Asunto(s)
Implantes Dentales , Cirugía Asistida por Computador , Algoritmos , Tomografía Computarizada de Haz Cónico , Implantación Dental Endoósea , HumanosRESUMEN
PURPOSE: To evaluate the influence of the time of deep caries on eruption of premolars. METHODS: Children in kindergarten in 2010 was selected to check caries of deciduous molars, then baseline data of population and personal oral health records were established. After data collection, from 2010 to 2017, according to the age of deep caries in deciduous molars, they were divided into 4 groups: four-year, five-year, six-year and seven-year. SPSS 20.0 software package was applied to analyze the results. RESULTS: Between 2010 and 2017, 994 children were investigated, including 528 boys and 466 girls. A total of 1220 maxillary first deciduous molars, 1307 maxillary second deciduous molars ,1244 mandibular first deciduous molars and 1253 mandibular second deciduous molars were investigated. At the age of 4 to 7, when the maxillary and mandibular deciduous molars suffered from deep caries, the replacement time of the premolars was earlier than cases with no caries. The difference was statistically significant (P<0.05); When deciduous molar decay occurred in young children, premolars had a tendency to erupt earlier, especially deciduous molars developed deep caries before 5 years, the difference was statistically significant (P<0.05). CONCLUSIONS: Prevention and intervention of dental caries in children is very important. Especially for children under 5 years old, caries in children's molars need early treatment, in order to decrease the impact on normal replacement of permanent teeth.