RESUMEN
PURPOSE: Clinical experience shows that formation of calculus is a very rare phenomenon in primary teeth, but it increases as the permanent teeth erupt. The purpose of this study was to assess the relationship between dental calculus, dental anatomy, and salivary factors in primary and mixed dentition stages. METHODS: A cross-sectional study was carried out to determine the buccolingual dimensions of the most concave and the most convex surfaces of the lingual aspect of mandibular central incisor crowns in a sample group of 120 three- to five-old children and 120 eight- to 10-year old children. Saliva samples were collected from 20 in each group. Data were analyzed using t tests. RESULTS: Significant differences were found between the ratio of the buccolingual dimensions of the most convex to the most concave areas of the lingual surfaces in primary and permanent incisors (P=0.028). Saliva analysis revealed significant differences in total protein (P=0.002), sodium (P=0.037), bicarbonate (P=0.003), and ammonia (P=0.025) between the two age groups. CONCLUSIONS: Anatomic and salivary factors may be important reasons for the differences in calculus formation.
Asunto(s)
Cálculos Dentales/etiología , Boca/anatomía & histología , Saliva/química , Niño , Estudios Transversales , Dentición Mixta , Femenino , Humanos , Masculino , Factores de Riesgo , Diente PrimarioRESUMEN
OBJECTIVES: This in-vitro study aimed to compare the push-out bond strength of composite to prepared and unprepared intracanal dentin using a 5th generation bonding agent in primary anterior teeth after etching for seven and 15 seconds. MATERIALS AND METHODS: Sixty primary anterior teeth were randomly divided into four groups. In groups one and two, intracanal dentin remained intact while in groups three and four it was prepared using a #5 round bur and low-speed handpiece. Single Bond 2 was used in groups one and three after 15 seconds and in groups two and four after seven seconds of etching with phosphoric acid. After restoring with composite resin and incubation, the specimens were subjected to push-out bond strength test. Data were analyzed using two-way ANOVA and Kaplan Meier curves. RESULTS: The mean bond strength was not significantly different between seven and 15 seconds etching times (P=0.198). Dentin preparation had no significant effect on the mean bond strength (P=0.838). The interaction effect of etching time and dentin preparation was not significant either (P=0.680). CONCLUSIONS: Decreasing the etching time from 15 to seven seconds and preparation of intracanal dentin had no significant effect on push-out bond strength of composite to intracanal dentin of primary anterior teeth.
RESUMEN
OBJECTIVES: This in-vitro study sought to assess the push-out bond strength of a total etch and 2 self-etch bonding systems to intracanal dentin of primary anterior teeth (PAT). MATERIALS AND METHODS: Thirty-six primary anterior teeth were randomly divided into 3 groups of 5(th) generation (Single Bond 2), 6(th) generation (Clearfil SE) and 7(th) generation (Single Bond Universal) bonding agents. The canal orifice was restored with composite resin and the push-out test was carried out to assess the bond strength. After applying the push-out load, specimens were evaluated under a light microscope at 40X magnification. One-way ANOVA and log-rank test on Kaplan-Meier curves were applied for the comparison of bond strength among the 3 groups. RESULTS: The mean± standard deviation (SD) bond strength was 13.6±5.33 MPa for Single Bond 2, 13.85±5.86 MPa for Clearfil SE and 12.28±5.24 MPa for Single Bond Universal. The differences in bond strength among the 3 groups were not statistically significant (P>0.05). CONCLUSION: All three bonding agents are recommended for use with composite posts in PAT. However, due to high technical sensitivity of the Total Etch system, single or two-step self etch systems may be preferred for uncooperative children.