X-ray evaluation of pulp calcification in adult permanent teeth after pulpotomy / 北京大学学报(医学版)

OBJECTIVE@#To compare the clinical effects of pulpotomy with two kinds of calcium silicate materials, and to evaluate the formation of dentin bridge and pulp calcification after pulpotomy of adult permanent teeth.@*METHODS@#Patients who visited the General Department of Peking University School and Hospital of Stomatology from November 2017 to September 2019 and planned for pulpotomy on permanent premolars and molars with carious exposed pulp were selected. They were randomly divided into two groups. Bioceramic putty material iRoot BP (iRoot group, n=22) and mineral trioxide aggregate MTA (MTA group, n=21) were used as pulp capping agents, respectively. The patients were recalled after one year and two years. The clinical efficacy, dentin bridge index (DBI) and pulp calcification index (PCI) were recorded. Blinding method was used for the patients and evaluators.@*RESULTS@#There was no significant difference in gender, mean age, dentition and tooth position between the two groups (P>0.05). Seven cases were lost during the first year (4 cases in iRoot group and 3 cases in MTA group). In the iRoot group, 1 case had transient sensitivity at the time of 1-year follow-up. The cure rate of the two groups was 100% at the time of 2-year follow-up. The proportion of dentin bridge formation was 38.9% one year after operation, 55.6% two years after operation. The proportion of partial or even complete disappearance of root canal image was 5.6% before operation, 38.9% and 55.6% one and two years after operation, respectively. The difference was statistically significant by rank sum test (P < 0.05). There was no significant difference in dentin bridge formation and pulp calcification between the two groups (P < 0.05). DBI and PCI after operation was as the same as those before operation (44.4% cases of DBI and 25% cases of PCI) or gradually increased (55.6% cases of DBI and 75% cases of PCI). Spearman's nonparametric correlation analysis showed that age was positively correlated with preoperative pulp calcification index (PCI0, P < 0.05), but not with the dentin bridge index (DBI1, DBI2), pulp calcification index (PCI1, PCI2) and the degree of change (DBI2 vs. DBI1, PCI1 vs. PCI0, PCI2 vs. PCI0) 1-year and 2-year after operation (P>0.05).@*CONCLUSION@#According to this study, good clinical effects were obtained within 2-year after pulpotomy of adult permanent teeth with MTA and iRoot. In some cases, the root canal system had a tendency of calcification aggravation, and there was no statistical difference in the development of this trend between the two groups.

Effects of bond strength evaluation on different durations of adult permanent teeth and youth permanent teeth by using universal adhesives to dentin / 华西口腔医学杂志

OBJECTIVE@#To compare the dentin bonding strength evaluation between adult permanent teeth and youth permanent teeth after treatment for different durations by universal adhesives.@*METHODS@#Ten adult permanent teeth and ten youth permanent teeth were selected for this study. The occlusal enamel layer was removed, and each tooth was cut into three pieces along the long axis. In total, 30 pieces of adult and youth teeth were prepared. The adult and youth teeth pieces were randomly divided into three groups and treated by universal adhesives for 10, 20, and 30 s. In this study, Scotchbond Universal (SBU) was selected as the universal adhesive. Slabs were treated by dual-cure resin cements. The specimens were tested by microshear strength test through a universal testing machine. Fracture modes were observed by a stereomicroscope. Other adult teeth and youth teeth were selected, two for each type, and treated and grouped in the same manner. Fluorescein (0.1% Rhodamine B) was dissolved in SBU adhesive, and the specimens were treated by the adhesives for 10, 20, and 30 s. Micromorphology of the resin protrusions on the adhesive surface was observed by laser confocal microscopy (CLSM).@*RESULTS@#For the adult teeth, the highest micro-shear bonding strength was observed in the 20 and 30 s groups, and the values were higher than that of the 10 s group (P0.05). The main break patterns in different groups comprised adhesive failure fractures and several mixed failure fractures. No resin fracture mode was observed. CLSM revealed very few short resin protrusions in 10 s adult teeth group, whereas the number and length of resin protrusions significantly increased in the 20 s adult teeth group. The resin protrusions of the 30 s group were shorter than those of the 20 s adult teeth group. In different durations, the bonding interface in different youth teeth groups presented the same trend of change as the adult teeth. However, the number and length of resin protrusions in the 10 s group of youth teeth were all higher than those of the 10 s adult teeth group.@*CONCLUSIONS@#In clinical practice, the bonding agent treatment duration shall be shortened appropriately for youth permanent teeth, and that for adult permanent teeth shall not be shortened to less than 20 s. On the whole, the bond strength of youth permanent teeth can achieve no significant difference with the adult permanent teeth.