OBJECTIVES: This study aims to evaluate the differences in shear bond strength, marginal adaptation, and nano-microleakage after aging among snowplow, layered filling, and lining techniques applied to the resin-bonded restoration of defective primary teeth. METHODS: In this study, 51 freshly extracted, crown-intact primary anterior teeth and 30 primary molars were collected. The experimental groups were as follows: layered filling group, lining group, and snowplow group. Experiments were performed to compare the differences in shear bond strength, marginal integrity, and silver ion nano-microleakage after aging among these groups. RESULTS: The median shear bond strength of the layered filling group, lining group, and snowplow group were 2.45, 5.72, and 9.43 MPa, respectively. The values for lining group and snowplow group were significantly higher than that for layered filling group (P<0.05). No statistically significant difference was found between lining group and snowplow group (P>0.05). The median overall margin integrity of the layered filling group, lining group, and snowplow group were 55.38%, 48.25%, and 65.63%, respectively. The difference among the three groups was not statistically significant (P>0.05). The median percentages of silver ion nano-microleakage in the layered filling group, lining group, and snowplow group were 11.71%, 9.47%, and 11.55%, respectively. The difference among the three groups was not statistically significant (P>0.05). CONCLUSIONS Applying the snowplow technique to restore defective primary teeth can improve the bond strength and margin integrity and reduce nano-microleakage.
Tooth, Deciduous ; Humans ; Dental Restoration, Permanent/methods* ; Dental Leakage ; Shear Strength ; Dental Bonding/methods* ; Molar ; Composite Resins ; Silver

Objective:To observe the application value of "Internet +" based case teaching method combined with objective structured clinical examination (OSCE) teaching method in the teaching of nursing students in the Department of Nephrology, and analyze its impact on nursing student satisfaction of teaching.Methods:A total of 60 nursing students who practiced in the Department of Nephrology, Jiangsu Provincial People's Hospital from January 2021 to June 2022 were selected as the research subjects. They were randomly divided into observation group and control group, with 30 students in each group. The control group adopted traditional teaching method, and the observation group adopted case teaching method based on "Internet +" combined with OSCE teaching method. SPSS 25.0 statistical software was used for data analysis, and independent sample t-test was used to compare the clinical practical work ability and teaching satisfaction of the two groups of nursing students after teaching. Results:After 4 weeks of teaching, the total scores of clinical thinking ability, disease observation and evaluation ability, mastery of medical knowledge, standardized operation ability, communicative ability, adaptive ability, humanistic care and health literacy of the observation group were higher than those of the control group [(29.84±3.52) vs. (25.67±3.36), (5.81±1.52) vs. (4.34±1.67), (17.93±2.24) vs. (15.52±2.05), (25.72±2.73) vs. (22.17±2.56), (4.18±0.75) vs. (3.56±0.69), (83.48±6.67) vs. (71.26±7.05)], with a statistically significant difference ( P < 0.05); after 4 weeks of teaching, the teaching preparation, teaching process, teaching ability, teaching attitude, teaching effect and total score of the observation group were higher than those of the control group [(17.13±2.42) vs. (15.07±1.84), (36.44±3.12) vs. (34.07±2.49), (21.97±2.36) vs. (21.37±2.01),(17.00±2.36) vs. (16.83±2.23), (17.73±2.00) vs. (14.07±2.55), (110.27±5.51) vs. (101.40±4.58)], and the difference was statistically significant ( P<0.05). Conclusions:The case teaching method based on "Internet +" combined with OSCE can not only effectively improve the clinical practical work ability of nursing students in the department of nephrology, but also improve student satisfaction of teaching.