Comparison of indirect pulp treatment and iRoot BP Plus pulpotomy in primary teeth with extremely deep caries: a prospective randomized trial.

OBJECTIVES: The purpose of this randomized controlled trial was to compare the 24-month success rates of indirect pulp treatment (IPT) and iRoot BP Plus pulpotomy of primary molars with extremely deep caries. MATERIALS AND METHODS: Generally healthy children aged 3-7 years requiring general anesthesia for treating primary molars with extremely deep caries or reversible pulpitis were recruited. Patients with systemic disease, mental health problems, or manifestations of irreversible pulpitis were excluded. In total, 175 molars were randomized and blinded for either IPT (n = 87) or iRoot BP Plus pulpotomy (n = 88). All teeth were restored with stainless steel crowns and evaluated after 6, 12, 18, and 24 months by two blinded calibrated investigators. Kaplan-Meier survival curves were used to compare the survival rates between the groups. The correlations between success rate and patient characteristics were explored with the Cox proportional hazards model. RESULTS: A total of 168 primary molars in 67 patients (average age: 3.83 years) were evaluated. The cumulative survival probability at 24 months was not significantly different between the IPT (93.8%) and pulpotomy (97.7%) groups (P = 0.238). IPT treatment success was significantly associated with age (odds ratio = 2.347; 95% CI: 1.068-5.156; P = 0.034) and preoperative sensitivity (odds ratio = 9.742; 95% CI: 1.079-87.970; P = 0.043). CONCLUSIONS: The 24-month success rates of IPT and iRoot BP Plus pulpotomy performed in primary molars with extremely deep caries were not significantly different. Increasing age and preoperative sensitivity were found to be associated with the cumulative survival probability in IPT-treated primary molars with extremely deep caries. Primary teeth with extremely deep carious lesions without signs of irreversible pulpitis can be treated successfully by either indirect pulp capping or iRoot BP Plus pulpotomy. TRIAL REGISTRATION: ChiCTR2000032462.

[Three dimensional bioprinting technology of human dental pulp cells mixtures].

OBJECTIVE: To explore the three dimensional(3D)bioprinting technology, using human dental pulp cells (hDPCs) mixture as bioink and to lay initial foundations for the application of the 3D bioprinting technology in tooth regeneration. METHODS: Imageware 11.0 computer software was used to aid the design of the 3D biological printing blueprint. Sodium alginate-gelatin hydrosol was prepared and mixed with in vitro isolated hDPCs. The mixture contained 20 g/L sodium alginate and 80 g/L gelatin with cell density of 1×10(6)/mL. The bioprinting of hDPCs mixture was carried out according to certain parameters; the 3D constructs obtained by printing were examined; the viability of hDPCs after printing by staining the constructs with calcein-AM and propidium iodide dye and scanning of laser scanning confocal microscope was evaluated. The in vitro constructs obtained by the bioprinting were cultured, and the proliferation of hDPCs in the constructs detected. RESULTS: By using Imageware 11.0 software, the 3D constructs with the grid structure composed of the accumulation of staggered cylindrical microfilament layers were obtained. According to certain parameters, the hDPCs-sodium alginate-gelatin blends were printed by the 3D bioprinting technology. The self-defined shape and dimension of 3D constructs with the cell survival rate of 87%± 2% were constructed. The hDPCs could proliferate in 3D constructs after printing. CONCLUSION: In this study, the 3D bioprinting of hDPCs mixtures was realized, thus laying initial foundations for the application of the 3D bioprinting technology in tooth regeneration.

[Determinations of the bonding strength with pressure in the same direction for two enamel adhesion techniques: self-etching and all-etching].

OBJECTIVE: To compare the shear strength of the self-etching techniques and the all-etching techniques for enamel adhesion and to provide evidence for the selection of different bonding methods in clinical practice. METHODS: Ten middle incisors recently extracted were collected, each was cut into two parts following its sagittal axis, thus divide each tooth into two groups. For group 1 Single Bond 2 was used to bond Filtek Z250 resin to the teeth. For group 2, SE Bond was used to bond Filtek Z250 resin to the teeth. After that, according to the principle of pressing from the incisal margin to the cervix, the shear strength of each bonding unit was tested and statistically analyzed. RESULTS: The shear strength of Single Bond 2 was significantly higher than that of SE Bond(P<0.01). CONCLUSION: All-etching bonding system can provide higher shear strength for enamel bonding than that of self-etching bonding system. It is suggested that all-etching technique should be selected for dental restoration with resin.