BACKGROUND:A number of in vitro experiments have confirmed that the tricalcium silicate not only can be closely integrated with the dentin through self-curing process, but also can induce dentin remineralization in the physiological environment, thereby effectively blocking the dentinal tubules.
OBJECTIVE:To further verify the effects of tricalcium silicate solution on the occlusion of dentinal tubules.
METHODS:Thirty-six dentinal discs were made of free first premolars from orthodontic patients, and divided into three pretreatment groups randomly. The teeth were soaked in pretreatment solution for 2 minutes, namely 0.29 mol/L ethylene diamine tetraacetie acid, 6%citric acid, and rinsed ultrasonical y with deionized water 20 minutes, respectively. Every above-mentioned group was randomly assigned into experimental group (tricalcium silicate), control group (sodium fluoride) and blank group, and corresponding materials in each group were used to coat the outer dentinal tubules (2 minutes/time). Then, the dentinal discs were saved in artificial saliva in a 37 observed using scanning electron microscope. Diameter and area of open dentinal tubules were calculated.
RESULTS AND CONCLUSION:After pretreatment, the dentinal tubules were at open state;except for the blank control group to maintain the original state, acid etching and ethylene diamine tetraacetie acid pretreatment solutions had a stronger capacity of demineralization, which led to the dentinal tubules open. After the dentinal tubules were treated with sodium fluoride and tricalcium silicate, there were varying degrees of sediments, and open dentinal tubule area and average diameter in the sodium fluoride and tricalcium silicate groups were lower than those in the control group (P<0.05). The dentinal tubule treated with tricalcium silicate was almost entirely closed homogeneously, and occasional y, a single open dentinal tubule was seen. Open dentinal tubule area and average diameter in the tricalcium silicate group were significantly lower than those in the sodium fluoride group (P<0.05). The findings verify that dentin occlusion using tricalcium silicate is superior to that using sodium fluoride;and dentin tubule pretreatment with acid etching or ethylene diamine tetraacetie acid is beneficial to desensitization effects.

Objective To compare the dosimetric difference between RapidArc and fixed gantry angle dynamic IMRT (dIMRT) for central-type lung cancer radiotherapy. Methods Therapy for 10 patients previously treated with dIMRT was replanned with RapidArc. Dose prescription was 66 Gy/33 fraction. Comparative endpoints were planning target volume (PTV) dose, doses to surrounding structures,number of monitor units, and treatment delivery time. Results There was no significant dosimetric difference between RapidArc and dIMRT. Compared with dIMRT, RapidArc slightly elevated target volume dose, lung V5, V10. The average values of lung V20, V30 and heart V30 were larger in dIMRT than those in RapidArc. The number of monitor units was reduced by 32% and the treatment time by 66% in RapidArc.Conclusions Both RapidArc and dIMRT plans could meet the clinical therapy needs. RapidArc could achieve similar target coverage and sparing of organs at risk, with fewer monitor units and shorter delivery time than dIMRT.

Objective To analyze relevant clinical and dosimetric factors associated with radiation pneumonitis in patients with stage Ⅲ non-small cell lung cancer after they received radical radiotherapy.Methods A total of 126 patients with stage Ⅲ non-small cell lung cancer who received precision radiotherapy in Peking University Cancer Hospital were analyzed from January 2013 to December 2014.Data were collected including various clinical factors (including sex,age,histological type,tumor location,history of diabetes,history of hypertension,history of smoking,the season patients received treatment,ECOG performance status before treatment,chemotherapy before radiotherapy,concurrent chemotherapy and the classification of radiation pneumonitis),as well as related dosimetric parameters [including GTV,lung volume (LV),bilateral V5,V10,V20,V30 and MLD].SPSS 19.0 software was used to analyze the relation between correlation factors and radiation pneumonitis (RP≥2).Results Among the patients,31 cases (24.6％) had occurrance of radiation pneumonitis ≥ 2.Univariate analysis showed that age,ECOG performance status before treatment,concurrent chemotherapy and GTV/LV ratio were significantly correlated with RP ≥ 2 (R =0.157-0.222,P ＜ 0.05).Further multivariate Logistic regression showed that age,concurrent chemotherapy and GTV/LV ratio were significantly correlated (Wald =4.754,6.422,14.79,P ＜ 0.05).Conclusions In patients with stage Ⅲ non-small cell lung cancer after receiving thoracic radical radiotherapy,increasing age and GTV/LV ratio≥3.2％ are risk factors of RP≥2.The concurrent chemotherapy with low-dose paclitaxel might also increase the risk of RP≥2.

Humans ; Botulinum Toxins, Type A/therapeutic use* ; Esotropia/drug therapy* ; Neuromuscular Agents ; Injections ; Treatment Outcome ; Oculomotor Muscles