Transformational Leadership and Employees' Thriving at Work: The Mediating Roles of Challenge-Hindrance Stressors.

Based on previous research, the conceptual model presenting the interaction between transformational leadership, challenge-hindrance stressors and thriving at work was constructed and used to generate the hypotheses for the study. Data were obtained from 542 questionnaires distributed across different organizations. The participants included ordinary employees, grassroots middle and senior managers from China. The major findings are as follows. First, transformational leadership directly is positively related to challenge stressors and thriving at work. Second, challenge stressors are positively relate to thriving at work, while hindrance stressors are negatively relate to thriving at work. Furthermore, challenge stressors mediate the relationship between transformational leadership and thriving at work. Given these findings, the study examined the moderating effect of supervisor developmental feedback on the relationship between transformational leadership and thriving at work. Results reveal that supervisor developmental feedback plays a positive regulatory role between challenge stressors and thriving at work. Additionally, it is shown that the mediating effect of challenge stressors on the relationship between transformational leadership and thriving at work is moderated by supervisor developmental feedback.

The dentin permeability of anti-inflammatory and antibacterial drugs: In vitro study.

BACKGROUND/PURPOSE: Stimuli from the oral cavity may penetrate through exposed dentinal tubules and evoke inflammatory pulp response. Anti-bacterial and anti-inflammatory drugs applied to exposed dentin may infiltrate through the dentinal tubules and cause pulp recovery. This study investigated the dentin permeability of anti-bacterial and anti-inflammation drugs via an in-vitro transwell dentin disc tube model. METHODS: Twenty-seven dentin discs prepared from extracted human molars were collected. Nine kinds of drugs were investigated with three dentin discs in each group. These nine drugs included two anti-bacterial drugs (ampicillin sodium and clindamycin phosphate), two corticosteroids (betamethasone sodium phosphate and hydrocortisone sodium succinate), three non-steroidal anti-inflammatory drugs (NSAIDs, piroxicam, lysine acetylsalicylate, and diclofenac sodium), and two natural extracts with anti-inflammatory effect (Ginsenoside Rg1 and Hinokitol). The drugs were introduced to the transwell dentin disc tube model and the 4-hour cumulative release of the drug was detected and recorded by UV-visible spectroscopy. RESULTS: We found that ampicilin sodium had better dentin permeability than clindamycin phosphate. Betamethasone sodium phosphate revealed better dentin permeability than hydrocortisone sodium succinate. Lysine acetylsalicylate showed the best dentin permeability among the three NSAIDs. Ginsenoside Rg1 had the best dentin permeability among the nine drugs tested. However, Hinokitiol could not penetrate the dentin disc after 4 h. CONCLUSION: Regarding the dentin permeability, Ginsenoside Rg1 is the best among the seven anti-inflammatory drugs tested and ampicilin sodium is the better one between the two anti-bacterial drugs tested. Therefore, these two drugs may have high potential for treating exposed dentinal tubule diseases.

Trigeminocardiac reflex during non-surgical root canal treatment of teeth with irreversible pulpitis.

BACKGROUND/PURPOSE: Trigeminocardiac reflex (TCR) is a unique clinical incident of acute change in hemodynamic balance, which may lead to hypotension, bradycardia, and even clinical crisis. Up to date, no study so far considers the impact of non-surgical root canal treatment (NSRCT) of irreversible pulpitis teeth under either local infiltration or block anesthesia on hemodynamic change possibly related to TCR. METHODS: This study enrolled 111 patients with 138 irreversible pulpitis teeth that were treated by two sessions of NSRCT. The first session involved mainly the removal of vital pulp tissue with the direct stimulation of the dental branches of the trigeminal nerve, and the second session included the root canal enlargement and debridement with minimal disturbance to the dental branches of the trigeminal nerve. Vital signs mainly the blood pressure were recorded during both NSRCT sessions. RESULTS: The incidences of NSRCT patients with MABP decrease ≧10%, ≧15%, or ≧20% were all significantly higher in the first NSRCT session than in the second NSRCT session (all the P-values < 0.001). In the first NSRCT session, the incidence of patients with MABP decrease ≧10% was significantly associated with tooth type. For both upper and lower teeth, the patients with premolars treated by NSRCR had significantly higher incidences of MABP decrease ≧10% than those with either anterior or molar teeth treated by NSRCR (all the P-values < 0.05). CONCLUSION: We conclude that vital pulp extirpation may lead to a substantial drop in patient's blood pressure possibly related to TCR.

Blood pressure reduction in patients with irreversible pulpitis teeth treated by non-surgical root canal treatment.

BACKGROUND/PURPOSE: The hypotension in patients during non-surgical root canal treatment (NSRCT) has not yet investigated. This study aimed to assess the mean systolic blood pressure (MSBP), mean diastolic blood pressure (MDBP), and mean arterial blood pressure (MABP) reduction percentages in patients with irreversible pulpitis teeth treated by NSRCT. MATERIALS AND METHODS: We prospectively recruited 111 patients with a total of 138 irreversible pulpitis teeth. All patients underwent two NSRCT sessions. The first NSRCT session involved mainly the removal of vital pulp tissue with the direct stimulation of the dental branches of the trigeminal nerve, and the second NSRCT session included the root canal debridement and enlargement with minimal disturbance to the dental nerves. The blood pressure of each patient was recorded before and during both NSRCT sessions. RESULTS: There were significantly higher reduction percentages of MSBP, MDBP, and MABP in the first NSRCT session than in the second NSRCT session for all treated patients (all the P-values < 0.001). If the patients were divided into 2 or more groups according to the clinical variables including the patients' gender, age, tooth type, and anesthesia type, we also found significantly higher reduction percentages of MSBP, MDBP, and MABP in the first NSRCT session than in the second NSRCT session for all treated patients except for patients below 40 years of age and for patients with lower anterior teeth treated (all the P-values < 0.05). CONCLUSION: The decrease in blood pressure in patients receiving vital pulpal extirpation is a relatively common phenomenon.