Effect of sodium ascorbate on the shear bond strength of orthodontic brackets to bleached enamel using universal dental adhesive

Background

The aim of this study was to investigate the effect of bleaching agent, sodium ascorbate as an antioxidant, and delay time on the shear bond strength (SBS) of orthodontic brackets to enamel using Transbond XT and universal adhesive.

Materials and Methods

In this in vitro experimental study, 80 extracted maxillary premolars without any defect or decay were randomly divided into eight groups of 1: no bleaching + Transbond XT (NB/TX) bonding agent, 2: no bleaching + All-Bond Universal (NB/AB), 3: bleaching + Transbond XT (B/TX), 4: bleaching + All-Bond Universal (B/AB), 5: bleaching + sodium ascorbate + Transbond XT (B/SA/TX), 6: bleaching + sodium ascorbate + All-Bond Universal (B/SA/AB), 7: bleaching + Transbond XT after a 3-week delay (B/3W/TX), and 8: bleaching + All-Bond Universal after a 3-week delay (B/3W/AB). After thermocycling (1000 cycles, 5-55°C), the SBS was measured, and the adhesive remnant index scores were determined to assess the failure mode. Data were analyzed by one-way analysis of variance, Tamhane's post hoc test, Kruskal-Wallis, and Mann-Whitney U-test at the significance level of P < 0.05.

Results

The mean SBS range was 5.5-29.78 MPa. The highest SBS values were related to Group 2 (NB/AB) which were significantly higher than all groups (P < 0.05) and the lowest values were observed in Group 5 (B/SA/TX) which were significantly lower than all groups except Group 3 (B/TX) (P < 0.05).

Conclusion

Bleaching with 40% hydrogen peroxide significantly decreased the SBS of orthodontic brackets, and 10% sodium ascorbate could not reverse the adverse effect of bleaching on SBS. Delaying the bonding procedure by 3 weeks using Universal adhesive considerably decreased the adverse effect of bleaching on SBS and increased the SBS to a clinically acceptable level for orthodontic treatment.

Reconstruction of a common bile duct injury by venous bypass

Hepaticojejunostomy is the standard technique for the reconstruction of severe iatrogenic lesions of the common bile duct (CBD), although the technique itself is major surgery with a complication rate up to 30%. We report a case of a male patient with a iatrogenic complete transsection of the CBD. Due to multiple previous operations and the present inflammation a standard reconstruction technique was not possible to perform. A neo-bile duct was created using a segment of the Great Saphenous Vein (GSV) synchronously with an external biliary drainage by PTCA and biliary stenting (after 4 weeks). The stent was removed 8 months later. Cholangiography showed normal bile flow without occlusion. Blood tests normalised. We believe that using an autologous vein graft in combination with a removable or biodegradable stent is the right track for the reconstruction of the CBD in the future.

Adenosine deaminase activity in fertile and infertile men

Adenosine deaminase (ADA; E.C.3.5.4.4) catalyses the deamination of adenosine to inosine. In the human reproductive system, the importance of enzymes that affect metabolism of adenosine, particularly adenosine deaminase, has been noticed. The purpose of this study was to determine the plasma activities of total adenosine deaminase (ADAT), and its isoenzymes, ADA1 and ADA2, in fertile and infertile men. Plasma activities of ADA and its isoenzymes were measured in 55 fertile men and 70 infertile men. There was a significant difference in the ADA1 and ADA2 activities between fertile and infertile individuals (P < 0.01). The activity of ADAT, ADA2 and ADA1 in infertile men was higher than that in fertile individuals. This alteration in ADA activity can lead to reduced adenosine levels, which may be involved in disturbing the fertility process.

Outpatient laparoscopic cholecystectomy in Belgium: what are we waiting for?

BACKGROUND

The current advances and expertise in minimally invasive surgery and the present importance of cost containment have encouraged the performance of laparoscopic cholecystectomy (LC) as an ambulatory procedure. A retrospective study was carried out to assess the feasibility, outcome and patients' preference and satisfaction after performing true day-case LC in a university teaching hospital.

METHODS

All patients admitted consecutively between January 2003 and March 2005 for LC were considered for inclusion in the study. Patients were offered ambulatory treatment if they were ASA class 1 or 2, had no clinical signs of acute cholecystitis or pancreatitis, and had a responsible carer at home. All others underwent a routine LC. Reasons for refusing day-surgery LC were analyzed. Postoperative complications, conversion rate, overnight stay and patient satisfaction were all evaluated.

RESULTS

A total of 249 LCs were performed. Only 15 (6%) were performed in an ambulatory setting. Reasons for refusing day-surgery were medical (42%), doubt about reimbursement by insurance companies (15%) or psychological (49%). All patients were treated for symptomatic cholecystolithiasis. Unplanned admission was 13% because of excessive nausea and vomiting. Outpatient follow-up showed that overall patient satisfaction was over 80%.

CONCLUSION

Considering an increasing trend towards reduced hospital stay, ambulatory LC is feasible and safe, showing high levels of patient satisfaction. Adequate prophylaxis of postoperative nausea, vomiting and pain management is necessary. However, the provision of adequate information to the patient by the referring physician is essential to avoid refusal of ambulatory treatment. Insurance companies have to be more liberal with their policies for day-case surgery.