Placement of Posterior Composite Restorations: A Cross-Sectional Study of Dental Practitioners in Al-Kharj, Saudi Arabia

Toward a Clinically Reliable Class II Resin Composite Restoration: A Cross-Sectional Study into the Current Clinical Practice among Dentists in Saudi Arabia

Objective

The aim of this study was to evaluate the current clinical practice of general dentists in Saudi Arabia in restoring class II cavities using direct resin composites and to set evidence-based practice recommendations of concern.

Methods

An online survey formed of 20 questions and classified into four domains was developed. 500 dentists in 5 Saudi provinces were invited to join the survey anonymously and voluntarily using poster announcements and e-mail invitations. Descriptive statistics were used to analyze participants' responses.

Results

343 responses were received. Dentists in Saudi Arabia vary in their clinical practices and techniques of insertion of resin composite in class II cavities. 67% of participants use cotton rolls for isolating the field while 32% use rubber dam isolation. 33% and 28% of respondents use circumferential matrix (Tofflemire) and AutoMatrix, respectively. Fracture, followed by recurrent caries and open proximal contacts, was the received main reason of failure of class II direct resin composite restorations.

Conclusion

Diversity of class II resin composite practices exists among dentists in Saudi Arabia. For ensuring optimum quality outcomes and high standards of restorative dentistry healthcare, several dentists in Saudi Arabia need to reconsider their clinical practice and modify their clinical procedures of direct class II resin composites. Several evidence-based practice guidelines are recommended to dentists in this article to improve their practice and enhance the clinical reliability and longevity of class II direct resin composite restorations.

Effects of thermal cycling on mechanical and antibacterial durability of bioactive low-shrinkage-stress nanocomposite

OBJECTIVES

Recent studies developed low-shrinkage-stress composite with remineralizing and antibacterial properties to combat secondary caries and increase restoration longevity. However, their long-term durability in thermal cycling is unclear. The objectives of this study were to develop an antibacterial, remineralizing and low-shrinkage-stress composite, and to investigate its durability in thermal cycling for 20,000 cycles, equivalent to two years of clinical life.

METHODS

The resin consisted of urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE). Composites were made with 5% dimethylaminohexadecyl methacrylate (DMAHDM) and 20% of nanoparticles of amorphous calcium phosphate (NACP). Composites were thermal cycled at 5°C and 55°C for 20,000 cycles. A human salivary biofilm model was used to evaluate antibiofilm activity before and after thermal cycling.

RESULTS

After 20,000 cycles, the flexural strength of bioactive low-shrinkage-stress composite matched commercial control with no antibacterial activity (p > 0.05). Surface roughness was clinically acceptable at less than 0.2 μm. UV+NACP+DMAHDM composite reduced the total microorganisms, total streptococci, and mutans streptococci by 2-5 logs, compared to commercial composite. Biofilm lactic acid production was reduced by 11 folds. The antibacterial performance was maintained after thermal cycling, with no decrease after 20,000 cycles.

CONCLUSIONS

Bioactive low-shrinkage-stress composite possessed good mechanical properties that matched commercial composite both before and after thermal cycling. The new composite had potent antibacterial activity, which was maintained and did not decrease after thermal cycling.

CLINICAL SIGNIFICANCE

The new bioactive low-shrinkage-stress composite could reduce polymerization shrinkage stress and release calcium and phosphate ions, with good mechanical properties and strong antibacterial function that were durable after thermal cycling. These properties indicate great potential for inhibiting recurrent caries and increasing the restoration longevity.

Activation of the stress response among the cardiac surgical residents: comparison of teaching procedures and other (daily) medical activities

BACKGROUND

The aim of this Pilot study was to investigate the cardiac surgical residents' workload during different surgical teaching interventions and to compare their stress levels with other working time spent in the intensive care unit or normal ward.

METHODS

The objective stress was assessed using two cardiac surgical residents' heart rate variability (HRV) both during surgical activities (32 selected teaching operations (coronary artery bypass graft n = 26 and transcatheter aortic valve implantation n = 6), and during non-surgical periods. Heart rate, time and frequency domains as well as non-linear parameters were analyzed using the Wilcoxon test.

RESULTS

The parasympathetic activity was significantly reduced during the surgical phase, compared to the non-surgical phase: Mean RR (675.7 ms vs. 777.3 ms), RMSSD (23.1 ms vs. 34.0 ms) and pNN50 (4.7% vs. 10.6%). This indicates that the residents had a higher stress level during surgical activities in comparison to the non-surgical times. The evaluation of the Stress Index during the operations and outside the operating room (8.07 vs. 10.6) and the parasympathetic nervous system index (- 1.75 to - 0.91) as well as the sympathetic nervous system index (1.84 vs. 0.65) confirm the higher stress level during surgery. This can be seen too used the FFT Analysis with higher intraoperative LF/HF ratio (6.7 vs. 3.8).

CONCLUSION

HRV proved to be a good, objective method of identifying stress among physicians both in and outside the operating room. Our results show that residents are exposed to high psychological workloads during surgical activities, especially as the operating surgeon.