Perception of patients attending a tertiary hospital in Nigeria about good dental practice: A pilot study

Background: Criteria for a good dental practice as expressed by patients have influence on their behavior in terms of compliance with clinical advice, less pain and anxiety and more utilization of dental care.Objective: To assess the opinion of patients attending the dental clinic of a tertiary hospital Southwestern, Nigeria about their perception of a good dental practice.Materials and Methods: A 16 item semi‑structured bi‑lingual interviewer‑administered questionnaire comprising socio‑demographic characteristics and 24 criteria of a good dental practice generated by clinicians and patients was administered to 156 patients who were blinded from knowing which criteria were clinicians’ or patients’ criteria. Patients were then asked to pick 12 criteria out of the 24 criteria that they considered of greater priority. Frequency of the most picked criteria in a descending order was determined. Student’s t‑test was used to compare mean scores at P < 0.05.Results: The mean age of study participants was 36.7 ± 13.8 years. The majority 139 (89.1%) of the study participants ranked ‘‘clinician’s procedure should be as painless as possible’’ as the most important clinician determined criteria of a good dental practice while 31 (19.9%) of them ranked hotlines available for emergencies as the least. The majority 133 (85.2%) of the study participants ranked ‘‘sterile procedure and proper handling of equipment’’ as the most important patient determined criteria of a good dental practice while 30 (19.2%) of them ranked patients being attended by just one clinician as the least. There was a statistically significant difference between mean scores of clinicians’ criteria and patients’ criteria (P = 0.00001), participants ranked more patients’ criteria than clinicians’ criteria.Conclusion: In determining the criteria for a good dental practice, clinicians’ perspective as well as patients’ perspective should be considered.Keywords: Clinicians, dental house officers, good dental practice, patientsNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue

Factors that influence the quality of final impressions for fixed dental prostheses in Nairobi, Kenya

Background: Good quality dental impressions free of air bubbles, voids, steps, drags, streaks and tears are a pre-requisite for the fabrication of well-fitting fixed dental prostheses (FDP). The quality of impressions is dependent on clinician and material factors. Aim: To evaluate factors that influence the quality of final impressions for FDP in Nairobi, Kenya.  Methods: In this cross-sectional study, 234 impressions received by five dental laboratories were analyzed. The study collected information on the type of tray, impression material, technique, type of prostheses, and clinically detectable errors, including voids, inadequate material at margins, tears, steps, drags, and streaks. Impression quality was the outcome assessed as good, fair, or poor by two investigators. The independent variables influencing impression quality included clinician specialty, experience, impression material, technique, and tray type. Results: Inter-rater agreement was 96.8% (p<0.001). Clinician experience ranged between 1-45yrs, median 13.5yrs and mean 8.39±11.96yrs. The majority were GPs, 80.8% while restorative dentists were 11.5% and other specialists, 7.7%. Most impressions were non-aqueous elastomers, 97.9% employing dual-viscosity technique, 75.6%. Impression trays included stock metal, 60.3%, stock plastic, 34.2%, and custom, 5.5%. Impression quality was good, 24.8%, fair, 37.2% or poor, 38.0%. Cumulatively, 74.5% impressions had bubbles/voids, 53.0% tears and 43.2% poor margins. Clarity of margins was associated with clinician specialty, (Fisher’s exact=9.372, p=0.047), and impression technique with impression quality, (Pearson’s ?2 = 6.385, p=0.041). Compared to restorative specialists, estimated odds of other specialists producing poor margins was 5.71, 95%CI 1.55,21.06, Wald ?2=5.24, p=0.009 while for GPs, the estimated odds was 2.19, 95%CI 0.88, 5.43, Wald ?2 = 2.86, p=0.09. Compared to dual viscosity, estimated odds of monophase giving a poor-quality impression was 1.52, 95%CI 0.83,2.78, Wald ?2 = 1.52, p=0.18. Conclusion: Most impressions were good or fair hence acceptable. Quality of impressions was influenced by clinician specialty and impression technique

Exploring the xylose paradox in Saccharomyces cerevisiae through in vivo sugar signalomics of targeted deletants

Background: There have been many successful strategies to implement xylose metabolism in Saccharomyces cerevisiae, but no effort has so far enabled xylose utilization at rates comparable to that of glucose (the preferred sugar of this yeast). Many studies have pointed towards the engineered yeast not sensing that xylose is a fermentable carbon source despite growing and fermenting on it, which is paradoxical. We have previously used fluorescent biosensor strains to in vivo monitor the sugar signalome in yeast engineered with xylose reductase and xylitol dehydrogenase (XR/XDH) and have established that S. cerevisiae senses high concentrations of xylose with the same signal as low concentration of glucose, which may explain the poor utilization. Results: In the present study, we evaluated the effects of three deletions (ira2δ, isu1δ and hog1δ) that have recently been shown to display epistatic effects on a xylose isomerase (XI) strain. Through aerobic and anaerobic characterization, we showed that the proposed effects in XI strains were for the most part also applicable in the XR/XDH background. The ira2δisu1δ double deletion led to strains with the highest specific xylose consumption- and ethanol production rates but also the lowest biomass titre. The signalling response revealed that ira2δisu1δ changed the low glucose-signal in the background strain to a simultaneous signalling of high and low glucose, suggesting that engineering of the signalome can improve xylose utilization. Conclusions: The study was able to correlate the previously proposed beneficial effects of ira2δ, isu1δ and hog1δ on S. cerevisiae xylose uptake, with a change in the sugar signalome. This is in line with our previous hypothesis that the key to resolve the xylose paradox lies in the sugar sensing and signalling networks. These results indicate that the future engineering targets for improved xylose utilization should probably be sought not in the metabolic networks, but in the signalling ones

Using phosphoglucose isomerase-deficient (pgi1Δ) Saccharomyces cerevisiae to map the impact of sugar phosphate levels on d-glucose and d-xylose sensing

Abstract Background Despite decades of engineering efforts, recombinant Saccharomyces cerevisiae are still less efficient at converting d-xylose sugar to ethanol compared to the preferred sugar d-glucose. Using GFP-based biosensors reporting for the three main sugar sensing routes, we recently demonstrated that the sensing response to high concentrations of d-xylose is similar to the response seen on low concentrations of d-glucose. The formation of glycolytic intermediates was hypothesized to be a potential cause of this sensing response. In order to investigate this, glycolysis was disrupted via the deletion of the phosphoglucose isomerase gene (PGI1) while intracellular sugar phosphate levels were monitored using a targeted metabolomic approach. Furthermore, the sugar sensing of the PGI1 deletants was compared to the PGI1-wildtype strains in the presence of various types and combinations of sugars. Results Metabolomic analysis revealed systemic changes in intracellular sugar phosphate levels after deletion of PGI1, with the expected accumulation of intermediates upstream of the Pgi1p reaction on d-glucose and downstream intermediates on d-xylose. Moreover, the analysis revealed a preferential formation of d-fructose-6-phosphate from d-xylose, as opposed to the accumulation of d-fructose-1,6-bisphosphate that is normally observed when PGI1 deletants are incubated on d-fructose. This may indicate a role of PFK27 in d-xylose sensing and utilization. Overall, the sensing response was different for the PGI1 deletants, and responses to sugars that enter the glycolysis upstream of Pgi1p (d-glucose and d-galactose) were more affected than the response to those entering downstream of the reaction (d-fructose and d-xylose). Furthermore, the simultaneous exposure to sugars that entered upstream and downstream of Pgi1p (d-glucose with d-fructose, or d-glucose with d-xylose) resulted in apparent synergetic activation and deactivation of the Snf3p/Rgt2p and cAMP/PKA pathways, respectively. Conclusions Overall, the sensing assays indicated that the previously observed d-xylose response stems from the formation of downstream metabolic intermediates. Furthermore, our results indicate that the metabolic node around Pgi1p and the level of d-fructose-6-phosphate could represent attractive engineering targets for improved d-xylose utilization