Does a selection interview predict year 1 performance in dental school?

It is important for dental schools to select students who will complete their degree and progress on to become the dentists of the future. The process should be transparent, fair and ethical and utilise selection tools that select appropriate students. The interview is an integral part of UK dental schools student selection procedures. OBJECTIVE: This study was undertaken in order to determine whether different interview methods (Cardiff with a multiple mini interview and Newcastle with a more traditional interview process) along with other components used in selection predicted academic performance in students. METHODS: The admissions selection data for two dental schools (Cardiff and Newcastle) were collected and analysed alongside student performance in academic examinations in Year 1 of the respective schools. Correlation statistics were used to determine whether selection tools had any relevance to academic performance once students were admitted to their respective Universities. RESULTS: Data was available for a total of 177 students (77 Cardiff and 100 Newcastle). Examination performance did not correlate with admission interview scores at either school; however UKCAT score was linked to poor academic performance. DISCUSSION: Although interview methodology does not appear to correlate with academic performance it remains an integral and very necessary part of the admissions process. Ultimately schools need to be comfortable with their admissions procedures in attracting and selecting the calibre of students they desire.

A comparison of computer- and hand-generated clinical dental notes with statutory regulations in record keeping.

INTRODUCTION: Dental patient records should be of high quality, contain information to allow for good continuity of care and clinical defence (should the need ever arise) and, ideally, facilitate clinical audit. Handwritten dental records have been assessed for their compliance to statutory regulations, but the same cannot be levelled at computer-generated notes. This study aimed to compare and analyse the compliance of both methods of data recording with statutory regulations. METHOD: Fifty consecutive sets of handwritten notes and 50 sets of computer-generated notes were audited for compliance with a number of legal requirements and desirable characteristics for dental records and the results compared. The standard set for compliance with all characteristics was 100%. RESULTS: The computer-generated notes satisfied the set standard for 8 of the 11 legal requirements and three of six desirable characteristics. The handwritten notes satisfied the set standard for 1 of 11 legal requirements and none of the desirable characteristics. A statistical difference (using a 95% confidence interval) between the two methods was observed in 5 of 11 legal characteristics and three of six desirable characteristics, all of which were in favour of computer-generated notes. CONCLUSIONS: Within the limitations of this study, computer-generated notes achieved a much higher compliance rate with the set parameters, making defence in cases of litigation, continuity of care and clinical audit easier and more efficient.

Tooth preparation for rest seats for cobalt-chromium removable partial dentures completed by general dental practitioners.

The aim of this project was to examine tooth preparations made by general dental practitioners (GDPs) for occlusal and cingulum rest seats for cobalt-chromium removable partial dentures (RPDs). Master casts and prescribed denture designs for cobalt-chromium RPDs produced by a commercial dental laboratory from impressions made by 45 GDPs across Wales were evaluated over a period of 5 months. Rest seats and associated interocclusal clearances were assessed using pre-determined criteria. A total of 68 casts were examined. Of these, 33 did not have rest seats included in their prescription. Of the remaining 35 casts, 81 rests had been prescribed of which only 24 (30%) had signs of tooth preparations for these rest seats. Using pre-determined criteria, 60% of rest seats were under-prepared in the mesio-distal plane and 30% were over-prepared in the bucco-lingual plane. In 17 cases where natural teeth opposed the rest seat, the mean interocclusal clearance was 1·5 mm (range 0·6-3·5 mm) with 6 of the 17 rests (35%) being less than the recommended thickness. In total, 18 of the 24 rests prepared did not meet the criteria, and 11 of the 21 rests prescribed had no obvious preparation and insufficient occlusal clearance. Where prescribed, the majority of rests did not meet the identified criteria. The rest seat preparations varied greatly in all planes including the interocclusal clearance. Further emphasis should be given to aspects of denture design in undergraduate and continuing education programmes for dentists.

Genetic basis for correction of very-long-chain acyl-coenzyme A dehydrogenase deficiency by bezafibrate in patient fibroblasts: toward a genotype-based therapy.

Very-long-chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency is an inborn mitochondrial fatty-acid beta-oxidation (FAO) defect associated with a broad mutational spectrum, with phenotypes ranging from fatal cardiopathy in infancy to adolescent-onset myopathy, and for which there is no established treatment. Recent data suggest that bezafibrate could improve the FAO capacities in beta-oxidation-deficient cells, by enhancing the residual level of mutant enzyme activity via gene-expression stimulation. Since VLCAD-deficient patients frequently harbor missense mutations with unpredictable effects on enzyme activity, we investigated the response to bezafibrate as a function of genotype in 33 VLCAD-deficient fibroblasts representing 45 different mutations. Treatment with bezafibrate (400 microM for 48 h) resulted in a marked increase in FAO capacities, often leading to restoration of normal values, for 21 genotypes that mainly corresponded to patients with the myopathic phenotype. In contrast, bezafibrate induced no changes in FAO for 11 genotypes corresponding to severe neonatal or infantile phenotypes. This pattern of response was not due to differential inductions of VLCAD messenger RNA, as shown by quantitative real-time polymerase chain reaction, but reflected variable increases in measured VLCAD residual enzyme activity in response to bezafibrate. Genotype cross-analysis allowed the identification of alleles carrying missense mutations, which could account for these different pharmacological profiles and, on this basis, led to the characterization of 9 mild and 11 severe missense mutations. Altogether, the responses to bezafibrate reflected the severity of the metabolic blockage in various genotypes, which appeared to be correlated with the phenotype, thus providing a new approach for analysis of genetic heterogeneity. Finally, this study emphasizes the potential of bezafibrate, a widely prescribed hypolipidemic drug, for the correction of VLCAD deficiency and exemplifies the integration of molecular information in a therapeutic strategy.

Embedding implant dentistry into the undergraduate dental curriculum.

This article represents the consensus from a meeting of the British Society of Prosthetic Dentistry's Education Group which met to discuss implant dentistry at the undergraduate student level. The consensus recognises the need to embed the teaching of implant supported prostheses if such a treatment modality is to be widely practised after graduation. This short article makes some recommendations as well as detailing some challenges and barriers that need to be overcome if implant dentistry is to be successfully embedded in an undergraduate dental curriculum.

FtsZ ring formation at the chloroplast division site in plants.

Among the events that accompanied the evolution of chloroplasts from their endosymbiotic ancestors was the host cell recruitment of the prokaryotic cell division protein FtsZ to function in chloroplast division. FtsZ, a structural homologue of tubulin, mediates cell division in bacteria by assembling into a ring at the midcell division site. In higher plants, two nuclear-encoded forms of FtsZ, FtsZ1 and FtsZ2, play essential and functionally distinct roles in chloroplast division, but whether this involves ring formation at the division site has not been determined previously. Using immunofluorescence microscopy and expression of green fluorescent protein fusion proteins in Arabidopsis thaliana, we demonstrate here that FtsZ1 and FtsZ2 localize to coaligned rings at the chloroplast midpoint. Antibodies specific for recognition of FtsZ1 or FtsZ2 proteins in Arabidopsis also recognize related polypeptides and detect midplastid rings in pea and tobacco, suggesting that midplastid ring formation by FtsZ1 and FtsZ2 is universal among flowering plants. Perturbation in the level of either protein in transgenic plants is accompanied by plastid division defects and assembly of FtsZ1 and FtsZ2 into filaments and filament networks not observed in wild-type, suggesting that previously described FtsZ-containing cytoskeletal-like networks in chloroplasts may be artifacts of FtsZ overexpression.

Molecular basis of dimethylglycine dehydrogenase deficiency associated with pathogenic variant H109R.

Dimethylglycine dehydrogenase (DMGDH) is a mitochondrial matrix flavoprotein that catalyses the demethylation of dimethylglycine to form sarcosine, accompanied by the reduction of the covalently bound FAD cofactor. Electron-transfer flavoprotein reoxidizes the reduced flavin and transfers reducing equivalents to the main mitochondrial respiratory chain through the enzyme ETF-ubiquinone oxidoreductase. DMGDH plays a prominent role in choline and 1-carbon metabolism. We have expressed the mature form of human DMGDH and the H109R variant identified in a DMGDH-deficient patient as N-terminally His(6)-tagged proteins in E. coli. The enzymes were purified to homogeneity by nickel affinity and anion exchange chromatography. The presence of FAD in the wild-type enzyme was confirmed by spectrophotometric analysis. The H109R variant, however, had only 47% of the wild-type level of bound flavin as expressed in E. coli, indicating its reduced affinity for FAD As previously described for rat enzyme studies, the wild-type human enzyme exhibited two K (m) values for N,N-dimethylglycine (K (m1) = 0.039 +/- 0.010 mmol/L and K(m2) = 15.4 +/- 1.2 mmol/L). The addition of 4 micromol/L tetrahydrofolate resulted in a slight decrease in specific activity and a substantial decrease in K (m2) (1.10 +/- 0.55 mmol/L). The flavinated H109R variant protein exhibited a 27-fold decrease in specific activity and a 65-fold increase in K (m), explaining its pathogenicity. Additionally, the current expression system represents a significant improvement over a previously described rat DMGDH expression system and will enhance our ability to further study this important metabolic enzyme.

The ability of fruit teas to remove the smear layer: an in vitro study of tubule patency.

OBJECTIVES: Fruit teas are know to have an erosive effect on enamel, but the effects on dentine are unknown. Lesions of dentine hypersensitivity have numerous patent dentinal tubules and the aim of this paper was to examine the ability of various fruit teas to remove the smear layer. METHODS: The erosive potential of a variety of fruit teas was assessed in the laboratory by measuring their pH and neutralisable acidity. Smeared dentine specimens were prepared from extracted teeth and the ability of each tea to remove the smear layer was assessed by measuring the diameter and area of the opened tubules and counting the number of patent tubules seen in a unit area using scanning electron microscopy. A 0.2% citric acid solution was used as a positive control. RESULTS: The pH of the fruit teas ranged from 2.98 to 3.95 and the neutralisable acidity ranged from 10.63 to 33.0 ml of 0.1 M NaOH. All the fruit teas tested were able to remove the smear layer. The mean diameter of the tubules ranged from 0.61 to 1.14 microm and the mean area ranged from 0.31 to 1.03 microm2. The number of patent tubules per specimen ranged from 13 to 121. CONCLUSION: All the fruit teas tested were found to be highly acidic and able to remove the smear layer.

A survey of general dental practitioners' opinions of response letters received from hospital specialists following a referred patient's first appointment.

OBJECTIVES: To discover what dentists require of a hospital response letter with regards to content and timeliness. DESIGN: Postal survey. SETTING: South Wales. SUBJECTS AND METHODS: A postal questionnaire was issued to all dentists (n = 256) who had referred a patient to the dental hospital between 1 January 2003 and 1 March 2003. RESULTS: The response rate was 60.2% (154). The preferred time frame for the receipt of a letter following a patient's appointment was one to three weeks for 96.4% (n = 133) of respondents, but 58.4% believed that they currently do not receive responses within this time frame. The preferred method of communication remained the letter (n = 82, 53%), followed by the telephone (n = 58, 38%). E-mail accounted for eight percent (n = 12) of communication. Most respondents (70%, n = 107) were satisfied with the letters' content. Eight of the ten items of information suggested as being appropriate in a response letter were considered essential by 53.2% of dentists (n = 82), and 55.8% (n = 76) believed the remaining two items to be desirable. CONCLUSIONS: Dentists agree closely on the information required in a response letter and most are satisfied with the content of current response letters. However, many dentists believe response letters arrive later than three weeks after their patient's appointment.

Enzymology of cottonseed microsomal N-acylphosphatidylethanolamine synthase: kinetic properties and mechanism-based inactivation.

An ATP-, Ca2+-, and CoA-independent acyltransferase activity, designated "N-acylphosphatidylethanolamine (NAPE) synthase", was reported to catalyze the direct acylation of phosphatidylethanolamine (PE) with free fatty acids (FFAs) in cottonseed microsomes [K.D. Chapman, T.S. Moore, Jr., Plant Physiol. 102 (3) (1993) 761-769]. Here, NAPE synthase was purified 138, 176-fold from crude cottonseed homogenates to a specific activity of 5.98 mumol min-1 mg-1 protein by immobilized artificial membrane chromatography. Enzyme purity was confirmed by the presence of a 64 kDa polypeptide in fractions analyzed by tricine-SDS-PAGE. Initial velocity measurements with various free fatty acids ([14C]-linoleic, -palmitic, -oleic, -stearic and -myristic acids) and saturating concentrations of dioleoyl-PE revealed non-Michaelis-Menten, biphasic kinetics with high and low affinity sites demonstrating positive cooperativity specific for each [14C]-FFA. In contrast to FFA substrates, no kinetic differences were observed for two different molecular species of PE, (18:1,18:1)-PE and (16:0,18:2)-PE, and biphasic curves were not pronounced. Neither [14C]-dipalmitoylphosphatidylcholine nor [14C]-palmitoyl-CoA served as acyl donors for the synthesis of NAPE, indicating a preference for FFAs as the acyl donor. Also, neither ethanolamine nor sphingosine functioned as acyl acceptor molecule to form N-acylethanolamine or ceramide, respectively, indicating specificity for the phospholipid PE. NAPE synthase was inactivated in a time- and concentration-dependent manner by diisopropylfluorophosphate (DFP) through the apparent modification of one serine residue. Palmitic acid protected the enzyme from DFP-inactivation and [14C]-DFP incorporation, suggesting that a serine residue probably binds FFAs in the enzyme's active site forming an acyl-enzyme intermediate. Collectively, these results provide new information on the kinetic behavior of a purified, integral membrane enzyme which synthesizes a bilayer-stabilizing product from two lipid-soluble substrates. The biochemical properties of cottonseed NAPE synthase are consistent with a possible free fatty acid scavenging role in vivo. (c) 1998 Elsevier Science B.V.

Photoaffinity labeling of cottonseed microsomal N-acylphosphatidylethanolamine synthase protein with a substrate analogue, 12-[(4-azidosalicyl)amino]dodecanoic acid.

N-Acylphosphatidylethanolamine (NAPE), an unusual acylated derivative of phosphatidylethanolamine (PE), is synthesized from free fatty acids and PE in cotton seedlings (Chapman and Moore (1993) Plant Physiol. 102(3), 761-769). Here we use a photoreactive dodecanoic acid analogue, [12-(4-azidosalicy)amino]dodecanoic acid (ASD), and its 125I-labeled derivative to identify a protein subunit which corresponds to this cottonseed NAPE synthase activity. Dodecylmaltoside (DDM)-solubilized microsomal NAPE synthase enzyme was irreversibly and progressively inactivated by adding increasing concentrations of ASD and illuminating with UV254 light. Protection from this photoinactivation was afforded by the natural substrate, palmitic acid. In low light, microsomal NAPE synthase utilized ASD as a substrate to synthesize NAPE; palmitic acid competed for this activity. NAPE synthase activity was measured directly in gel slices following nondenaturing PAGE of DDM-solubilized microsomal membrane proteins. Two-dimensional electrophoresis (nondenaturing PAGE, followed by SDS-PAGE) of photoaffinity-labeled, DDM-solubilized microsomal proteins revealed a 64 kDa polypeptide that was associated with the active NAPE synthase enzyme. Also, a 64 kDa protein was photoaffinity labeled in all NAPE synthase isozyme fractions isolated by preparative isoelectric focusing; photoaffinity labeling of this 64 kDa polypeptide was diminished in the presence of exogenously supplied palmitic acid. Collectively, our results demonstrate that ASD specifically interacts with NAPE synthase in a manner analogous to its fatty acid substrate and indicate that a 64 kDa polypeptide is a component of cottonseed microsomal NAPE synthase. ASD will be a useful molecular probe in future studies aimed at understanding the physiological role of this NAPE synthase enzyme in membranes of plant cells.

Does your practice website need updating?

The internet is becoming a more and more powerful tool and many dental practitioners use it to advertise their dental service; some dental practices even offer on-line appointment booking! It is not unreasonable to surmise that use of the internet is likely to become increasingly common practice by dentists in the future. This is not surprising as the World Wide Web (WWW) provides an opportunity for dentists to advertise themselves and their practices to a wide audience in a relatively economical manner.

Thermal diffusivity of composite restorative materials.

The substantial increases in the filler volume fraction of the current generation of composite resins, and the incorporation of radiopacifying heavy elements in many of these fillers, constitute significant changes which may affect thermal transport properties. Thermal diffusivity has been determined for 21 of these composite materials recommended for anterior and posterior applications. For radiopaque hybrid and for microfine composites, there was, however, only a gradual trend to increased thermal diffusivity with increasing volume fraction of inorganic filler. The diffusivity values were not greatly in excess of the level observed for dentin. Nevertheless, a small group of materials, incorporating substantial amounts of quartz or silicon nitride filler particles, exhibited high rates of thermal diffusion, up to three times the level exhibited by dentin.

Rapid purification of cotton seed membrane-bound N-acylphosphatidylethanolamine synthase by immobilized artificial membrane chromatography.

N-Acylphosphatidylethanolamine synthase (NAPES) is a membrane-bound enzyme present in cotton seedlings at a concentration of < or = 0.02% of the total protein. NAPES was purified to electrophoretic homogeneity in a single chromatographic step using immobilized artificial membrane (IAM) chromatography. The IAM column used for NAPES purification was etherIAM.PEC10/C3 and this surface contains a monolayer of immobilized phosphatidyl-ethanolamine (PE). Since PE is an analogue of the natural substrate for NAPES, etherIAM.PEC10/C3 columns function as an affinity column for this enzyme. Detergent-solubilized microsomal proteins from cotton were loaded on to the etherIAM.PEC10/C3 column and eluted with buffered mobile phases containing 0.2 mM dimyristoylphosphatidylethanolamine (DMPE) and 2 mM dodecylmaltoside. Little NAPES functional activity eluted if DMPE was removed from the mobile phase. Mobile phase DMPE is also a substrate for NAPES, both the mobile phase and IAM surface contains NAPES substrates. Mobile phase DMPE may function as both a surfactant-type affinity displacing ligand effecting protein elution and also a stabilizing factor of NAPES functional activity. The loading capacity on semi-preparative etherIAM.PEC10/C3 (6.5 x 1.0 cm) columns was ca. 5 mg of total detergent solubilized microsomal proteins, and protein recovery was quantitative. This one-step IAM purification of NAPES resulted in a single band on silver-stained polyacrylamide gels, and 3940 fold increase in NAPES specific activity. The molecular mass of the purified NAPES protein is 64,000. 125I labeled [12-(4-azidosalicyl)amino]dodecanoic acid is a photoreactive fatty acid substrate of NAPES that was used to confirm protein purity.

Effects of toothbrushing prior and/or subsequent to dietary acid application on smear layer formation and the patency of dentinal tubules: an SEM study.

Dentine sensitivity is a quite common condition, associated with open dentinal tubules patent all the way to the pulp. The purpose of this in vitro study was to assess the effects of toothbrushing preceded and/or followed by dietary acid application on the patency of dentinal tubules. Dentine sections were prepared from recently extracted human molars and, after removal of the smear layer, were treated as follows: 1) toothbrushing alone; 2) toothbrushing followed by exposure to orange juice; and 3) toothbrushing subsequent to orange juice exposure. All specimens were observed in the scanning electron microscope (SEM) at a standard magnification and the patency of the dentinal tubules estimated. Results showed that toothbrushing alone was the most effective in occluding the tubules, followed by toothbrushing subsequent to dietary acid application, and then by toothbrushing prior to dietary acid application. From the results of this study it may be that in cases of dentine sensitivity toothbrushing should not precede or follow dietary acid application but be separate from mealtimes. Clinical research is required to confirm the findings of this in vitro study.

A report of an elective to the Hospital for Sick Children and Bloorview Macmillan Centre, Toronto.

The Department of Dentistry based at the Hospital for Sick Children and Bloorview MacMillan Centre in Toronto is unique. It provides treatment for cleft lip and palate patients and all forms of specialist dental treatment to children and adolescents resident in Ontario. The quality of service provided by the department has been externally recognised and validated through an ISO 9002 award (February 1999). At that time, it was the first Dental Clinic in North America to receive the ISO 9002 standard. In addition, the American Cleft Palate-Craniofacial Association has recognised the department for its organisation and contributions in the field of cleft lip and palate and craniofacial surgery.

A radiographic study of post-retained crowns in patients attending a dental hospital.

A total of 327 post-retained crowns were examined radiographically and a number of features were assessed including the length of post, length of remaining root filling, periapical condition, fit and angulation of the post and quality of root filling. The post length was equal to or greater than that of the crown in only 34% of cases. Although the majority of posts fitted well laterally, 43% did not extend longitudinally as far as the end of the prepared post hole. Some 20% deviated from the line of the root canal but the number of actual lateral perforations was small. A total of 47% of the teeth had areas of radiolucency around the root apices. A majority of root fillings were judged to be unsatisfactory and there was no radiographic evidence of any root filling at all in nearly 10% of cases.

Opinions of dental consultants on the standard of referral letters in dentistry.

AIM: To ascertain the views of dental consultants on the relative importance of a range of topics relevant to specialist referral. SUBJECTS: 200 randomly selected dental consultants working in the UK in 1995. MAIN OUTCOME MEASURES: Data items which referral letters should contain; standard of referral letters; appropriate reasons for referral; how referrals could be improved; should restrictions be placed on specialist referrals. RESULTS: 161 replies were received. Overall there was only slight variation between specialities with regard to data items, appropriateness of referral and standard of referral letter. The perceived standard of referral letters was adequate or better on 76% of occasions; 21% were deemed to be of a poor standard; 2% were described as appalling. CONCLUSIONS: A Section 63 course on how to refer competently could be of benefit. Consultants were generally not in favour of restricting referrals to them.

Case report: the use of heat-treated gold alloy following palatal tooth surface loss.

The use of veneers in dentistry has become a widely used and accepted technique for the treatment of various dental anomalies. The literature is replete with reference to the use of labial veneers but with less on the use of palatal veneers. This paper reports on the use of gold palatal veneers in the treatment of palatal tooth surface loss in two patients. Although not new the technique described has much to commend it; it is simple, not tooth destructive and has been shown to be successful in the treatment of palatal tooth surface loss.

Case report: treatment of the late eruption of an ectopic maxillary canine.

A case is documented which presents an unusual sequence of events that led to the eruption of a previously impacted tooth. Treatment using fixed appliances and restorative measures achieved an acceptable result for the patient.