Complete dentures: an update on clinical assessment and management: part 2.

The ability to provide high quality complete dentures remains an important skill for general dental practitioners. The prevalence of edentulism is increasingly concentrated within an older patient cohort and general dental practitioners may face challenges associated with providing care for these patients. This two-part series explores various aspects of complete denture provision and is designed to act as a refresher on the management of edentulous patients. This second part focuses on the copy denture technique as well as discussing strategies for assessing and managing gag reflexes, prominent palatal and lingual tori and microstomia.

Complete dentures: an update on clinical assessment and management: part 1.

The ability to provide high-quality complete dentures has been a key skill for general dental practitioners throughout the history of dental care. The prevalence of edentulism is becoming increasingly concentrated in an older patient cohort and general dental practitioners may more commonly face challenges associated with providing care for these patients. This two-part series explores various aspects of complete denture provision and is designed to act as a refresher on core aspects of managing these patients, while also covering common challenges associated with anatomical or patient factors. This first part will explore changes in the provision and teaching of complete denture care in the UK and will describe important aspects of patient examination. It will discuss the management of unstable lower dentures and fibrous replacement ridges. Part two will cover management of the gag reflex, tori, microstomia and copy dentures.

Glucodynamics of long-acting basal insulin peglispro compared with insulin glargine at steady state in patients with type 1 diabetes: substudy of a randomized crossover trial.

AIMS: To compare, in an open-label, randomized, crossover phase II substudy, the glucodynamics of insulin glargine and those of basal insulin peglispro (BIL) in patients with type 1 diabetes. METHODS: Patients (n = 23) underwent 24-h euglycaemic clamps after 8 weeks of treatment with glargine or with BIL. Clinically-titrated basal insulin doses (BIL group 16-64 U; glargine group 19-60 U) were administered on the morning of the clamp. RESULTS: At baseline, the patients' mean ± standard deviation (s.d.) body mass index was 26.78 ± 4.20 kg/m2 and glycated haemoglobin was 7.69 ± 0.99%. The mean ± s.d. endpoint dose for the BIL group was 0.42 ± 0.13 U/kg and for the glargine group was 0.42 ± 0.10. The daily mean ± s.d. blood glucose concentration was 7.7 ± 1.2 in the BIL group and 7.9 ± 1.2 mmol/l in the glargine group (p = 0.641). The mean ± s.d. total and nocturnal hypoglycaemia rates/30 days were 2.7 ± 2.3 and 0.5 ± 0.8, respectively, for the BIL group, and 3.0 ± 2.4 and 0.7 ± 1.1, respectively, for the glargine group (p = 0.112 and 0.428). The mean glucose infusion rate (GIR) normalized to insulin unit was lower for BIL than for glargine. One patient in the glargine group and eight patients in the BIL group had minimal (<0.8 g/kg) GIRs over 24 h. The mean ± s.d. total glucose infused over 24 h (GTOT(0-24) ) was 1.22 ± 0.82 g/kg in the BIL group and 1.90 ± 1.01 g/kg in the glargine group (p = 0.002). The mean ± s.d. total glucose infused during hours 0-6 (GTOT(0-6) ) was 0.21 ± 0.22 in the BIL group and 0.41 ± 0.22 g/kg in the glargine group (p < 0.001), while the mean total glucose infused during hours 18-24 (GTOT(18-24) ) in the BIL group was 0.28 ± 0.18 g/kg and in the glargine group was 0.35 ± 0.23 g/kg (p = 0.198). The peak-to-trough ratio was 1.41 for BIL versus 2.22 for glargine. CONCLUSIONS: BIL has a flatter profile than glargine, with potentially more stable metabolic control. The lower GTOT(0-24) observed in the BIL group is consistent with BIL's reduced peripheral action.

Effects of sulfur and acidity on performance and digestibility in feedlot lambs fed dried distillers grains with solubles.

Negative interactions of the acidity and S content of dried distillers grains with solubles (DDGS) have not been quantified. The objectives of this study were to determine the effects of dietary S, dietary acidity, and their interactions on growth, feed efficiency, ruminal H2S concentration, and apparent nutrient digestibility in lambs fed DDGS-based diets. To neutralize acidity, the DDGS was untreated or treated with 2% NaOH. Dietary S content was adjusted with Na2SO4 to achieve a 0.2 percentage unit difference in dietary S. Experiment 1 included 72 ewe and wether lambs (BW = 24.9 ± 0.4 kg) penned by sex in 24 pens, blocked by BW, and allotted in a 2 × 2 factorial arrangement of treatments for a 60 d feeding trial. On a DM basis, diets were: i) 60% DDGS + 0% Na2SO4, ii) 60% DDGS + 0.88% Na2SO4, iii) 62% NaOH-treated DDGS + 0% Na2SO4, and iv) 62% NaOH-treated DDGS + 0.83% Na2SO4. There were no interactions (P ≥ 0.19) of dietary S concentration and NaOH treatment. Lambs fed DDGS treated with 2% NaOH had 4% greater (P = 0.05) final BW and tended (P ≤ 0.07) to have greater DMI and ADG than lambs fed untreated DDGS; however, NaOH treatment did not affect (P = 0.42) G:F. Increasing dietary S with Na2SO4 tended (P = 0.07) to reduce DMI; however, dietary S did not affect (P > 0.17) ADG, G:F, or final BW. Rumen H2S concentration in gas samples collected on d 32 and 60 were not (P > 0.17) affected by dietary S or NaOH treatment. Experiment 2 included 24 lambs (initial BW = 43.0 ± 4.4 kg) used to determine the effects of NaOH treatment of DDGS and sulfur (Na2SO4) supplementation on N retention and the apparent digestibility of NDF, ADF, and OM. Treatments were similar to those used in Exp. 1, except that dietary DDGS was reduced to 45% of DM. Intake of DM, NDF, ADF, and N was not affected (P > 0.16) by NaOH treatment of DDGS or dietary S (Na2SO4) content. Treating DDGS with 2% NaOH reduced (P = 0.05) NDF digestibility by 10% compared with lambs fed untreated DDGS. Urine pH for lambs consuming DDGS treated with 2% NaOH was increased (P = 0.01) 1.74 pH units compared with urine from lambs fed untreated DDGS. Nitrogen intake and retention were not affected (P > 0.35) by dietary S concentration or NaOH treatment of DDGS. For feedlot lambs, treating DDGS with 2% NaOH did not lower ruminal H2S concentrations, but tended to increase ADG and DMI. Although treating DDGS with 2% NaOH was an effective way to neutralize the acidity in DDGS, this treatment reduced NDF digestibility.

Safety, pharmacokinetics and pharmacodynamics of multiple-ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus.

AIMS: To assess the safety, pharmacokinetics and pharmacodynamics of multiple-ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus (T2DM). METHODS: This randomized, single-blind, placebo-controlled, monotherapy study was carried out in two parts. In part A, 32 patients received AZD1656 (7, 20, 40 or 80 mg) twice daily or placebo for 8 days in hospital. In part B, another 20 patients received, as outpatients, individually titrated AZD1656 15-45 mg twice daily or placebo for 28 days. Safety, pharmacokinetics and pharmacodynamic variables were evaluated. RESULTS: AZD1656 was generally well tolerated. Pharmacokinetics of AZD1656 were virtually dose- and time-independent. AZD1656 was rapidly absorbed and eliminated. An active metabolite was formed which had a longer half-life than AZD1656, but showed ∼15% of the area under the plasma concentration versus time curve from 0 to 24 h compared with that of AZD1656. Renal excretion of AZD1656 and the metabolite was low. In part A, fasting plasma glucose (FPG) was reduced by up to 21% and mean 24-h plasma glucose was reduced by up to 24% with AZD1656 versus placebo, depending on dose. No dose-related changes in serum insulin or C-peptide were observed with AZD1656 at the end of treatment. Results in part B confirmed the glucose-lowering effect of AZD1656 versus placebo. CONCLUSIONS: AZD1656 was well tolerated with predictable pharmacokinetics in patients with T2DM. Dose-dependent reductions in plasma glucose were observed.

Neuropsychological assessment, depression, and past exposure to organic solvents.

This study assessed neuropsychological performance in persons with a history of exposure to organic solvents and nonexposed healthy controls. Structured clinical interviews were also done to determine current Axis I diagnosis of mood disorder to assess the contribution of mood disorder to neuropsychological performance. Solvent-exposed participants were found to have significantly reduced scores on 3 of 5 neuropsychological clusters (learning and memory, visuospatial, psychomotor speed) compared to controls. No differences were found between the groups on measures of general intelligence. Within the exposed group, 50% met current Axis I criteria for mood disorder. Hierarchical multiple regression, controlling for age and education, revealed that mood disorder was significantly related to performance on only the visuospatial domain. There was no association between mood disorder and measures of learning and memory, attention, motor speed, and general intelligence. Higher ratings of past exposure were associated with poorer scores on learning and memory tests and slower times on speeded tests. These findings are consistent with other research documenting deficits in neuropsychological and psychiatric functioning in exposed workers.

Respiratory sinus arrhythmia in persons with organic solvent exposure: comparisons with anxiety patients and controls.

Persons exposed to organic solvents have psychiatric symptomatology and cognitive impairments. The results of several studies have suggested that some psychiatric symptoms in these patients reflect similar reactions observed in patients with anxiety disorders. Respiratory sinus arrhythmia provides an indication of impaired autonomic functioning. Whereas decreased respiratory sinus arrhythmia has been reported in anxiety patients, investigators have also noted that higher respiratory rates in these patients obscure differentiation of respiratory sinus arrhythmia from normal values. In this study, the authors recorded multiple parameters of respiratory sinus arrhythmia under a paced-breathing condition in 28 patients with solvent exposure, in 18 patients with anxiety disorder, and in 31 controls. The authors observed a high 1-y retest reliability for a subset of the subjects. Significantly reduced respiratory sinus arrhythmia was observed in both anxiety and solvent-exposed patients, compared with controls. Maximum mean heart rates/cycle did not differ among groups, but minimum heart rates were significantly lower for controls than for the two patient groups. The findings suggested that reduced respiratory sinus arrhythmia among patients is not related to higher maximum rates but, rather, to a decrease in vagally mediated alteration associated with respiratory changes observed in both patient groups.

Clinical crown length changes from age 12-19 years: a longitudinal study.

OBJECTIVE: The objective of this study was to investigate the relationship between age, gender and clinical crown length using a longitudinal study design. METHOD: Four hundred and fifty-six sets of study models initially obtained for a large prospective longitudinal cohort study of orthodontic needs were examined. Each set of models corresponded to subjects at three different ages: 11-12, 14-15 and 18-19years old. The clinical crown height of the maxillary right central incisor (11), maxillary right canine (13), maxillary left lateral incisor (22) and mandibular left central incisor (31) was measured from gingival crest to the incisal edge using digital calipers. RESULTS: Analysis revealed a significant (p<0.0001) age effect on crown length for all four teeth investigated. A significant gender effect was found in relation to the maxillary right canine, maxillary right central incisor and maxillary left lateral incisor. Pairwise comparisons of the means for each age group for the maxillary right canine, maxillary right central incisor and maxillary left lateral incisor revealed significant (p<0. 0001) increases in clinical crown length between each assessment period. CONCLUSION: The findings of the present study indicate that, the process of passive eruption, resulting in increased clinical crown length appears to continue throughout the teenage years. This finding is considered to be of importance to the clinician making treatment decisions for teenagers and young adults requiring treatment in the anterior segments of the mouth.

Mood and behavioral symptoms in individuals with chronic solvent exposure.

Psychiatric symptoms have been reported for individuals who experience chronic exposure to low levels of organic solvents. However, it is not known what proportion of such individuals experience psychiatric disorder; which specific disorders may be characteristic of this population; or whether bioaccumulation of lead contributes to the relationship between solvent exposure and psychiatric symptoms. Twenty-nine male journeymen painters and 32 male non-painter control subjects were administered semi-structured diagnostic interviews for DSM-III-R Axis I and Axis II disorders. Career solvent exposure and blood lead levels were also measured. Painters and control subjects did not differ significantly with respect to age, intelligence, or demographic characteristics. Results showed that the probability of being diagnosed with a mood disorder differed significantly in painters (41%) and control subjects (16%). Painters (66%) and control subjects (50%) did not differ for substance use diagnoses. Groups also did not differ for personality disorders involving an onset before 25 years of age. In contrast, painters exhibited a sub-clinical pattern of personality dysfunction involving symptomatology that was measured allowing for late onset (after age 25). Finally, a significant dose-response relationship was observed between career solvent exposure, blood lead level, and personality symptoms. In summary, these data showed an increased rate of psychological disturbance in a significant and substantial number of painters. However, not all painters were so characterized. This overall pattern raises a question regarding a potential role for differential vulnerability, which requires empirical validation.

Students' perceptions of seminar and lecture-based teaching in restorative dentistry.

In an era of self-directed learning, it is important to seek the views of dental students regarding their learning experience. Using an anonymous questionnaire, clinical dental students' perceptions of seminar and lecture-based teaching in restorative dentistry were sought. 116 of 136 questionnaires circulated were returned for analysis giving a response rate of 85%. Clinical seminars as opposed to lectures were, in the opinion of the students, a more effective way of learning, more relevant to self-development and more interactive. Seminar-based learning was considered to be more amenable to self-direction than formal didactic lectures. It is concluded that the students included in this study were found to prefer seminar-based learning opportunities as opposed to more traditional styles of learning, specifically, didactic lectures.

Increased incidence of anxiety and depressive disorders in persons with organic solvent exposure.

OBJECTIVE: The purpose of this study was to determine whether the prevalence of current and past DSM-IV axis I psychiatric disorders is higher among persons with a history of exposure to organic solvents than among a demographically similar group of nonexposed control subjects. METHODS: Thirty-eight solvent-exposed subjects and 39 nonexposed healthy control subjects were evaluated for axis I disorder with the Structured Clinical Interview for DSM-IV. RESULTS: A significantly higher number of solvent-exposed subjects (71%) met criteria for current DSM-IV axis I disorder in comparison with control subjects (10%). The most prevalent diagnosis in exposed subjects was within the anxiety and mood clusters, with a high percentage (36%) of exposed subjects meeting criteria for a dual diagnosis of mood and anxiety disorder. There were no differences between the groups in past psychiatric disorders or current or past substance abuse or dependence. CONCLUSIONS: The rates of past psychiatric disorders among solvent-exposed subjects are similar to those among normal control subjects, but the prevalence of current DSM-IV axis I psychiatric disorders is significantly higher among exposed subjects than among control subjects.

Case report: restorative maintenance of prostheses stabilised by non-endosseous implants.

For over a century, dentists have looked to dental implants to enhance the stability of dental prostheses. During this time, many approaches and different materials have been used. The purpose of this article is to report on two cases where non-endosseous implant systems were used and to outline how the replacement prostheses were customiZed to comply with the different implant types. Intramucosal inserts and sub-periosteal implants are briefly reviewed in the context of current prosthodontic practise. There are still a small number of patients with clinically acceptable intramucosal and subperiosteal implant retained prostheses, which will continue to need servicing and replacement.

A chemomechanical method for caries removal.

Over recent years the dental profession has shifted towards practising preventive dentistry and adopting more conservative and tooth-preserving procedures. Such progression is considered to be a response to the decline in the level of dental caries and advances in materials science. This shift in caries management will no doubt continue over the coming decades, based on rational clinical and scientific principles. Chemomechanical caries removal involves the application of a solution that selectively softens the carious dentine, thus facilitating its removal. This limits the removal of sound tooth structure, the cutting of open dentinal tubules, pulpal irritation and pain compared with conventional mechanical methods.

Neurobehavioral effects of acute exposure to inorganic mercury vapor.

Mercury has well-established toxic effects on the central nervous system. This article describes comprehensive neuropsychological and emotional functioning of a group of 13 workers exposed to inorganic mercury vapor compared to that of a normal control group. The exposed group was exposed over a 2- to 4-week period and had elevated blood mercury levels. The evaluations were conducted between 10 and 15 months after exposure was terminated. Observed cognitive deficits included impairment in the following domains: motor coordination, speeded processing with and without a motor component, cognitive flexibility, verbal fluency, verbal memory, and visual problem solving and conceptualization. Emotional problems included increased focus on physical functioning, depression, anxiety, and social withdrawal. Cognitive deficits were, for the most part, not significantly associated with the degree of depression present.

Predictors of involvement in P300 latency in solvent-exposed adults.

Persons with a history of exposure to organic solvents have been shown to have cognitive and personality changes, as well as abnormalities on measures of neurophysiology (e.g., delays in P300 latency). Studies assessing long-term sequelae in exposed persons have been limited, especially those using neurophysiologic measures. This study assessed cognitive event-related potentials (ERPs) in 16 persons with a history of organic solvent exposure at two testings, separated, on average, by 1.5 years. The sample was divided into persons who showed improvement on P300 latency (e.g., reduction in latency of 1.5 SD of control group) and those who did not. Sixty-three percent showed no improvement, whereas 37% showed significant improvement. Recency of exposure and the interaction of exposure duration and history of peak exposure significantly predicted group membership. That is, persons with shorter duration of exposure coupled with no peak exposures and longer time from exposure to test were more likely to fall in the improved group. Substituting age for duration of exposure in the interaction term improved classification of the two groups. The results support previous findings that most exposed persons do not show significant improvements over time. The results further suggest that there is a need to assess factors, such as aging, which may make one more vulnerable to the neurotoxic effects of solvents.

PET scan findings in a patient with a remote history of exposure to organic solvents.

This is a single-case study employing positron emission tomography (PET) scanning and neuropsychological assessment on a 47-year-old male with a 15-year history of repeated respiratory and dermal exposure to high levels of organic solvents with at least 750 peak exposures (i.e., solvent "intoxication"). At age 43, he presented with neuropsychological symptoms of a solvent encephalopathy and multiple abnormalities in his peripheral neurological examination but had normal MRI and EEG findings. Four years after cessation of exposure to degreasing and solvent chemicals, the patient produced a grossly abnormal PET scan in which frontal, hippocampal, and parietal hypometabolism were particularly noteworthy. During this same 4-year period of nonexposure, modest improvements in neuropsychological testing were noted, along with substantial improvements in partial seizurelike symptoms. Frontal lobe deficits elicited in testing and from collateral interview, however, did not change. Findings suggest that repeated peak exposures to organic solvents m y result in a neurobehaviorally complex solvent syndrome caused by central nervous system damage that is readily apparent on PET scan, even though it is not evident in either imaging technologies. In addition, the case is the first reported in which functional neuroimaging was employed to study a patient with chronic solvent encephalopathy many years after cessation of solvent exposure.

Neuropsychological performance of journeymen painters under acute solvent exposure and exposure-free conditions.

Journeymen painters were evaluated with a comprehensive battery of neuropsychological tests and compared to demographically similar nonexposed controls. For painters, a cumulative exposure to solvents was estimated from a structured interview that derived an index based on lifetime exposure and exposure in the past year. Painters were tested either shortly after having painted or after an exposure-free interval. Significant between-group differences were found on a cluster of tests measuring learning and memory. Within the painter group, scores on the learning and memory tests were significantly related to the interaction of condition and exposure. That is, those painters who were tested soon after painting and who also had a higher overall lifetime exposure, performed worst on tests of learning and memory. These results are consistent with the view that neuropsychological function--particularly learning and memory--may be compromised in active workers with a history of chronic solvent exposure. Furthermore, both the chronicity of solvent exposure, as well as the acuteness of the exposure, are significant factors in cognitive performance.

Testing the neural sensitization and kindling hypothesis for illness from low levels of environmental chemicals.

Sensitization in the neuroscience and pharmacology literatures is defined as progressive increase in the size of a response over repeated presentations of a stimulus. Types of sensitization include stimulant drug-induced time-dependent sensitization (TDS), an animal model related to substance abuse, and limbic kindling, an animal model for temporal lobe epilepsy. Neural sensitization (primarily nonconvulsive or subconvulsive) to the adverse properties of substances has been hypothesized to underlie the initiation and subsequent elicitation of heightened sensitivity to low levels of environmental chemicals. A corollary of the sensitization model is that individuals with illness from low-level chemicals are among the more sensitizable members of the population. The Working Group on Sensitization and Kindling identified two primary goals for a research approach to this problem: to perform controlled experiments to determine whether or not sensitization to low-level chemical exposures occurs in multiple chemical sensitivity (MCS) patients; and to use animal preparations for kindling and TDS as nonhomologous models for the initiation and elicitation of MCS.

Comorbid illness is associated with survival and length of hospital stay in patients with chronic disability. A prospective comparison of three comorbidity indices.

OBJECTIVES: This study was designed to determine if comorbidity added more information than knowing only the patient's age in predicting survival and length of hospital stay. METHODS: The authors compared the relative predictive validity of three comorbidity indices: the Cumulative Illness Rating Scale, the Charlson Index, and a count of International Classification of Diseases, 9th Revision, Clinical Modification medical diagnoses in relation to survival and length of hospital stays in patients with spinal cord injury. The sample consisted of 330 longitudinally followed spinal-cord injured patients admitted between January 1989 and December 1990 who were followed for an additional 18 months. RESULTS: During the follow-up, 25 (7.5%) patients died and 249 (75.5%) were readmitted to hospital with a median of one admission (range, 1-8). The corresponding lengths of hospital stay ranged from 0 to 548 days, with a median of 7 days. CONCLUSIONS: Patients who died were not significantly older but had higher comorbidity scores. Using patients alive at the end of the follow-up period, linear regression models were fit to the data to determine if comorbidity added more information regarding length of hospital stay than knowing only the patient's age. In the model that included only age as an independent variable, there was a significant relation between age and length of stay (F(1,303) = 5.2; P = 0.012). The R2 value for this model was 0.017. In further models that included age and each of the three comorbidity scores (separately) as the independent variables, the model that included age and the Cumulative Illness Rating Scale yielded the highest R2 value (R2 = 0.062). This study is among the first to compare three different measures of comorbidity and documents that comorbidity provides more information than knowing only the patient's age in relation to survival and length of hospital stay.