Failed attendances at hospital dental clinics among young patients with cleft lip and palate.

OBJECTIVE: To determine the frequency of missed dental appointments among children with a cleft lip and/or palate (CL/P). DESIGN: A prospective study of failed appointments over a 12-month period. SETTING: Three different CL/P clinics within a British dental hospital. PATIENTS: Forty-five CL/P children (mean age of 8.8 years) and 45 age-matched, gender-matched, and postal code-matched noncleft patients. MAIN OUTCOME MEASURES: The overall percentage of missed appointments at three different clinics by CL/P patients and the difference in attendance rates at the pediatric dentistry clinic between CL/P and non-CL/P children. RESULTS: Pediatric dentistry had the highest rate of missed appointments (22.4%), followed by the multidisciplinary cleft clinic (9.2%) and the orthodontic clinic (8.8%). CL/P patients missed a significantly greater proportion of their pediatric dentistry appointments than noncleft children (22.4% versus 11.9%). Patients with a bilateral CL/P were significantly more likely to miss an appointment than patients with a unilateral CL/P. Age, gender, medical history, and distance traveled had no significant effect on attendance rates. CONCLUSIONS: Further work is needed to identify risk factors for poor attendance and to develop strategies to reduce the frequency of missed appointments in this vulnerable group.     

The pharmacokinetics and cardiovascular effects of high-dose articaine with 1:100,000 and 1:200,000 epinephrine

OBJECTIVES: The authors conducted a randomized, double-blind, two-way crossover clinical trial to compare the pharmacokinetics and cardiovascular effects of 11.9 milliliters of 4 percent articaine hydrochloride (HCl) plus 1:100,000 epinephrine (A100) with those of 11.9 mL of 4 percent articaine HCl plus 1:200,000 epinephrine (A200). METHODS: During two testing sessions, the authors administered injections of A100 and A200 over a seven-minute period (in one-cartridge doses unless otherwise noted): maxillary right first molar infiltration, maxillary left first molar infiltration, maxillary right first premolar infiltration, maxillary left first premolar infiltration, right inferior alveolar injection, left inferior alveolar injection, right long buccal infiltration (one-half cartridge) and left long buccal infiltration (one-half cartridge). They analyzed venous blood samples for articaine levels. They used noninvasive acoustic tonometry to measure a variety of cardiovascular parameters over a two-hour period. RESULTS: Plasma concentration curves of articaine over time were similar for both solutions, with peak concentrations and times to maximum concentration being 2,037 nanograms per milliliter and 22 minutes for A100 and 2,145 ng/mL and 22 minutes for A200. At the 10-minute point, the mean systolic blood pressure and heart rate were significantly elevated (P < .05) with A100 versus A200. CONCLUSIONS: Maximum dose recommendations for the A100 solution also can be applied to the A200 solution. A200 produces less cardiovascular stimulation than does A100. CLINICAL IMPLICATIONS: A200 is as safe as A100, and may be preferable to A100 in patients with cardiovascular disease and in those taking drugs that reportedly enhance the systemic effects of epinephrine.     

Differential growth factor retention by platelet-rich plasma composites.

PURPOSE: This study evaluates the temporal sequence and growth factor release from platelet-rich plasma (PRP) combined with different bone substitutes (BS), to identify an optimal substrate for extended growth factor retention. MATERIALS AND METHODS: PRP was clotted with bovine thrombin or thrombin receptor activator peptide-6 (TRAP). In addition, PRP was clotted using Allogro (Ceramed, Lakewood, CO), BioGlass (Mo-Sci, Rolla, MN), or BioOss (Osteohealth, Shirley, NY). The effects of media exchange and BS on platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF beta) release were quantified via enzyme-linked immunosorbent assay. RESULTS: At day 1, the thrombin group released 36% more PDGF than the TRAP group and 80% more than the BS groups. At 7 days, PDGF release was the greatest for the TRAP group. PDGF release was minimal for all groups at day 14, with BS groups retaining 60% more PDGF than thrombin clots. Similarly, the thrombin group released the greatest amount of TGF beta (81.4% of the total), whereas TRAP and BS groups released significantly less TGF beta at day 1. Compared with thrombin, TRAP retained 39.2% more TGF beta, whereas BS groups retained even greater levels (Allogro, 54.3%; BioOss, 45.8%; BioGlass, 67.0%). No significant difference in TGF beta release was observed among the substitutes after day 1. The BS groups continued to retain TGF beta after 14 days, whereas all TGF beta in the thrombin clots was depleted. CONCLUSIONS: PRP preparation with thrombin results in a large, immediate release of growth factors that could be lost into the interstitium in vivo. TRAP-BS may prove more efficacious than thrombin in sustaining growth factor levels critical for the cascade of events leading to bone formation.     

The effects of an immediately pre-surgical chlorhexidine oral rinse on the bacterial contaminants of bone debris collected during dental implant surgery

Dental implant surgery produces bone debris that can be used in the "simultaneous augmentation" technique. Although this debris is contaminated with oral bacteria, a stringent aspiration protocol has been shown to reduce the levels of contamination. Chlorhexidine mouthrinse is a well-proven antibacterial rinse that has been shown to reduce infectious complications associated with dental implants. This study examined the effect of pre-operative rinsing with a 0.1% chlorhexidine digluconate mouthrinse on the bacterial contaminants present in collected bone debris bone (CBD). Twenty partially edentate patients were randomly allocated into equal groups and underwent bone collection using the Frios Bone Collector (FBC) during the insertion of two dental implants. In group T a pre-operative chlorhexidine rinse was used, whilst in group C sterile water was used. For both groups, a stringent bone collection protocol was used. Bone samples were immediately transported for microbial analysis. Colonial and microscopic morphology, gaseous requirements and identification kits were utilised for identification of the isolated microbes. Thirty-nine species were identified including a number associated with disease, in particular Actinomyces odontolyticus, Clostridium bifermentans, Prevotella intermedia, and Propionibacterium propionicum. Samples from group T (chlorhexidine mouthrinse) yielded significantly fewer organisms (P < 0.001) than in group C (sterile water mouthrinse). Gram-positive cocci dominated the isolates from both groups. It is concluded that if bone debris is to be used for the purpose of immediate simultaneous augmentation, a preoperative chlorhexidine mouthrinse should be utilised in conjunction with a stringent aspiration protocol to reduce further the bacterial contamination of CBD.     

Comparative immunohistochemical analysis of the peptidergic innervation of human primary and permanent tooth pulp

This immunohistochemical study sought to determine whether there are any differences in the peptidergic innervation of these pulps and whether dental caries is associated with changes in neuropeptide expression. Mandibular first permanent molars and second primary molars (n=120) were obtained from children requiring dental extractions under general anaesthesia. Extracted teeth were split longitudinally, placed in fixative, and categorized as intact, moderately carious or grossly carious. The coronal pulps were removed and 10-microm frozen sections were processed for indirect immunofluorescence. Double labelling employed combinations of the following antisera: (1) protein gene product 9.5, a general neuronal marker; (2) one of the neuropeptides calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), galanin (GAL), enkephalin (ENK) and somatostatin (SOM). Image analysis was then used to determine the percentage area of immunostaining for each label within different anatomical regions of the coronal pulp. Sparse or absent immunoreactivity for GAL, ENK and SOM made analysis impossible. Analysis of CGRP, SP and VIP revealed significant interdentition differences, with their expression being significantly greater in permanent teeth, but this was not the case for NPY, with primary and permanent teeth demonstrating a similar amount of label for this peptide. Both dentitions showed significant increases in CGRP, SP, VIP and NPY expression with caries progression. These findings could have biological and clinical importance in connection with nociception, inflammation and healing.     

Mandibular overdenture treatment. Case report

Complete mandibular dentures have a significantly lower success rate compared with complete maxillary dentures. Overdentures are feasible alternatives in many instances in attempting to achieve an optimal clinical result. The case of a 56-year-old female patient requiring prosthetic rehabilitation is discussed. A complete maxillary denture and a complete mandibular overdenture were constructed.     

Gene expression analysis in cells of the dentine-pulp complex in healthy and carious teeth

Knowledge of the molecular events that occur in carious disease has so far been constrained due to difficulties in obtaining sufficient quantities of the dental tissues and cells involved. Our histological findings indicate that a pulp-odontoblast cellular complex can be obtained from carious and healthy human teeth when exposed to low-temperatures prior to pulpal extirpation and from rodent teeth processed at room-temperature. In contrast, pulpal tissue extracted from room-temperature processed human teeth and low-temperature processed rodent teeth resulted in the odontoblast layer remaining attached to the pulp chamber. Semi-quantitative RT-PCR (sq-RT-PCR) analysis confirmed that markers previously shown to be preferentially expressed in odontoblasts, namely dentin sialophosphoprotein (DSPP) and Nestin, amplified more readily from the extracted pulp-odontoblast complex, as compared to pulpal tissue alone, in both human and rodent samples. Subsequent gene expression analysis of collagen-1alpha and collagen-3alpha indicated levels were significantly higher in carious pulpal tissue. In addition, analysis characterising the expression of members of the transforming growth factor and bone morphogenic protein families and their receptors indicated in general, that these genes were expressed by healthy odontoblasts and up-regulated in both pulpal cells and odontoblasts in response to carious injury. Use of this temperature-sensitive dental tissue preparation procedure allows detection of differential gene expression in odontoblasts and other pulpal cells in healthy and carious tissue.     

An evaluation of commercial pastes for finishing composite resin surfaces

A study was conducted to determine the effectiveness of several commercial pastes in polishing the surfaces of composite resin material. Five samples of Concise composite resin contained within Plexiglas block holders were prepared using Mylar matrices. One block was disked only; three blocks were disked and polished, each with a different paste. The remaining block was the control. The surface roughness of all samples was measured with a stylus profile instrument. Five extracted teeth were prepared in the same manner with Concise composite resin and Mylar strip matrix. In each tooth, the surface was finished by disking only or by disking followed by polishing with one of three pastes. The fifth tooth was the control. The samples were examined by use of a scanning electron microscope. Quantitative evaluation of over-all computer data indicated that the smoothest surface was found immediately ater removal of the Mylar matrix and that pastes leave a rougher surface than is left with a disc.     

Weight loss from lifestyle interventions and severity of sleep apnoea: a systematic review and meta-analysis

Background

Excess body weight is a risk factor for obstructive sleep apnoea (OSA). The aim of the systematic review was to establish whether weight loss via lifestyle interventions such as diet and exercise are useful in the treatment of OSA.

Methods

A literature search was conducted between 1980 and February 2012. Systematic reviews and randomised controlled trials (RCTs) with participants who had OSA, were overweight or obese, and who had undergone lifestyle interventions with the aim of improving sleep apnoea were included. Meta analyses were conducted for a subset of RCTs with appropriate data.

Results

Two systematic reviews and eight RCTs were included. Meta-analyses were conducted for four RCTs comparing intensive lifestyle interventions to a control. The overall weighted mean differences for weight change, change in apnoea -hypopnoea index (AHI) and change in oxygen desaturation index of ≥4% were as follows: −13.76 kg (95% confidence interval (CI) −19.21, −-8.32), −16.09 (95% CI −25.64, −6.54) and −14.18 (95% CI −24.23, −4.13), respectively. Although high heterogeneity within the meta analyses, all studies favoured the interventions. Long-term follow-up data from three RCTs suggest that improvements in weight and AHI are maintained for up to 60 months.

Conclusions

Intensive lifestyle interventions are effective in the treatment of OSA, resulting in significant weight loss and a reduction in sleep apnoea severity. Weight loss via intensive lifestyle interventions could be encouraged as a treatment for mild to moderate OSA.     

Self‐rated preparedness of Australian prevocational hospital doctors for emergencies

Objective: To determine perceived preparedness of Australian hospital‐based prevocational doctors for resuscitation skills and management of emergencies, and to identify differences between doctors who perceive themselves well prepared and those who perceive themselves poorly prepared for emergencies, in demographics and exposure to desired learning methods. Methods: Questionnaire consisting of a mix of graded Likert scales and free‐text answers distributed to 36 Australian hospitals for secondary distribution to hospital medical officers. Results: From 2607 questionnaires posted, 470 (18.1%) were returned. Thirty‐one per cent (95% confidence interval [CI] 26–35%) felt well prepared for resuscitation and management of emergencies, 41% (CI 37–45%) felt adequately prepared and 28% (CI 24–32%) felt they were not well prepared. Those who felt well prepared reported that they had experienced more exposure to a range of educational methods, including consultant contact, supervisor feedback, clinical skills, high fidelity simulator sessions and unit meetings. Well‐prepared and poorly prepared doctors had similar opinions of the usefulness of various learning methods, but the poorly prepared group more frequently expressed a desire for increased exposure to contact with registrars and consultants, clinical skills sessions and hospital and unit meetings. There were no differences in gender, age or country of origin (Australia vs international medical graduates) between those who felt well or poorly prepared. Conclusions: Many prevocational hospital doctors feel inadequately prepared for the management of emergencies. Perceived preparedness is associated with more exposure to particular educational activities. Increasing exposure to learning of emergencies in undergraduate and prevocational years could reduce the number of junior doctors who feel poorly prepared for emergencies.