Conservative aesthetic techniques for discoloured teeth: 2. Microabrasion and composite

The first article in this series discussed the minimal intervention approach to discoloured teeth, starting with dental bleaching. This second article goes on to explain the technique of microabrasion and the use of direct composite techniques. CLINICAL RELEVANCE: Microabrasion and composite can provide minimally invasive treatments for discoloured teeth.     

A slow release calcium delivery system for the study of reparative dentine formation

Abstract— Several liquid, semi-solid and solid delivery systems were formulated and tested to devise a method of reproducibly administering accurate micro-doses of calcium into a 700 μm diameter cakity in a rat maxillary incisor tooth, in the absence of hydroxyl ions. Development of this delivery system was necessary to facilitate studies of the mechanisms of pulpal repair and odontoblast differentiation. The principal requirements for the delivery system were that it should be easily administered into a small pulp exposure in the rat incisor and that a greater than 1000-fold range in calcium ion concentrations could be incorporated and delivered for a period of 2–3 days, preferably in an acidic environment to minimize the effect of non-specific nucleation under alkaline conditions. Poly ethylene) glycol microspheres were found to be an ideal vehicle. Under the in vivo dissolution conditions used, complete release of all calcium salts occurred within 12–15 hours, except for the very water-insoluble calcium stearate. It was anticipated that the re lease of calcium ions would be significantly more prolonged in vivo because of the physical constraints of the prepared cavity as well as the restricted access to fluid flow.     

Testing the applicability of a conceptual model of oral health in housebound edentulous older people

Abstract – Objectives: The aim of the study was to test prospectively Wilson and Cleary’s ( 1 ) conceptual model of the direct and mediated pathways between symptom burden, functional status and health perceptions in relation to the oral health of housebound elderly edentulous people. Methods: The data were collected as part of a community based randomized control trial of a domiciliary denture service for older people. Measures of self‐reported symptoms, functional status and global oral and general health perceptions were collected from 133 participants prior to treatment and at 3‐month follow‐up. Results: The results indicated support for the dominant direct and indirect pathways within the model; worse patient reported symptoms predicted a lower functional status; worse daily functioning predicted lower global oral health perceptions. In addition, the impact of symptom status on oral health perceptions was mediated by patient reported functioning. The treatment (domiciliary denture service) significantly improved functional status and global oral health perceptions. All relationships were significant prospectively that is, from baseline, prior to the intervention, to 3‐month follow‐up, with the exception of between symptoms functioning. Conclusion: The results support Wilson and Cleary’s conceptual model of patient outcomes as applied to elderly edentulous people. They highlight the importance of assessing a range of patient‐orientated variables in order to help gain a greater understanding of how oral health impacts on individuals’ daily lives and well‐being. Further conceptual development of the model is discussed, particularly the role of individual difference factors.     

Ultrastructural characteristics of axons in traumatic neuromas of the human lingual nerve

AIMS: To determine the ultrastructural characteristics of axons in traumatic neuromas of the human lingual nerve during the surgical removal of lower third molar teeth and to establish whether any characteristics were different between patients with dysesthesia and patients without dysesthesia. METHODS: Transmission electron microscopy was used to determine the ultrastructural morphological characteristics of human lingual nerve neuromas (n = 34) removed at the time of microsurgical nerve repair. From a sample population of myelinated and nonmyelinated fibers within the neuromas, fiber diameter, myelin thickness, g-ratio, and the number of mitochondria per axon were quantified. Comparisons were made with normal control lingual nerve specimens (n = 8) removed at the time of organ donor retrieval. RESULTS: Significant differences in ultrastructural morphology were found between the neuromas and control nerves. The neuromas contained a higher proportion of small (2- to 8-microm diameter) myelinated nerve fibers than controls, and the mean myelinated fiber diameter was significantly lower in neuromas than in controls. Mean myelin sheath thickness was significantly thinner in neuromas (0.6 +/- 0.1 microm) than in controls. However, the g-ratio, which is a measure of the myelination status of the nerve fibers in relation to their diameter, was found to be similar in each group, suggesting a normal process of myelination in the damaged axons. Nonmyelinated axon diameter was also significantly smaller in the neuromas than in the controls, and Schwann cells were found to sheathe more nonmyelinated axons in neuromas than in controls. The ratio of nonmyelinated to myelinated axons was significantly higher in neuromas than in controls. However, no significant differences were found between patients with dysesthesia and those without dysesthesia. CONCLUSION: Damage to the lingual nerve results in marked changes to axon diameter, myelin sheath thickness, and Schwann cell-axon relationships. These ultrastructural changes could contribute to the altered electrophysiological properties of axons trapped within neuromas. However, no significant differences in the ultrastructural characteristics studied were found between specimens from patients with or without symptoms of dysesthesia.     

Experimental observation of a theoretically predicted nonlinear sleep spindle harmonic in human EEG

Objective: To investigate the properties of a sleep spindle harmonic oscillation previously predicted by a theoretical neural field model of the brain.     

Validation of the Defining Characteristics of the Nursing Diagnosis Ineffective Airway Clearance

The investigators designed this validation study to determine the defining characteristics of the nursing diagnosis ineffective airway clearance. Using Fehring's Diagnostic Content Validity Model, 546 nurses who care for respiratory clients validated one major and 19 minor defining characteristics. Nine characteristics previously described in the literature were eliminated. Clarification of the defining characteristics of this diagnosis improves communication in practice, education and research.     

An early shoulder repositioning program in birth-related brachial plexus injury: a pilot study of the Sup-ER protocol

Background

Birth-related brachial plexus injury (BRBPI) occurs in 1.2/1,000 births in British Columbia. Even in children with “good” recovery, external rotation (ER) and supination (Sup) are often weaker, and permanent skeletal imbalance ensues. A preventive early infant shoulder passive repositioning program was created using primarily a novel custom splint holding the affected arm in full ER and Sup: the Sup-ER splint. The details of the splint and the shoulder repositioning program evolved with experience over several years. This study reviews the first 4 years.

Methods

A retrospective review of BCCH patients managed with the Sup-ER protocol from 2008 to 2011 compared their recovery scores to matched historical controls selected from our database by two independent reviewers.

Results

The protocol was initiated in 18 children during the study period. Six were excluded due to the following: insufficient data points, non-compliance, late splint initiation, and loss to follow-up. Of the 12 matches, the Sup-ER group final score at 2 years was better than controls by 1.18 active movement scale (AMS) points (p = 0.036) in Sup and 0.96 AMS points in ER (but not statistically significant (p = 0.13)). Unexpectedly, but importantly, during the study period, zero subjects were assessed to have the active functional criteria to indicate brachial plexus reconstruction, where previously we operated on 13 %.

Conclusions

Early application of passive shoulder repositioning into Sup and ER may improve outcomes in function of the arm in infants with BRBPI. A North American multi-site randomized control trial has been approved and has started recruitment.