Evaluation of the integrity of dental sealants by optical coherence tomography

Objectives

The purpose of the present research was to demonstrate images of failures into the structure of pit and fissure sealants using optical coherence tomography (OCT).

Methods

Five human third molars were selected and the sealant ALPHA SEAL LIGHT/DFL was applied according to the manufacturer instructions. For evaluation of the structure of pit and fissure sealants, twenty OCT images of each tooth were performed before and after application of sealant. A total of 200 images were evaluated. A home built spectral OCT system used was operating in spectral domain (SD-OCT), at 840 nm and a measured spatial resolution of 10 μm. The system is based on the Michelson interferometer set-up and is controlled by the software OCT 800 - Complex Square/LabView, that collects data and generates the image. The occlusal surfaces were scanned in a bucco-lingual direction and tomographic images parallel to long axis of tooth were obtained. After the achievement of the images by OCT, the crown of each tooth was sectioned in a occlusogingival direction (buccolingually). Images from each section were obtained and evaluated by an optical microscope. OCT and microscopic images were compared.

Results

Representative images showed that OCT image provides the insight into sealant material. It was possible to clearly identify the internal structure of sealant and the subjacent enamel. Sealant and enamel are very well distinguished, and failures at the interior and at surface are well detected.

Significance

OCT could generate images of the features of fissures, bubbles and failures in the adaptation of sealants, opening up possibilities in the future to monitoring sealant application and retention in short and long term.     

Estimating the need for dental sedation. 1. The Indicator of Sedation Need (IOSN) - a novel assessment tool

While the control of pain and anxiety is fundamental to the practice of dentistry, the use of conscious sedation in dentistry is very variable among dentists. The need for conscious sedation could be considered by assessing and ranking a combination of information on patient anxiety, medical history and the complexity of the anticipated clinical treatment. By undertaking this systemtic assessment an indication of sedation need may be developed which would act as an aide to decision making and, potentially, referral management. Such a tool could also be used by commissioners who need to identify patients who need conscious sedation for dental treatment in order to plan, commission and deliver appropriate sedation services.     

Mucosal malignant melanomas in head and neck surgery: a retrospective study of six patients and review of the literature

Introduction

Of all malignant processes of the oral mucosa, 0.5% are malignant melanomas. Because of late diagnosis, pattern of growth, close proximity to the bone (particularly in palatinal localizations), and the correlated infiltration, malignant melanomas have a bad prognosis.

Patients and methods

In this retrospective study, six cases of patients with oral mucosal malignant melanoma are evaluated, and a critical review of the literature is presented. The female to male proportion was 1:1 with an average age of 60.2 years; all patients were treated between January 1999 and July 2007. A neck dissection was performed on two patients because of clinically positive lymph nodes; one patient received interleukin 2 therapy, and three patients received postoperative radiotherapy. Two male patients died.

Conclusions

We recommend biopsy on every growing lesion, pigmented or nonpigmented, for the required diagnosis and, in cases of malignant melanoma, wide excision as a second step. Neck dissections should be performed in patients with clinically positive lymph nodes. Concerning interleukin 2 therapy, further studies should be performed in order to evaluate a routine application.     

The limited value of three pathogen species in predicting healing of periodontal pockets

Baseline level of Actinobacillus actinomycetemcomitans has been suggested as being predictive of periodontal treatment outcome. We analyzed the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in 55 deep periodontal pockets of 29 patients (18 men, 11 women, 37-75 years) before and after periodontal treatment. At baseline and after treatment, 62% and 33%, respectively, of the subjects presented with 1, 2, or a combination of all 3 pathogens. The mean pocket depth of 6.6 mm (0.4 mm) before treatment decreased to 2.2 mm (0.4 mm) in response to treatment (P<0.001). The treatment plan of non-surgical or surgical treatment was based on pocket depths and tooth morphology only. No antimicrobial medications were used during the treatment. Eighty-two percent of the deep pockets healed satisfactorily to < or = 4 mm. The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, or Prevotella intermedia at baseline was not associated with the outcome of the periodontal therapy. In conclusion, we found that the presence of the 3 periodontopathogen species had little or no value in predicting healing of periodontal pockets.     

Initial orthopaedic displacement compared with longitudinal displacement of the maxilla after a forward force application. An experimental study in dogs

The aim of this study was to compare the initial orthopaedic displacement of the maxilla in vivo and the longitudinal changes after a forward force application. The sample consisted of five 1-year-old dogs. An anterior force of 5 N on the maxilla was applied by a coil spring system pushing between Br?nemark implants and a maxillary splint. The initial displacement of the maxilla after force application was measured by means of speckle interferometry. The longitudinal displacement of the maxilla after a force application during 8 weeks was measured by superimposing standardized lateral cephalograms. The initial, as well as the longitudinal, displacement of the maxilla of the dogs was in a forward direction with some counterclockwise rotation. There was no statistical difference between the initial and longitudinal displacement. The biological response after force application during 8 weeks can be predicted by the initial orthopaedic displacement.     

Sedation in pediatric dentistry: a practical assessment procedure

An assessment model for evaluating sedation in pediatric dental patients has been described. The model in whole or in part can be a valuable asset in drug trials and clinical evaluations. The unique characteristics of this model include: assessments are easily and quickly carried out without interruption of normal patient care; the criteria for sedation behavior can be standardized and are clinically relevant; a determination of the level of consciousness using an airway obstruction maneuver permits an assessment of safety; and the reliability of the observer ratings is extremely high, thereby avoiding the necessity of specially trained personnel. Using the assessment procedure, a placebo-controlled, double-blind clinical trial of various doses of chloral hydrate with and without N2O was performed. The results indicate that: children receiving the placebo treatment behaved favorably for at least 46% of the ratings; the 20 mg/kg and 40 mg/kg chloral hydrate groups showed little or no improvement when compared with the placebo group; the group receiving 60 mg/kg chloral hydrate had as much as a 33% improvement in behavior as compared with placebo; and with the addition of 40% N2O/60% O2 to 60 mg/kg chloral hydrate premedication, four of 15 children (27%) were unable to maintain a patent airway when intentionally obstructed.