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.