ABSTRACT
INTRODUCTION: This 10-year retrospective study analyzed the incidence of malignant transformation of oral lichen planus (OLP). The study also included dysplasia and oral lichenoid lesion (OLL) in the initial biopsy as a potential differential diagnosis. MATERIAL AND METHODS: A total of 692 scalpel biopsies were taken from 542 patients (207 [38.2%] men and 335 [61.8%] women). Clinical and histopathological parameters were analyzed. RESULTS: The parameters gender (p = 0.022) and smoking behavior (p < 0.001) were significantly associated with the severity of diagnosis. Mucosal lesions with an ulcerative appearance (p = 0.006) and those located on the floor of the mouth (p < 0.001) showed significantly higher degrees of dysplasia or were diagnosed as oral squamous cell carcinoma (OSCC). Smoking and joint disease appeared to be significant risk factors. Treatment with tretinoin in different concentrations (0.005-0.02%) significantly improved diagnosis. Twelve patients (8 female, 4 male) showed malignant transformation to OSCC within an average period of 1.58 years. The malignant transformation rate (MTR) was higher for OLL (4.4%) than OLP (1.2%). If the first biopsy showed intraepithelial neoplasia, the risk of developing OSCC increased (by 3.5% for squamous intraepithelial neoplasia (SIN) II and by 6.7% for SIN III). CONCLUSION: Although we cannot rule out that OLP is a premalignant oral condition, we can confirm that OLP had the lowest MTR of all diagnoses.
Subject(s)
Lichen Planus, Oral/diagnosis , Lichen Planus, Oral/pathology , Lichenoid Eruptions/diagnosis , Lichenoid Eruptions/pathology , Mouth Diseases/diagnosis , Mouth Diseases/pathology , Mouth Neoplasms/diagnosis , Mouth Neoplasms/pathology , Precancerous Conditions/diagnosis , Precancerous Conditions/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Biopsy , Cell Transformation, Neoplastic/pathology , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Mouth Mucosa/pathology , Retrospective Studies , Young AdultABSTRACT
PURPOSE: Resin to metal bond strength of two commercial and one experimental metal-resin bonding system for crown and bridge veneer composites was evaluated. MATERIALS AND METHODS: All specimens were prepared and tested according to ISO 10477 Amendment 1. A high precious alloy (HPA), a Co/Cr-alloy (Co/Cr) and pure titanium (Ti) were wet-ground to a final surface finish of 800 grit and air-dried. Twenty specimens of each metal were treated with Rocatec (RO), 20 with a Silano-Pen (SP), and 20 with the experimental spark-erosion (SE) bonding system. A light-curing opaque and a crown and bridge veneer composite were applied to each metal specimen. Ten specimens of each metal and bonding system were stored in water for 24h at 37 degrees C, 10 were thermocycled (TC) 5000 times in a water-bath between +5 and +55 degrees C prior to measuring shear bond strength (SBS). Scanning electron microscopy (SEM) was used to examine the treated metal surfaces. RESULTS: After 24h SE generated significantly higher SBS values on Ti than RO (p<0.05). SP revealed the highest SBS for Co/Cr. After TC significant decreases occurred for RO on HPA, for SP on Co/Cr and Ti, and for SP on Ti. SE revealed the highest mean bond values for all metals. These results and SEM proved that no sandblasting is required for SE to obtain good bond strength. SIGNIFICANCE: The experimental spark-erosion bonding system is an easy and very effective method for surface-treating alloys to obtain high SBS values for crown and bridge veneer composites.
