EFFECT OF VARIOUS STERILIZATION AND DISINFECTION PROTOCOLS OF TOOTH PREPARATION BURS ON THEIR CUTTING EFFICIENCY AND THEIR RELATION TO THE SURFACE ROUGHNESS OF TOOTH PREPARATION – AN INVITRO STUDY

AIM: This study aims to evaluate the effect of sterilization and disinfection of rotary diamond burs on their cutting efciency and their relation to their surface roughness. A total of 12 (n=12) burs and acrylic typodont teeth of (n=36) were taken MATERIALS AND METHODS: which consists of Diamond TF-13 (MANI) (n=6) and Tungsten carbide bur 169L bur (Prima Dental, Prima Classic) (n=6). These burs were divided into 6 groups. Each group consists of Sub Groups A & B. Sub Group A in each Group Contains Diamond TF-13 (n=1) and Sub Group B in each group contains Tungsten carbide bur 169L bur (n=1). Each single Group is subjected to different methods of sterilization and disinfection with Autoclave, Hot air oven, Ultrasonic, Glass bead, Chemical Disinfection (KORSOLEX) after the tooth preparation. Samples of crown preparation were prepared by placing the mounted tooth on a Modied Milling Machine. After each use, these diamonds and burs were sterilized for 3 cycles of tooth preparation simultaneously and the tooth were evaluated for the surface roughness with a surface prolometer and the resultant values were noted and statistically analyzed. The burs were evaluated for the surface quality under Stereomicroscope and scores were given from 0 to 5 according to the grits and wear present on the surface of the burs. Diamond rotary burs CLINICAL SIGNIFICANCE: should be sterilized and disinfected as it has become a mandatory protocol for the dental professionals to prevent cross-contamination and cross infection between the dentist and dental personnel. However, different sterilization and disinfection methods can have undesirable effects on the ability of the burs to effectively reduce the tooth structure. Irrespective of the type of bur and sterilization process used, the cutting efciency decreases after multiple usage of the burs.

An Ultrastructural Study on the Effect of High Temperatures on Teeth and Restorative Materials That Aids in the Identification of Human Remains

Introduction. In most disasters, teeth are the only means of positive identification of an otherwise unrecognizable body, as there has been tremendous increase in the use of dental restorations that have different resistance to prolonged high temperature which is an important aid in identifying burned victims. Application of SEM/EDS in forensics was found useful in areas where there is a need for good imaging with high magnification combined with elemental analysis. The objective of this study was to analyze incineration effects on teeth and restorative materials using SEM/EDS. Materials and Method. 128 extracted teeth were collected, 96 were restored with silver amalgam, composite, and GIC of 32 each, and crown preparation was done in 32 teeth for which metal ceramic crowns were prepared. These teeth were subjected to 4 different temperatures (500°C, 700°C, 900°C, and 1100°C) for 20 minutes, and they were analyzed macroscopically and by using SEM for the changes subsequent to their exposure to such high temperatures. Results. All the restorations which were very difficult to identify by naked eye were identified with the help of SEM/EDS. Conclusion. Elemental analysis of the specific restorative material proves to be an essential tool for the forensic odontologist.

Can Dental Office Lighting Intensity Conditions Influence the Accuracy of Intraoral Scanning?

The aim of this study was to evaluate the influence of different settings of ambient light intensity inside the dental office on the accuracy (trueness and precision) of an intraoral scanner (IOS). A full crown preparation was conducted on a resin molar which was scanned using a high resolution extraoral scanner to obtain a reference model. Six light settings were chosen based on the most clinically relevant light conditions inside the workspace, and the preparation was scanned using an intraoral scanner (PlanScan, Planmeca). The obtained data was analyzed using a professional 3D quality control software (Geomagic Control X). There was no statistically relevant difference between the groups when regarding trueness, although a slight influence of the light intensity could be observed on the trueness values. Regarding precision, the best results were obtained in the 3800 lux group, with the other groups presenting close values, excepting the extreme values (400 lux and 11 000 lux) groups that proved to be the most deficient.

In Vitro Infrared Thermographic Assessment of Temperature Change in the Pulp Chamber during Provisionalization: Effect of Remaining Dentin Thickness

Interim crowns and partial fixed dental prosthesis materials generate exothermic heat during polymerization. The amount of heat transmitted to the pulp chamber can be a function of several factors, including the thickness and quality of the remaining dentin after crown preparation. The aim of this in vitro study was to measure with infrared thermography the temperature changes on the adjacent surface of the chamber roof of premolar teeth extracted from young and old patients (having different thicknesses of remaining dentin after crown preparation) during fabrication of provisional resinous restorations. Twenty extracted human first and second maxillary premolar teeth (10 from young patients, with a relatively large pulp chamber, and 10 from older patients, with a relatively small pulp chamber) were used. The roots were sectioned to expose the inner side of the chamber roof, and the crowns were provisionalized after preparation for a metal-ceramic crown. Two provisional materials, Turbo Temp 2 and Luxatemp Fluorescence, were used. Temperature changes on the inner side of the chamber roof were measured at 2-second intervals using an infrared thermal imaging camera. After completion of the temperature recordings, the teeth were sectioned and the remaining dentin thickness was determined. The older group (mean thickness: 2.82 mm) and younger group (mean thickness: 1.9 mm) differed significantly in dentin thickness ( P < 0.014 ). The mean greatest temperature increases recorded on the chamber roof of teeth with less remaining dentin were 4.07°C for Turbo Temp 2 and 3.94°C for Luxatemp Fluorescence, while increases in the premolars with greater dentin thickness were 1.69°C for Turbo Temp 2 and 1.64°C for Luxatemp Fluorescence. Significant interactions were found between tooth groups ( P < 0.000001 for Turbo Temp 2 and for Luxatemp Fluorescence). No significant differences were found between assessed materials regardless of the thickness of the remaining dentin ( P > 0.38 for the older group and P > 0.29 for the younger group). Dentin had a significant effect in limiting the temperature increase generated during polymerization of provisional materials, indicating good thermal insulating properties of this tissue. A remaining dentin thickness of 1.9 mm or more is sufficient to protect the pulp from any temperature increase during provisionalization using tested materials.

Management of Ellis Class III Fracture in Two Maxillary Incisivus

Introduction. Trauma injury in the oral cavity due to collisions can cause tooth fracture. Ellis class III fracture is a fracture of the crown with an open pulp. Teeth with exposed pulp will cause irritation of the pulp resulting in pulp inflammation (pulpitis). One visit pulpectomy and jacket crown with posts were carried out to achieve optimal dental functions. Case report. A 27-year-old male patient came to Dental Hospital of Universitas Gadjah Mada complained about his broken front teeth due to accident three days earlier. The crown of the maxillary right lateral incisor and the maxillary left central incisor with open pulp was seen. The tooth 11 was avulsion, which lost at the location of accident. The diagnosis of 12 and 21 were Ellis class III fracture. Initially an infiltration anaesthesia was done, followed by one visit root canal treatment (RCT). On the second visit, the teeth were asymptomatic, hence the jacket crown preparation and fiber post insertion were performed. On the third visit, a porcelain jacket crown was cemented into teeth 12 and 21. A week later the patient came for recall and no complaints were noted. Conclusion. One visit pulpectomy followed by restoration with porcelain crown and fiber posts can be undertaken to achieve the optimal functions of teeth, namely aesthetic, mastication, phonetics, and protection of supporting tissues function.