Bruxism

Abstract

This paper review of bruxism phenomenon that refers to the grainding or cleanching of the teeth during awake or night sleep. The prevalence of bruxism decreases with age from 14% to 18% in childhood, 8% of adult population and 3% in the eldery. According to the existing literature, two groups of proposed etiological factors can be distinguished: peripheral (morphological) and central (pathophysiological and pshychological). At present, the bruxism is more often thought to be regulated centrally, not peripherally. Signs and symptoms of bruxism such as tooth wear/dental attrision, abfractions, orofacial pain, change of periodontal ligament, mobility, tooth sensitivity, fractured teeth and fillings, earache, headache, tightness of jaw muscle, chewed tissue on the inside of your cheek, impact on yhe esthetic appearance of a smile. There have been many clinical approaches to the treatment of bruxism. These can be categorized as acute, preventive and chronic management of bruxism, based on patien's signs and symptoms. In the case of acute symptomps with patient's experiencing pain, pharmacotherapeutics may be required. Meanwhile, if tooth wear is present an occlusal splint and stress management are recommended. Dentists and health professionals should be aware of the phenomenon of bruxism.

Key words : bruxism, signs and symptoms, etiology, occlusal splint/night guard.
Author : Sri Wendari A. Hartono, Nunung Rusminah, Aprillia Adenan.

The influence of acid concentration in soft drink on mineral tooth dissolving

Abstract

Demineralization or mineral tooth dissolving can occour if the tooth are under 5.5 pH environtment. Currently, some soft drink under 5.5 pH have been consumpted in general society. The low pH contributes in demineralization because it increases the concentration of hydrogen and this ion will damage hydroxyapatite. The objective of this study was to evaluate the influence of acid concentration in soft drink on mineral tooth dissolving. Design of this study was quasee experiment, included 15 samples of tooth fragment that have been divided into 3 groups. Every sample has been measured for its weight before being immersed in soft drink, and be noted as pre test. Subsequently, Group I, was being immersed in soft drink that contains carbonate acid; Group II, in phosphate acid, and Group III, in the water (control). The measurement of sample weight was done after 24, 48, and 72 hours after immersing, and be noted as post-test. The results of the study shown that the samples that had been immersed in carbonate acid beverages lead to a greater mineral dissolving than phosphate acid and the water.
Keywords :demineralization, soft drink
Author : Nurlindah Hamrun, Dewi Kartika.

Effect ulee kareng aceh coffee on surface hardness of acrylic denture base

Abstract

Hardness of a denture base a patient charge associated with the habit of consuming foods and beverages most commonly consumed. Ulee Kareng coffee was very popular, especially in the areas of Aceh. It was kind of Robusta coffee which contains acidic properties : pH of water mixed (5 grams of coffe in 120 ml of water) before = 3.00 and after = 5.74. The purpose of this study was to determine the change of surface hardness of acrylic denture base after being immersed in Ulee Kareng coffee for 3 days. Twelve cylinder specimens ( 5 mm diameter and 2 mm thickness) were randomly distributed in two groups : control (immersion in distilled water) and experimental (immersion in Ulee Kareng coffee). Hardness was measured before and after immersion using Knoop Microhardness tester by Shimadzu. Data were analyzed statistically by Mann Whitney and Wilcoxon test. The results of the studied showed that there was a significant difference between groups. The surface hardness of acrylic denture base decreased after immersion for both group.
Keywords : acrylic denture base, Ulee Kareng Coffee, hardness.

Author : Rini Defika Putri, Viona Diansari, Iin Sundari.

Alveolar ridge augmentation using distraction osteogenesis

Abstract

Augmentation of the alveolar ridge is widwly used in implant treatment to create predictable function and esthetics in area with inadequate bone volume. There are different ways to augment the alveolar ridge. Distraction osteogenesis is a new method in increasing the width of the ridge and preparing a sufficient bed for implant or prosthesis. Distraction osteogenesis result in formation of new bone between bone segments that separated gradually by incremental traction. Alveolar widening by distraction osteogenesis is an alternative method for reconstracting alveolar atropy that is similar to alveolar splint grafting but without the graft which is offers many anvantages over traditional technique. This paper is aimed to discuss considerations and technique alveolar ridge augmentation for preparing adequate bone volume before applying implant using distraction osteogenesis method.
Keywords :  alveolar ridge augmentation, distraction osteogenesis, implant.

Penulis : Sitti Sarah Aulia Amrullah, Rosida Sani, Nurfadhillah Arifin, Muhammad Ruslin

PROPERTIES OF DENTAL MATERIALS 4

SOLUBILITY AND SORPTION

The solubility of materials in the mouth and the sorption (adsorption plus absorption) of oral fluids by the material are important criteria in their selection. Frequently, laboratory studies have have evaluated materials in distilled water. At times these studies gave results inconsistent with clinical obsevations becaused  materials in the mouth are covered with plaque and therefore are exposed to various acids and organic materials. An example of the inconsistency is that zinc phosphate cements are considerably more soluble in the mouth than laboratory tests in water indicate. Also, the loss of zinc phosphate cements retaining a gold crown is a result of dissolution followed by and accompanied by disintegration. Nevertheless, laboratory tests usually rank materials correctly, so only  the actual magnitude of the numbers should be taken with grain of salt.

Solubility and sorption are reported in two ways : (1) in weight percent of soluble or sorbed material, and (2) as the weight of dissolved or sorbed material per unit of surfaces area (e.g., miligram per square centimeter).

Absorption refers to the upteke of liquid by the bulk solid; for example, the equilibrium absorption of water by acrylic plastics is in the range of 2%. Adsorption indicates concentration of molecules at the surface of a solid or liquid, an example being the adsorption of components of saliva at the surface of tooth structure, or of a detergent adsorbed an the surface of a wax pattern.

Taken from : Dental Material, Robert G. Craig
 

PROPERTIES OF DENTAL MATERIALS 3

ELECTRICAL PROPERTIES

                Two electrical properties of interest are galvanism and corrosion. Galvanism results from the presence of dissimilar metals in the mouth. Metals placed in an electrolyte (a liquid that contains ions) have various tendencies to go into solution.

Aluminium, alloys of whichare sometimes used as temporary crows, has a strong tendency to go to into solution an has an electrode potential 0f + 1.33 volts. Gold on the other hand, has a little tendency to go into solution, as indicated by an electrode potential of - 1.36 volts. The oral fluids function as the electrolyte, and the system is similar to that of an electrical cell. When the two restoration touch, current flows because the potential difference is 2.69 volts, and the patient experiences pain and fraquently complains of a metallic taste. The some effect can be experienced if a piece of aluminium foil from a baked potato becomes wedged between two teeth and contacts a gold restoration. Temporary plastic crown are used to prevent this problem because they are poor electrical conductors.

Corrosion also can result from this same condition when adjacent  restorations are of dissimilar metals. As a result of the galvanic action, material goes into solution, and roughness and pitting occur. This effect also may occur if a gold alloy is contaminated with a metal such as iron during handling in the dental laboratory or because of variations in concentaration of elements from one part of the restoration to another. Corrosion also may result from chemical attack of metals by components in food or saliva. Dental amalgam, for exapmle, reacts with sulfides and chlorides in the mouth, as shown by polished amalgams becoming dull and discolored with time. This effect sometimes is reffered to as tarnish.

Taken from : Dental Material, Robert G. Craig

PROPERTIES OF DENTAL MATERIAL 2

THERMAL DIMENSIONAL CHANGE

Restorative dental materials are subjected to temperature changes in the mouth. These change result in dimensional changes  in the materials and to the neighbouring tooth structure. Because the thermal expansion of the restorative material usually does not match that of the tooth structure, a differential expansion occurs that may result in leakage of oral fluids between the restoration and the tooth.

The thermal coefficient of expansion is not uniform throughout the entire temperature range and is usually higer for liquids than for solids. The thermal coefficient of expansion for a solid, such a dental wax, generally increase at some point as the temperature is increased. The linear rather than the volumetric of thermal expansion usually is reported.

The relationship between the coefficients of thermal expansion of human teeth and restorative materials is important. The values for amalgam and composites are about two to five times those human teeth. The values for unfilled plastics, however, are five tp seven times those teeth, with porcelain being one half to one third and gold alloys being approximately the same as for human teeth.

A clinical effect of this difference is as follows. If a tooth that contains a nonadhesive plastic restoration is cooled by the drinking of a cold liquid, the restoration contracts substantially more than the tooth, and a small space results at the junction between the two materials. Oral fluids can penetrate this space. When the temperature returns to normal, this fluid is forced out of the space. The phenomenon is called percolation and occurs with a number of restorative dental materials, depending on the relationship of the thermal coefficient of expansion of the material and human teeth and the extent of bonding. Percolation is thought to be undesirable because of possible irritation to the dental pulp and recurrent decay. Dental amalgam is unusual in that percolation decreases with time after insertion, presumably as aresult of the space being filled with corrotion products from amalgam.

THERMAL CONDUCTIVITY                           

                Qualitatively, materials have different rates of conducting heat; metals have higer values than plastics and ceramics. When a portion of a tooth is replaced by a metal restoration such as amalgam or gold alloy; the tooth may be temporarily sensitive to temperature changes in the mouth. Individuals who wear orthodontic appliances or complete denture also notice temperature effects different from those experienced without these appliances.

                Thermal conductivity has been used as a measure of the heat transferred and is defined as the numer of calories per second flowing through an area of 1 cm² in which temperature drop along the length of the specimen is 1⁰C/cm. This is rather complicated quantitative term, but qualitatively it is related simply to the rate of heat flow.

                Human enamel and dentin are poor thermal conductors compared with gold alloys and dental amalgam, although amalgam is substantially lower than gold. Zinc oxide-eugenol and zinc phosphate cements approximately replace lost tooth structure with respect to thermal conductivity. The reason for using cements as thermal isulating base in deep cavity preparations necause although dentin is a poor thermal conductor, a thin layer of it does not provide enough thermal insulation for the pulp unless a cement base is used under the metal restoration. Composite restorations have thermal conductivities comparable to tooth structure and do not present a problem with this property. Cavity varnishes have low thermal conductivities, as do unfilled acrylics, but are used in layers so thin that they are ineffective as thermal insulators.

Taken from : Dental Material, Robert G. Craig