Hydrofluoric Acid: Burns and Systemic Toxicity, Protective Measures, Immediate and Hospital Medical Treatment.

BACKGROUND: Hydrofluoric acid is a commonly used chemical in many industrial branches, but it can also be found as an ingredient in household products such as cleaning agents. Possessing high corrosive potential, HF acid causes burns and tissue necrosis, while when absorbed and distributed through the bloodstream, its extremely high toxic potential is expressed. Acute symptoms are often followed by pain, particularly in the case of skin burns, which intensiveness does not often correlate with the expressiveness of the clinical findings. Even exposure to low-concentrated solutions or gasses, or low-doses of high-concentrated acid, may provoke delayed systemic disorder which may eventually have a lethal outcome. AIM: Therefore, having information regarding the possible hazardous effects of hydrofluoric acid usage, a variety of symptoms, as well as a treatment approach, is of great importance in the case of HF exposure. METHODS: Available scientific articles published in literature databases, scientific reports and governmental recommendations from the internet websites, written in English, using the following search terms "Hydrofluoric acid, skin burns, eye injury, ingestion, inhalation, systemic toxicity, decontamination, antidote, medical treatment" have been reviewed. RESULTS: This review is useful not only for physicians but for everyone who may come in contact with a person exposed to HF acid. CONCLUSION: It highlights the mechanism of action, presents the acute and chronic symptoms, personal and general protective measures and devices that should be used, as well as decontamination procedures, immediate, antidote and hospital medical treatment.

Advantages of CAD/CAM versus Conventional Complete Dentures - A Review.

BACKGROUND: The introduction and evolution of CAD/CAM technology into complete dentures fabrication brought high expectations in improving disadvantages associated with conventional methods. AIM: The purpose of this review was to analyse the existing literature on computer-engineered complete dentures and to determine their advantages over the conventional dentures. MATERIAL AND METHODS: An electronic search of the English literature from January 1994 to March 2018 was performed in PubMed/MEDLINE, using the following keywords: CAD/CAM complete dentures, computer-engineered complete dentures, complete digital dentures, complete milled dentures, and rapid prototyping dentures. RESULTS: A total of 179 English language titles were obtained from the database, and 14 were relevant to fulfil the purpose of this review. A review of 7 articles is summarized in 2 tables for presenting a comparison between CAD/CAM and conventional dentures in clinical and laboratory studies. CONCLUSION: Following the review of articles that discussed the comparison between CAD/CAM and conventional complete dentures in clinical studies, it can be concluded that the main advantages of CAD/CAM dentures are the reduced clinical chair time and the number of visits, digital archiving, significantly higher retention, and more favorable clinical and patient-centered outcomes. As a result of the review of laboratory studies, superior mechanical and physical properties in CAD/CAM dentures were revealed, concerning enhanced accuracy of fit of milled denture bases, less denture tooth movement and increased toughness, ultimate flexural strength, and higher elastic modulus.

Retention of Approximal Guiding Plane Surfaces in Removable Partial Skeletal Prosthesis.

BACKGROUND: The morphology of the retention tooth often does not correspond with the required design; hence there is often an indication for enamel recontouring or other restorative procedures. AIM: The study aimed to determine the impact of changing the path of insertion of the prosthesis by reshaping the anatomical and morphological structures of the natural teeth predetermined for the retention of the prosthesis. MATERIAL AND METHODS: The group of 40 patients with Class II, Subclass 1 according to Kennedy was formed, and 120 approximal surfaces of retention teeth were obtained. Two different types of prostheses were made on the models: one group in the zero point position of the model, and another group in the zero position of the model, with changing of the direction of input at an angle of 2°. RESULTS: The difference between the established and theoretical normal distribution of frequencies was tested with the Kolmogorov-Smirnov and Lilliefors tests (r < 0.10; r < 0.01). The first group showed a retention force of 0.08 N. In the second group the retention force was 0.94 N. CONCLUSION: It could be concluded that the change in the path of insertion of the dental prosthesis with conservative restorations as composite inlays, as well as the accurate extension of the prosthesis onto guiding plane surfaces, will undoubtedly increase the retention force of the prosthesis.

Prosthodontics Status and Treatment Needs among the Elderly in the Republic of Macedonia.

BACKGROUND: Oral health care management among the elderly differs from the rest of the population, due to some specific physiological changes and general health status related to age. We know very little about the oral health in elderly in the Republic of Macedonia, because there are only a few articles published about dental health status and edentulism of this population. AIM: The study aimed to evaluate the prosthodontic status of older adults over 65 years in the Republic of Macedonia, about their socio-economic status and individual factors. MATERIAL AND METHODS: A cross-sectional study was conducted in 8 regions, in rural and urban areas of Macedonia and a representative sample of 432 people (age > 65 years) was examined. Statistical analyses of the data were made by chi-square tests and the corresponding C-coefficient. RESULTS: Only 6% of all participants had not any prosthetic appliance, 9.5% had more than one bridge, 28.7% of examinees had partial dentures, both bridge(s) and partial denture(s) had 10.7% participants, and 45.1% of examinees were toothless. There was a significant difference between patients who visited the dentist more than once a year and those who did not (χ2 = 14.2; df = 4, p < 0.01). From all of the participants, 40.3% used public dental care organisations. CONCLUSIONS: We found a high prevalence of edentulousness among older adults over 65 years in Macedonia. The study confirmed the necessity for establishing healthcare educational programs for the dental treatment of elderly in Macedonia.

Acid Etching as Surface Treatment Method for Luting of Glass-Ceramic Restorations, part 1: Acids, Application Protocol and Etching Effectiveness.

AIM: The purpose of this review is to represent acids that can be used as surface etchant before adhesive luting of ceramic restorations, placement of orthodontic brackets or repair of chipped porcelain restorations. Chemical reactions, application protocol, and etching effect are presented as well. STUDY SELECTION: Available scientific articles published in PubMed and Scopus literature databases, scientific reports and manufacturers' instructions and product information from internet websites, written in English, using following search terms: "acid etching, ceramic surface treatment, hydrofluoric acid, acidulated phosphate fluoride, ammonium hydrogen bifluoride", have been reviewed. RESULTS: There are several acids with fluoride ion in their composition that can be used as ceramic surface etchants. The etching effect depends on the acid type and its concentration, etching time, as well as ceramic type. The most effective etching pattern is achieved when using hydrofluoric acid; the numerous micropores and channels of different sizes, honeycomb-like appearance, extruded crystals or scattered irregular ceramic particles, depending on the ceramic type, have been detected on the etched surfaces. CONCLUSION: Acid etching of the bonding surface of glass - ceramic restorations is considered as the most effective treatment method that provides a reliable bond with composite cement. Selective removing of the glassy matrix of silicate ceramics results in a micromorphological three-dimensional porous surface that allows micromechanical interlocking of the luting composite.

Oral Hygiene Index in Early Childhood Caries, Before and After Topical Fluoride Treatment.

BACKGROUND: Circular caries occurs in the earliest age of the children (1 - 1.5 year), immediately after the eruption of the deciduous teeth. During this period, children are too young to be able to properly implement oral hygiene. Consequently, it is at a negligible level, with plenty of soft plaque on the deciduous tooth surfaces. OBJECTIVE: The main objective of this clinical trial was to determine the correlation between oral hygiene shown with Oral Hygiene index, and the initial stages of circular caries (initial lesion and superficial form), before and after topical fluoride treatment. MATERIAL AND METHODS: For determination of the OHI - index we used the method of Green - Vermillion. It was determined two times in 117 patients, during the first visit and immediately before physiological replacement of deciduous teeth. Patients were two to three years old and diagnosed with initial stages of circular caries. Amino fluoride solution was applied once a week, during six months. RESULTS: We obtained statistically significant improvement of OHI - index at the end of the test, among treated subjects from both major groups. CONCLUSION: It can be concluded that the level of oral hygiene is correlated with the progression of changes in enamel. Topical fluoride treatment has a positive impact on reducing ECC.

Temporomandibular Disorders Treatment with Correction of Decreased Occlusal Vertical Dimension.

BACKGROUND: The term decreased occlusal vertical dimension refers to the reduced distance between two anatomical points while the teeth are in a state of occlusion. The development of this situation is about some parafunctional activities of the masticatory system. AIM: To evaluate the value of decreased occlusal vertical dimension in cases with temporomandibular disorder and to follow up the influence of corrective treatment with occlusal splints and definitive prosthetic construction upon the elimination of clinical symptoms. MATERIAL AND METHODS: Eight cases with decreased occlusal vertical dimension accompanied with temporomandibular disorders were treated with an occlusal splint, as part of reversible occlusal treatment. After reducing, or complete elimination of the symptoms related to problems of decreased occlusal vertical dimension, the definitive prosthetic therapy was performed. RESULTS: The mean value of decreased occlusal vertical dimension in our patients is 8.5 mm, and the mean value of therapy time with an occlusal splint in these patients was 3.5 months. CONCLUSION: Occlusal splint is a part of reversible occlusal therapy in cases with decreased occlusal vertical dimension. After reducing the symptoms related to decreased occlusal vertical dimension definitive prosthetic therapy can be done.

Prosthodontic Rehabilitation of Patient with Anterior Hyper Function Syndrome.

BACKGROUND: The success of prosthetic rehabilitation in patients with removable dentures depends on the achievement of the aesthetics, phonetics and most of all, proper use in the mastication process. All the patients that receive removable prostheses need a feeding education program. They must cut the food into smaller pieces, extend the length of time necessary for chewing and place the food upon both the right and left sides of the mouth at once. Bilaterally chewing with dentures will contribute to increased efficiency and denture stability during mastication. Using the anterior teeth for biting, as a result of increased pressure on the anterior ridge may lead to the anterior hyperfunction syndrome. CASE REPORT: The patient requested dental rehabilitation in our clinic for prosthetic dentistry two and a half years ago. We examined him and made therapy plan, for complete removable maxillary denture and partial mandibular denture. Besides our instructions for proper use of dentures and necessity for regular controls, his next visit was after two and a half years. He came with enlarged tuberosity and papillary hyperplasia in the pre-maxillary region. After oral surgery treatment (laser removing of hyperplastic tissue) and a healing period of four weeks, we made indirect relining on the upper denture, re-occlusion and re-articulation achieving weak contacts between the lower natural teeth and upper teeth of the complete denture. The patient was advised not to bite food with his anterior teeth, and avoid chewing very hard food which tends to imprint and displace dentures. CONCLUSION: Anterior hyperfunction syndrome with its high incidence is a disease with the need of interdisciplinary therapy approach. Fast diagnosis, thorough clinical examination using all available diagnostic tools, and choosing the right treatment is very challenging.

Technology and the use of acrylics for provisional dentine protection.

Acrylics are compounds polymerized from monomers of acrylic, metacrylic acid or acrylonitrates. The purpose of this paper is to present the technology and use of acrylics for provisional dentine protection in the practice of dental prosthodontics. For this reason, we followed 120 clinical cases from the everyday clinical practice, divided into 4 groups of 30 patients who needed prosthetic reconstruction. The first group included cases in which we applied celluloid crowns for dentine protection, for the second group we used acrylic teeth from a set of teeth for complete dentures; in the third and fourth groups the fabrication was done with the system of an impression matrix and the acrylic resin block technique respectively. In all the examined patients, the gingival index by Silness and Loe and the vitality of the dental pulp were verified clinically, after preparation and 8 days from the placement of the provisional crown. The value for dental sensitivity measured after preparation was 2.59, and 8 days after the placement of the provisional crown it bwas 3.1. From these results we can conclude that after the 8th day from the placement of the provisional crown, there was an adaptation period, characterized by a decrease in the painful sensations. The value of the Silness and Loe gingival index measured after the preparation was 1.34, and 8 days from the placement of the provisional crown was 0.94. The results inclined us to the fact that the provisional acrylic crowns facilitated the reparation of the periodontal tissue.