Implementation Challenges of 3D Printing in Prosthodontics: A Ranking-Type Delphi

The reduction in cost and increasing benefits of 3D printing technologies suggest the potential for printing dental prosthetics. However, although 3D printing technologies seem to be promising, their implementation in practice is complicated. To identify and rank the greatest implementation challenges of 3D printing in dental practices, the present study surveys dentists, dental technicians, and 3D printing companies using a ranking-type Delphi study. Our findings imply that a lack of knowledge is the most crucial obstacle to the implementation of 3D printing technologies. The high training effort of staff and the favoring of conventional methods, such as milling, are ranked as the second and third most relevant factors. Investment costs ranked in seventh place, whereas the lack of manufacturing facilities and the obstacle of print duration ranked below average. An inclusive implementation of additive manufacturing could be achieved primarily through the education of dentists and other staff in dental practices. In this manner, production may be managed internally, and the implementation speed may be increased.

MODERN TECHNOLOGIES FOR THE MANUFACTURE OF GLASS-CERAMIC DENTAL PROSTHESES

The relevance of the problem of improving the quality of life and protecting human health in the context of the successful development of the modern society was presented. A literary review of well-known modern technologies for the design and manufacture of dental prostheses was carried out, as well as the leading domestic and foreign companies that were engaged in this were given. The history of the development of materials for obtaining clinical restorations (crowns, inlays, onlays, etc.) was considered and the main directions of the development of innovative ceramic materials for dental prosthetics were outlined. Based on the analysis of the properties of various types of materials for dental prosthetics, the prospects of using glass-ceramic materials in the development of dental prostheses have been substantiated. The chemical compositions of lithium silicate glasses for the synthesis of the glass matrix have been developed and the technological parameters for the production of glass-ceramic dental prostheses have been selected (Тgl. melting = 1350–1400 °С, Тheat treatment = 600–650 °С). Preliminary heat treatment before the formation of products ensures the formation of the required number of the nucleus of crystalline phase and the prerequisites for creating a volume crystallized structure under conditions of short-term heat treatment. The glass-ceramic prosthesis with a formed interpenetrating sitallized structure was obtained by the method of hot pressing with a short exposure (18-20 min). It was found that the obtained glass-ceramic material containing lithium disilicate as a crystalline phase in an amount of 40-60 vol. %, had high values of bending strength (σ = 400 MPa) and fracture toughness. The indicated mechanical properties of the developed materials, along with the approximate values of their modulus of elasticity to natural teeth, will significantly extend the service life of products under conditions of significant alternating loads that arise during the chewing cycle. A comparative assessment of the competitiveness of the developed dental prostheses based on lithium disilicate with world analogues was carried out, in particular the products of Ivoclar Vivadent and Vita Zahnfabrik, in terms of the main operational parameters. The positive effect of the introduction of domestic developed glass-ceramic dental prostheses to reduce import dependence has been determined.

The Problem of Halitosis in Prosthetic Dentistry, and New Approaches to Its Treatment: A Literature Review

The aim of this work is a review of recent information about halitosis among patients using prosthetic dentures. Halitosis is a condition in which an unpleasant smell comes out of the oral cavity, which is caused mainly by volatile sulfur and non-sulfured compounds. The etiology of halitosis may be intra- or extra-oral; in most patients, however, it is due to the activity of microorganisms in the oral cavity. The problem of the occurrence of halitosis has accompanied patients for many years. In dental prosthetics, the problem of halitosis occurs in patients using removable or fixed dentures. In both cases, new niches for the development of microorganisms may be created, including those related to halitosis. It should be noted that dentures—both fixed and removable—are a foreign body placed in the patient’s oral cavity which, in case of insufficient hygiene, may constitute a reservoir of microorganisms, causing this unpleasant condition. Conventional treatment of intraoral halitosis reduces microbial activity via chemical and/or mechanical action. Currently, the search for new strategies in the treatment of halitosis is in progress. One idea is to use photodynamic therapy, while another is to modify poly(methyl methacrylate) (PMMA) with silver and graphene nanoparticles. Additionally, attempts have been made to combine those two methods. Another unconventional method of treating halitosis is the use of probiotics.

Assessment of Oral Hygiene in Patients Using Fixed and Removable Dentures Treated at the University Dental Clinic in Krakow

Apart from local lesions, the presence of dental plaque may also have an effect on health, especially in people with general diseases. The aim of this project was to assess the oral hygiene of patients prosthetically treated at the Dental Prosthetics Clinic of the University Dental Clinic in Krakow (Poland) using fixed and removable dentures and to determine the demographic relationships and data related to the education of the respondents. The research material consisted of 120 patients who used fixed (group I) and removable (group II) restorations. Basic dental examinations and oral hygiene examinations were carried out with the use of the API (Approximal Plaque Index) and PI (Plaque Index) plaque indices. This study presents the percentage of respondents in terms of sex, place of residence, and education. The mean PI (plaque index) values were 46.73% (Group I) and 50.05% (Group II). (p = 0.4839). The mean values of API (Approximal Plaque Index) amounted to 65.14% (Group I) and 68.94% (Group II) (p = 0.4695). Patients using dentures showed insufficient oral hygiene, and the hygiene status of patients did not depend on the type of dentures used. The group that is most often treated with prosthetics is women with secondary education. The most numerous group of patients at the Dental Prosthetics Clinic are people living in large cities which results from easier access to health care.

INCREASING THE MEDICAL AND SOCIAL EFFECTIVENESS OF THE PREFERENTIAL DENTAL PROSTHETICS PROGRAM FOR CERTAIN CATEGORIES OF CITIZENS IN THE REPUBLIC OF TATARSTAN

Background. The study is devoted to improving the medical and social effectiveness of the Privileged Dental Prosthetics Program for certain categories of citizens in the Republic of Tatarstan. Aim. The aim of the study was to develop new tactical approaches to implement a targeted program of dental prosthetics for certain groups of the population in the Republic of Tatarstan in the complete absence of teeth aimed at the introduction of modern treatment technologies.Material and methods. We applied a complex method using: method of expert evaluation of the Program of free dental prosthetics in the Republic of Tatarstan, method of organizational modeling for the development of new tactical approaches in the implementation of the Program, method of statistical cost prediction in comparing three approaches to dentures for edentulous mandibles at the expense of the Program. Analysis of aggregate data obtained in the calculation of the comparative economic efficiency of the traditional method, the use of dental implant quota and the introduction of the number of applications for the fabrication of a complete removable denture in persons over 60 years in the medium­term forecast of 10 years was conducted. Statistical processing was performed in MS Windows software. Results and discussion. At the level of the Ministry of Health of the Republic of Tatarstan, when implementing the additional MHI program of free denture prosthetics for certain categories of citizens, tactical approaches have been introduced, implying a frequency of visits with complete removable prosthetics – once every three years, according to the service life of the prosthesis. Every year since 2015, an order has been issued by the Ministry of Health of the Republic of Tatarstan. Saving funds of the Program for this section of dental prosthetics reaches more than 8,8 million rubles (67%) per year. Rational use of the funds of the compulsory medical insurance program makes it possible to manufacture modern constructions with the use of dental implantation in 200 people a year. Conclusion. The developed tactical approaches of using the funds of the Territorial Program of Compulsory Medical Insurance for free dental prosthetics in the Republic of Tatarstan serve as a reserve for the introduction of modern technologies of treatment with the use of dental implants on edentulous jaws.

Romanian dentists’ perception of flexible removable partial dentures

Introduction. A flexible partial denture, as a treatment solution for partial edentulousness, is a current alternative in dental prosthetics, due to simplified design, aesthetic and biomechanical qualities of resin materials, that contribute to the favourable distribution of masticatory forces on the dental and mucosal support. Objective. This study aims to highlight the medical perception of Romanian dentists regarding the evolution of patients treated with flexible partial dentures. Material and method. The research was carried out over a period of two years (2017-2019), on a study group composed of 84 Romanian dentists. Subjects were asked to answer an anonymous questionnaire consisting of 14 closed questions, to outline frequently aspects encountered in practice related to the clinical evolution of the patient rehabilitated with flexible partial removable dentures. Outcomes. Patient comfort (76%) and higher aesthetic properties (54%) were the main reasons why dentists chose a partially flexible prosthetic for the prosthetic treatment of the patient. In the evolution of prosthetic patient, the main problems found at the partial flexible prosthesis were food pigment impregnation of the base (51%) and limited possibilities of repair (34%). Changes in maintenance, support, stability, aesthetic or possible fractures of base and clasps were seen by 46% of respondents, at approximately 1 to 2 years after the application of flexible partial dentures. Conclusions. Flexible partial prosthesis is a method of treatment, whose main advantages are represented by esthetics and superior adaptation of the patients, but because of the deficiencies that occur over time, it is better to be recommended as a provisional treatment solution.

MICROBIOLOGICAL STUDY OF THE ORAL CAVITY FOR PROSTHETICS OF DEFECTS OF DENTITION

Prosthetic materials interact with the tissuesof the prosthetic role and often harmthe oral cavity condition. This depends on the material from which the prosthesis is made, the specificsof its structure, the state of oral hygiene, and the body's characteristics. The use of dental prosthetics is anintervention that changes the biological balance and microflora in thetissues of the oral cavity. It plays an important role in formingsoft and hard caries on the surface of the denture and the structure of damage in it.Keywords: defects of the tooth row, oral cavity, microbiology