Iliyana Stoeva

This narrative review examines contemporary applications of polymeric materials in dentistry from 2020 to 2025, spanning prosthodontics, restorative dentistry, orthodontics, endodontics, implantology, diagnostics, and emerging technologies. We searched PubMed, Scopus, Web of Science, and Embase for peer reviewed English language articles and synthesized evidence on polymer classes, processing routes, mechanical and chemical behavior, and clinical performance. Approximately 116 articles were included. Polymers remain central to clinical practice: poly methyl methacrylate (PMMA) is still widely used for dentures, high performance systems such as polyether ether ketone (PEEK) are expanding framework and implant-related indications, and resin composites and adhesives continue to evolve through nanofillers and bioactive formulations aimed at improved durability and reduced secondary caries. Thermoplastic polyurethane and copolyester systems drive clear aligner therapy, while polymer-based obturation materials and fiber-reinforced posts support endodontic rehabilitation. Additive manufacturing and computer aided design computer aided manufacturing (CAD CAM) enable customized prostheses and surgical guides, and sustainability trends are accelerating interest in biodegradable or recyclable dental polymers. Across domains, evidence remains heterogeneous and clinical translation depends on balancing strength, esthetics, biocompatibility, aging behavior, and workflow constraints.

The purpose of the present study is to evaluate the effectiveness and safety of intracanal cryotherapy in porcine models using thermography. Five porcine mandibles with the premolars and molars are selected. Muscles, gingiva and mucosa are retained. Endodontic preparation is done, and the jaws are annealed. Thermal imaging is conducted throughout the experiments, at a set photography interval of 15 s using ThermaCAM FLIR infrared camera. The irrigation protocol is performed with 2.5 °C 0.9% NaCl for 5 min with different volumes of irrigants – 5 mL, 10 mL, 15 mL. The irrigants are delivered using the macro cannula and the handpiece of the EndoVac system. The thermal images show the cooling of the teeth and the adjacent structures – muscles, gingiva and mucosa in the course of the experiment. The lowest temperature values reached are more than 10 °C lower than the initial values, which proves the effectiveness of the intracanal cryotherapy. The reported minimal variations (1—2 °C) in temperature values on the gingiva during intracanal cryotherapy make the method safe for use in the oral cavity. The ease of visualization makes thermal imaging a method that can be successfully applied in in vivo settings where the use of thermal sensors is impossible. Thermography is an easy, noninvasive and accurate method which can successfully be used in dental medicine.

Introduction : Titanium dental implants are the most common type of dental implants. Although titanium and its alloys are considered biocompatible, there are concerns about the induction of metal allergy with dental implants. Aim : To evaluate the presence of titanium sensitization by patch testing in patients who intend to have titanium dental implants. Materials and methods : A retrospective study was performed in which data on sensitization to titanium collected from the Allergy Office at the Faculty of Dentistry in Plovdiv from January 2022 to April 2024 were analyzed. We analyzed data from 95 patients who had patch testing done before their dental implant surgery. Results : Thirty-eight (40.0%) patients exhibited positive patch test reactions to at least one metal. The most common allergen was nickel (32.6%). Titanium (IV) oxalate was the only one with a positive rate (7.4%) among titanium reagents. Almost one-half (42.9%) of the patients were monosensitized to titanium (IV) oxalate. No association between positive reaction to titanium (IV) oxalate and history of suspected metal allergy was identified ( p =0.064). Conclusions : The absence of positive reactions to other titanium reagents, as well as a correlation with a history of metal allergy and other allergies in patients who tested positive for titanium oxalate, makes determining the clinical relevance of the positive reactions difficult. Standardization in titanium allergy research is required to ensure the accuracy of the findings.

The objective of this study was to compare the results of the measurements made using two methods for determining the retromolar eruption spaces and the mesiodistal inclinations of impacted mandibular third molars. These are the main parameters based on which the eruption of these teeth can be predicted. A Sirona GALILEOS Compact/Comfort CBCT scanner was used for the study. A total of 127 patients were included in the study. We made the measurements using our integrated method and the standard method used in the dental practice for determining the eruption space and the mesiodistal inclination of these teeth, and then we compared the results. The mean difference between the two methods for estimating the retromolar space deficiency on the left was 1.70 mm and standard deviation (SD) 2.95; mean error of the mean was 0.29; and Student t-test (paired t-test) = 5.86, significant level of the correlation was 0.001, t-test performed found a statistically significant difference between the methods in determining the retromolar eruption spaces (t-test (paired t-test) = 5.13; significant level of the correlation 0.001; p < 0.05). The mean difference (in degrees) between the measurements of the inclinations of the teeth on the left using the two methods was 3, 50°; SD = 7.25; mean error of the mean = 1.81; t-test = 2.481; significant level of the correlation 0.025; and p > 0.05. As for the teeth on the right, it was 2.41°, SD = 9.57, mean error of the mean = 2.39, t-test 0.175, significant level of the correlation = 0.863, and >0.05. No statistically significant difference was found between the two methods in measuring the inclinations of impacted third molars. The conclusion of our study is that the determination of the mesiodistal inclination of the teeth and the available eruption space using the method developed by us is more accurate compared to the standard method, because constant points and planes are used. This method allows for predicting the eruption of impacted mandibular third molars.

Background. CAD/CAM technologies facilitate using powder CoCr alloys to produce metal-ceramic dental restorations. However, base alloys may induce oxidative stress in the oral cavity due to corrosion and ion release. This study evaluated resistance to corrosion and release of metal ions from 3D printed CoCr dental alloy and their effect on oral oxidative stress. Methods. Metal-ceramic crowns with 3D printed copings from CoCr alloy EOS CobaltChrome SP2 (EOS, Germany) were fabricated for 35 patients. Inductively coupled plasma mass spectrometry (ICP-MS) was used for measuring the concentration of Co and Cr ions in non-stimulated saliva before prosthetic treatment (BPT), at 2 h and 7 days after the dental treatment (APT2, APT7, respectively). Open circuit potentials (Eocp) were evaluated at APT2 and APT7. Estimating oral oxidative stress, measurements of 8-isoprostaglandin F2-alpha were conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS) at stages BPT, APT2, and APT7. Results. Salivary Co level increased at APT2 and decreased to the initial levels at APT7. No statistical difference was found between the levels of 8-isoPGF2-alpha measured, and between the Eocp measurements at APT2 and APT7. Conclusions. The studied alloy showed stable corrosion resistance and the metal ion release did not induce oral oxidative stress.

Background: Dental workers are exposed to allergenic materials in the workplace. Objectives: To summarize patch test results in dental staff with work-related dermatitis. Materials and Methods: Cross-sectional study of dental staff with dermatitis was conducted. Symptoms, clinical findings and results from patch tests with 40 dental allergens were summarized. Results: Of 329 participants, 155 (47.1%) had at least one positive patch reaction. The highest frequency of positive reactions was observed for metals (38.6%), acrylics (7.3%) and additives in acrylic resins (3.6%). One hundred and eighty-five (56.2%) participants were currently symptomatic; in this group, 79 (42.7%) had current dermatitis. Thirty-eight patients had at least one positive patch test considered occupationally related to their current dermatitis. Conclusion: Almost half of the dental staff with dermatitis had at least one positive patch test and approximately 12% had current occupational relevance of the allergens. Our results underscore the importance of patch testing in the evaluation of dental staff with dermatitis.

Background: Prosthetic rehabilitation requires application of materials with different chemical, mechanical and biological properties which must provide longevity, esthetics, and safe use. Corrosion resistance and metal ion emission are the major factors defining biocompatibility of base dental alloys. Digitalization in Dentistry leads to development of new materials suitable for CAD/CAM technologies. Cobalt-chromium powder alloys are used for additive manufacturing of PFM crowns. The aim of this study is to evaluate corrosion resistance and metal ion emission of Cobalt-chromium dental alloy for 3D printing. Materials and methods: 35 metal copings were designed using digital files of intraoral scans of 35 patients. CoCr dental alloy EOS CobaltChrome SP2 (EOS, Germany) was used to produce the copings by DMLS (direct laser metal sintering). Tests for presence of free Cobalt ions were conducted at several stages of the production process. Open circuit potential measurements were conducted 2 hours, 24 hours, and 7 days after placing the copings in artificial saliva. Metal ion emission was assessed by inductively coupled plasma mass spectrometry (ICP–MS) after 24 hour- and 7 day-period of stay in the solution. Results: Tests for free Cobalt ions were positive at all stages during production of the metal copings. Eocp measurements showed high corrosion resistance which increased in time. ICP-MS showed significantly higher amount of cobalt and chromium ions after 7-day period of stay compared to 24-hour period. Conclusion: Studied alloy showed high corrosion resistance at in vitro conditions. Detected ion emission requires further investigations on the biological properties.

Background: As dental technicians are exposed to a variety of airborne chemicals that can act as irritants and sensitizers, and may give rise to work-related respiratory symptoms, the aim of this study was to estimate the prevalence of respiratory symptoms of exposure to substances in the...

Objectives: Dentists are exposed to a variety of airborne chemicals that can act as irritants and sensitizers and may give rise to work‐related respiratory symptoms. The aim of this study was to estimate the prevalence of respiratory symptoms of exposure to substances in the workplace and associated risk factors in Bulgarian dentists.Methods: A cross‐sectional study was performed among Bulgarian dentists by using a self‐report questionnaire. A direct acyclic graph (DAG) was elaborated to illustrate the direct and indirect causal pathways between exposure to irritants and/or allergens from dental environment and work‐related respiratory symptoms among dentists. Multiple logistic regression analysis was conducted in order to investigate the relationship between sex, work experience, daily exposure to chemicals from dental environment, history of atopic disorder and work‐related respiratory symptoms.Results: A total of 4675 dentists completed the questionnaire (response rate 48.1%). The prevalence of self‐reported work‐related respiratory symptoms was 20.7%. The most common repeated causes of respiratory reactions were disinfectants (65.7%) and materials based on acrylic resins (29.7%). Factors associated with work‐related respiratory symptoms are personal history of asthma (odds ratio (OR) 2.50, 95% confidence interval [CI]: 1.71‐3.64), work experience >20 years (OR 2.17, 95% CI: 1.74‐2.70) and female gender (OR 2.14, 95% CI: 1.81‐2.56).Conclusion: Work‐related respiratory symptoms are frequent among dentists and indicate a need for efforts to establish effective programmes and techniques of reducing or eliminating direct exposure to airborne chemicals in the dental environment.