Correlation Theory of the Maxillary Central Incisor, Face and Dental Arch Shape in the Serbian Population.

Background and Objectives: According to the modified Williams theory, the shape of the maxillary central incisor corresponds to the shape of the maxillary alveolar ridge (dental arch) and the shape of the face. Moreover, the standards of beauty suggest that the center of the face of an individual with a full set of teeth should match the center of the maxillary and mandibular dental arches. The purpose of this study is to conduct a comparative cross-sectional study on the matching of the shape of the face, maxillary central incisor and maxillary dental arch as well as the matching of the midfacial line and dental arches in subjects with complete dentition. Materials and Methods: The study included 90 subjects of both sexes. The matching of the shape of the face and midfacial line, i.e., dental arches and maxillary incisors, was determined by analysing photographs, whereas the shape of the dental arch was determined by analysing plaster models. Results: No significant gender-related differences were found either in the shape of the maxillary central incisor that matched the shape of the maxillary dental arch (p = 0.349) or in the shape of the dental arch that matched the shape of the face (p = 0.697). However, a significant difference was noted in the shape of the teeth that matched the shape of the face (p = 0.043), which was more significantly impaired in men. In addition, the matching of the mid-face and the mid-dental arch was significantly greater in women (p = 0.016). Conclusions: The modified Williams theory was confirmed in most subjects, thus it can be considered a relevant guideline when determining the shape of teeth after their loss. The highest percentage of matching in both sexes was with the shape of the face and dental arch. There was no positive correlation between the middle of the maxillary and mandibular dental arch in most cases.

Development and psychometric properties of the Serbian version of the Orofacial Esthetic Scale.

OBJECTIVE: The aim of the study was to develop the Serbian language version of the Orofacial Esthetic Scale questionnaire (OES SERB) and to evaluate its psychometric properties. METHODS: The study included 226 subjects - 110 dental students and 116 patients (the validation sample). The students answered all the questions individually with the help of supervisors, whereas the prosthodontic patients were interviewed by the same trained dentist. The reliability and validity of the questionnaire were assessed. RESULTS: Internal consistency of the OES-SERB was considered satisfactory (Cronbach's alpha 0.92, inter-item correlation coefficient ranged between 0.735 and 0.898). The construct validity of the OES was proved using exploratory factor analysis, which confirmed the one- dimensional model of the OES-SERB that assumed 66.549% of the variance. The Bartlett's test of sphericity was 1380.134 (df = 28, p < 0.001) and the Kaiser-Meyer-Olkin (KMO) test was 0.900. The total score was statistically significantly different between students and patients (p < 0.001), which confirmed the discriminant validity. CONCLUSION: The Serbian version of the OES, adapted to the cultural setting of the Republic of Serbia, has exhibited excellent psychometric properties and has been confirmed as a one-dimensional tool for self-assessment of the appearance of the orofacial region. CLINICAL SIGNIFICANCE: The Serbian version of the OES has good psychometric properties and is a valuable instrument for self-assessment of the appearance of the orofacial region.

Cytomorphometric and Clinical Changes in Gingival Tissue after Subgingival Tooth Preparation-A Pilot Study.

Tooth preparation for a metal-ceramic crown with a subgingival finish line can lead to inflammatory changes in the gingival tissue, often accompanied by cell damage. This study aimed to evaluate the clinical signs of inflammation and the cytomorphological status of the gingival tissue before and after tooth preparation. The research included a homogeneous group of 19 patients with an indication for upper canine preparation. Before and after treatment, the gingival and the gingival bleeding indexes were determined, gingival swabs were taken, and direct smears prepared on slides for cytomorphometric analysis. The values of the measured gingival indexes were statistically significantly higher (p < 0.001) after tooth preparation. They decreased over time, which indicated the reversibility of the resulting changes. Cytological examination showed no statistically significant difference between the values of nuclear area, perimeter, Feret diameter, Feret angle, integrated optical density, MinFeret, and roundness, before and after the treatment. Significantly higher values of circularity, integrated optical density, MinFeret (p < 0.05), as well as roundness (p < 0.001) were found after 72 h, compared to those taken 15 min after tooth crown preparation. This study is a pioneering attempt to show gingival changes during fixed prosthodontic treatment and may shed new light on pathogenetic events in prosthodontic patients.

The Use of Acrylate Polymers in Dentistry.

The manuscript aimed to review the types of acrylate polymers used in dentistry, as well as their chemical, physical, mechanical, and biological properties. Regarding their consistency and purpose, dental acrylate polymers are divided into hard (brittle), which includes acrylates for the production of plate denture bases, obturator prostheses, epitheses and maxillofacial prostheses, their repairs and lining, and soft (flexible), which are used for lining denture bases in special indications. Concerning the composition and method of polymerization initiation, polymers for the production of denture bases are divided into four types: heat-, cold-, light-, and microwave-polymerized. CAD/CAM acrylate dentures are made from factory blocks of dental acrylates and show optimal mechanical and physical properties, undoubtedly better monomer polymerization and thus biocompatibility, and stability of the shape and colour of the base and dentures. Regardless of the number of advantages that these polymers have to offer, they also exhibit certain disadvantages. Technological development enables the enhancement of all acrylate properties to respond better to the demands of the profession. Special attention should be paid to improving the biological characteristics of acrylate polymers, due to reported adverse reactions of patients and dental staff to potentially toxic substances released during their preparation and use.

Antimicrobial Properties of Silver-Modified Denture Base Resins.

The surface quality of denture base resins allows for easy colonization by microorganisms including Candida albicans and Staphylococcus aureus, which cause major diseases of the oral cavity such as denture stomatitis. The widespread use of silver nanoparticles (AgNPs) in various fields of medicine has led to research of their possible application in dentistry, mostly in the prevention of bacterial adhesion, proliferation, and biofilm formation. The aim of the study was to synthesize cold and heat-curing denture base resins modified with AgNPs and AgCl, and evaluate the potential of the modified resins to reduce the growth of C. albicans and S.aureus. The produced material was characterized by Fourier transform infrared spectroscopy (FTIR). The antimicrobial potential of the modified material was demonstrated by the disc-diffusion method, microdilution method, and a modified microdilution method (i.e., disk-diffusion method in broth with viable counting). Spectroscopy confirmed the incorporation of biocidal materials into the structure of the denture base resins. The AgCl and AgNPs modified resins showed an antimicrobial effect. The significance of the study is in the potential therapeutic effects of the modified materials for prevention and threating staphylococci and candida in elderly patients, who are in most cases denture wearers and have a greater susceptibility to develop opportunistic infections. Modified denture base resins can significantly reduce the presence of infection at the point of contact between the denture and the mucous membrane of the prosthetic restoration. Biological tests of modified denture base resins will follow.

Poly(methyl methacrylate) with Oleic Acid as an Efficient Candida albicans Biofilm Repellent.

Poly(methyl methacrylate) (PMMA), widely used in dentistry, is unfortunately a suitable substrate for Candida (C.) albicans colonization and biofilm formation. The key step for biofilm formation is C. albicans ability to transit from yeast to hypha (filamentation). Since oleic acid (OA), a natural compound, prevents filamentation, we modified PMMA with OA aiming the antifungal PMMA_OA materials. Physico-chemical properties of the novel PMMA_OA composites obtained by incorporation of 3%, 6%, 9%, and 12% OA into PMMA were characterized by Fourier-transform infrared spectroscopy and water contact angle measurement. To test antifungal activity, PMMA_OA composites were incubated with C. albicans and the metabolic activity of both biofilm and planktonic cells was measured with a XTT test, 0 and 6 days after composites preparation. The effect of OA on C. albicans morphology was observed after 24 h and 48 h incubation in agar loaded with 0.0125% and 0.4% OA. The results show that increase of OA significantly decreased water contact angle. Metabolic activity of both biofilm and planktonic cells were significantly decreased in the both time points. Therefore, modification of PMMA with OA is a promising strategy to reduce C. albicans biofilm formation on denture.

Bleeding Index and Monocyte Chemoattractant Protein 1 as Gingival Inflammation Parameters after Chemical-Mechanical Retraction Procedure.

OBJECTIVE: A widely used chemical-mechanical method of gingival retraction can cause gingival tissue damage. The aim of this study was to test the influence of the chemical-mechanical gingival retraction procedures on the gingival bleeding index (GBI) and the salivary concentration of monocyte chemoattractant protein 1 (MCP-1) as an indicator of inflammatory changes in the gingiva. MATERIALS AND METHODS: The effects of 2 different retraction agents (aluminum chloride and ferric sulfate) were compared, particularly their tissue damaging effect during tooth preparation. Therefore, GBI values and the salivary concentration of MCP-1 were assessed during the chemical-mechanical method of gingival retraction in a homogenous group of respondents. The subjects (n = 60) were divided into 2 experimental groups (G1 and G2) regarding the need for tooth preparing and making artificial crowns. Each group was further divided into 2 subgroups (R1 and R2) according to the type of the gingival retraction agent used (aluminum chloride and ferric sulfate). RESULTS: Compared to the values at the study start, a statistically significant increase in GBI and salivary MCP-1 (p < 0.001) 1 day after gingival retraction agent application was observed in both experimental groups. After 72 h, the values were lower than in the second observation period but still statistically significantly higher compared to the study start (p < 0.001), which indicated the reversibility of the tissue changes. CONCLUSION: Higher values of the investigated parameters were observed in the group of subjects with prepared teeth, and clinical changes were more pronounced after the use of ferric sulfate.

Determination of Salivary Myeloperoxidase, Immunoglobulin E, and Tumor Necrosis Factor-α after Complete Denture Insertion.

OBJECTIVE: To detect activities of salivary myeloperoxidase (MPO) and concentrations of salivary tumor necrosis factor (TNF)-α as indicators of inflammatory reaction and salivary immunoglobulin E as an indicator of allergic reaction after complete insertion of acrylic dentures. SUBJECTS AND METHODS: Complete dentures were made for a uniform group of elderly patients, and saliva samples were taken immediately before they were given to the patients, as well as 2, 3, 7, and 30 days after insertion of the dentures, with simultaneous monitoring of changes in the oral mucosa. RESULTS: After 7 and 30 days of wearing upper and lower complete dentures, nonsignificant increases in salivary MPO and TNF-α were proven to be indicators of inflammation. No changes were observed in the values of salivary immunoglobulin E during a 30-day observational period, which excluded the appearance of allergic reactions to acrylic materials in the tested group of patients. CONCLUSION: A nonsignificant increase in the levels of MPO was observed on day 7; it decreased after 30 days. TNF-α also tended to increase in a nonsignificant manner.

Artificial saliva effect on toxic substances release from acrylic resins.

BACKGROUND/AIM: Acrylic-based resins are intensively used in dentistry practice as restorative or denture-base materials. The purpose of this study was to analyze the surface structure of denture base resins and the amount of released potentially toxic substances (PTS) immediately upon polymerization and incubation in different types of artificial saliva. METHODS: Storage of acrylic samples in two models of artificial saliva were performed in a water bath at the temperature of 37 +/- 1 degrees C. Analysis of the surface structure of samples was carned out using scanning electronic microscopy analysis immedidtely after polymerization and after the 30-day incubation. The amounts of PTS per day, week and month extracts were measured using high-pressure liquid chromatography. RESULTS: Surface design and amount of PTS in acrylic materials were different and depended on the types and duration of polymerization. The surfaces of tested acrylates became flatter after immersing in solutions of artificial saliva. The degree of acrylic materials release was not dependent on the applied model of artificial saliva. CONCLUSION: In order to improve biological features of acrylic resin materials, it was recommended that dentures lined with soft or hard cold-polymerized acrylates should be kept at least 1 to 7 days in water before being given to a patient. So, as to reach high degree of biocompatibility preparation of prosthetic restorations from heat-polymerized acrylate was unnecessary.

Oral health-related quality of life of edentulous patients after complete dentures relining.

BACKGROUND/AIM: Tooth loss affects oral health-related life quality. More than a third of edentulous patients are not fully satisfied with their complete dentures and mainly complain of insufficient stability, retention, and pain during mastication. Solving the problem may include relining by materials that are based on silicone or acrylic. The aim of this study was to determine the level of patients' satisfaction before and after relining upper dentures with soft and rigid liners. METHODS: The patients (n=24) were divided into two study groups. Maxillary denture relining of the first group of patients was performed with hard acrylic based resins while in the second group of patients complete denture was relined with a silicone-based soft liner. They were asked the questions from the specifically adapted the Oral Health Impact Profile Questionnaire for edentulous patients before and three months after relining dentures. RESULTS: After relining the patients showed a higher degree of satisfaction with their dentures in all the tested domains (masticatory function, psychological discomfort, social disability and retention and hygiene). The padents with soft denture relines were more satisfied. CONCLUSION: Refining of maxillary complete dentures significantly positively impacts the quality of life of patients in all the tested domains (masticatory function, psychological discomfort, social disability, pain and oral hygiene). Better results were achieved using a silicone-based soft liner, which recommends it as the material of choice for relining dentures.

Determination of vertical dimension of occlusion by using the phonetic vowel "O" and "E".

BACKGROUND/AIM: The vertical dimension of occlusion is a very important parameter for proper reconstruction of the relationship between the jaws. The literature describes many methods for its finding, from the simple, easily applicable clinically, to quite complicated, with the use of one or more devices for determination. The aim of this study was to examine the possibility of determining the vertical dimension of occlusion using the vocals "O" and "E" with the control of values obtained by applying cognitive functions. METHODS: This investigation was performed with the two groups of patients. The first group consisted of 50 females and 50 males, aged 18 to 30 years. In this group the distance between the reference points (on top of the nose and chin) was measured in the position of the mandible in the vertical dimension of occlusion, the vertical dimension at rest and the pronunciation of the words "OLO" and "ELE". Checking the correctness of the particular value for the word "OLO" was also performed by the phonetic method with the application of cognitive exercises when the patients counted from 89 to 80. The obtained difference in the average values in determining the vertical dimension of occlusion and the "OLO" and "ELE" in the first group was used as the reference for determining the vertical dimension of occlusion in the second group of patients. The second group comprised of 31 edentulous persons (14 females and 17 males), aged from 54 to 85 years who had been made a complete denture. RESULTS: The average value obtained for the vertical dimension of rest for the entire sample was 2.16 mm, for the word "OLO" for the entire sample was 5.51 mm and for the word "ELE" for the entire sample was 7.47 mm. There was no statistically significant difference between the genders for the value of the vertical dimension at rest, "ELE" and "OLO". There was a statistically significant difference between the values f or the vertical dimension at rest, "OLO" and "ELE" for both genders. There was a statistically significant correlation between the value for the vertical dimension at rest, "OLO" and "ELE", for both groups of subjects. CONCLUSION: Determining the vertical dimension of occlusion requires 5.5 mm subtraction from the position of the mandible in pronunciation of the word "OLO" or 7.5 mm in pronunciation of the word "ELE".

[Scanning electron microscopy analysis of marginal adaptation of composite resines to enamel after using of standard and gradual photopolimerization].

INTRODUCTION: Bonding between composite and hard dental tissue is most commonly assessed by measuring bonding strength or absence of marginal gap along the restoration interface. Marginal index (MI) is a significant indicator of the efficiency of the bond between material and dental tissue because it also shows the values of width and length of marginal gap. OBJECTIVE: The aim of this investigation was to estimate quantitative and qualitative features of the bond between composite resin and enamel and to determine the values of MI in enamel after application of two techniques of photopolymerization with two composite systems. METHODS: Forty Class V cavities on extracted teeth were prepared and restored for scanning electron microscope (SEM) analysis of composite bonding to enamel. Adhesion to enamel was achieved by Adper Single Bond 2 - ASB (3M ESPE), or by Adper Easy One--AEO (3M ESPE). Photopolymerization of Filtek Ultimate--FU (3M ESPE) was performed using constant halogen light (HIP) or soft start program (SOF). RESULTS: Quantitative and qualitative analysis, showed better mikromorphological bonding with SOF photopolymerization and ASB/FU composite system. Differences in MI between different photopolymerization techniques (HIP: 0.6707; SOF: 0.2395) were statistically significant (p < 0.001), as well as differences between the composite systems (ASB/FU: 0.0470; AEO/ FU: 0.8651) (p < 0.001) by two-way ANOVA test. CONCLUSION: Better marginal adaptation of composite to enamel was obtained with SOF photopolymerization in both composite systems.