Microbial adhesion and viability on novel CAD/CAM framework materials for implant-supported hybrid prostheses.

The aim of the study was to investigate the adhesion and viability of Streptococcus oralis and Candida albicans under in vitro conditions on CAD/CAM framework materials for implant-supported hybrid prostheses. Twenty-nine specimens were prepared from each of three different materials: ZR (zirconia), PEEK (polyether ether ketone) and CoCr4 (CoCr4 alloy). The experimental part included surface roughness (SR) and contact angle of water (CAW) measurements, followed by colony forming unit (CFU), cell viability assay and scanning electron microscopy (SEM) analyses of Strep. oralis and C. albicans biofilms on the materials' surfaces. Kruskal-Wallis and one-way analysis of variance (ANOVA) tests were used for differences between materials, and the correlation between measurements was estimated using Spearman's correlation coefficient. PEEK specimens revealed higher SR, CAW and CFU mean values, than ZR and CoCr4 specimens. Strong positive correlation was found between SR and CFU and between CAW and CFU for both microbial species. Cell viability assay revealed similar values for both species across materials. Higher numbers of Strep. oralis and C. albicans on PEEK specimens confirm the impact of the higher surface roughness and contact angle values on the microbial adhesion and describes PEEK as less desirable than ZR and CoCr4 from microbiological aspect.

Subjective and Objective Assessment of Chewing Performance in Older Adults with Different Dental Occlusion.

OBJECTIVES: Satisfactory masticatory function is a significant indicator of improved oral health-related quality of life in older adults, either with or without artificial teeth. The purpose of this study was to examine masticatory performance of older adults with different prosthodontic reconstructions and occlusion, as well as to compare subjective and objective assessment of chewing performance. MATERIAL AND METHODS: This study included 100 participants aged 65 and more. The chewing function questionnaire (CFQ) with answers on the Likert scale 0-4 (0 = no difficulties; 4 = maximum difficulties) was used as an indicator of subjective masticatory assessment. The two-color chewing gum test was used as objective assessment of masticatory function (mixing ability), based on the Z-score values. Dental occlusion was assessed using functional teeth units (FTU). RESULTS: The results obtained using the CFQ and the clinical mixing ability test are in compliance with each other (r = 0.742). A decrease in the number of natural teeth, especially posterior teeth, progressively reduced chewing ability and increased difficulties in mastication. Participants with less FTUs, or with FTUs that are a part of removable denture, had greater reduction in masticatory function compared to those with FTUs composed of natural teeth or fixed partial dentures. CONCLUSION: This study revealed a strong positive correlation between the subjective masticatory assessment in older adults using the validated questionnaire and the objective clinical test of the mixing ability of two chewing gums. Our data on influence of the number and the type of FTU on masticatory performance will be valuable when planning prosthodontic therapy.

Mini-Implants Retaining Removable Partial Dentures in Subjects without Posterior Teeth: A 5-Year Prospective Study Comparing the Maxilla and the Mandible.

Background and objectives: Long-term studies of clinical outcomes of mini-implants (MDIs) in the first premolar/canine sites retaining a bilateral free-ending removable partial dentures (RPD) in Kennedy class I subjects have not been well documented. The aim was to assess clinical outcomes in a prospective 5-year cohort study comparing the mandible and maxilla. Material and Methods: Participants (n = 92) who received two MDIs each and a new RPD were reviewed after one, three and five years. A total of 71 participants (82 mini-implants in the mandible; 58 in the maxilla) completed the study. Marginal bone level change, success, survival rates, Modified Plaque (MPI) and Bleeding Indices (MBI) were assessed. Results: The five-year success rate was 93.3% and 93.4% (p > 0.05), in the mandible and the maxilla, respectively. Mean peri-implant bone loss (MBL) increased significantly over five years (p < 0.01) to 0.50 mm in the mandible and 0.52 mm in the maxilla. Age had a significant effect on the MBL (higher rates in younger participants), while jaw of insertion, gender, and antagonistic jaw status did not. MPI and MBI were not significantly correlated with MBL. Conclusions: The insertion of two MDIs in previous first premolar/canine sites for retention of a free-end saddle RPD can be a successful treatment modality in subjects with narrow alveolar ridges.

Study on the surface properties of different commercially available CAD/CAM materials for implant-supported restorations.

OBJECTIVE: To determine if there are any differences in surface characteristics (surface roughness and contact angle) among different CAD/CAM materials indicated for fabricating implant-supported restorations, following all the material preparation protocols provided by the manufacturer. MATERIALS AND METHODS: One-hundred forty-four specimens were divided into six groups: RBC (resin-based composite), PMMA (polymethyl methacrylate), PEEK (polyether ether ketone), ZP (zirconia polished), ZG (zirconia glazed) and CoCr4 (CoCr4 alloy). The experimental part included surface roughness (SR) and contact angle of water (WCA) analyses, fulfilled with Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) view of surface topography. The data were analyzed using Kruskal-Wallis test with a Dunn's post hoc analysis, the correlation between measurements was tested using Spearman's rank correlation coefficient and all data were presented as mean ± SD. RESULTS: ZG specimens were significantly rougher compared to other groups (p ≤ 0.05). The WCA measurements revealed significantly lower mean values in ZG group (p ≤ 0.05), contrary to PEEK and CoCr4 , where significantly higher mean values were observed, compared to other groups (p ≤ 0.05). There exist a moderate negative correlation between the SR and WCA (ρ = -0.41). AFM 3D and SEM 2D images presented more or less heterogeneous surface of all materials. CONCLUSIONS: There were statistically significant differences in surface roughness and contact angle among tested material groups. Moderate negative correlation was found between surface roughness and contact angle of tested material groups. CLINICAL SIGNIFICANCE: The study gives us a better understanding of influence of physicochemical characteristics of investigated materials on their surface properties and provides useful knowledge for future researches in a view of material's behavior under in vivo conditions, when it comes to a question of features related to surface quality, such as microbial adhesion, corrosion, wear, biocompatibility and esthetics.

Oral Health Status and Nutritional Habits as Predictors for Developing Alzheimer's Disease.

OBJECTIVE: Poor oral health, mainly tooth loss, has been suggested to pose a risk factor for Alzheimer's disease (AD). The nature of this relationship can be explained by mastication deficit and nutritional status. Also, the influence of nutritional parameters on cognitive impairment has been documented. The aim of this study was to investigate whether poor dental status and nutrition habits can be potential separate or associated risk factors for development of the AD. METHODS: The study sample included 116 patients with AD and 63 controls. Sociodemographic variables were investigated as factors potentially associated with AD. Dental examination included recording the number of natural teeth, presence of fixed or removable dentures, and the number of functional tooth units (FTUs). Nutritional status analysis included qualitative nutrition information, body mass index, serum albumin level, food consistency, and need for assistance in feeding. Regression analysis was used to investigate the predictors for development of AD. RESULTS: Variables with significant differences between groups, which were analyzed by using the binary regression analysis, were marital status, residence, number of total FTUs (no matter whether the contacts were between natural teeth or dentures), eating meat/fish and fruits/vegetables, food consistency, and serum albumin level. Logistic regression analysis showed that being single/widowed/divorced, eating more meat/fish or fruit/vegetable, eating blended/mashed/liquid food, having low levels of serum albumin, and having less FTUs were significant predictors for developing dementia. CONCLUSION: Having fewer occlusal contacts, consumption of soft food, and lower serum albumin levels can be considered as associated risk factors for AD.

Analysis of abutment teeth in partially edentulous patients.

The aim of the study was to examine changes in the position of the abutment teeth (AT), size of undercuts for a denture clasp, as well as an existence of an adequate preparation of abutment teeth. A total of 156 casts of partially edentulous jaws, with 460 AT, were analyzed. The size of undercuts, a degree of abutment rotation, inclination and migration were measured using a dental parallelometer. The abutment teeth position was related to the level of occlusal plane in a dental articulator. Furthermore, the existence of an adequate preparation of abutment teeth, as well as a type of a denture and a type of a denture retention element were also considered. Analysis were carried out twice on casts made from a hard stone, the first time before the denture treatment had begun and the second time on the new casts obtained after new dentures had been delivered. The first analysis (prior dental treatment) revealed that a total of 33.9% of the analyzed AT were rotated, 31.3% were inclined, 12.1% had migrated, and 57.3% were elongated above the occlusal plane. On the casts obtained after the new dentures had been made, it was observed that none of the AT had an adequate preparation. Only 37.6% of all retention elements were located in adequate undercut positions on the AT. Upon the results of the present study a conclusion can be established that many abutment teeth are rotated, elongated, inclined, and migrated, which point to a requirement for AT preparation prior the manufacture of new denture; however none of the AT was adequately prepared considering insertion plane and many denture elements were located in an inadequate undercut size.

Biofilm Formation on the Surfaces of CAD/CAM Dental Polymers.

Dental polymers are now available as monolithic materials which can be readily used in computer-aided design and computer-aided manufacturing (CAD/CAM) systems. Despite possessing numerous advantages over conventionally produced polymers, the polymers produced by either of these systems fail to exhibit immunity to surface microbial adhesion when introduced into the oral environment, leading to the development of oral diseases. The aim of this study was to analyze the biofilm formation of six microorganisms from the oral cavity and its correlation to the surface characteristics of CAD/CAM dental polymers. A total of ninety specimens were divided into three groups: resin-based composite, polymethyl methacrylate, and polyether ether ketone. The experimental procedure included surface roughness and water contact angle measurements, colony forming unit counting, and scanning electron microscopy analysis of biofilm formed on the surface of the tested materials. The data were analyzed using the Kruskal-Wallis test, with a Dunn's post hoc analysis, and one way analysis of variance, with a Tukey's post hoc test; the correlation between the measurements was tested using Spearman's correlation coefficient, and descriptive statistics were used to present the data. Despite using the same manufacturing procedure, as well as the identical manufacturer's finishing and polishing protocols, CAD/CAM dental polymers revealed significant differences in surface roughness and water contact angle, and the increased values of both parameters led to an increase in biofilm formation on the surface of the materials. The CAD/CAM resin-based composite showed the lowest number of adhered microorganisms compared to CAD/CAM polymethyl methacrylate and CAD/CAM polyether ether ketone.

Prevalence, severity, and clinical determinants of oral impacts in older people in Bosnia and Herzegovina.

This study aimed to assess the prevalence and the severity of oral impacts and the relationships between oral health-related quality of life (OHRQoL) and clinical measures of oral function in a sample of older adults in Bosnia. The sample comprised 261 community-dwelling adults of ≥65 yr of age. Participants were randomly drawn from three senior day-centres for elderly people. Data were collected using clinical examination and a questionnaire. The OHRQoL was assessed through the Oral Impacts on Daily Performances (OIDP) measure, in terms of the prevalence, intensity, and extent of oral impacts. Overall, 55.2% reported at least one oral impact in the last 6 months. Difficulty eating (43.3%) and difficulty speaking (34.1%) were the most common impacts. These were also the most severely affected performances, while 'going out' and 'enjoying the contact of other people' were the least severe. A higher number of natural teeth, natural occluding pairs, and anterior and posterior occluding pairs were all significantly associated with a lower prevalence of oral impacts and correlated with the OIDP score, even after adjusting for sociodemographic factors. The prevalence of oral impacts was high and there was a strong and consistent association between OHRQoL and clinical dental indicators of function.

Validity and reliability of the Oral Impacts on Daily Performance (OIDP) scale in the elderly population of Bosnia and Herzegovina.

OBJECTIVES: To adapt the Oral Impacts on Daily Performance (OIDP) index for elderly people in Bosnia and Herzegovina and test its validity, reliability and responsiveness to change. BACKGROUND: Clinical measures alone may not be adequate for assessing the oral health of individuals. Subjective oral health indicators tested within a particular cultural context may not be relevant across cultures. MATERIALS AND METHODS: The study population comprised 231 free-living adults aged 65 years or older. The OIDP was cross-culturally adapted from English into the Serbian language and its psychometric properties were tested. Data were collected using a clinical examination and a questionnaire containing the OIDP. RESULTS: In terms of reliability, Cronbach's alpha coefficient was 0.82 and the intraclass correlation coefficient 0.88. The very high correlation of OIDP with self-rated oral health (r = 0.78) verified criterion validity, while construct validity was demonstrated through its significant and graded associations with other subjective health measures. OIDP change scores on a treated subsample showed moderate effect size (0.59) and were associated with perceptions of oral health change, providing evidence for its responsiveness to change. CONCLUSION: The Bosnian version of the OIDP showed satisfactory validity, reliability and responsiveness to change confirming its appropriateness for use among older populations in Bosnia and Herzegovina.

Translation and preliminary validation of the Serbian version of an ageism scale for dental students (ASDS-Serb).

AIMS: The ageist attitudes among dental clinicians may result in inadequate treatment planning and reduce quality of life for older adults. This study aimed at performing a preliminary validation of an ageism scale for dental students (ASDS) in Serbia (ASDS-Serb). METHODS AND RESULTS: The 27-item ASDS was translated from English into Serbian and completed by 129 dental students. Principal component analysis (PCA), Confirmatory factor analysis (CFA), internal consistency reliability and discriminant validity were estimated. PCA produced a 17-item scale distributed into five factors that explain 64.24% of the total variance. All items showed high to moderate reliability (0.50-0.83). CFA indicates an acceptable model fit with significant standardized factor loadings ranging from 0.14-0.99. The first factor dealt with negative views of older adults' life and dental treatment, the second factor related to ethical values about older people, the third factor compared younger and older adults in dental care and the fourth factor related to difficulties in medical history taking. The fifth factor related to perceptions of oral health and treatment of older adults. Discriminant validity revealed significant differences related to the semester of studies, gender and having older people in the family. CONCLUSION: The preliminary validation of the ASDS-Serb resulted in a 17-item scale distributed into the five factors with acceptable validity and reliability.

Adaptation to New Dentures and 5 Years of Clinical Use: A Comparison between Complete Denture and Mini-implant Mandibular Overdenture Patients based on Oral Health-Related Quality of Life (OHRQoL) and Orofacial Esthetics.

Objective of work: It is unclear how long patients need to adapt to new dentures. This study assessed adaptation and five years of clinical use, comparing complete denture wearers (CDs) and mini-implant mandibular overdenture wearers opposing a maxillary CD (MDI-OD), based on oral health reported quality of life (OHRQoL) and orofacial esthetics (OES). Material and Methods: A total of 36 subjects in the CD group (25 females) and 30 subjects in the MDI group (20 females) completed the 5-year study. All patients received new CDs, but in the MDI-OD group, four mini-implants were inserted interforaminally in the mandible before denture manufacture. Participants filled in the OHIP-EDENT and OES questionnaires one day after dentures' delivery, on the 3rd, 8th, 15th, 30th day, and at the 1-, 3- and 5-year follow-up examinations. Statistical analysis comprised descriptive methods, X 2 test, independent t-test, Friedman, and Mann-Whitney test. Results and Conclusions: Both groups' adaptation to new dentures was completed within a month. The MDI-OD group had significantly better OHRQoL in all follow-ups except for the 3rd and 8th day, probably due to soreness and pain, the reason why the MDI-OD group had limitation in functioning in the first days after new dentures' delivery. Already after the third year and at the fifth year, OHRQoL worsened (p<0.01) in both groups. However it was significantly more pronounced in the conventional CD wearers (p<0.01) than in the MDI-OD group. Orofacial esthetics was highly scored in both groups. The scores dropped down only after three years, equally in both groups. Keywords: OHRQoL, OES, prospective study, complete dentures, mini-implants, adaptation. MeSH Terms: Complete Dentures; Dental Implants; Quality of Life; Dental Esthetics.

Using role play to develop positive attitudes toward people with disabilities among dental students: An exploratory pilot study.

INTRODUCTION: Comprehensive and interprofessional undergraduate teaching and training in special care dentistry (SCD) could influence future dentists' attitudes towards patients with disabilities. The aim of the study was to assess the influence of role play as part of SCD training on the attitudes of undergraduates towards patients with disabilities. METHOD: The students attending the SCD module during the autumn semester of 2019 comprised our target population. A quasi-experimental design was used to compare the attitudinal scores between three groups of students exposed to different modalities of SCD teaching: group 1 - didactic teaching (N = 92), group 2 - didactic teaching and clinical training in the dental treatment of children or elderly patients with disabilities (N = 142), group 3 - theoretical teaching and clinical training, accompanied by role play sessions featuring persons with disabilities (N = 20). The contact rate was 100%. The outcomes of the intervention were measured using the altruism scale, which forms part of the International Association for Disability and Oral Health (iADH) Toolbox for measuring attitudes and intended behaviors towards persons with disabilities. RESULTS: The analysis revealed the two-factor structure of the nine-item altruism scale. The first factor was described as the acceptance of oral health care as a universal human right, while the second was the perception of the contribution of marginalised groups, including people with disabilities, to the community. The students participating in the role play scored higher on both factors in comparison to those attending other modes of SCD training. CONCLUSION: The presented findings suggested role play as a powerful tool in fostering positive attitudes towards persons with disabilities in the education of dental students and highlighted the importance of multidisciplinary training.

COVID-19 Impact on Public Dental Healthcare in Bosnia and Herzegovina: Current Situation and Ongoing Perspectives.

BACKGROUND: As the pandemic time went by in Bosnia and Herzegovina (B&H), various patterns toward COVID-19 itself and its impacts, implementation of prescribed preventive measures among the team members, and those of their patients, including immunization process, have been revealed. These patterns were of both empirical and evidence-based kind and consequently formed dental personnel behavior. The aim was to evaluate and compare the COVID-19 status of dentists in B&H, implementation of prescribed preventive measures, and usage of various kinds of PPE, at the beginning of the pandemics and now, 2.5 years later, including dentists' current vaccination status, and their opinions and attitudes toward the national COVID-19 economic impact on dental practice. METHODOLOGY: Study research was in a form of a cross-sectional longitudinally designed online survey and was conducted in two parts. RESULTS AND CONCLUSIONS: Dental professionals in B&H had a high frequency of COVID-19 symptoms in the second pandemic year. The vaccination status of dentists in B&H was in line with the global average values of vaccinated professionals. Dentists used patient management preventive measures and PPE recommended by WHO, but some preventive measures have been changed and prioritized recently. The economic impact of pandemics on dentistry was predominantly negative.

The effect of COVID-19 pandemic on final year dental students' self-confidence level in performing clinical procedures.

BACKGROUND: The outbreak of COVID-19 pandemic in 2020 has dramatically changed teaching approach in dental schools due to the switch to distance learning and the lack of practice training in direct contact with patients with possible impact on clinical skills of students. The aim of the study was to assess the level of the 2020 final year dental students' self-confidence in performing different dental procedures through specially designed questionnaire and compare it to self-confidence of the 2019 final year students. MATERIALS AND METHODS: An anonymous questionnaire consisting of 40 questions regarding self-confidence level in performing 40 different dental procedures and based on five points Likert-like scale was distributed during November 2020 to final year dental students whose studies were disrupted by the COVID-19 pandemic lockdown in one semester. The study group comprised their answers. The comparison was done with the control group that consisted of students' answers on the same questionnaire from previous 2019 year conducted as a part of regular internal educational evaluation. RESULTS: Response rate was 74.2% in study group and 89.3% in control group. Mean level of self-confidence reported by 115 students in study group was significantly lower than that reported by 100 students in control group (3.28±1.08 vs. 3.58±0.88, respectively) and the distribution of self-confidence scores were different in observed groups. Graduates from study group felt less confident than those from control in 8 clinical skills. CONCLUSION: Abrupt changes in teaching modalities caused by COVID-19 pandemic had significant impact on final year dental students' self-confidence indicating additional educational needs in postgraduate period.

Psychometric Characteristics of the Croatian and the Serbian Versions of the Oral Health Impact Profile for Edentulous Subjects, with a Pilot Study on the Dimensionality.

INTRODUCTION: The aim was to adapt the Croatian and the Serbian versions of the Oral Health Impact Profile for the edentulous population (OHIP-EDENT-CRO and OHIP-EDENT-SRB). METHODS: The translation and cross-cultural adaptation were carried out in accordance with accepted international standards. A total of 95 and 177 removable denture wearers were recruited in Croatia and Serbia respectively. The reliability was evaluated by calculating Cronbach's alpha coefficient and by test-retest (30 participants in each country). The concurrent validity was determined by calculating the Spearman's rank coefficient between the OHIP-EDENT summary scores and one question related to removable denture satisfaction. Construct validity was determined by exploratory factor analysis (EFA). Responsiveness was determined by comparison of the OHIP-EDENT summary scores before and after dental implant placement to support mandibular overdentures (23 patients in Croatia, 21 in Serbia). RESULTS: Cronbach's alpha coefficient was 0.92 in Croatia and 0.87 in Serbia. The intraclass correlation coefficient was 0.98 in Croatia and 0.94 in Serbia. In Croatia the Spearman's correlation coefficient was -0.71 (p<0.001) and in Serbia -0.74 (p<0.001). Both confirmed concurrent validity. Construct validity was tested by EFA, which extracted four factors in each country, accounting for 66.59% of the variance in Croatia and 59.33% in Serbia. Responsiveness was confirmed in both countries by a significant OHIP-EDENT summary score reduction and a high standardised effect size (3.9 in Croatia, 1.53 in Serbia). CONCLUSION: The results prove that both instruments, the OHIP-EDENT-CRO and the OHIP-EDENT-SRB, have very good psychometric properties for assessing OHRQoL in the edentulous population.

Apolipoprotein ɛ4 Allele and Dental Occlusion Deficiency as Risk Factors for Alzheimer's Disease.

Compromised dentition has been suggested to pose a significant risk factor for dementia. It was mainly investigated through insufficient tooth number, disregarding contact between opposing teeth (dental occlusion). The ɛ4 allele of apolipoprotein (APOE4) is the primary genetic marker for the late onset of Alzheimer's disease (AD). However, APOE4 and dental occlusion have not yet been investigated as possible associated risk factors for AD. The study was aimed to examine the impact of dental status and different APOE gene variants on AD occurrence. Secondly, sociodemographic variables were investigated as factors potentially associated with AD. The case-control study included two groups: 116 patients with AD (according to the NINDS-ADRDA criteria) and 63 controls (Mini-Mental State Examination scores ≥24). The analysis of APOE gene polymorphism was conducted through PCR reaction. Dental examination included recording of number of teeth, presence of fixed or removable dentures, and number of functional tooth units (FTU). Regression analysis was used to investigate the joint effect of the clinical and genetic variables on AD. Results showed that patients with AD were more often carriers of ɛ3/ɛ4 genotype and ɛ4 allele, had lower number of teeth and FTU, and were less likely to be married, live in home, and had less chronic diseases, compared to the controls. Regression analysis showed that presence of APOE4 allele and the number of total FTU remained associated with AD, even when adjusted for age, sex, and level of education. In conclusion, deficient dental occlusion and presence of APOE4 may independently increase risk for AD.

Caregivers' attitudes, knowledge and practices of oral care at nursing homes in Serbia.

Background/Aim: Within the elderly population, residents in nursing homes, there is a greather risk of caries, periodontal disease and teeth loss. Assistance of caregivers in maintaininig good oral hygiene besides improving oral health can improve of residents general health and the qulity of their lives. The aim of this study was to examine the attitudes of caregivers and knowledge about oral health, as well as the practice regarding oral care they apply at nursing homes in Serbia. Methods: The survey was conducted at the Gerontology Center Belgrade, consisting of four nursing homes located in the urban area. The study included 58 caregivers. They were contacted on working days, in all work shifts, during January, February and March of 2013. They were asked to fill in a self-administered questionnaire consisting of 26 closed-type questions. Results: The caregivers mostly considered that it was very important to take care of oral health of the residents, but 69% responded that the level of their oral health was low or very low. As the main barriers to oral hygiene maintenance, the caregivers indicated lack of time. The caregivers had more knowledge about periodontal disease than about the main cause of caries and its prevention. Formal medical education had the influence on the knowledge about oral diseases. Oral hygiene procedures carried out by the mayority of caregivers were denture cleaning and tooth brushing. Conclusion: The caregivers were aware of the limitations in everyday oral care of nursing homes residents in Serbia, although solving these problems requires the involvement of the entire public health service.