Clinical performance of a glass-hybrid system in comparison with a resin composite in two-surface class II restorations: a 5-year randomised multi-centre study

OBJECTIVE

To evaluate the 5-year clinical performance of a glass hybrid restorative system and a nano-hybrid resin composite in moderate to large two-surface class II cavities.

MATERIALS AND METHODS

This study was carried out by dental schools in Zagreb, Croatia; Izmir, Turkey; Belgrade, Serbia; and Milan, Italy. A total of 180 patients requiring two class-II two-surface restorations in the molars of the same jaw were recruited. The teeth were randomly restored with either a nano-hybrid resin composite (Tetric EvoCeram, Ivoclar Vivadent) or a glass-hybrid material (EQUIA Forte, GC). During the 5-year follow-up, two calibrated evaluators at each centre scored the restorations annually using the FDI-2 scoring system. The survival rates were calculated using the Kaplan-Meier method and compared using non-parametric matched pair tests (p < 0.05).

RESULTS

There were no statistically significant differences between the overall survival and success rates of the two types of restorations (p>0.05). The success rates (FDI-2 scores 1-3) for EQUIA Forte were 81.9% (average annual failure rate: 3.9%) and 90.7% for Tetric EvoCeram (average annual failure rate: 1.9%). The survival rates (FDI-2 scores 1-4) for EQUIA Forte and Tetric EvoCeram were 94.5% and 94.4%, respectively, with an average annual failure rate of 1.1%.

CONCLUSIONS

In terms of success and survival rates, both the glass-hybrid restorative system and the nano-hybrid resin composite have been shown to perform satisfactorily.

CLINICAL RELEVANCE

The results of this study indicate that EQUIA Forte can be one of the therapeutic options for moderate to large two-surface class II restorations of posterior teeth.

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.

The Participation of Pediatric Dentists in Oral Health Promotion and Education in Serbia

Objectives

To identify the involvement of Serbian paediatric dentists in oral health promotion and education, and to propose further actions for the improvement of these activities.

Methods

This is an analysis of data collected by a cross-sectional, questionnaire-based survey of 445 dentists involved in the provision of dental health services to children at the primary healthcare level. We explored dentists' involvement in oral health education and promotion and the cooperation with other health professionals at the healthcare centre and the community level as well as their attitudes towards the importance of some factors influencing their work.

Results

Dentists estimate their cooperation with different services with ratings higher than 3 on the scale of 1 to 5. They reported the highest satisfaction in cooperation with paediatric services for preschool and schoolchildren (4.0±1.0). At the community level, they reported excellent cooperation with kindergartens (4.4±0.8), while collaboration with Roma health mediators (3.14±1.34) and nongovernmental organizations (2.5±1.4) received lower ratings. According to the average rating (4.7±0.7), dentists perceive the motivation of patients and/or their guardians for keeping good oral health as the factor with the highest importance for the quality of interventions they provide.

Conclusions

Dentists involved in the provision of dental healthcare for children and adolescents in primary healthcare centres in Serbia participate in different oral healthcare education and promotion activities in the community, and highlight the importance of strengthening cooperation with healthcare and other professionals and services aimed at vulnerable population groups, both within the health sector and nongovernmental organizations.

EO-based mouthwashes: Is there something that should be known?

The possibility to utilize the antibacterial and antibiofilm potential of essential oils (EOs) in dentistry is recognized and best seen in the design of EO-based mouthwashes. The up-to-date results, obtained with the most commonly used formulation being consisted of thymol, eucalyptol, menthol, and methyl salicylate (Listerine), proved its efficacy against plaque and gingival inflammation. However, novel alcohol-free products remain to be further investigated. Commercially available mouthwash containing curcumin, clove oil, mentha oil, eucalyptol, thymol and tea tree oil, and the mouthwash based on ginger EO (a-zingiberene, b-bisabolene, b-sesquiphellandrene, curcumene), reduced plaque index and improved periodontal status of the patients. The plaque index was also reduced and overall healing was improved after the surgical removal of the third molar by mouthwash containing John wort oil. In addition, Cinnamomum zeylanicum EO-based mouthwash and mouthwash containing peppermint oil were efficient against stomatitis and xerostomia, respectively. In addition to beneficial effects achieved in the mouth, i.e. at the appropriate site of application, novel investigations pointed-out that EO-based mouthwashes could be recognized as efficient in the reduction of bacterial and viral aerosols. This has been shown for Listerine, and for several mouthwashes containing following active substances of plants' EO origin: a-farnesene, b-farnesene, farnesol, nerolidol, a-bulnesene, eremanthin, b-sesquiphellandrene, spiroether, cinnamylacetate, cinnamaldehyde, eugenol, menthol, and carvacrol. This finding could be of special interest, in order to be included in further clinical studies related to COVID -19 pandemic.

Essential oils as adjuvants in endodontic therapy: myth or reality?

To enhance endodontics, the search for new antibacterials that can improve infected tooth root canal treatment is ongoing. As potent antibacterial and antibiofilm agents, essential oils (EOs) have been suggested as novel endodontic materials. Several studies indicate that EO-based irrigants and medicaments show promising reductive potential against the most important intracanal pathogen, Enterococcus faecalis, and notably contribute to intracanal biofilm eradication. In terms of additional benefits that EO-based endodontic materials can provide, their antioxidant and anti-inflammatory potential are also important, but they have only scarcely been explored in research. Investigations into the benefits of EO-based endodontic materials together with their biocompatibility are needed. The results presented in this review strongly encourage further research on this topic.

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.

Mesenchymal Stromal Cells from Healthy and Inflamed Human Gingiva Respond Differently to Porphyromonas gingivalis

Gingiva-Derived Mesenchymal Stromal Cells (GMSCs) have been shown to play an important role in periodontitis. However, how P. gingivalis, one of the key etiological agents of the disease, affects healthy (H)- and periodontitis (P)-GMSCs is unknown. To address this problem, we established 10 H-GMSC and 12 P-GMSC lines. No significant differences in morphology, differentiation into chondroblasts and adipocytes, expression of characteristic MSCS markers, including pericyte antigens NG2 and PDGFR, were observed between H- and P-GMSC lines. However, proliferation, cell size and osteogenic potential were higher in P-GMSCs, in contrast to their lower ability to suppress mononuclear cell proliferation. P. gingivalis up-regulated the mRNA expression of IL-6, IL-8, MCP-1, GRO-α, RANTES, TLR-2, HIF-1α, OPG, MMP-3, SDF-1, HGF and IP-10 in P-GMSCs, whereas only IL-6, MCP-1 and GRO-α were up-regulated in H-GMSCs. The expression of MCP-1, RANTES, IP-10 and HGF was significantly higher in P-GMSCs compared to H-GMSCs, but IDO1 was lower. No significant changes in the expression of TLR-3, TLR-4, TGF-β, LAP, IGFBP4 and TIMP-1 were observed in both types of GMSCs. In conclusion, our results suggest that P-GMSCs retain their pro-inflammatory properties in culture, exhibit lower immunosuppressive potential than their healthy counterparts, and impaired regeneration-associated gene induction in culture. All these functions are potentiated significantly by P. gingivalis treatment.

Analysis of the pattern, type and the extent of dental services provided to children and youth on the territory of Republic of Serbia

Background/Aim: The requirements for dental specialties and the number of specialists in each country are unique and strong indicator of the availability and affordability of primary health care for children and adolescents. The aim of this study was to determine the pattern, type and the extent of dental services, as well as the influence of regional factors and data on whether services are provided by a pediatric dentist or general dentist have effect on these parameters, based on information obtained from dentists providing dental care to children and youth. Material and Methods: Within the project "Program for the improvement of oral health of children and youth in the Republic of Serbia", supported by the Ministry of Health of Serbia, a research was conducted among dentists involved in dental care for children and youth in Serbia. Data collection from primary health care facilities was performed through a specially designed questionnaire. A total of 445 questionnaires were collected from dentists from 102 health centers in Serbia in the period June - October 2019. Results: There are significant differences between regions in the pattern, type and the extent of dental services. In the quantitative analysis, there are no significant differences in the type of dental services between pediatric and preventive dentistry specialists and general dentists. Conclusions: The data from the conducted research speak in favor of a large daily workload of dentists who deliver oral health care for children and youth in Serbia. Additional multifactorial analysis, which includes epidemiological data from the region, but also environmental, demographic and cultural parameters of oral health could be the basis for improving the provision of preventive dental and preventive oral care

Analysis of oral health care delivery in patients with autism

Background/Aim: Autism spectrum disorder (ASD) is pervasive neurodevelopmental condition with raising prevalence over the last decades. Oral health related problems arise mostly due to challenging behavior, communication limitation, and resistance to receiving dental treatment. The aim of this retrospective study was to investigate the frequency, quality and type of dental care during routine appointments and under general anesthesia (GA) in persons with ASD. Matreial and Methods: The data were obtained in retrospective cross-sectional study by analyzing patients' records from the central electronic database of the Clinic for Dentistry of Vojvodina. Demographic, medical and dental data were analyzed employing Mann Whitney U test, Kruskal Wallis test and CATREG regression analysis. Results: A total of 51 patients from 4.2-47.6 years of age had an average of 13.2 ±13.5 dental appointments, with 2.27±4.23 treatments done under GA in a period of 7 years. The average number of restored teeth was 3.64±4.42 and 4.64±5.95 teeth were extracted. Only 21.5% of participants regularly attended scheduled appointments. Patients who started oral health care earlier had more teeth restored and extracted during RDT, and were less subjected to treatment under GA. Conclusions: Dental services to patients with ASD are commonly limited to more radical approach comprising multiple teeth extractions and repeated treatment under GA. It is of utmost importance to tailor comprehensive plan for dental care provision in individuals with ASD at earliest possible age.

Cymbopogon citratus essential oil: an active principle of nanoemulsion against Enterococcus faecalis root canal biofilm

Aim: The objective was to formulate and characterize the nanoemulsion based on Cymbopogon citratus oil, intended for use in infected teeth root canal therapy. The investigation of the antioxidant and antibiofilm potential toward Enterococcus faecalis was aimed as well. Materials & methods: Characterization of oil (by GC/MS analysis) and nanoemulsion (by dynamic light scattering instrument), and determination of antibacterial (by microdilution assay), antibiofilm (by crystal violet assay) and antioxidant properties (by 2,2-diphenyl-1-picryl-hydrazyl-hydrate and thiobarbituric acid assay methods) were provided. Antibiofilm efficacy of irrigation procedure including nanoemulsion was screened on extracted teeth (by CFU-counting assay). Results: Notable antibacterial and antibiofilm activity, both against forming and preformed biofilms of oil, was observed. Irrigation involved nanoemulsion showed remarkable antibiofilm potential. Both substances induced some antioxidant activity. Conclusion: Results encourage further research with the aim of application of the nanoemulsion in dental practice.

Clinical Performance of a Glass-Hybrid System Compared with a Resin Composite in the Posterior Region: Results of a 2-year Multicenter Study

PURPOSE

To compare the clinical performance of a glass hybrid restorative system, EQUIA Forte, with that of a nanohybrid resin composite, Tetric EvoCeram, in two-surface class II cavities.

MATERIALS AND METHODS

This multicenter, randomized controlled clinical study was conducted at four different dental schools. In total, 360 restorations were placed in patients in need of two class-II, two-surface restorations in the molar region of the same jaw. Each patient received one glass hybrid restoration (EQUIA Forte, GC) and one resin composite restoration (Tetric EvoCeram, Ivoclar Vivadent). Two independent evaluators performed a clinical evaluation of each site after 1 week (baseline), 1 year, and 2 years using the criteria of the FDI World Dental Federation (FDI-2).

RESULTS

The estimated survival rates at the 2-year recall were 93.6% and 94.5% for EQUIA Forte and Tetric EvoCeram, respectively. There were no significant differences in the survival rates or in any of the evaluated esthetic, functional or biological properties between EQUIA Forte and Tetric EvoCeram restorations (p ˃ 0.05).

CONCLUSION

Both the glass-hybrid restorative system and nanohybrid resin composite showed good clinical performance in moderate to large two-surface class II restorations in a 2-year follow-up.

Sequential Dispersive Measurement of a Superconducting Qubit

We present a superconducting device that realizes the sequential measurement of a transmon qubit. The device disables common limitations of dispersive readout such as Purcell effect or transients in the cavity mode by turning on and off the coupling to the measurement channel on demand. The qubit measurement begins by loading a readout resonator that is coupled to the qubit. After an optimal interaction time with negligible loss, a microwave pump releases the content of the readout mode by upconversion into a measurement line in a characteristic time as low as 10 ns, which is 400 times shorter than the lifetime of the readout resonator. A direct measurement of the released field quadratures demonstrates a readout fidelity of 97.5% in a total measurement time of 220 ns. The Wigner tomography of the readout mode allows us to characterize the non-Gaussian nature of the readout mode and its dynamics.

Nanostructured endodontic materials mixed with different radiocontrast agents-biocompatibility study

The aim of this study was to investigate the biocompatibility of nanostructured materials based on highly active calcium silicates mixed with different radiocontrast agents in comparison to MTA⁺ using in vitro and in vivo model. Morphology of materials' samples was analyzed using SEM while the phase compositions were identified by XRD. pH values of materials' suspensions were conducted by pH-meter. The cytotoxicity of materials' solutions was tested by MTT test (100, 50, 25 and 12.5 mg/ml). LDH and ³H-thymidine assay were utilized for biocompatibility investigations of materials' eluates (24 h, 7 day and 21 day). Eighteen Guinea pigs were used for intramuscular implantation, as teflon tubes with freshly prepared materials were placed into intramuscular pockets. All samples were composed of round and needle-like particles equally distributed with Ca/Si ratio ~2.7 at%, with the presence of hydrated calcium silicate phases. The pH values of ALBO-MPCA₁ and ALBO-MPCA₂ were high alkaline, while in case of MTA⁺ they were lower and continuously declined (p < 0.05). Investigated materials didn't exhibit dose-dependent effect on metabolic activity of L929 cells (p > 0.05). Significant differences in the percentage of cytotoxicity between diluted and undiluted extracts between all tested materials after 24 h and 7 day were noticed (p < 0.05). Increase in L929 cells proliferation was noticed in case of undiluted eluates of ALBO-MPCA₁ and ALBO-MPCA₂ after 7 day (p < 0.05). There were no statistically significant differences in the intensity of inflammatory response between investigated materials and control group after 60 day (p > 0.05). Evaluation of biocompatibility of both ALBO-MPCA₁ and ALBO-MPCA₂ indicate their potential clinical use.

Demonstration of an Effective Ultrastrong Coupling between Two Oscillators

When the coupling rate between two quantum systems becomes as large as their characteristic frequencies, it induces dramatic effects on their dynamics and even on the nature of their ground state. The case of a qubit coupled to a harmonic oscillator in this ultrastrong coupling regime has been investigated theoretically and experimentally. Here, we explore the case of two harmonic oscillators in the ultrastrong coupling regime. Probing the properties of their ground state remains out of reach in natural implementations. Therefore, we have realized an analog quantum simulation of this coupled system by dual frequency pumping a nonlinear superconducting circuit. The pump amplitudes directly tune the effective coupling rate. We observe spectroscopic signature of a mode hybridization that is characteristic of the ultrastrong coupling. We experimentally demonstrate a key property of the ground state of this simulated ultrastrong coupling between modes by observing simultaneous single- and two-mode squeezing of the radiated field below vacuum fluctuations.

Assessment of risk factors and preventive measures and their relations to work-related musculoskeletal pain among dentists

BACKGROUND

Dentists have a high prevalence of musculoskeletal (MS) pain, which is the most common symptom associated with work-related musculoskeletal disorders (WMSDs). To overcome this problem, identification of the risk factors and preventive measures for MS pain are of paramount importance to dentists in order to improve their quality of life and work.

OBJECTIVES

The aims of this study were to recognize the risk factors for MS pain and their impact on dental work, as well as to identify preventive measures of MS pain among dentists.

METHODS

Self-reporting questionnaire consisting of 78 questions was exclusively developed for the study and sent to 500 working active dentists in Serbia.

RESULTS

Response rate was 71.2% (356 dentists). The prevalence of MS pain was 82.6% among dentists. The main risk factors for MS pain were advanced age, female dentists, presence of chronic diseases, long working hours, and high frequency of treated patients. The most effective preventive measures in preventing MS pain were massage treatments and physical activities. Followed by use of ergonomically designed equipment, correct and dynamic working positions, and an adequate workflow organization.

CONCLUSION

The risk factors for MS pain and their impact on dental work should widely be disseminated among dentists. Importantly, proper implementation in everyday life of adequate preventive measures is essential for preventing MS pain and development of WMSDs.

Extraordinary biological properties of a new calcium hydroxyapatite/poly(lactide-co-glycolide)-based scaffold confirmed by in vivo investigation

This study examined the potential of a new porous calcium hydroxyapatite scaffold covered with poly (lactide-co-glycolide) (PLGA) as a bone substitute, identifying its advantages over Geistlich Bio-Oss®, considered the gold standard, in in vivo biofunctionality investigations. Structural and morphological properties of the new scaffold were analyzed by scanning electron and atomic force microscopy. The biofunctionality assays were performed on New Zealand white rabbits using new scaffold for filling full-thickness defects of critical size. The evaluated parameters were: the presence of macrophages, giant cells, monoocytes, plasma cells, granulocytes, neoangiogenesis, fibroplasia, and the percentage of mineralization. Parallel biofunctionality assays were performed using Geistlich Bio-Oss®. The appearance of bone defects 12 weeks after the new scaffold implantation showed the presence of a small number of typical immune response cells. Furthermore, significantly reduced number of capillary buds, low intensity of fibroplasia and high degree of mineralization in a lamellar pattern indicated that the inflammation process has been almost completely overcome and that the new bone formed was in the final phase of remodeling. All biofunctionality assays proved the new scaffold's suitability as a bone substitute for applications in maxillofacial surgery. It showed numerous biological advantages over Geistlich Bio-Oss® which was reflected mainly as a lower number of giant cells surrounding implanted material and higher degree of mineralization in new formed bone.

Diode Laser Irradiation in Endodontic Therapy through Cycles - in vitro Study

Background/Aim: The aim of this in vitro study was to investigate the influence of irradiation cycles and resting periods, on thermal effects on the external root surface during root canal irradiation of two diode laser systems (940 nm and 975 nm), at output powers of 1 W and 2 W in continuous mode. In previous studies the rising of temperature above 7°C has been reported as biologically accepted to avoid periodontal damage on the external root surface. Material and Methods: Twenty human inferior incisors were randomly distributed into four groups, the 940 nm, and the 975 nm diode laser irradiation, both with an output power of 1 W and 2 W, in continuous mode. The thermographic camera was used to detect temperature variations on the external root surface. Digital radiography of the samples was made. Results: After three cycles of irradiation, at apical third of the root, mean temperature variation by 940 nm diode laser irradiation was 2.88°C for output power of 1 W, and 6.52°C for output power of 2 W. The 975 nm laser caused a higher temperature increase in the apical region, with temperature variation of 13.56°C by an output power of 1 W, and 30.60°C at 2 W, with a statistical significance of p ≤ 0.0001 between two laser systems compared for the same power. The resting periods of 20 s between cycles were enough to lower temperature under 7°C in the case of 1 W and 2 W for 940 nm diode laser, while for 975 nm laser, after three irradiation cycles overheating occurred at both output power rates. Conclusion: Three cycles irradiation of 940 nm diode laser, with resting periods of 20 seconds, allowed safe usage of 1 W and 2 W in CW for endodontic treatment. For 975 nm at a power rate of 1 W, the last resting period drop the temperature near the safe limit and it came under 7°C in a period less than a minute, while at the power of 2 W the resting periods were not long enough for the safe temperature decrease.

In vitro biocompatibility of nanostructured endodontic materials using SCAP cells

Background/Aim: Lately, fully innovative sol-gel method with high-temperature self-propagating reaction was used for the synthesis of new nanostructured endodontic materials, in combination with different radiopacifiers: bismuth (ALBO-MPCA1) and barium (ALBO-MPCA2). The aim of this study was to investigate the biocompatibility of nanostructured endodontic materials based on highly active calcium silicates and mixed with different radiopacifiers in comparison to MTA+ using human stem cells from the apical papilla- SCAP cells. Material and Methods: Morphology of the samples was studied by SEM. The tested materials were mixed with distilled water in a ratio 2:1 (m/m). Fifteen minutes after the preparation, samples were used in the experiment. The biocompatibility of fresh materials, after 3h and 7 days, was tested using 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide- MTT test. Results: Samples mostly consisted of spherical and rode-like. The relative viability of cells increased following the exposure time. Conclusion: The biocompatibility of synthesized materials is comparable to the control material MTA+, and therefore these materials can be recommended for further clinical studies.

Hyomental distance in the different head positions and hyomental distance ratio in predicting difficult intubation

The hyomental distance ratio (HMDR) is the ratio between the hyomental distance (HMD) (the distance between the hyoid bone and the tip of the chin) at the extreme of head extension (HMDe) and the one in the neutral position (HMDn). The objective of the study was to examine the predictive value, sensitivity, and specificity of HMDe, HMDn, and HMDR in predicting difficult endotracheal intubation (DI). A prospective study included 262 patients that underwent elective surgical operations. The following parameters were observed as possible predictors of DI: HMDR, HMDe, HMDn, Mallampati score, and body mass index (BMI). The cut-off points for the DI predictors were HMDe <5.3 cm, HMDn ≤5.5 cm, and HMDR ≤1.2. The assessment that DI existed was made by the anesthesiologist while performing laryngoscopy by applying the Cormack-Lehane classification. DI was present in 13 patients (5%). No significant difference was observed in the frequency of DI with regard to the sex, age, and BMI of the patients. Our research indicated HMDR as the best predictor of DI with a sensitivity of 95.6% and specificity of 69.2%. HMDR can be used in the everyday work of anesthesiologists because HMDR values ≤1.2 may reliably predict DI.

Cytotoxicity investigation of a new hydroxyapatite scaffold with improved structural design

INTRODUCTION

Biodegradable porous scaffolds are found to be very promising bone substitutes, acting as a temporary physical support to guide new tissue regeneration, until the entire scaffold is totally degraded and replaced by the new tissue.

OBJECTIVE

The aim of this study was to investigate cytotoxicity of a synthesized calcium hydroxyapatitebased scaffold, named ALBO-OS, with high porosity and optimal topology.

METHODS

The ALBO-OS scaffold was synthesized by the method of polymer foam template. The analysis of pore geometry and scaffold walls’ topography was made by scanning electron microscope (SEM). The biological investigations assumed the examinations of ALBO-OS cytotoxicity to mouse L929 fibroblasts, using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromidefor (MTT) and lactate dehydrogenase (LDH) tests and inverse phase microscopy.

RESULTS

The SEM analysis showed high porosity with fair pore distribution and interesting morphology from the biological standpoint. The biological investigations showed that the material is not cytotoxic to L929 cells. Comparison of ALBO-OS with Bio-Oss, as the global gold standard as a bone substitute, showed similar results in MTT test, while LDH test showed significantly higher rate of cell multiplication with ALBO-OS.

CONCLUSION

The scaffold design from the aspect of pore size, distribution, and topology seems to be very convenient for cell adhesion and occupation, which makes it a promising material as a bone substitute. The results of biological assays proved that ALBO-OS is not cytotoxic for L929 fibroblasts. In comparison with Bio-Oss, similar or even better results were obtained.

Evaluation of Ergonomic Risks during Dental Work

Aim: The purpose was to assess ergonomic risk level in dentistry, which may contribute to manifestation of musculoskeletal disorders (MSD).

Methods and Materials: The study included ten dentists, postgraduate students, mean age (33 ± 3.4). Participants were asked to perform typical dental examination in standing and sitting positions. The surface electromyography (EMG) was recorded during dental work from both left and right shoulder muscles: descendent trapezius muscle (T); back muscles: erector spinae muscle (ES); and neck muscles: sternocleidomastoid muscle (SCM) and splenius capitis muscle (SC).

Results: High muscles forces, greater than 21% of the maximal voluntary contraction (MVC), which could be indicative of high risk, particularly occurred in muscles SC on both sides of the body in the sitting position. The medium risk level occurred in the same muscles on both sides in standing position. Left and right T muscles were under medium ergonomic risk level in both, sitting and standing working positions. SCM muscles on the left and right side of the body in both working positions were under low risk level, lower than 10% of the MVC. In sitting position, medium risk level occurred in ES muscles on both body sides, while in standing position the risk was low.

Conclusion: Dentists are exposed to ergonomic risk. By combining both sitting and standing position the risk can be reduced.

PREDICTORS OF DIFFICULT AIRWAY MANAGEMENT IN THYROID SURGERY: A FIVE-YEAR OBSERVATIONAL SINGLE-CENTER PROSPECTIVE STUDY

Difficult tracheal intubation (DI) is more common in thyroid than in other surgical branches due to thyromegaly. Proper preoperative airway evaluation is necessary in order to reduce the potential numerous complications. The study examined the incidence of DI in thyroid surgery and the influence of tracheal dislocation and other risk factors on DI. A prospective study was conducted on 2379 patients who underwent thyroidectomy at the Center for Endocrine Surgery, Clinical Center of Serbia, from 2007 to 2012. Patients were divided into groups with (n = 162) and without DI (n = 2217). Besides tracheal dislocation, another 13 risk factors contained in 13 screening tests and three additional factors of gender, age and diagnosis were defined. The incidence of DI in our study was 6.81%. The presence of tracheal dislocation was statistically significant, but not an independent predictor of DI. The diagnosis, large circumference and small neck length, previous DI, recessive mandible, tooth characteristics and oral anomalies were the most significant and independent predictors of DI. Neck circumference and small neck length had highest sensitivity. Previous DI had highest specificity. Thyromegaly, if causing tracheal dislocation and/or stenosis, represents a significant DI predictor, not individually, but in combination with other factors.

[The Presence of Non-Carious Lesions in Children]

INTRODUCTION

A non-carious lesion (NCL) is the loss of hard dental tissue on the neck, tuberculum and incisal edges of the teeth. Interest in clinical presence and in unclear etiology of these lesions allows for their future prevention and treatment.

OBJECTIVE

The aim of the study was to determine presence and clinical characteristics of NCLs and dentine hypersensitivity (DH), as well as their possible risk factors in children, in the population of the city of Novi Sad.

METHODS

A total of 55 subjects were included in the present study, aged between three and 18 years. Each subject completed a structured questionnaire related to the etiological factors, and all teeth of each subject were examined by two independent clinical dentists to determine NCLs and DH. In the case of small children, their parents or guardians filled out the questionnaire. Teeth with NCLs and DH were diagnosed according to the Basic Erosive Wear Examination (BEWE) index and by a blast of air according to Schiff and Hypersensitivity Index. The review was carried out by inspection and probing.

RESULTS

The data were analyzed by clinical examination and comparison of the answers to the questionnaires. We observed an increased presence of non-caries lesions on primary teeth, compared to permanent teeth, with a statistically significant difference (X2=3.86, df=1, p=0.04). The changes were observed in 82 teeth, and were most frequent on the canine deciduous teeth (65%) and canine permanent teeth (51%). BEWE index was 10-11% to 92-100% in permanent, and 51-57% in deciduous teeth. Majority of patients with primary teeth (89.36%) did not respond to air stimulus, while most patients with permanent teeth (74.29%) did not react to Schiff Index. In the estimate of sensitivity, the respondents reported hypersensitivity on 6.38% of the deciduous teeth and 22.86% of the permanent teeth. Comparison of etiology factors did not reveal a direct link with the appearance of NCLs.

CONCLUSION

Research has shown that despite the lack of subjective symptoms, these lesions have distinct clinical characteristics. The fact that they occur even in deciduous dentition justifies the need for further investigations.

History of dentistry in central Serbia

History of dentistry in the Central Serbian District of Jagodina has been influenced by traditional medicine for centuries. Development of dentistry in the region of Jagodina was slow, the level of oral and general hygiene was low and the sanitary prevention was absent. Trained physicians started to practice medicine and dentistry in the first half of the nineteenth century and they were educated in abroad universities. However, common people used to address to these physicians only when the traditional medicine were unable to help. Until the end of the World War II, common, mostly rural people, with the urgent dental treatment need were usually referred to the barbers, healers or empirics in the nearby villages rather than the dentists. Medications used for the urgent dental treatment were balsams and solutions made of herbs. After the World War II, the dental technicians who finished special courses started to practice dentistry. In 1947 the Regional Dental Office in Jagodina was opened and in 1955 the first Doctor of Dental Medicine who graduated from the School of Dental Medicine of University of Belgrade was employed. Nowadays, the Department of Dentistry represents is an important and independent part of the Health Care Centre in Jagodina.

Application of high-power diode laser and photodynamic therapy in endodontic treatment: Review of the literature

Lasers have found important role in clinical application, science and scientific research. The aim of this review is to focus on using soft tissue laser in endodontic treatments. The main goal of endodontic treatment is elimination of pathogenic microorganisms from root canal system. Laser light has the ability to reach parts of the tissue and areas where classical techniques and instruments cannot. New approaches to disinfecting root canals have been proposed recently, which include the use of high-power diode lasers, as well as disinfection of the root canal by using photodynamic therapy. A research is necessary to define a precise protocol for high-power laser and photodynamic therapy in treatment of the root canal system.

Factors associated with positive outcome of avulsion injuries in children

INTRODUCTION/AIM

Avulsions are severe dental injuries with high impact on patients' quality of life due to prolonged treatment and possible severe complications. The aim of the study was to analyze the epidemiological factors related to the occurrence, treatment and outcome of avulsions in Serbian children.

METHODS

This research included 2,194 patients aged 1-18 years with traumatic dental injuries. The history, demographic, clinical and radiographic data of the patients were observed from dental medical records.

RESULTS

A total of 266 avulsions were observed in 207 patients. The frequency of avulsions was 12% in primary dentition and 5% in permanent dentition. A statistically significant relationship between place, cause of avulsion and outcome was observed. Replantation of permanent teeth was performed in 46.7% with a mean time 6.9 h. Almost a half of permanently avulsed teeth (48.7%) were not retrieved from the accident site and 11.3% of replanted teeth were transported in adequate media. The observed incidence of complications was 31.9%.

CONCLUSION

Replantation was not performed in more than a half of all eligible teeth due to either loss or inadequate/delayed transport, which emphasizes the need for preventive strategies and health education in population.

The efficacy of hydrothermally obtained carbonated hydroxyapatite in healing alveolar bone defects in rats with or without corticosteroid treatment

BACKGROUND/AIM

Autogenous bone grafting has been the gold standard in clinical cases when bone grafts are required for bone defects in dentistry. The study was undertaken to evaluate multilevel designed carbonated hydroxyapatite (CHA) obtained by hydrothermal method, as a bone substitute in healing bone defects with or without corticosteroid treatment in rats as assessed by histopathologic methods.

METHODS

Bone defects were created in the alveolar bone by teeth extraction in 12 rats. The animals were initially divided into two groups. The experimental group was pretreated with corticosteroids: methylprednisolone and dexamethasone, intramuscularly, while the control group was without therapy. Posterior teeth extraction had been performed after the corticosteroid therapy. The extraction defects were fulfilled with hydroxyapatite with bimodal particle sizes in the range of 50-250 μm and the sample from postextocactional defect of the alveolar bone was analyzed pathohystologically.

RESULTS

The histopatological investigations confirmed the biologic properties of the applied material. The evident growth of new bone in the alveolar ridge was clearly noticed in both groups of rats. Carbonated HA obtained by hydrothermal method promoted bone formation in the preformed defects, confirming its efficacy for usage in bone defects. Complete resorption of the material's particles took place after 25 weeks.

CONCLUSION

Hydroxyapatite completely meets the clinical requirements for a bone substitute material. Due to its microstructure, complete resorption took place during the observation period of the study. Corticosteroid treatment did not significantly affect new bone formation in the region of postextractional defects.

An FPGA-based platform for accelerated offline spike sorting

There is a push in electrophysiology experiments to record simultaneously from many channels (upwards of 64) over long time periods (many hours). Given the relatively high sampling rates (10-40 kHz) and resolutions (12-24 bits per sample), these experiments accumulate exorbitantly large amounts of data (e.g., 100 GB per experiment), which can be very time-consuming to process. Here, we present an FPGA-based spike-sorting platform that can increase the speed of offline spike sorting by at least 25 times, effectively reducing the time required to sort data from long experiments from several hours to just a few minutes. We attempted to preserve the flexibility of software by implementing several different algorithms in the design, and by providing user control over parameters such as spike detection thresholds. The results of sorting a published benchmark dataset using this hardware tool are shown to be comparable to those using similar software tools.

Microleakage, adaptation ability and clinical efficacy of two fluoride releasing fissure sealants

BACKGROUND/AIM

Retention of fissure sealants and good adaptation to enamel are essential for their success. Fluoride releasing resin-based materials are widely accepted for pit and fissure sealing, but newly designed glass ionomers can serve as a good alternative. The aim of this study was to evaluate microleakage and sealing ability in vitro, and to clinically assess two fluoride releasing fissure sealants.

METHODS

The sample for experimental study consisted of 20 freshly extracted intact human third molars, divided in two experimental groups according to the sealing material: fluoride releasing resin-based (Heliosel F) and glass ionomer (Fuji Triage) material. Digital images and scanning electron microscope were used to assess microleakage and adaptation ability. Sample for clinical study consisted of 60 children, aged 6-8 years, with high caries risk, divided in two groups according to the sealant material. Fissure sealant was applied to all erupted, caries-free first permanent molars. Sealants were evaluated after 3, 6 and 12 months using modified Ryge criteria for retention, marginal adaptation, colour match, surface smoothness and caries.

RESULTS

Microleakage was detected in more than half of the specimen, without significant differences between the two groups (p > 0.05). Both materials exhibited acceptable sealing ability. Complete retention at the end of the observation period was 81.8% for resin-based, and 21.1% for glass-ionomer fissure sealant (p < 0.001). The presence of caries in sealed molars has been detected in one patient in both groups. During the 12-month observation period, Helioseal F demonstrated better retention, marginal adaptation and surface smoothness (p < 0.001). There were no differences between the two materials regarding caries and color match (p > 0.05).

CONCLUSION

Both tested materials demonstrate satisfactory clinical and caries prophylactic characteristics that justify their use in contemporary preventive dentistry.

Preoperative preparation of patients with arterial or pulmonary hypertension in noncardiac surgery

Arterial hypertension is not an independent risk factor in cardiovascular complications in noncardiac surgery. Nevertheless, preoperative evaluation is necessary and includes estimation of arterial hypertension grade and possible damage of target organs. In patients with first and second grade of arterial hypertension postponement of elective intervention is not necessary, only optimization of therapy. On the other hand, patients with third level arterial hypertension have benefit if intervention is postponed till the reduction of arterial pressure. There is no indication that any of the antihypertensive drug groups has advantage in the preoperative treatment of hypertension. Unlike arterial hypertension pulmonary hypertension increases the risk of cardiac morbidity and mortality in the perioperative period. In patients with pulmonary hypertension, anesthesia and surgery may be complicated with heart failure, hypoxia and arrhythmias. Preoperative and postoperative treatments include calcium channel blockers, prostanoids, endothelin receptor antagonists and inhibitors of phosphodiesterase type 5.

Preoperative assessment and preparation of patients with diseases affecting the central nervous system

PURPOSE OF REVIEW

This review will examine the most important issues of preoperative evaluation and preparation in relation to patients with deseases affecting the central nervous system. Those patients may undergo various forms of surgery unrelated to the central nervous system disease. We discuss the effect of physiologic and pharmacological factors on cerebral autoregulation and control of intracranial pressure alongside its clinical relevance with the help of new evidence.

RECENT FINDINGS

Regardless of the reason for surgery, coexisting diseases of brain often have important implications when selecting anesthetic drugs, procedures and monitoring techniques. Suppression of cerebral metabolic rate is not the sole mechanism for the neuroprotective effect of anaesthetic agents. There are certain general principles, but also some specific circumstances, when we are talking about optimal anesthetic procedure for a patient with coexisting brain disease. Intravenous anesthesia, such as combination of propofol and remifentanil, provides best preservation of autoregulation. Among inhaled agents isoflurane and sevoflurane appear to preserve autoregulation at all doses, whereas with other agents autoregulation is impaired in a dose-related manner. During maintenance of anesthesia the patient is ventilated by intermittent positive pressure ventilation, at intermediate hyperventilation (PaCO2 25-30 mmHg).

SUMMARY

Intraoperative cerebral autoregulation monitoring is an important consideration for the patients with coexisting neurological disease. Transcranial Doppler based static autoregulation measurements appears to be the most robust bedside method for this purpose.

Preoperative preparation of vascular patients undergoing nonvascular surgery

Patients with vascular diseases mainly caused by atherosclerosis, that are undergoing nonvascular surgery, often have co-existing conditions which affect their cardiovascular system. Cardiovascular complications are among the most common perioperative complications including respiratory complications and infections. These include coronary disease, hypertension, heart insufficiency, pulmonary hypertension, and renovascular hypertension, among others. Preoperative preparation must include the use of beta-blocker therapy, antihypertensive, antithrombotic and antilipogenic therapy. Electrocardiogram (ECG) and trans-thoracic echocardiography are the minimum preoperative diagnostic evaluations that should be performed, because complications may arise even in patients without prior cardiovascular symptomatology. Venous diseases are the most common contemporary diseases affecting people of all age groups and races. Invasive-diagnostic-therapeutic procedures may cause lesions of venous endothelium, hence perioperative prevention of deep vein thrombosis (DVT) with the use of heparin or low-molecular -weight heparin (LMWH) should be undertaken.

Preoperative assessment and management of patient with psychiatric comorbidity

This article explains the most frequent psychiatric disorders such as co-morbidity in the acute surgical treatment, along with its position and importance for the surgical procedure. Besides basic features of these disorders, epidemiology and clinical expression, this article holds the latest therapeutic approach, side effects, toxicity and drug interactions, during the surgical procedure. Frequent postoperative problems, delirium, and postoperative cognitive disorders are noted in these patients. To avoid these complications, it is recommended to use a mini-mental score examination to re-evaluate the decision and indication for high risk surgery patient.

A system-level view of optimizing high-channel-count wireless biosignal telemetry

In this paper we perform a system-level analysis of a wireless biosignal telemetry system. We perform an analysis of each major system component (e.g., analog front end, analog-to-digital converter, digital signal processor, and wireless link), in which we consider physical, algorithmic, and design limitations. Since there are a wide range applications for wireless biosignal telemetry systems, each with their own unique set of requirements for key parameters (e.g., channel count, power dissipation, noise level, number of bits, etc.), our analysis is equally broad. The net result is a set of plots, in which the power dissipation for each component and as the system as a whole, are plotted as a function of the number of channels for different architectural strategies. These results are also compared to existing implementations of complete wireless biosignal telemetry systems.

Perioperative fluid balance in patients with heart failure

Careful assessment of fluid balance is required in the perioperative period since appropriate fluid therapy is essential for successful patient outcomes. Volume status is frequently assessed by different hemodynamic variables that could be targeted as endpoints for fluid therapy and resuscitation. Goal directed fluid therapy is a method for correction of fluid status in individual patients that includes invasive hemodynamic monitoring and aggressive perioperative correction of hemodynamics. Heart failure is a syndrome of ventricular dysfunction. It is associated with a variety of patophysiological disturbances, hydro-electrolyte balance disorders and compensatory mechanisms. Heart failure indicates careful assessment of fluid balance in perioperative period. The aim of this article is to describe actual techniques of hemodynamic measurements as well as main principles of fluid therapy to maintain hydro-electrolyte balance in patients with heart failure.

[Endotracheal intubation without the use of muscle relaxants in patients with myasthenia gravis]

INTRODUCTION

Although muscle relaxants have been widely used to facilitate endotracheal intubation, the administration of these drugs in myasthenic patients may be associated with adverse events.

MATERIAL AND METHODS

After obtaining Institutional Reviewing Board approval and informed, patient consent, 30 patients with myasthenia gravis were enrolled in a prospective, double-blind, randomized clinical trial. We compared intubating conditions (ease of laryngoscopy, vocal cords, cough, jaw relaxation, limb movement) following fentanyl 2 mg/kg and propofol 2 mg/kg (group PRO, n = 15) vs fentanyl 2 mg/kg and sevoflurane 5% in a 1:2 mixture of oxygen and nitrous oxide (group SEVO, n = 15). The statistical analysis was performed using Student's t test and Chi-quadrate test, p < 0.05 being regarded as significant.

RESULTS

The overall intubating conditions were excellent in 67% of patients in the group PRO vs 80% of patients in the group SEVO (p > 0.05). One patient in each group had clinically unacceptable conditions for intubation. The mean intubation score was 5.7 +/- 1.0 in the group PRO vs 5.9 +/- 0.9 in the group SEVO (p > 0.05). Three patients receiving propofol and one patient receiving sevoflurane had mild hoarseness after the surgery (p > 0.05).

CONCLUSION

Both propofol and sevoflurane, supplemented with fentanyl, provide good intubating conditions without the use of muscle relaxants in patients with myasthenia gravis.

[Assessment of perioperative fluid balance]

Careful assessment of the fluid balance is required in the perioperative period since appropriate fluid therapy is essential for successful patient's outcome. Haemodynamic monitoring allows understanding the physiology of the circulation and changes of fluid balance in the perioperative period. This is diagnostic aid and guide for fluid replacement therapy. Patient's volume status is frequently assessed by different haemodynamic variables that could be targeted as the endpoints for fluid therapy and resuscitation. Fluid balance is the crucial factor in the maintenance of haemodynamic stability, tissue oxygenation and organ function. When the haemodynamic monitoring is applied in a rigorous and consistent manner, it reduces mortality and length of stay as well as costs incurred. There are a number of tests which describe the effectiveness of the invasive haemodynamic monitoring procedures usage. Since the pulmonary artery catheter (PAC) had been introduced into clinical practice it was considered as a golden standard for cardiac output measurements, haemodynamic and fluid balance assessment. Nevertheless, in previous 10 years new minimally invasive and noninvasive simple techniques for haemodynamic monitoring and patient's hydroelectricity status evaluation have been developed. They can replace PAC under different clinical circumstances and some of these techniques

[A look into the larynx--two centuries along the path of laryngoscopy]

Both the design and purpose of the laryngoscope have been changed significantly since Alfred Kirstein invented his own "laryngeal mirror"--the autoscope. An initially straight, rigid oesophageal tube has been reshaped into a number of laryngeal blade modifications, suitable for use in various patient subpopulations. A tool initially intended to help otorhynolaryngologists diagnose and treat laryngeal diseases has been transformed into an instrument intended to help anesthesiologists intubate the trachea for the purpose of either anesthesia administration or airway maintenance. As direct laryngoscopy depends greatly upon individual manual skills, there has been almost no beginner who feels no proud of his first successful intubation. Thus, we should never forget the pioneers of laryngoscopy whose curiosity, creativity, and enthusiasm enabled us to give a clear and safe look into the larynx.

Simultaneous surgical treatment of ruptured abdominal aortic aneurysm and acute carotid occlusive disease

Combined rupture of abdominal aortic aneurysm and acute thrombosis of internal carotid artery is extremely rare but fatal combination resulting in high mortality rate. Presented case, shows successfully performed simultaneous surgery of ruptured abdominal aortic aneurysm and acute cerebrovascular insult caused by thrombosis of carotid artery in 81 year-old male. Post operative course was uneventfull. At 24 months follow up patient was in good condition, with full neurological recovery. Simultaneous surgical treatment of acute occlusive carotid disease and ruptured abdominal aortic aneurysm (RAAA) seems to be the only life saving procedure for this rare, but very complicated condition. To our knowledge, this is the first reported successful simultaneous surgical treatment of RAAA and acute thrombosis of internal carotid artery.

[Molar incisor hypomineralisation in the first permanent teeth]

The aim of this study was to point out the prevalence of hypomineralised molars and incisors and emphasize importance of this condition in paediatric dentistry. This condition is defined as hypomineralisation of one or more first permanent molars frequently affecting incisors and referred to as molar incisor hypomineralisation (MIH). Aetiology of MIH has not been fully clarified and numerous aetiological factors have been cited. Hypomineralised molars are more prone to caries, cause severe restorative problems and are frequently extracted due to serious damage and caries complications. Incisors can present demarcated enamel opacities, while enamel breakdown is uncommon. Considering the fact that permanent first molars with severe defects demand complex treatment, they represent a serious problem for the patient as well as for the dentist.