Evaluating the Dental Hygienists' Exposure to the Risk of Musculoskeletal Disorders.

OBJECTIVES: The aim of the study was to evaluate dental hygienists' exposure to the risk of musculoskeletal disorders (MSDs), by the worksheets compatible with the Rapid Entire Body Assessment (REBA). MATERIALS AND METHODS: The research included 272 dental hygienists aged 23 to 52 years from the two administrative regions of Poland. STATISTICAL ANALYSIS: STATISTICA 12 and Microsoft Excel were used to analyse the results. The level of significance was p<0.05. The normality of the distribution was tested with the Shapiro-Wilk test. The relationships between the variables were assessed with the χ2 test. Due to the lack of "normality" of the REBA risk distribution, the Mann-Whitney test was used to verify the hypotheses. RESULTS: Overall, 48.5% of the examined showed a neck flexion >20, torsion of 80.1%, and 37.5% declared the presence of both types of loads. Also, 14.3% of the examined kept a vertical position, 53.7% flexion to the torso up to 20degrees, 31.4% to 60degrees, and 2.1% to >60degrees. Further, 78.3% of people indicated that they twist the torso. Then, 7% marked the low load's arms position, 45.6% marked the range from 20 to 45degrees, and 39.7% marked the range from 45 to 90degrees. Over 55% showed additional load related to the raising or abduction of the shoulders. Overall, 43% showed a wrong position of forearms. Also, 62.9% showed wrists flexed <15° and the rest showed >15degrees. Again, 79% showed additional twisting and flexion of the wrists. Almost 75% of the examined are exposed to overloads associated with the static load. The examined are not exposed to excessive loads resulting from sudden exertion. REBA scores indicate that the negligible MSDs risk concerns 0.7% examined; low risk, 5.5%; medium risk, 33,1%; high risk, 49.3%; and very high risk, 11.4%. The correlation coeffcients analysis showed that exposure risk is strongly correlated with the overloads on the tested parts of the body in both groups. CONCLUSION: The levels of MSDs risk indicate that hygienists more often should be subjected to periodic check-ups in the workplace. They also need ergonomic interventions (education, preventive technique, physical activity, and improvement of the working environment) and modifications of hygienist's college programs in the field of work ergonomics can be also considered.

Long COVID Oral Cavity Symptoms Based on Selected Clinical Cases.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is characterized by variable clinical features, different durations, and several previously unheard-of late complications. Knowledge about this infection is constantly evolving.The aim of the study is to present selected cases of the most common symptoms of long COVID in the oral cavity.Among the 1,256 studied patients, 32% of them had discoloration, ulceration, and hemorrhagic changes on the oral mucosa, 29.69% had mycosis located on the tongue, 25.79% of patients had aphthous-like lesions on the hard palate, and in 12.5% atrophic cheilitis was observed. During the anamnesis, approximately 60% of patients reported salivary secretory disorders in the initial period of infection, which is 6.68% prolonged up to 4 months after systemic symptoms disappeared. In an extreme case, an aphthous-like lesion was located on the hard palate, which persisted for 6 months. Approximately 36% of patients did not agree to the proposed treatment. As a result, they only received recommendations on the use of oral hygiene products and received weekly check-ups. In this group of patients, most pathological changes spontaneously cleared after 3 weeks. The elderly with coexisting diseases, persons with a more severe SARS-CoV-2, and hospitalized patients had more extensive and severe lesions in the oral cavity that persisted for a long time after infection.In patients after the SARS-CoV-2 infection and suspected of this infection, a detailed intraoral examination should be performed, and the patient must be obligatorily monitored for a minimum period of 6 months. Depending on the patient's clinical condition, changes in the oral cavity require observation, basic or specialist treatment. In the case of changes in the cavity without pain symptoms, observation should be made for approximately 4 weeks and wait for the spontaneous regression of the changes. However, when pain occurs, a good solution is to use laser biostimulation. In the case of complex pathological changes occurring in the oral cavity, the patient should be directed for specialist treatment.

Minimally Invasive Transcrestal Sinus Floor Elevation Procedure in Severely Atrophic Ridge: A Case Report.

Typically, the greater the atrophy of the process, the more extensive and invasive the sinus floor elevation procedure is. This case of a 39-year-old man demonstrates a minimally invasive hydrostatic sinus lift from 1.7-mm height process in the site of lost tooth No. 16. Using a small flap, safe drills for a crestal approach diameter of 2.8 mm, 2 mL of saline solution under pressure of a syringe plunger, and 1 g of particulated bovine xenograft, a 14-mm height and 12-mm width sinus floor elevation was obtained. The implant was placed with a torque of 30 Ncm, and a healing cap was attached. Despite the very difficult conditions, the presented method not only resulted in a very good therapeutic effect but also reduced the number of procedures and time necessary for complete rehabilitation of the patient. The total treatment time to the final crown delivery was 6 months.

Comparison of Dental Stone Models and Their 3D Printed Acrylic Replicas for the Accuracy and Mechanical Properties.

This study was conducted to test possibilities of application of 3D printed dental models (DMs) in terms of their accuracy and physical properties. In this work, stone models of mandibles were cast from alginate impressions of 10 patients and scanned in order to obtain 3D printed acrylic replicas. The diagnostic value was tested as matching of model scans on three levels: peak of cusps, occlusal surface, and all teeth surfaces. The mechanical properties of acrylic and stone samples, specifically the impact strength, shore D hardness, and flexural and compressive strength were investigated according to ISO standards. The matching of models' surfaces was the highest on the level of peaks of cusps (average lack of deviations, 0.21 mm) and the lowest on the level of all teeth surfaces (average lack of deviations, 0.64 mm). Acrylic samples subjected to mechanical testing, as expected, showed higher mechanical properties as compared to the specimens made of dental stone. In the present study we demonstrated that 3D printed acrylic models could be ideal representatives in the case of use as a diagnostic tool and as a part of medical records. The acrylic samples exhibited not only higher mechanical properties, but also showed better accuracy comparing to dental stone.

Repeatability of Freehand Implantations Supported with Universal Plastic Sleeves-In Vitro Study.

Repeatability and precision are major factors which have an influence on final implant treatment results. The aim of this study was to evaluate the repeatability of freehand implant procedures assisted with special plastic sleeves which are placed on the drill to guarantee the proper mesiodistal distance from the landmark's surface. Patient data required for implant treatment, including images of mandibles from CBCT scans and virtual models of soft tissues and teeth, were used to prepare complete virtual models of patient clinical conditions. The models were saved as STL files and 3D printed in five copies. Drilling procedures were done at positions 37, 46 and 47. Each model was scanned with pins in the osteotomies and compared using digital aligning of the models' surfaces. The average deviation was -1.38 ± 1.4 mm. Average deviations on guide pins placed at position 37 were -0.46 ± 0.59 mm, at position 46 were -1.46 ± 0.88 mm (landmark's surface of both: distal tooth's surface), and at position 47 were the highest: -2.69 ± 1.62 mm (landmark's surface: surface of plastic sleeve). The following conclusion was drawn: Using universal plastic sleeves could improve implant procedure precision especially in the case of partially edentulous patients.

Assessment of Hypodontia Treatment of Maxillary Lateral Incisors in Adult Patients After 9 Years of Follow-up: A Retrospective Study.

PURPOSE: To assess the effects of maxillary lateral incisor hypodontia treatment following the use of implantation procedures, fixed and removable dental prostheses, and change in the shape of the canine. MATERIALS AND METHODS: Hypodontia treatment effects were retrospectively evaluated in 129 patients aged 18 to 60 years. The assessment covered esthetic, biologic, and functional aspects of the restored missing teeth within 9 years after treatment. The analysis of the findings took into account the percentage of positive effects of treatment for each method and assessment year and also included statistical tests based on the F statistic, which allowed comparison of the effectiveness of the applied methods of hypodontia treatment. RESULTS: In years 1 to 3, the effects of treatment were wholly positive; in subsequent years, the applied methods differed in terms of effectiveness. After 9 years, there was full clinical success for the implant-prosthetic method and for three-unit porcelain-fused-to-metal (PFM) fixed partial dentures (FPDs), 77.77% success for fiber-reinforced composite (FRC) FPDs, 73.68% for multi-unit PFM FPDs, 67.56% for canine shape change, and 23% for metal-alloy removable partial denture (RPD) prostheses. CONCLUSION: The results of this study indicate that the use of mini-implants with PFM crowns and three-unit PFM FPDs are the most effective treatment methods. A less favorable clinical effect was obtained with the use of FRC FPDs and multi-unit PFM FPDs. Changing the canine shape led to an acceptable clinical effect in over two-thirds of case histories. Metal-alloy RPD prostheses yielded the weakest effects.

Assessment of the influence of selected electrolytic polishing process parameters on the surface roughness of casts made of the CoCrMo alloy.

BACKGROUND: To fabricate some prosthetic restorations, such as metal alloy frameworks for removable partial dentures (RPDs), casting techniques must be used. The penultimate stage of the cast finishing procedure is electropolishing. OBJECTIVES: The aim of the study was to assess the influence of selected electrolytic polishing process parameters on the resulting surface smoothness of the cobalt-chromium-molybdenum (CoCrMo) alloy. MATERIAL AND METHODS: The CoCrMo alloy, 3 experimental and 2 name-brand electrolytes, were used in the study. A total of 25 samples, 63 mm × 10 mm × 1 mm in size, were cast using the Nautilus® equipment. The cast samples were shaped using metal cutters and carborundum stones and separators, and were sandblasted. The prepared samples were placed in an electrolysis cell as an anode. For each sample, measurements were made by changing the potential of the electrode by 0.2 V in the range from 1.2 V to 7.0 V. The surface of the samples was analyzed using a profilometer. An optical microscope and a scanning electron microscope (SEM) were used to examine the structure of the surface. RESULTS: An analysis of the obtained results showed no statistically significant differences between the BEGO Wirolyt® electrolytic polishing liquid (WB) and experimental electrolytes K15, K8 and K13, all of which were significantly better than the Dentaurum Electrolyt® polishing solution (ED). The microscope images indicated differences in the surface structure of the samples; in the SEM images, inclusions were also visible. CONCLUSIONS: The experimental electrolytes did not differ in quality from one of the name-brand electrolytes and were even better than the other one. The obtained surface roughness values (Ra) did not differ significantly from those achieved by other researchers.

Fluoride penetration from three orthodontic adhesives: an experimental study.

OBJECTIVE: To examine the prophylactic potential of 3 orthodontic bonding adhesives: Fuji Ortho SC, Illuminate, and Resilience. METHODS: Thirty-six Wistar Wag rats were randomly divided into 4 groups consisting of 9 rats each. One of the groups received no treatment and was used as a control. In the other groups, individual bands coated with one of the 3 adhesives were cemented to the lower incisors. Enamel samples were obtained after 6 and 12 weeks and analyzed using scanning electron microscopy in combination with energy dispersive spectrometry. RESULTS: Six weeks after band cementation, no fluoride was found in the enamel of the lower incisors. After 12 weeks, there was no fluoride in the enamel of teeth coated with the Resilience composite. However, in the case of the Illuminate composite and the resin-modified glass ionomer Fuji Ortho SC cement, the depth of fluoride penetration reached 2 µm and 4.8 - 5.7 µm, respectively. CONCLUSIONS: Fluoride ions from orthodontic adhesives can be incorporated into the surface layer of the enamel. Orthodontists may apply orthodontic adhesives, such as the Fuji Ortho SC, to reduce the occurrence of caries during orthodontic treatment with fixed appliances.