The Second International Congress of the Faculty of Dental Medicine, “Carol Davila” University of Medicine and Pharmacy Bucharest, Romania, and the 17th International Congress for Students and Young Doctors “stuDENT”
Beam profile characterization of a dental light curing unit using a spectrometer-based method
Jean-François Roulet, Mateus Garcia Rocha, Chiayi Shen, Marwah Majid Khudhair, Dayane
Carvalho Ramos Salles de Oliveira (abstract)Aim: The study aimed to characterize a broad spectrum light curing unit (LCU) by measuring the light beam profile output of the LCU using a spectrometer-based method and correlate it with a standard camera-based beam profile method. Materials and Methods: A broad spectrum LED LCU (Ascent OL5, CAO Group) was mounted above a spectrometer (MARC® Resin Calibrator, BlueLight Analytics) at exposure distances of 1.0, 1.5 or 2.5 mm. The position of the center of the LCU was aligned with the spectrometer’s cosine corrector sensor, and then moved in 1-mm increments in the x-y plane, while concomitantly recording the irradiance. The recorded irradiance was systematically organized and reported in function of the distance from the center of the LCU exiting window. Using a standard camera-based beam profiler, a beam profile of the LCU was obtained and the above approach was emulated to the beam profile. For both methods, the irradiance decreases related to the value measured at the center position was analyzed by calculating the slope, using a linear correlation. Results: Both methods showed that moving away from the center showed decreased irradiation. The beam profile of the LCU is asymmetric. The inhomogeneity of the beam was slightly lower with farther distance from the LCU’s light exciting window. Conclusion: The spectrometer-based method was able to characterize the beam profile of the LCU and can be used in the evaluation of LCUs. Keywords: light curing units, beam profile, spectrometric analysis. | (read pdf) |
RESTORATIVE DENTISTRY
Comparative study regarding the effect of different finishing and polishing systems on a bulk-fill composite resin surface
Irina Nica, Simona Stoleriu, Gianina Iovan, Cristina-Angela Ghiorghe, Galina Pancu, Adriana
Munteanu, Sorin Andrian (abstract)Introduction: One of the main objectives of composite restorations procedure is to obtain a smooth surface for aesthetic reasons and for oral health. The aim of this study was to assess the surface morphology of a bulk fill composite material after finishing and polishing with three different finishing and polishing systems. Materials and methods: Filtek Bulk Fill Posterior composite resin was chosen for this study (3M ESPE St. Paul, MN, USA). Twenty cylindrical samples 5 mm in diameter and 2 mm thick were made using plastic molds. They were randomly and equally assigned to four groups. In group 1 (control) the samples were not subjected to finishing and polishing procedure. In study groups 2-4, the samples were finished using two tungsten carbide burs and then polished using one step Occlubrush system (KerrHawe SA, Switzerland) – group 2, with the two step Sof-Lex system (3M ESPE) – group 3, and with the multi-step Super Snap system (Shofu, Inc. Kyoto, Japan) – group 4. The surface characteristics of the samples were quantitatively analyzed using profilometry and qualitatively evaluated by scanning electron microscopy. The Kolmogorov-Smirnov normality test was used to determine the distribution of data in groups. ANOVA and Tukey post hoc statistical tests were used to compare the results in groups. Results: Finishing with tungsten carbide burs and two-steps Sof-Lex polishing system and one-step polishing system Occlubrush determined, higher roughness when comparing to multi-step Super Snap system. Conclusion: The surface characteristics of the studied composite resin were influenced by the type of finishing and polishing system used. Keywords: bulk-fill composite, finishing and polishing systems, profilometry, SEM. | (read pdf) |
ORTHODONTICS
Soft-tissue facial asymmetry before and after orthognathic surgery: application of a new 3D protocol
Filippo Da Pozzo, Francesca M.E. Rusconi, Giada Anna Beltramini, Daniele M. Gibelli, Valentina
Pucciarelli, Aldo Bruno Giannì, Chiarella Sforza (abstract)Introduction: Skeletal Class III patients often present a major facial asymmetry. In the current investigation, a quantitative method to assess 3D facial asymmetry was applied to an orthognathic surgery patient to quantify possible postsurgical modifications. Methodology: Soft-tissue facial scans of a 20-year-old man with skeletal Class III, candidate to orthognathic surgery, were collected in the pre-surgery stage and 6, 12, 24 months post-surgery with a stereophotogrammetric system. Soft tissue asymmetry was calculated in the facial thirds according to a published protocol (J Craniomaxillofac Surg 2017;45(1):76-81), and the relevant time-related modifications described. The results were also compared to normal values from a group of 23 control subjects (10 men, 13 women, mean age 26) by using z-scores. Results: The longitudinal analysis of the soft-tissue facial asymmetry showed a marked difference in the analysed time points: orthognathic surgery did reduce facial symmetry in the present patient. The comparison between the patient and the control subjects by using z-scores highlighted a clear difference in all-time points: the patient with facial dysmorphia had a higher degree of asymmetry than healthy subjects. Conclusion: The measurements of soft-tissue facial asymmetry using 3D optical digitisers can provide clinically useful information. The graphical representation of results can help in the patient’s understanding of the treatment phases, thus increasing compliance. Keywords: face, soft tissues, orthognathic surgery, symmetry. | (read pdf) |
ORTHODONTICS
Bonding orthodontic resin cement to zirconium oxide under orthodontics load and thermocycling effect
Hind S. Hussein, Nader Abdulhameed, Chiayi Shen, Calogero Dolce, Jean-François Roulet (abstract)Purpose: Evaluate the microshear bond strength (µSBS) of orthodontic resin cement to monolithic zirconium oxide ceramic (MZ) under orthodontic load (OL) and thermocycling (TC) effect. Materials and Methods: Glazed MZ blocks (Zenostar, Ivoclar Vivadent) were tested after air abrasion with 30-µm silica coated aluminum oxide (Al2O3) particles (CoJet, 3M ESPE). The specimens were randomly divided into 4 groups (n = 15): G1, OL with TC; G2, OL without TC; G3 no OL with TC; and G4, no OL, no TC (control). Orthodontic cement cylinders (Heliosit Orthodontic, Ivoclar Vivadent) were bonded to the primed samples (Monobond Plus, Ivoclar Vivadent) using the Ultradent SBS system and light cured (SmartLite Max, Dentsply Sirona, 1400 mW/cm2, 40 s). G1 and G2 were subjected to 70 ± 15 N load perpendicular to the cylinder axis, G1 and G3 were thermo-cycled (5000 cycles 5-55°C, 90 s/cycle). G2 and G4 were stored in distilled water at 37 ± 1°C. The specimens were subjected to µSBS test (crosshead speed 0.5 mm/min). Data were analyzed using two-way ANOVA, and one-way ANOVA and Tukey test (HSD). Results: Two-way ANOVA for µSBS values (MPa) showed significant (p = 0.0004) load effects, but not thermal effect (p = 0.2455) with significant load/thermocycling interactions (p < 0.0001). The ranking of the single groups by Tukey test (α = 0.05) showed that G1 exhibited the highest µSBS (8.4 ± 2.8 MPa), G4 (6.3 ± 1.1 MPa) and G2 (5.8 ± 1.1 MPa) as a group was second, and G2 and G3 (4.7 ± 1.1 MPa) as a group was the lowest. Conclusion: G1, which is the closest to clinical reality, yielded the best results. Keywords: orthodontics, dental materials, orthodontic resin cement, monolithic zirconium oxide ceramic, microshear bond strength test. | (read pdf) |
COMPUTERIZED DENTAL PROSTHETICS
Intraoral scans for CAD/CAM application
Judit Borbély, Alexandra Czigola, Viktoria Vitai, Ivett Róth, Péter Hermann (abstract)Introduction: There is no doubt the world of dentistry is rapidly changing. Digital innovations are replacing our traditional techniques. Dentists need to keep up with the speed of today’s ever changing digital world. The aim of the paper is to educate about the concept of digital dentistry, its advantages and limitations, and to provide an overview of digital impression taking procedures and the digital workflow for CAD/CAM application. Materials and methods: The Department of Prosthodontics, Faculty of Dentistry, Semmelweis University (SU) published a series of articles in Hungarian dental paper as part of the continuing education program to educate Hungarian dentists at the postgraduate level. Digital technologies and their novel materials are also introduced into the SU undergraduate dental curricula. A Bachelor of Science (BSc) digital dental designer training program is also aimed at the Faculty of Dentistry SU in cooperation with the Neumann University of Technology and Economics to modernizate the classic profession of dental technician. This paper gives a summary of the basic knowledge published in digital dentistry series. Results: The CAD/CAM technology offers a quick and comfortable experience to the patients and an efficient workflow to the dentist and dental technicians. The learning curve is steep to adopt that new technology both in the dental office and on the laboratory side. Educated dental students and digital designers have the potential to keep pace with the digital era change. Keywords: CAD/CAM, scanner, intraoral, workflow, dental impression technics. | (read pdf) |
GERODONTOLOGY
Comparison of dental status and oral function between the elderly with and without temporomandibular disorders
Minh Son Nguyen, Ülle Voog-Oras, Triin Jagomägi, Mare Saag (abstract)Introduction: Temporomandibular disorders (TMD) are a group of disorders that may cause functional limitations. The aim of the study was to compare the differences in dental status, oral behaviour, and mandibular functional limitations between TMD and non-TMD elderly people in Vietnam. Methodology: The sample consisted of 146 TMD and 112 non-TMD elderly. The dental and periodontal status were evaluated with DMFT and CPI indices. The participants self-rated frequency of oral behaviour activities (21-item Oral Behaviour Checklist) and mandibular functional limitations (20-item Jaw Functional Limitation Scale). Results: The mean number of missing teeth in TMD group was 9.6 ± 8.6, while it was 7.6 ± 6.4 in non-TMD group (p = 0.036). Gingival bleeding in TMD group was detected at 18.3 ± 10.2 teeth, which was less than in non-TMD group (21.0 ± 8.7, p = 0.023). The mean number of sextants with a 0–3 mm clinical attachment loss was high for non-TMD group (1.4 ± 2.0, p = 0.021), while the mean number of excluded sextants was high for TMD group (1.3 ± 1.8, p = 0.037). The TMD elderly group reported more frequent instances of “Hold, tighten, or tense muscles” than non-TMD group. No significant differences were found in the self-rated mandibular functional limitations between the two groups. Conclusion: TMD were associated with missing teeth and periodontal diseases. There was no association between TMD and mandibular functional limitations. The elderly suffering from TMD tended to have increased frequency of holding, tightening, or tensing muscles. Keywords: dental caries, elderly, mastication, oral function, temporomandibular disorders. | (read pdf) |
PRODUCT NEWS
The way to reach the gold standard in dental surgery: Integrated Surgical
Studio Design KYRI
Color in Dentistry
A Clinical Guide to Predictable Esthetics Stephen J. Chu / Rade D. Paravina / Irena Sailer / Adam J. Mieleszko
Publisher: Quintessence Publishing Co Inc
(read book review)
Implant Therapy in the Esthetic Zone
Current Treatment Modalities and Materials for Single-tooth Replacements Daniel Buser / Stephen Chen / Daniel Wismeijer (Ed.)
Publisher: Quintessence Publishing Co Inc
(read book review)
