Nicoleta Ilie, Eva-Maria Plenk (abstract)Introduction: The study aimed to quantify the amount of light that passes through different resin-based composite (RBC) types and to assess if a clinically used polymerization procedure in curing incrementally filled deep cavities is justified. Methodology: Light transmission through 2-mm thick specimens made of three regular RBCs – a nano, a flowable nano and a microhybrid – of the same shade A3, was analyzed under 24 different curing conditions, that resulted by varying the curing mode, exposure distance and exposure time when using a violet-blue LED light curing unit. Incident and transmitted irradiances were assessed in real-time on a spectrophotometer and radiant exposure, transmittance (T) and absorbance (A) were calculated. A multivariate analysis assessed the effects of various parameters on T and A. Results: Incident irradiance varied among 656.4 (8.1) mW/cm² (Standard mode, exposure distance = 7 mm) and 3361.5 (33.6) mW/cm² (Plasma Emulation mode, 0 mm). The filler amount (weight and volume %) exerted a significant effect on transmitted irradiance (p < 0.001; partial eta squared ηP² = 0.400 and 0.362, respectively) while the effect of exposure distance was low (p < 0.001, ηP² = 0.141). Light transmittance was material-dependent and very low. The significant lowest absorbance was identified in Filtek Supreme XTE flow (1.11 ± 0.09), followed by Filtek Silorane (1.21 ± 0.03) and Filtek Supreme XTE (1.62 ± 0.13). Incident and transmitted radiant exposure correlated exceptionally well in each RBC (Pearson correlations coefficient > 0.99). Conclusion: When restoring a deep cavity with regular RBCs, each increment needs to be cured adequately, since final curing to compensate for deficits in polymerisation is insufficient. Keywords: resin-based composites, light curing unit, irradiance, radiant exposure, transmittance, absorbance. | (read pdf) |
DENTAL MATERIALS
The effect of ceramic light scattering on an inhomogeneous beam profile
Jean-François Roulet , Marwah Majid Khudhair, Chiayi Shen (abstract)Aim: The study aimed to measure light scattering of a broad spectrum light curing unit (LCU) as influenced by ceramic type, shade and thickness as well as exposure distance and LCU’s position. Methodology: A broad spectrum LED LCU (ASCENT OL5) was mounted above a spectrometer (MARC Resin Calibrator, Blue, Light Analytics) at exposure distances of 1.0, 1.5 or 2.5 mm. The position of the center of the head was aligned with the spectrophotometer’s sensor and then moved in 1 mm increments in the X-Y plane, while concomitantly recording the irradiance. The process was repeated with lithium disilicate and leucite glass ceramic slabs of similar thicknesses. The loss in irradiance related to the value measured at center position was analyzed by means of linear regressions and multiple ANOVA analysis. Results: The regressions showed a good fit (90% – 99%). Moving away from the center showed decreased irradiance. Values of slope obtained were divided by their respective intercept to eliminate the influence of the irradiance measured at the center. Two three-way ANOVA’s were performed. One examined the influence of ceramic slab, direction and translucency/shade. It shows only the direction of measurement exhibited significant influence (p < 0.0001) on the mean normalized slope values. The other one examined the influence of ceramic slab, direction and slab thickness. It shows the mean normalized slope values are significantly influenced by the direction of measurement and the slab thickness (p < 0.0001). Values of the slopes indicated the ceramic scattering effect of the light. Thicker samples showed more scattering. Conclusion: The ceramic types, translucency/ shade had no significant effect on the light scattering. The thicker the ceramic the less irradiance changes were found indicating that the ceramics were scattering the light and thus slightly alleviating the effect of the inhomogeneous beam profile. Keywords: light curing, beam profile, glass ceramics, light scattering. | (read pdf) |
DENTAL MATERIALS
Effect of whitening on the optical and mechanical properties of aged resin composites
Ingrid Fernandes Mathias-Santamaria, Ayla Macyelle de Oliveira Correia, Débora Cristina Barbosa Dantas, Márcia Carneiro Valera, Renata Marques de Melo, Eduardo Bresciani (abstract)Objectives: To evaluate the effect of bleaching on colour, gloss, translucency, and microhardness of two types of resin composites (Charisma Classic and Filtek Z350 XT), previously aged. Materials and methods: Forty specimens of each material were artificially aged for 300 hours (UV-accelerated aging). Specimens were then treated with 35% hydrogen peroxide (Whiteness HP) in four 15-minutes sessions, totaling one hour of bleaching. Colour coordinates CIE L*a*b* and parameters of translucency (PT) were measured using a spectrophotometer (CM2600d – Konica Minolta), surface gloss readings were performed with a glossmeter (Novo-Curve – Rhopoint TM), and microhardness was assessed using a hardness device (FM-700, Future-Tech). Measurements have been performed after artificial aging as well as after the first and last bleaching protocol. Data were analyzed by two-way ANOVA and two-way repeated measures ANOVA, followed by Tukey’s test (5%). Results: The bleaching procedures of aged resin composites decreased the gloss and increased the translucency, but did not alter colour and microhardness. Conclusion: Bleaching procedures should be used carefully when resin composite restorations are present. Keywords: colour, hardness, gloss, bleaching agents, composite resins. | (read pdf) |
ORAL MEDICINE
Salivary matrix metalloproteinases activity levels in autoimmune diseases
Iulia-Ioana Stănescu , Alina Dima, Eugenia Bălănescu, Daniela Miricescu, Alexandra Totan, Radu Rădulescu, Bogdan Calenic, Paula Perlea, Daniela Bălan, Maria Greabu (abstract)Introduction: It is widely recognized that saliva represents a solid alternative as a diagnostic fluid in a wide range of oral and general diseases. Autoimmune diseases constitute an important health threat to both men and women worldwide with matrix metalloproteinases (MMPs) playing significant roles in pathogenesis and development of these diseases. The specific aim of the present study is to asses, for the first time, salivary levels of a selected panel of MMPs in several autoimmune diseases. Methodology: The study included 30 patients divided into groups such as: systemic sclerosis, vasculitis and healthy subjects. Salivary levels of MMP-1, -2, -7, -9 and -10 were analyzed using magnetic bead-based multiplex assays and Luminex technology. Results: MMP-2 salivary levels were statistically elevated in systemic sclerosis, while MMP-10 were also increased in vasculitis patients. Salivary levels of MMP-9 were found significantly increased in all analyzed groups. Conclusion: Taken together, our results promote saliva as a reliable diagnostic fluid for quantifying MMPs in autoimmune diseases. Keywords: saliva, autoimmune diseases, matrixmetalloproteinase, vasculitis, systemic sclerosis. | (read pdf) |
MAXILLOFACIAL SURGERY
Efficacy of a dental extraction policy designed to prevent osteoradionecrosis: a retrospective study in 100 oral cancer patients treated with intensity-modulated radiotherapy
Constantinus Politis, Paul Deckers, Matthias Schol, Daan Nevens, Sandra Nuyts, Joseph Schoenaers, Reinhilde Jacobs (abstract)Introduction: The aim was to determine the efficacy of an extraction policy designed to prevent osteoradionecrosis (ORN) in dentate areas of the jaw after intensity-modulated radiotherapy (IMRT). A secondary aim was to establish whether our extraction policy risked unnecessary tooth extractions for areas designated to be not-at-risk of ORN. Methodology: Data were retrospectively collected from 100 oral cancer patients, including the fate of 1430 individual teeth, from diagnosis to follow-up. Results: Eight percent of IMRT-treated patients developed ORN; spontaneous cases (5) outnumbered those provoked by dental issues (3). All cases of ORN arose in regions irradiated with > 60 Gy, with the posterior mandible as preferred location, with non-spontaneous cases primarily due to progressive periodontitis. No correlation was found between the likelihood of extraction and cancer stage. Conclusions: A more robust extraction policy of teeth affected with periodontitis and pocket depths of 4 – 5 mm might be advocated in molar areas predicted to receive > 60 Gy. Unfortunately, our study’s retrospective design precluded any detailed analyses of the underlying reasons for the 88 extractions that occurred at lower radiation dose thresholds; a more conservative approach may therefore be warranted for these low-risk areas. Keywords: osteoradionecrosis, intensity-modulated radiotherapy, dosimetric distribution, tooth extraction, oral cancer. | (read pdf) |
ORAL IMPLANTOLOGY
The efficacy of bone scraper for bone window osteotomy in the course of sinus augmentation
Liat Chaushu, Hadar Better, Samuel Porphirio Xavier, Sarit Naishlos, Joseph Nissan, Gabi Chaushu (abstract)Introduction: The aim was to determine the efficacy of the bone scraper in the course of sinus augmentation. Methodology: A total of 50 sinus augmentation procedures performed in 35 patients were included in this study. The outcome parameters included membrane perforation and bone volume collected. Results: Twenty-two were female, and 13 males. The age ranged from 55 to 80 years. The average osteotomy site dimensions were (12 ± 2) x (10 ± 2) mm. There were no perforations of the sinus membrane during the creation of the bony window. The average bone volume from the 50 osteotomies was 0.75 ± 0.25 cm3. There were no statistically significant differences between edentulous vs. partially edentulous patients, men vs. women, or time length of edentulism. Conclusions: The proper use of the bone scraper allows autogenous bone harvesting and prevents sinus membrane perforation during the creation of the bony window and is cost-effective financially. Keywords: bone scraper, sinus floor, augmentation, perforation, membrane, bone graft. | (read pdf) |
CASE REPORT
RESTORATIVE DENTISTRY
Resin infiltration as a minimal invasive esthetic treatment for a mild fluorosis case
Rasha Owda, Hande Şar Sancaklı (abstract)Aim: The present case report aimed to describe a minimally invasive method to mask the white opaque lesions of enamel in a mild fluorosis case (Dean’s Index code 3) to improve its esthetic outcome. Summary: Dental fluorosis (DF) is a developmental disturbance of enamel caused by excessive ingestion of fluoride on ameloblasts during enamel formation. The clinical manifestations depend on the severity of fluorosis. In mild cases, there are white opaque striations across the enamel surface, whereas in more severe cases, the porous regions increase in size, with enamel pitting, and secondary discoloration of the enamel surface. Patients often suffer from the discoloration and the pitted surface of the teeth which are the major characteristics leading to an unaesthetic appearance. A minimally invasive treatment approach of in-office bleaching followed by a resin infiltration technique was applied to enhance the porous fluorosed enamel surface. The combination of the two techniques resulted in a perfectly satisfactory aesthetic outcome with a clinical follow-up for 12 months. Key learning points: fluorosis, minimal invasive approach, bleaching, resin infiltration, esthetic. | (read pdf) |
PRODUCT NEWS
Gold Standard in Dental Photography: Digital Camera for Professional Dental Photography, EyeSpecial C-III
