Papers by Theodore Eliades
Dental Materials, 2015
OBJECTIVE: To assess the in vivo amount of BPA released from a visible light-cured orthodontic ad... more OBJECTIVE: To assess the in vivo amount of BPA released from a visible light-cured orthodontic adhesive, immediately after bracket bonding. METHODS: 20 orthodontic patients were recruited after obtaining informed consent. All patients received 24 orthodontic brackets in both dental arches. In Group A (11 patients), 25 ml of tap water were used for mouth rinsing, whereas in Group B (9 patients) a simulated mouth rinse formulation was used: a mixture of 20 ml de-ionized water plus 5 ml absolute ethanol. Rinsing solutions were collected before, immediately after placing the orthodontic appliances and after washing out the oral cavity and were then stored in glass tubes. Rinsing was performed in a single phase for 60s with the entire volume of each liquid. The BPA analysis was performed by gas chromatography-mass spectrometry. RESULTS: An increase in BPA concentration immediately after the 1st post-bonding rinse was observed, for both rinsing media, which was reduced after the 2nd postbonding rinse. Water exhibited higher levels of BPA concentration than water/ethanol after 1st and 2nd post-bonding rinses. Two-way mixed Repeated Measures ANOVA showed that the primary null hypothesis declaring mean BPA concentration to be equal across rinsing medium and rinsing status was rejected (p-value <0.001). The main effects of the rinsing medium and status, as well as their interaction were found to be statistically significant (p-values 0.048, <0.001 and 0.011 respectively). SIGNIFICANCE: A significant pattern of increase of BPA concentration, followed by a decrease that reached the initial values was observed. The amount of BPA was relatively low and far below the reference limits of tolerable daily intake.
American Journal of Orthodontics and Dentofacial Orthopedics, 2020
Orthodontic treatment with sequential aligners has seen a considerable surge in the last decades,... more Orthodontic treatment with sequential aligners has seen a considerable surge in the last decades, and is currently used to treat malocclusions of varying severity. To enhance tooth movement and broaden the spectrum of malocclusions that can be treated with aligners, composite resin attachments are routinely bonded with the acid-etch technique on multiple teeth, a process known to impose irreversible alterations of the enamel structure, color, gloss, and roughness. Additionally, this clinical setting introduces a unique scenario of different materials applied in a manner that involves the development of friction and attrition between the attachment and the softer aligner material, all performing in the harsh conditions of the oral environment, which impact the aging of these materials. The latter may give rise to alterations of the aligners and the composite attachments and potential intraoral release of Bisphenol A, a known endocrine disrupting agent. Furthermore, at the final stages of contemporary aligner treatment, the removal of multiple, sometimes bulky, composite attachments with a volume and surface far greater than the remnant adhesive after debonding of brackets, through grinding that might be associated with pulmonary effects for the patient or staff. Because of the extensive enamel involvement in bonding, the release of factors from the attachment-aligner complex during service, the aging of these entities in the oral environment, and the laborious debonding/composite grinding process coupled with the hazardous nature of aerosol produced during the removal of these bulky specimens, appropriate risk management considerations should be applied and an effort to confine the application of multiple composite specimens bonded to enamel to the absolutely necessary should be pursued.
American Journal of Orthodontics and Dentofacial Orthopedics, 2020
The purpose of this critical review is to list the sources of aerosol production during orthodont... more The purpose of this critical review is to list the sources of aerosol production during orthodontic standard procedure, analyze the constituent components of aerosol and their dependency on modes of grinding, the presence of water and type of bur, and suggest a method to minimize the quantity and detrimental characteristics of the particles comprising the solid matter of aerosol. Minimization of water-spray syringe utilization for rinsing is suggested on bonding related procedures, while temporal conditions as represented by seasonal epidemics should be considered for the decision of intervention scheme provided as a preprocedural mouth rinse, in an attempt to reduce the load of aerosolized pathogens. In normal conditions, chlorhexidine 0.2%, preferably under elevated temperature state should be prioritized for reducing bacterial counts. In the presence of oxidation vulnerable viruses within the community, substitute strategies might be represented by the use of povidone iodine 0.2%-1%, or hydrogen peroxide 1%. After debonding, extensive material grinding, as well as aligner related attachment clean-up, should involve the use of carbide tungsten burs under water cooling conditions for cutting efficiency enhancement, duration restriction of the procedure, as well as reduction of aerosolized nanoparticles. In this respect, selection strategies of malocclusions eligible for aligner treatment should be reconsidered and future perspectives may entail careful and more restricted utilization of attachment grips. For more limited clean-up procedures, such as grinding of minimal amounts of adhesive remnants, or individualized bracket debonding in the course of treatment, handinstruments for remnant removal might well represent an effective strategy. Efforts to minimize the use of rotary instrumentation in orthodontic settings might also lead the way for future solutions. Measures of self-protection for the treatment team should never be neglected. Dressing gowns and facemasks with filter protection layers, appropriate ventilation and fresh air flow within the operating room comprise significant links to the overall picture of practice management. Risk management considerations should be constant, but also updated as new material applications come into play, while being grounded on the best available evidence.
Australasian Orthodontic Journal, 2021
Aim To assess the in vivo colour alterations of two different clear thermoplastic retainers. Meth... more Aim To assess the in vivo colour alterations of two different clear thermoplastic retainers. Methods Thirty patients were randomly allocated into two Groups (N = 15) following the completion of active orthodontic treatment. Group 1 received Vivera® and Group 2 Essix® C+ thermoplastic retainers. Each patient was provided with two fabricated retainers (one for use and the other to serve as a control). The CIELAB parameters of the patients’ upper central incisors were measured with a SpectroShade™ spectrophotometer immediately after retainer placement (T0) and again after 15 days (T1), one month (T2) and three months (T3). The measurements were also performed on teeth without the retainer in place. ΔE differences were calculated. Methods ΔE changes from T0 to Tp T2 or T3 showed no statistically significant differences between Groups 1 and 2 within any combination of measurements or teeth. ΔEļŢ3-Ţ0ļ changes for used retainers were 1.55 times higher than control appliances (p = 0.002) an...
Australasian Orthodontic Journal, 2021
Aim The aim of the present study was to characterise the chemical and mechanical properties of co... more Aim The aim of the present study was to characterise the chemical and mechanical properties of contemporary thermoplastic orthodontic materials. Materials and methods Four thermoplastic materials were tested: Clear Aligner (Scheu-Dental), ACE and A+ (Dentsply), and Invisalign (Align Technology). Eight appliances were fabricated from each material and a small portion from each was analysed by ATR-FTIR spectroscopy. The appliances were cut and, following metallographic grinding and polishing, were subjected to instrumented indentation testing (IIT) employing a Vickers indenter. Martens Hardness (HM), Indentation Modulus (EIT), Elastic to Total Work Ratio (elastic index (ηIT)) and Indentation Creep (CIT) were determined according to ISO 14577-1. The mean values of the mechanical properties were statistically analysed by one way ANOVA and Tukey Kramer multiple comparison test at a = 0.05. Results ATR-FTIR analysis identified that Invisalign was a polyurethane-based material, whereas the...
Materials, 2019
The aim of this study was to estimate the possible changes of surface roughness and the mechanica... more The aim of this study was to estimate the possible changes of surface roughness and the mechanical properties of Invisalign® appliances over one- and two-week of service. Forty appliances with attachments were retrieved after the end of orthodontic treatment from different patients. Half of them had been used for one week (1W), and the rest for two weeks (2W). Ten unused Invisalign® appliances were used as the control (CON). An equal number of teeth possessing attachments were cut of aligners deriving from all groups (1W, 2W, and CON), and the Sa, Sq, Sz, Sc, and Sv roughness parameters of the internal surface of the aligner attachment area and the opposite lingual side (which was in contact to enamel) were determined by optical profilometry. Then, ten first molars originating from all groups were embedded in acrylic resin, and were ground and polished. Instrumented indentation testing (IIT) was performed in order to determine the Martens hardness (HM), indentation modulus (EIT), an...
Materials, 2019
The aims of this study were twofold: a) to characterize a wide array of time-independent and -dep... more The aims of this study were twofold: a) to characterize a wide array of time-independent and -dependent properties and b) to find possible correlations among the properties tested. Seven commercially available orthodontic adhesives were included in this study and ten cylindrical specimens were prepared from each material. Five specimens from each material were used for the characterization of Martens Hardness (HM), indentation modulus (EIT), and elastic index (ηIT), and the remaining five for the determination of indentation creep (CIT). Al the aforementioned properties were identified by employing an Instrumented Indentations Testing (IIT) device with a Vickers indenter. The results of HM, EIT, ηIT, and CIT were statistically analyzed by one way ANOVA and Tukey post hoc test, while the possible correlations among the aforementioned properties were determined by Spearman correlation test. Statistical significant differences were identified for all properties among the materials test...
Progress in orthodontics, 2018
Fixed orthodontic appliances might be associated with intraoral adverse effects on enamel, due to... more Fixed orthodontic appliances might be associated with intraoral adverse effects on enamel, due to plaque accumulation and their colonization by oral microbes. At the same time, the demand for esthetic alternatives to orthodontic treatment, like thermoplastic aligners, is growing. However, thermoplastic aligners may behave differently intraorally than fixed appliances in terms of bacterial colonization and biofilm formation. Therefore, the aim of this prospective cohort study was to assess the salivary prevalence of the cariogenic bacteria Streptococcus mutans, Lactobacillus acidophilus, and Streptococcus sanguinis among adolescents treated orthodontically with thermoplastic aligners or fixed appliances. Thirty adolescent patients (17 girls/13 boys; mean age 13.8 years old) were assigned to treatment with either (i) self-ligating fixed appliances with nickel-titanium archwires or (ii) aligners constructed from clear transparent polyethylenterephthalat-glycol copolyester (PET-G) therm...
Australian Dental Journal, 2017
Adverse effects can arise from the clinical use of orthodontic materials, due to the release of c... more Adverse effects can arise from the clinical use of orthodontic materials, due to the release of constituent substances (ions from alloys and monomers, degradation by-products, and additives from polymers). Moreover, intraoral aging affects the biologic properties of materials. The aim of this review is to present the currently identified major adverse effects of the metallic and polymeric components found in orthodontic appliances and materials. Corrosion in metallic orthodontic attachments releases metal ions, mainly iron, chromium, and nickel. The latter has received the greatest attention because of its reported potential for an allergic response. The formation of an oxide layer may inhibit the outward movement of ions, thereby acting as an obstacle for release. Titanium alloys have superior corrosion resistance than stainless steel. The efficiency of polymerisation is considered an essential property for all polymers. A poor polymer network is susceptible to the release of biologically reactive substances, such as bisphenol-A (BPA), which is capable of inducing hormone-related effects. The close proximity of a light-curing tip to the adhesive, pumice prophylaxis after bonding, indirect irradiation and mouth rinsing during the first hour after bonding may decrease BPA release. The adverse effects of some orthodontic materials should be considered during material selection and throughout orthodontic treatment, in order to minimise possible undesirable implications.
Journal of orofacial orthopedics = Fortschritte der Kieferorthopadie : Organ/official journal Deutsche Gesellschaft fur Kieferorthopadie, Jan 10, 2017
Although several prescriptions and techniques exist for comprehensive fixed appliance treatment, ... more Although several prescriptions and techniques exist for comprehensive fixed appliance treatment, their treatment effects have not yet been adequately assessed in an evidence-based manner. The aim of this systematic review was to assess the therapeutic and adverse effects of various prescriptions or techniques for orthodontic appliances from randomized clinical trials on human patients. Eight databases were searched up to July 2016 for randomized trials assessing any orthodontic prescriptions or techniques in human patients. After elimination of duplicate studies, data extraction, and risk of bias assessment according to the Cochrane guidelines, random effects meta-analyses with mean differences (MD) and their 95% confidence intervals (CIs) were performed. Compared to Roth preadjusted appliances, both Begg and modified Begg appliances were associated with statistically significantly worse occlusal outcome assessed with Peer Assessment Review (PAR) scores (1 trial, MD 3.1 points, 95% ...
The European Journal of Orthodontics, 2016
Background: Although orthodontic white spot lesions (WSLs) are one of the most often and most evi... more Background: Although orthodontic white spot lesions (WSLs) are one of the most often and most evident adverse effects of comprehensive fixed appliance treatment, the efficacy of interventions for WSLs has not yet been adequately assessed in an evidence-based manner. Objective: Aim of this systematic review was to assess the therapeutic and adverse effects of interventions to treat post-orthodontic WSLs from randomized trials in human patients. Search methods: An unrestricted electronic search of eight databases from inception to May 2016. Selection criteria: Randomized controlled trials assessing any interventions for post-orthodontic WSLs on human patients. Data collection and analysis: After duplicate study selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of mean differences (MDs), standardized mean differences (SMDs), and odds ratios (ORs), including their 95% confidence intervals (CIs) were performed, followed by subgroup and sensitivity analyses. Results: A total of 20 unique studies and a total of 942 (42 per cent male and 58% per cent female) patients were included, with an average age of 16.2 years and a mean number of 8.2 WSLs (range 2.2 to 45.4) per patient. These were allocated to adjunct treatment with casein phosphopeptidestabilized amorphous calcium phosphate creams, external tooth bleaching, low-or highconcentration fluoride films, gels, mouthrinses or varnishes, resin infiltration, miswak chewing sticks, bioactive glass toothpastse, or to no adjunct treatment (i.e. conventional oral hygiene). The monthly use of fluoride varnish was the best supplement to improve WSLs in terms of lesion area (1 trial; MD = −0.80 mm 2 ; 95% CI = −1.10, −0.50 mm 2 ; P < 0.05; high quality) and enamel fluorescence (3 trials; SMD = −0.92; 95% CI = −1.32, −0.52; P < 0.05; high quality), followed by the use of fluoride film. WSL treatment did not provide a considerable improvement in their clinical evaluation (3 trials; OR = 0.97; 95% CI = 0.60, 1.56; P > 0.05; moderate quality), with imprecision due to small sample size being the main limitation of existing evidence. Conclusions: Based on the existing trials, interventions for post-orthodontic WSLs, mainly fluoride varnish, seem to be effective, but further research is needed to elucidate their clinical relevance.
Biomedical Engineering / Biomedizinische Technik, 2017
Objective:The aim of the present study was to test the mechanical properties of different adhesiv... more Objective:The aim of the present study was to test the mechanical properties of different adhesives used in orthodontics for fixed retainers and to investigate their possible interrelations.Materials and methods:Specimens of six different adhesive resins were prepared: Transbond XT, Transbond LR and an experimental BPA-free orthodontic adhesive, as well as IPS Empress Direct (IPS-ED), ZNano and Accolade. The mechanical properties tested were Martens hardness (HM), indentation modulus (EResults:Significant differences were identified among all the materials tested for HM, with Transbond LR presenting the highest value. This resin presented the highest EConclusions:The materials tested demonstrated significant differences in their mechanical properties, and thus differences in their clinical performance are anticipated.
European Journal of Oral Sciences, 2016
The aim of this systematic review was to compare the therapeutic and adverse effects of lingual a... more The aim of this systematic review was to compare the therapeutic and adverse effects of lingual and labial orthodontic fixed appliances from clinical trials on human patients in an evidence-based manner. Randomized and prospective non-randomized clinical trials comparing lingual and labial appliances were included. Risk of bias within and across studies was assessed using the Cochrane tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Random-effects metaanalyses were conducted, followed by subgroup and sensitivity analyses. Six electronic databases were searched from inception to July 2015, without limitations. A total of 13 papers pertaining to 11 clinical trials were included with a total of 407 (34% male/66% female) patients. Compared with labial appliances, lingual appliances were associated with increased overall oral discomfort, increased speech impediment (measured using auditory analysis), worse speech performance assessed by laypersons, increased eating difficulty, and decreased intermolar width. On the other hand, lingual appliances were associated with increased intercanine width and significantly decreased anchorage loss of the maxillary first molar during space closure. Based on existing trials, there is insufficient evidence to make robust recommendations for lingual fixed orthodontic appliances regarding their therapeutic or adverse effects, as the quality of evidence was low.
Journal of the World Federation of Orthodontists, 2015
Background: The purpose of this study was to identify the effects of bracket-base design and adhe... more Background: The purpose of this study was to identify the effects of bracket-base design and adhesive on adhesive remnant index (ARI) and enamel surface area covered by adhesive. Methods: The sample consisted of 32 recently extracted premolars. The teeth were randomly assigned to one of four groups: conventional mesh base and composite resin; laser-etched base and composite resin; conventional mesh base and resin-modified glass ionomer; and laser-etched base and resin-modified glass ionomer. After a week, all brackets were debonded. The debonded bracket-base surface and the buccal surface of each tooth were studied under the microscope, and the remaining adhesive was scored using the ARI. The extent of coverage of the tooth by adhesive remnants was also calculated, outlining the different areas of adhesive. Results: A Fisher's exact test indicated significant differences between the groups. The adhesive resin group showed the highest ARI scores independent of the bracket-base design, whereas between the two bracket-base designs, the laser-etched bracket design showed higher ARI. ARI scores reliably depict the extent of enamel covered by adhesive compared with the measurement of the actual area covered. Conclusion: Varying the bracket base and adhesive may result in different ARI scores, which can affect the enamel surface during debonding.
American Journal of Orthodontics and Dentofacial Orthopedics, 2011
Introduction: Our aim was to quantitatively determine the bisphenol-A (BPA) released from a light... more Introduction: Our aim was to quantitatively determine the bisphenol-A (BPA) released from a light-cured orthodontic adhesive used to bond lingual fixed retainers. Methods: Eighteen recently extracted premolars, divided into 3 groups of 6 teeth each, were embedded in plaster in an arch shape. A light-cured adhesive (Transbond XT, 3M Unitek, Monrovia, Calif) was bonded to a .0195-in, 3-strand heat-treated twist flex wire (Wildcat, GAC International, Bohemia, NY) adjusted to the lingual surface of the teeth, and the arches were immersed in doubled-distilled water for 10, 20, and 30 days. The concentration of BPA in the 3 eluents was investigated with gas chromatography-mass spectroscopy; all assays were performed in triplicate, and the results were averaged. Results: Measurable amounts of BPA were identified for all groups, with the highest found in the immersion media of the 1-month groups (2.9 mg/L), whereas the control (tooth storage solution) had 0.16 mg/L. Conclusions: The BPA released from a light-cured adhesive used to bond lingual fixed retainers might be assigned to the application mode of the material that differs from conventional use. Further testing including estrogenicity assays will assess the potential estrogenic action of this application. Composite restorative resins should replace orthodontic adhesives that were not intended to function with their surfaces in the oral cavity; alternatively, canine-bonded fixed retainers might reduce the amount of adhesive used.
The release of compounds and identification of the pathways involved in the cytotoxicity and xeno... more The release of compounds and identification of the pathways involved in the cytotoxicity and xeno-estrogenicity of polymeric dental biomaterials utilized in Orthodontics and Paediatric Dentistry
American Journal of Orthodontics and Dentofacial Orthopedics, 2014
W hen chemicals with the ability to alter reproductive, neurologic, and metabolic development are... more W hen chemicals with the ability to alter reproductive, neurologic, and metabolic development are found in common items, the attention they draw can become intense. Bisphenol A (BPA) is 1 such chemical. BPA-based materials are used in food and beverage containers, protective coatings, optical lenses, adhesives, powder paints, paper coatings, and dental polymers. Even at low exposures, BPA might cause various adverse effects on reproduction and development, especially during embryonic development. The latest book to shed light on this topic presents a comprehensive review of our current knowledge of BPA release from dental polymers, including some used by orthodontists. This text was conceived and written by brothers Theodore and George Eliades. Ted heads the Department of Orthodontics and Paediatric Dentistry in Zurich, Switzerland, and is an associate editor of the AJO-DO; George manages the Department of Biomaterials at the University of Athens in Greece. As orthodontics is practiced now, adhesives polymers can be exposed to the oral environment in 3 ways: at the peripheral margins of the bracket, during the use of bonded retainers, and after removal of the brackets and cleaning of the enamel surface. When the average
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Papers by Theodore Eliades