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ABSTRACT: Our objective was to determine whether components of fixed orthodontic appliances as received from the manufacturers and after exposure to the clinical environment are free from microbial contamination before clinical use. A pilot molecular microbiologic laboratory study was undertaken at a dental hospital in the United Kingdom.
A range of orthodontic materials "as received" from the manufacturers and materials "exposed" to the clinical environment were studied for bacterial contamination. After growth on blood-rich media, cultured bacteria were identified by 16S rDNA polymerase chain reaction amplification and sequence phylogeny.
Bacteria were isolated from "as received" bands, archwires, and impression trays, but the level of contamination was low (0.5 × 10 to 1.825 × 10 CFU/mL). Various bacterial species were isolated from "clinic exposed" bands, archwires, impression trays, coil springs, and elastomeric modules, but the level of contamination was low (0.5 × 10 to 8.0 × 10 CFU/mL). The most commonly identified bacterial species was Staphylococcus epidermidis, followed by Kocuria, Moraxella, and Micrococcus species.
New materials "as received" from the manufacturers and those exposed to the clinical environment are not free from bacterial contamination before use in patients, but this contamination is low considering the potential for aerosol and operator contamination and could be considered insignificant. Further studies would be required to determine the level of risk that this poses.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 03/2013; 143(3):317-23. · 1.33 Impact Factor
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ABSTRACT: Abstract Objective: To determine the reliability and reproducibility of using three-dimensional (3D) digital models, as an alternative to plaster models for rating dental arch relationships in patients born with unilateral cleft lip and palate (UCLP). Design: Reliability and reproducibility study. Methods: Study models of 45 patients born with UCLP were made available in plaster and 3D digital models. Records were scored a week apart by three examiners using the 5-year olds' Index reference models, in the same two formats as the patient models. To assess reproducibility the study was repeated four weeks later under similar conditions, to minimise the influence of memory bias on the results. The reliability of using the 3D digital models was determined by comparing the scores for each examiner with the plaster model scores. Results: Weighted kappa statistics indicated repeatability for the plaster models was very good (0.83 to 0.87). For the 3D digital models it was good to very good (0.74 to 0.83). Overall the use of the 3D digital models showed good agreement with the plaster model scores, on both occasions. Conclusion: 3D digital models appear to be a good alternative to plaster models for assessing dental arch relationships using the 5-year olds' Index. Key Words: Dental arch relationships, cleft lip and palate, 3D models, dental models.
The Cleft Palate-Craniofacial Journal 03/2012; · 0.82 Impact Factor
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ABSTRACT: An increasing interest in dental erosion as a clinical and scientific phenomenon has led to concerted efforts to identify agents which might protect against erosion. In this study, nanoindentation was used to investigate inhibition of erosive enamel demineralisation over time scales with direct clinical relevance. Nanohardness of polished human enamel specimens (n = 8 per group) was measured at baseline (B), after demineralisation (D1: citric acid, 0.3% w/v, pH3.20, 20s), after treatment (T), and after a second demineralisation (D2: as above). Data were analysed using repeated measures ANOVA. All specimens exhibited a similar reduction in nanohardness B-D1 in the range 35.2-39.5%. The positive control solution (saturated hydroxyapatite solution) and 4500 mg/L fluoride as NaF significantly increased nanohardness D1-T by 19.9% and 24.1%, respectively, whereas 1400 mg/L fluoride as NaF, casein phosphopeptide-amorphous calcium phosphate mousse and negative control (deionised water) had no significant effect. Nanohardness at D2 was indistinguishable for all groups, with total reduction in nanohardness B-D2 of 31.6% (4500 mg/L fluoride), 35.2% (positive control), 39.9% (1400 mg/L fluoride), 42.4% (negative control), and 43.7% (CPP-ACP product). In summary, 4500 mg/L fluoride significantly increased the nanohardness of previously demineralised enamel and resulted in the smallest total reduction in nanohardness but there were few statistically significant differences among the groups.
International Journal of Dentistry 01/2012; 2012:768126.
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ABSTRACT: This article aims to describe the current status of 3-dimensional (3D) imaging in dental practice. Advances in this field have made 3D imaging far more accessible in all dental fields. This paper describes methods of imaging dental hard and soft tissues and their clinical uses. In addition, the potential advantages and disadvantages of various systems are discussed, as well as expected future developments.
Dental update 12/2011; 38(10):679-82, 684-6, 688-90.
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ABSTRACT: Dental technicians are exposed to respirable particles during their everyday work. This study investigated particulate production during dental laboratory procedures. Real-time air sampling of dental laboratory production processes was carried out, including the use of a plaster hopper, trimming study models and the trimming and polishing of removable orthodontic appliances. Respirable dust volumes in mg/m(3) were determined using real-time air sampler and were compared with the Workplace Exposure Limits (WELs) advised by the Control of Substances Harmful to Health regulations. The use of the plaster hopper produced the highest level of respirable dusts, which might exceed the recommended WELs for respirable dusts. Trimming study models and removable orthodontic appliances using suitable ventilation produced levels of respirable dusts, well below the WEL. Suitable ventilation adjacent to the plaster hoppers is advisable in order to reduce any inhalation risk to dental technicians.
Journal of Exposure Science and Environmental Epidemiology 09/2011; 21(5):536-40. · 2.93 Impact Factor
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ABSTRACT: INTRODUCTION: Previous studies have shown that most practitioners plan to maintain intercanine and intermolar widths during orthodontic treatment with fixed appliances. The aim of this study was to determine whether this was put into practice by clinicians during the latter stages of orthodontic treatment with fixed appliances. METHODS: This 2-part investigation was a laboratory-based measurement study at Bristol Dental Hospital, United Kingdom, from 2005 to 2007. Using standardized maxillary and mandibular study models with identical intermolar and intercanine widths but with differing degrees of tooth misalignment, 30 clinicians were asked to fabricate final working archwires according to their normal clinical practice. Then the intercanine and intermolar widths of the archwires were measured. In the second part of the study, the same intra-arch dimensions were measured directly from 50 pretreatment and posttreatment patient study models obtained from a subsample of 10 of the clinicians. RESULTS: The intercanine and intermolar widths measured on the adapted archwires from the standardized study models showed wide variations in the results, even though the intercanine and intermolar widths of the models were identical. Data from 50 treated patients also showed that, in most, there were wide variations in intercanine and intermolar widths between the patients' pretreatment and posttreatment study models. CONCLUSIONS: Although most clinicians aim to maintain the pretreatment arch form, this study shows that this is often not transferred to clinical practice.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 09/2010; 138(3):257-9. · 1.33 Impact Factor
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ABSTRACT: Previous studies have shown that most practitioners plan to maintain intercanine and intermolar widths during orthodontic treatment with fixed appliances. The aim of this study was to determine whether this was put into practice by clinicians during the latter stages of orthodontic treatment with fixed appliances.
This 2-part investigation was a laboratory-based measurement study at Bristol Dental Hospital, United Kingdom, from 2005 to 2007. Using standardized maxillary and mandibular study models with identical intermolar and intercanine widths but with differing degrees of tooth misalignment, 30 clinicians were asked to fabricate final working archwires according to their normal clinical practice. Then the intercanine and intermolar widths of the archwires were measured. In the second part of the study, the same intra-arch dimensions were measured directly from 50 pretreatment and posttreatment patient study models obtained from a subsample of 10 of the clinicians.
The intercanine and intermolar widths measured on the adapted archwires from the standardized study models showed wide variations in the results, even though the intercanine and intermolar widths of the models were identical. Data from 50 treated patients also showed that, in most, there were wide variations in intercanine and intermolar widths between the patients' pretreatment and posttreatment study models.
Although most clinicians aim to maintain the pretreatment arch form, this study shows that this is often not transferred to clinical practice.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 09/2010; 138(3):257.e1-8; discussion 257-9. · 1.33 Impact Factor
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ABSTRACT: The aim of this research was to determine the choices made by clinicians with respect to archwires and arch form during the initial and latter stages of orthodontic treatment with fixed appliances. A questionnaire-based study was carried out at Bristol Dental Hospital between November 2005 and March 2006. Questionnaires were distributed within the dental hospital and at local meetings in order to obtain a mixed sample of hospital and practice-based orthodontists. The clinicians asked to complete the questionnaire were consultant orthodontists (n = 37), specialist practitioners (n = 36), senior specialist registrars in orthodontics (n = 10), and dentists with a special interest in orthodontics (n = 17). The questionnaire consisted of two parts: the first was concerned with the initial alignment phase of treatment and the second with the space-closing phase of treatment in premolar extraction cases. The choice of archwires, significance of arch form, and intra-arch dimensions considered important at both stages were assessed. The clinicians were also asked about their usual practice with regard to adaptation of working archwires and the use of study models and symmetry charts. One hundred questionnaires were returned, giving a response rate of 92.6 per cent. The majority of clinicians felt that preservation of the pre-treatment arch form was essential in the latter but not in the early stages of treatment. In particular, conservation of the original intercanine width was considered important. However, there was no uniformity in how arch form should be preserved. Some respondents used study models and symmetry charts as an aid, but even then they were used in different ways. There was no uniformity in the landmarks used when adapting stainless steel archwires to arch form. Therefore, even when clinicians do adapt their archwires carefully with the intention of preserving arch form, are they choosing the correct arch form?
The European Journal of Orthodontics 09/2009; 32(1):54-9. · 0.89 Impact Factor
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ABSTRACT: To test the scientific properties of a patient-based questionnaire developed to measure adolescent patient's satisfaction with the process of orthodontic treatment.
Forty-nine consecutive patients aged 9 to 17 years undergoing orthodontic treatment were asked to complete the questionnaire on two separate occasions. Test-retest reliability, readability, ease of administration, criterion validity, and construct validity were tested. All patients answered the questionnaire at time 1 and took part in the construct validity study. Ten patients took part in an ease of administration study and 17 patients took part in the criterion validity study.
Thirty-one patients completed the questionnaire at time 2, giving a response rate of 63.3%. The test-retest reliability was excellent in one section, moderate in six sections, and poor in one. The questionnaire had a Flesch Reading Score of 79.8, equivalent to a reading age of 10 years and was easily administered in 5 to 15 minutes. Although the construct validity of the questionnaire was excellent in five of the six measures and moderate in the other, the criterion validity was poor for 7 of the 14 items selected to test.
This pilot study demonstrates the need to test a questionnaire before use in audit or research.
The Angle Orthodontist 08/2009; 79(4):759-65. · 1.21 Impact Factor
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ABSTRACT: The objectives of this investigation were firstly to quantitatively and qualitatively determine particulate production during orthodontic debond and enamel cleanup procedures, and secondly to examine what methods can be employed to minimize operator exposure to such dust particles.
A qualitative study was performed to determine the aerodynamic diameters and compositions of particulates produced during simulated clinical debonds and enamel cleanup procedures on extracted teeth. In each case the enamel was cleaned using tungsten carbide burs in either a high or slow speed handpiece, with or without water coolant spray, with or without high volume evacuation (HVE) or a face mask.
The use of a high speed handpiece with a tungsten carbide bur and water irrigation at enamel cleanup produced the greatest concentration of respirable particulates. Within this dust, calcium, phosphorus, aluminum and silicon were the most commonly found elements. The dust levels observed did not exceed limits advised for respirable dusts in general. However, the concentration of silica within the dusts created is unknown. The face mask and HVE were effective at reducing exposure to respirable particles, but the mask was most effective, reducing exposure by up to 96%.
A face mask is an effective means of reducing dust inhalation and is advised for all clinical procedures that produce dusts.
Dental materials: official publication of the Academy of Dental Materials 06/2009; 25(9):1155-62. · 2.88 Impact Factor
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ABSTRACT: The purpose of this research was to investigate the effects of decontamination and clinical exposure on the elastic moduli, hardness and surface roughness of two frequently used orthodontic archwires, namely 0.020in.x0.020in. heat activated (martensitic active) nickel titanium archwires and 0.019in.x0.025in. austenitic stainless steel archwires.
This study was a prospective clinical trial in which 20 consecutive patients requiring an archwire change as part of their course of orthodontic fixed appliance therapy, had either a nickel titanium or stainless steel archwire fitted as deemed clinically necessary. The effect of clinical use was determined by comparing distal end cuts of the "as received" archwires before and after decontamination, with the same retrieved archwires following clinical use and decontamination. Hardness, elastic modulus and surface roughness were determined using an atomic force microscope (AFM) coupled with a nanoindenter.
The results showed that the decontamination regimen and clinical use had no statistically significant effect on the nickel titanium archwires, but did have a statistically significant effect on the steel archwires. Decontamination of the steel wires significantly increased the observed surface hardness (p=0.01) and reduced the surface roughness (p=0.02). Clinical use demonstrated a statistically significant increase in the observed elastic modulus (p<0.001) and a decrease in surface roughness (p=0.001).
At present it is difficult to predict the clinical significance of these statistically significant changes in archwire properties on orthodontic tooth movement.
Dental materials: official publication of the Academy of Dental Materials 05/2009; 25(8):1039-43. · 2.88 Impact Factor
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ABSTRACT: Most previous research on non-nutritive sucking habits has been cross-sectional in nature. This study determined the prevalence of non-nutritive sucking habits and the effects on the developing dentition within a longitudinal observational cohort.
The Children in Focus group of the Avon Longitudinal Study of Pregnancy and Childhood study was studied. Questionnaire data on non-nutritive sucking habits were collected on the children at 15 months, 24 months, and 36 months of age. Dental examinations were performed on the same children at 31 months, 43 months, and 61 months of age.
At 15 months, 63.2% of children had a sucking habit, 37.6% used just a dummy, and 22.8% used a digit. By 36 months, sucking had reduced to 40%, with similar prevalence of dummy and digit sucking. Both habits had effects on the developing dentition, most notably in upper labial segment alignment and the development of anterior open bites and posterior crossbites.
The majority of children had non-nutritive sucking habits up until 24 months of age. Both digit and dummy sucking were associated with observed anomalies in the developing dentition, but dummy-sucking habits had the most profound influence on the anterior and posterior occlusions of the children.
International Journal of Paediatric Dentistry 06/2008; 18(3):178-88. · 1.01 Impact Factor
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ABSTRACT: Contemporary orthodontics relies on various bonded attachments, archwires, and other devices to achieve tooth movement. These components are composed of varying materials with their own distinctive physical and mechanical properties. The demands made on them are complex because they are placed under many stresses in the oral environment. These include immersion in saliva and ingested fluids, temperature fluctuations, and masticatory and appliance loading. The combination of these materials in close proximity and in hostile conditions can result in corrosion. Our purpose in this article was to consider the literature to date with regard to potential mechanical, clinical, and health implications of orthodontic corrosion.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 05/2008; 133(4):584-92. · 1.33 Impact Factor
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ABSTRACT: This multicentre, retrospective, study assessed the cost, and factors influencing the cost, of combined orthodontic and surgical treatment for dentofacial deformity. The sample, from a single region in England, comprised 352 subjects treated in 11 hospital orthodontic units who underwent orthognathic surgery between 1 January 1995 and 31 March 2000. Statistical analysis of the data was undertaken using non-parametric tests (Spearman and Wilcoxon signed rank). The average total treatment cost for the tax year from 6 April 2000 to 5 April 2001 was euro6360.19, with costs ranging from euro3835.90 to euro12 150.55. The average operating theatre cost was euro2189.54 and the average inpatient care (including the cost of the intensive care unit and ward stay) was euro1455.20. Joint clinic costs comprised, on average, 10 per cent of the total cost, whereas appointments in other specialities, apart from orthodontics, comprised 2 per cent of the total costs. Differences in the observed costings between the units were unexplained but may reflect surgical difficulties, differences in clinical practice, or efficiency of patient care. These indicators need to be considered in future outcome studies for orthognathic patients.
The European Journal of Orthodontics 03/2008; 30(1):31-9. · 0.89 Impact Factor
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ABSTRACT: During enamel cleanup after the removal of fixed appliances, aerosols, splatter, and dust are produced that can be inhaled. Although most inhaled particles are harmless, some might be associated with chronic diseases. Modern laboratory methods can now accurately simulate the human lung and predict the site of deposition of these inhaled particles.
Orthodontic brackets and bands were attached to extracted teeth to simulate complete dental arches. Four variations of enamel cleanup were used: the variables were hand-piece speed and presence or absence of water. Air sampling was conducted by using a cascade impactor, and the filter media collected from each experiment were viewed under a scanning electron microscope to locate the particulate matter. X-ray microanalysis was used to identify particle composition.
The amount of debris deposited on the filter media was highly variable. The combination of fast hand piece with water irrigation demonstrated the highest concentration of debris deposited at the greatest depth in the (artificial) lung. Although the particles are most likely to be deposited in the conducting airways and terminal bronchi, some might be deposited in the terminal alveoli of the lungs and cleared only after weeks or months. The most common elements identified were calcium, phosphorus, silica, and aluminum. Other elements included iron and lanthanum.
Aerosol particulates produced during enamel cleanup might be inhaled irrespective of hand-piece speed or the presence or absence of water coolant.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 02/2008; 133(1):11-7. · 1.33 Impact Factor
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ABSTRACT: Vacuum-formed retainers (VFRs) are often prescribed by orthodontists in the British National Health Service (NHS). There is no good evidence that VFRs are more effective than Hawley retainers. The aim of this study was to compare the clinical effectiveness of Hawley and VFRs over a 6-month period of retention. The study design was a randomized clinical trial, performed in a single orthodontic practice.
Eligible patients treated by a specialist orthodontist were randomly allocated to either Hawley retainers (n = 196) or VFRs (n = 201). Two technicians fabricated the retainers to standardized designs. A blinded, dentally qualified examiner analyzed the records. Maxillary and mandibular dental casts at debond and 6 months into retention were assessed for tooth rotations mesial to the first permanent molars, intercanine and intermolar widths, and Little's index of irregularity.
The results showed significantly greater changes in irregularity of the incisors in the Hawley group than in the VFR group at 6 months. There were otherwise no statistically significant differences.
VFRs are more effective than Hawley retainers at holding the correction of the maxillary and mandibular labial segments. The median differences were 0.56 mm in the mandibular arch and 0.25 mm in the maxillary arch. Although this difference is unlikely to be clinically significant in the maxillary arch, it could be considered clinically significant in the mandibular arch if located to a single tooth displacement.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 01/2008; 132(6):730-7. · 1.33 Impact Factor
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ABSTRACT: To determine whether lower lingual, canine to canine, bonded multistrand retainers prevent relapse of lower labial segment alignment following fixed appliance therapy and to compare this with lower Hawley-type removable retainers.
Two groups of 29 patients were identified. Group 1 had bonded lower canine to canine multistrand retainers placed following debonding, whereas Group 2 had lower Hawley-type retainers (with acrylic labial to the incisors) fitted following debonding. Study models were taken of all patients at debonding (T(1)) and at least 1 year post debonding (T(2)). Changes in Little's index over the study period were recorded using a reflex microscope.
Statistically significant changes in Little's index occurred in the lower labial segment of both study groups (P = .001) over the observation period. There was no statistically significant difference in the amount of change in Little's index between the bonded and removable retainer groups (P = .13). Bonded retainers tended to be placed in older patients (P = .02).
Relapse can occur in the lower labial segment with both fixed and removable retainers. The amount of relapse seen with both types of retainer is not statistically significantly different.
The Angle Orthodontist 12/2007; 77(6):954-9. · 1.21 Impact Factor
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ABSTRACT: The antisialagogue atropine sulphate has been used for many years as an adjunct to orthodontic bonding to reduce moisture contamination. The aims of this study were to investigate the effect of atropine sulphate premedication on orthodontic bond failures and to evaluate the attitudes of patients and parents toward its use in orthodontics.
After ethics committee approval, 51 patients (mean age, 14 years 7 months) were enrolled in this clinical trial. They were randomized to receive 2 interventions, atropine sulphate premedication (600 microg) or no premedication (control) with a Battenburg design (split-mouth). Overall, 852 brackets and 362 molar tubes were bonded. Bond failure data were collected over a 12-month period and analyzed with Kaplan-Meier survival probabilities and the log rank and Wilcoxon tests. Patient-centered outcome measures included a questionnaire relating to treatment with antisialagogues.
The results showed no statistically significant difference in the bond survival rates between the 2 interventions--antisialagogue premedication or no premedication (P >.05). From the questionnaire, 94.1% of the subjects said they took the atropine sulphate before the bond appointment. Approximately 76% of them thought that taking medication before placement of orthodontic appliances was an acceptable part of treatment.
Although the use of a premedication to induce hypo-salivation before orthodontic bonding appears to be an acceptable procedure to most patients and their parents, we did not find a statistically significant effect on the observed bond failure rates. There is no evidence to support the routine use of atropine sulphate before orthodontic bonding.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 11/2007; 132(5):663-70. · 1.33 Impact Factor
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ABSTRACT: Previous research has shown that ibuprofen provides effective relief from orthodontic pain. The aim of this study was to ascertain whether paracetamol (also known as acetaminophen) provided pain relief of equivalent or greater magnitude.
A multicenter, noninferiority, randomized clinical trial was conducted in 3 orthodontic clinics; 159 patients aged 12 to 16 years attending for routine orthodontic treatment were randomly allocated to receive either 400 mg of oral ibuprofen or 1 g of oral paracetamol an hour before and again 6 hours after separator placement. Pain scores were recorded on 7 visual analog scales (10 cm) over a week. The margin of equivalence was defined as 10 mm.
Mean orthodontic pain from 2 hours after separation to bedtime was 8.5 mm (90% CI: lower, 3.7; upper,13.2) higher in the paracetamol group. This confidence interval lies partly outside the margin of equivalence, suggesting that paracetamol is not equivalent, and excludes the value 0, suggesting that ibuprofen is superior. From day 1 onward, there was a trend for patients who had taken ibuprofen to experience less pain at most time intervals compared with the paracetamol group. Two doses of ibuprofen, taken on the day of separator placement, were insufficient to control orthodontic pain on day 1 after placement.
A combination of preoperative and postoperative ibuprofen is more effective than paracetamol in the control of orthodontic pain.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 11/2007; 132(4):511-7. · 1.33 Impact Factor
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ABSTRACT: Two main types of particulate matter may be produced during routine dental procedures, namely aerosols and splatter. The principal difference between them is the size of the particles from which they are made. The behaviour of such particles in air and their possible health risks are complex. However, the use of high volume evacuation, pre-procedural mouthrinses and rubber dam are the most effective methods of reducing the unwanted risk of exposure.
Dental update 01/2007; 33(10):601-2, 604-6.
