Nickel Release and the Viability of Streptococcus mutans Corresponding to Low Risk of Dental Caries in Artificial Saliva Containing Orthodontic Appliances: In Vitro Study

Objective: The aims of this study were to determine the effect of different levels of Streptococcus mutans that correspond to a low risk of dental caries on nickel release and to determine the viability of S. mutans.Methods: Simulated fixed orthodontic appliances composed of copper nickel titanium, nickel titanium, or stainless steel were immersed in Klimek artificial saliva for 10 days with or without S. mutans inoculation on day 7. Same levels of S. mutans cultures (4 × 104 cfu/mL) were inoculated into the artificial saliva without orthodontic appliances. Nickel release was detected by inductively coupled plasma mass spectrometry. The archwire surface was analyzed by atomic force microscopy and scanning electron microscopy.Results: The density of S. mutans significantly increased in the artificial saliva without orthodontic appliances (P < .05). Appliances with nickel titanium alloys showed higher nickel release in the artificial saliva with or without S. mutans than those with copper nickel titanium or stainless steel archwires (P < .05). However, S. mutans increased nickel release only in orthodontic appliances with stainless steel archwires (P < .05). Although atomic force microscopy showed that the surface of as-received stainless steel archwires was smoother than that of nickel titanium or nickel titanium archwires, S. mutans increased the surface roughness of only the SS archwires. S. mutans adhered to all archwire types.Conclusion: While corrosion or corrosion-related processes may have decreased the growth capacity of S. mutans, reciprocally, S. mutans influenced corrosion. Rough surfaces can also promote corrosion; therefore, the surface roughness of metal alloy orthodontic appliances should be evaluated to determine their corrosion behavior

Effect of Cleft Width on the Outcome of Presurgical Nasoalveolar Molding in Patients With Unilateral Cleft Lip and Palate

The purpose of this study was to investigate the short-term effects of presurgical nasoalveolar molding (PNAM) according to cleft width (CW) in patients with unilateral cleft lip and palate (UCLP). In this retrospective study, 32 newborns with nonsyndromic UCLP treated with PNAM were allocated to 2 groups based on CW (group A, CW 5 mm). The following measurements were carried out using standardized photographs taken before and after PNAM therapy (before primary lip surgery): nostril axis inclination of healthy (NAI-NC) and cleft sides (NAI-C), columellar angle (CA), nasal base inclination (NBI), nasal floor width ratio (NFWR), alar base height ratio (ABHR), and columellar length ratio. Before PNAM therapy, there were significant differences between the 2 groups with respect to NAI-C, NBI, NFWR, and ABHR, indicating greater deformation of the nose in group B. After PNAM therapy, CA, NAI-C, NAI-NC, NFWR, and columellar length ratio were significantly improved in both the groups, whereas NBI and ABHR significantly worsened in group B. The improvement in CA, NAI-C, and NFWR was significantly greater in group B. Although a larger CW had some negative effects on the outcome of PNAM, it was found to be advantageous for nasal symmetry, if initiated as early as possible. Nevertheless, it is important to consider those aspects of the nasolabial area that are involved in the perception of symmetry when evaluating the effect of CW on PNAM outcomes in UCLP

Alt kesici ankrajını korumada "İki boyutlu Edgewise tekniği" nin etkinliği

The aim of the present study was to investigate cephalometrically the effectiveness of two dimensional edgewise technique in order to maintain the lower incisor anchorage in minimal anchorage cases where lower first premolars are extracted. This study was undertaken on 15 individuals having normal or slightly increased overjet, requiring moderate or maximum anchorage on maxilla and minimum anchorage on mandibula. The data obtained from cephalometric radiographs immediately before closure and after closure of first premolar extraction space was evaluated statistically. This study demonstrated that two dimensional edgewise technique provides sufficient intraoral anchorage with minimal lower incisor retraction.Bu çalışmanın amacı, birinci premolar dişlerin çekildiği mandibular minimum ankraj vakalarında, iki boyutlu edgewise tekniği ile alt kesici ankrajının ne derece korunabildiğinin sefalometrik olarak araştırılmasıdır. Araştırma; tedavileri alt çenede minimum, üst çenede moderate ile maksimum ankraj olarak planlanan, normal veya hafifçe artmış overjete sahip 15 birey üzerinde yürütülmüştür. Birinci premolar çekim boşluğunun kapatılma öncesi ve hemen sonrası alınan lateral sefalometrik radyografiler istatistiksel olarak değerlendirilmiştir. Bu çalışma iki boyutlu edgewise tekniğinin alt kesicilerde minimal retraksiyon ile yeterli intraoral ankrajı sağlayabileceğini ortaya koymuştur

Survey on Retention Protocols Among Turkish Orthodontists

WOS: 000439323600001PubMed ID: 30112475Objective: The purpose of this study was to identify general retention protocols practiced by Turkish orthodontist and to compare the results obtained with those of similar studies in Western countries. Methods: The Web-based survey consisted of 29 questions: 3 to identify the demographic characteristics of the participants and 26 to examine how orthodontists manage the retention phase. Data was interpreted by descriptive statistical methods such as the median test, the Mann-Whitney U-test and logistic regression analysis. Results: The survey return rate was 73.8%. Pretreatment malocclusion status (87%), oral hygiene status (78%), and presence of third molars (63%) were reported to be the most important factors in determining the type of retainer. Bonded retainers, either alone (29% in maxilla and 34% in mandible) or supplemented with vacuum-formed retainers (27% in maxilla and 32% in mandible) were the most commonly used type of retainer. The preference for lifelong retention varied from 7% to 19%. Female orthodontists scheduled the first appointment after debonding sooner than male orthodontists (p<0.05). Orthodontists working in universities scheduled first appointments later than orthodontists working in private practices (p<0.05). Conclusion: Turkish orthodontists still give importance to the third molars in their retention protocols, contrary to what is suggested in the current literature, and lifetime retention is rarely preferred as compared to other countries

Root resorption due to orthodontic treatment using self-ligating and conventional brackets

WOS: 000432291600004PubMed ID: 29651519Objective Purpose of the present study was to compare external root resorption (ERR) volumetrically in maxillary incisors induced by orthodontic treatment using self-ligating brackets (Damon Q, DQ) or conventional brackets (Titanium Orthos, TO) with the help of cone-beam computed tomography (CBCT). Patients and methods A sample of 32 subjects, with Angle Class I malocclusion and anterior crowding of 4-10 mm, was divided randomly into two groups: a DQ group, in which self-ligating DQ brackets with Damon archwires were used; and a TO group, in which conventional TO brackets with large Orthos archwires were applied. The study was conducted using CBCT scans taken before (T1), and near the end (9 months after the initiation of treatment; T2) of the orthodontic treatment. The extent of ERR was determined volumetrically using Mimics software. Changes in root volume were evaluated by repeated-measures analysis of variance as well as by paired and independent t-tests. Results While significant differences were found between T1 and T2 for root volume in both groups (p 0.05). Maxillary central and lateral incisors showed similar volume loss (p > 0.05). Furthermore, the TO group showed a higher prevalence of palatinal and proximal slanted RR compared with the DQ group (p < 0.05). Conclusions It is not possible to suggest superiority of one bracket system over the other only considering root resorption pattern or amount. Higher incidence of slanted RR found in patients treated with the TO system warrants further research to identify possible specific causes