Effect of Different Cleaning Regimes on Biofilm Formation of Acrylic-Based Removable Orthodontic Appliance: A Randomized Clinical Trial.

Objectives: This study aimed to evaluate the effects of different cleaning regimes of acrylic-based removable orthodontic appliances on bacterial biofilm formation and whether the surface modification, i.e., polished acrylic fitting surface, reduces biofilm formation. Materials and Methods: This double-blind, parallel, randomized clinical trial involved thirty-nine orthodontic patients indicated for removable orthodontic appliances. The patients were allocated into three groups according to the cleaning method: brushing with a denture brush and chlorhexidine (CHX) toothpaste, Lacalut cleaning tablet, and a combination of both cleaning methods. Each patient wore an upper removable appliance containing eight wells fitted with eight detachable acrylic tiles (four polished and four unpolished) for seven days. Five types of oral microbiota were evaluated using selective growth media and biochemical tests. The biofilm cleaning efficacy was assessed using the colony-forming unit (CFU) and scanning electron microscopy (SEM). Statistical Analysis. Data from the CFU using different cleansing regimes were compared, following log transformation, using one-way analysis of variance (ANOVA). The polished and unpolished tiles were compared for biofilm formation on each cleansing method using an independent t-test. Results: There was no significant difference among the three cleaning methods on the polished or unpolished tiles. However, in polished tiles, streptococci were significantly reduced in all cleaning methods, whereas staphylococci and Staphylococcus aureus were markedly decreased in brushing and combination cleaning methods. However, the total number of anaerobic bacteria was significantly reduced in polished tiles using the combination method only. Conclusions: Polishing the fitting surface of an acrylic-based orthodontic appliance reduced the tested bacterial biofilm formation and may enhance cleaning efficiency. Brushing and combination methods showed superior cleaning effects compared to cleaning tablets. This trial is registered with NCT05707221.

Effect of vitamin D deficiency on postorthodontic relapse: An animal study.

OBJECTIVES: This study aims to evaluate the effect of vitamin D deficiency (VDD) on orthodontic tooth movement (OTM), retention, and relapse and to assess the effect of systemic administration of vitamin D (VD) in a rat model. MATERIALS AND METHODS: A total of 32 male Wistar rats were divided into two groups, a control group of 11 rats and an experimental group of 21 rats with VDD, after enhancement using a custom diet. Of the VDD group, 11 rats were supplemented with systemic vitamin D3 and categorized as vitamin (VD supplement [VDS]) groups. The VDS group received 40,000 IU/kg via intramuscular injection on Days 1 and 15 of the orthodontic treatment period. A modified orthodontic appliance was fitted to apply 0.5 N of force to move the maxillary right first molars mesially for 14 days, followed by retention and relapse periods for 7 days. Space created during OTM was measured and reassessed after the retention and relapse periods. The relapse ratio was estimated, and histomorphometric analysis was performed to assess the number of osteoblasts, osteoclast bone cells, and bone area. RESULTS: A significant increase in the relapse ratio and a reduction in osteoblast cells and bone area were observed in the VDD group. By contrast, the amount of tooth movement was significantly higher together with osteoblast cells and bone marrow in VDS with a significant reduction in relapse ratio. CONCLUSION: VDD was associated with a significant reduction in osteoblast cell count and total bone area in addition to a significant increase in relapse ratio. Routine screening of VD may be beneficial before commencing orthodontic treatment.

The relationship between orthodontic treatment and temporomandibular disorders: A dental specialists' perspective.

INTRODUCTION: The relationship between temporomandibular disorders (TMDs) and orthodontic treatment/malocclusion has changed from a cause-and-effect association to an idea without sufficient evidence. OBJECTIVE: This survey was designed to assess the beliefs of different disciplines - orthodontists, oral surgeons, and oral medicine specialists - on the relationship between TMDs and orthodontic treatment, with regard to treatment, prevention and etiology of TMDs. METHOD: A survey in the form of questionnaire was designed and distributed to 180 orthodontists, 193 oral surgeons and 125 oral medicine specialists actively involved in treating TMDs. The questionnaire aimed to collect basic information about each participant and their beliefs, and clinical management of patients with TMDs. RESULTS: Halve of the responding orthodontists and most of the oral surgeons (69.9%) were male participants, whereas the majority of oral medicine specialists (83.3%) were female respondents. The participants' age ranged from 29 to 58 years. The majority of orthodontists believes that there is no relationship between orthodontic treatment and TMDs, and that orthodontic treatment does not provoke TMDs or prevent the onset of the disorder. However, oral surgeons and oral medicine specialists have different and conflicting opinions. Most surgeons tended to treat those patients, while most of the other two disciplines tended to seek an interdisciplinary approach. Chi-square test was done to find an association between the referral status and specialists' experience, and to compare between the different disciplines' belief. CONCLUSIONS: Orthodontist's beliefs were in accordance with the scientific evidence, whereas most oral surgeons and oral medicine specialist believed that orthodontic treatment may provoke TMDs. Therefore, continuing program series development is important to embrace the concept of the multidisciplinary team approach and improve the health care and quality of life for those patients.

The effects of calcitonin on post-orthodontic relapse in rats.

OBJECTIVES: To determine the effects of systematic calcitonin administration on post-orthodontic relapse in rat model. MATERIAL AND METHODS: This experimental animal model involved 36 male Wister rats. The maxillary right first molars were moved mesially, using a modified orthodontic appliance delivered 50 gm, for 14 days, retained for 4 days and left to relapse for 10 days. The study group was divided into three subgroups in which a single injection of calcitonin (20 IU/Kg), three injections of calcitonin (20 IU/Kg), each every other day, and normal saline were administered subcutaneously after orthodontic tooth movement has finished. The relapse ratio, histomorphometric analysis including osteoblasts, osteoclasts numbers and bone area and immunohistochemical analysis including the expression of receptor activator of nuclear factor kappa Β (RANK), receptor activator of nuclear factor kappa Β ligand (RANKL) and osteoprotegerin (OPG) were measured and assessed. RESULTS: The relapse ratio was significantly reduced in the three-dose calcitonin group (28%) compared to the single dose calcitonin group (34%) and the control group (46%). This was accompanied by a nonsignificant increase in osteoblasts number and bone area in three-dose calcitonin group and a nonsignificant reduction in osteoclast number. However, the immune histochemical expression of RANK, RANKL and OPG did not show statistically significant difference at the end of relapse period. CONCLUSIONS: Systemic administration of three doses of calcitonin may minimize the relapse ratio in experimentally moved rat molars.

The influence of surface roughness and surface dynamics on the attachment of Methicillin-Resistant Staphylococcus aureus onto orthodontic retainer materials.

Staphylococci species have been isolated from removable orthodontic retainers. The aims of this study were to determine the most suitable device to analyze surface roughness of autopolymerized acrylic and thermoplastic materials and whether the surface dynamics of these materials influences the attachment of Methicillin-Resistant Staphylococcus aureus (MRSA). Clinically simulated samples of autopolymerized acrylic and thermoplastic material were first evaluated using laser non-contact, stylus mechanical profilometries and atomic force microscopy (AFM) followed by contact angle measurement to characterize their surface dynamics. Finally, an in vitro biofilm assay was carried out using a constant depth film fermentor to assess biofilm attachment. The results showed a significant difference between the roughness values obtained from the tested profilometers with the AFM exhibiting the most consistent roughness values. MRSA tended to accumulate initially within the microscopic irregularities of autopolymerized acrylic samples whereas acid-base and electron donor interactions influenced the bacterial attachment onto the thermoplastic samples.