International Orthodontics最新文献

Introduction

Material and methods

Results

Discussion

Conclusion

Introduction

Aim

Treatment protocol

Results and conclusions

Background

The removal of adhesive remnants after bracket debonding has been shown to cause damaging effects on the enamel surface. This study aimed to investigate the efficacy of stained adhesive remnant removal (ARR) on enamel roughness compared to translucent composite.

Material and methods

Thirty extracted premolar teeth were divided equally into three groups; conventional composite control group (CC), stained composite group (SC) and stained bonding solution group (SB). The buccal surface of each tooth was cleaned, dried and the surface roughness (Ra) was evaluated using a contact prophylometer (T0). After bracket debonding, a high-speed carbide bur under a water-cooling system was used for ARR in one direction and the time consumed for ARR was recorded. After ARR, the second mean Ra values were recorded (T1). The samples were then polished using polishing paste with low-speed rubber cup and the third mean Ra values were recorded (T2).

Results

Repeated one-way ANOVA revealed a significant difference in the mean Ra values at T0, T1 and T2 within each group P ˂ 0.05. A statistically significant difference in the changes of the mean Ra values after ARR (T1–T0) and after polishing (T1–T2) was found between the CC group and both SC and SB groups. A significant difference in the time consumed for ARR was found between the three groups with CC group being the most time-consuming group.

Conclusion

Stained composite material followed by the stained bonding solution provided better visibility during ARR with lower mean Ra values and less time for ARR compared totranslucent composite material.

Premature loss of first permanent molars is a common occurrence in clinical practice, leading to abnormal occlusion and inefficient mastication for patients. This case report presented the orthodontic retreatment of a 32-year-old female patient who suffered from premature loss of mandibular bilateral first molars. The mesial tipping of the mandibular second molars led to an occlusal interference, resulting in a clockwise rotation of the lower jaw and an anterior open bite (AOB). We achieved long-distance molar mesialization using clear aligners with Albert cantilever arms. After 42 months of treatment, the patient's occlusion and facial profile significantly improved. The cantilever combined with the cleat aligner treatment has been clinically effective for the protraction of mandibular posterior teeth, extending the field of application of clear aligners.

Introduction

Obstructive sleep apnoea (OSA) is a long-term disorder characterized by frequent blockages in the upper respiratory tract during sleep, often leading to abrupt awakenings, with or without a decrease in oxygen levels. The systematic review and meta-analysis aimed to assess the effect of continuous positive airway pressure therapy (CPAP) on blood interleukin (IL) levels of IL-6, IL-10, IL-18, IL-1β, IL-4, and IL-17 in OSA adults.

Materials and methods

The published databases from PubMed, Scopus, Web of Science, and Cochrane Library were searched from 2003 to 2024, without any restrictions. The Review Manager software 5.3 was employed to compute effect sizes, which were presented as the standardized mean difference (SMD) along with a 95% confidence interval (CI).

Results

In total, 320 records were identified through database searching; ultimately, 42 articles were included in the qualitative synthesis and then the meta-analysis. The CPAP therapy significantly reduces IL-6 levels, as indicated SMD = 0.64 [95% CI: 0.35, 0.93] and P < 0.0001. CPAP therapy significantly reduced IL-18 and IL-1β levels in adults with OSA, but there is no significant difference in IL-10, IL-4, or IL-17 levels. Age, blood sample, body mass index, ethnicity, and treatment duration for IL-6 and apnoea-hypopnea index with IL-10 levels were effective factors in the pooled results. Experimentally, there was an interaction between IL-18 and IL-1β.

Conclusions

CPAP therapy has a positive impact on inflammatory markers in OSA adults; remarkably, it reduces IL-6 and IL-1β levels. Nevertheless, more evidence (such as the role of ethnicity) and understanding of interactions are needed.

Purposes

The aim of this study was to examine the effects of post material type and the presence of ferrules on the torque and intrusion load of the upper central tooth using finite element analysis.

Methods

The upper central tooth and surrounding tissues (cortical bone, cancellous bone, and periodontal ligament) were modelled in three dimensions using the Spaceclaim software. Five simulated models (SM) different modifications were made to this main model: metal cast post (SM1) and glass fiber post-core with zirconium crown and without a ferrule (SM2), metal cast (SM3) post and glass fiber post with a ferrule and zirconium crown (SM4) and only zirconium crown (SM5). In all five simulations, in order to simulate lingual root torque movement, a total load of 40 grams was applied to the bracket slot as 20 grams of force couples and in order to simulate intrusion movement, a load of 40 grams was applied to the superior wall of the bracket slot. The stress caused by the applied loads on the root surfaces was determined using finite element analysis. Maximum principal stress (MPS) value was used in the comparison.

Results

The highest root surface MPS values for both intrusion and torque loads belonged to SM2 (3.864 and 0.379 MPa, respectively). The presence of ferrules in both intrusion and torque loads reduced the stress by approximately half (from 3.864 to 2.004 MPa). In all five models, the radicular area with higher stress was located in the cervical third on the lingual surface when both torque and intrusion loads were applied.

Conclusion

The amount and localization of stress was affected by the type of post material. The variation in stress values between the materials remains within a safe range (0.099 and 3.87 MPa), making both materials suitable for use under orthodontic forces.

Introduction

Treatment of impacted upper incisors in a labially inverted position is challenging for orthodontists, and its prognosis has not been established in the literature. Thus, this systematic review aimed to determine the effectiveness and side effects of orthodontic traction of impacted maxillary incisors in a labially inverted position.

Methods

A comprehensive search was conducted in multiple databases, including MEDLINE (via PubMed), Scopus, Embase, Science Direct, and LILACS, up to June 30, 2024. Initially, 1640 articles were identified, and after applying specific selection criteria, 11 articles were selected for full-text evaluation. Following the review, only six studies were deemed relevant, comprising one before-and-after study, two longitudinal retrospective studies, and three cross-sectional studies. Newcastle-Ottawa and Risk of Bias (ROB-2) tools were used to assess the risk of bias in the selected studies.

Results

The average duration of traction for maxillary labially inverted impacted central incisors ranged from 8.60 ± 1.26 months to 18 ± 6.0 months, with all cases being successfully treated. Following traction, the clinical crown height of the incisors was significantly higher compared to the control group (P < 0.01). Similarly, the root length of the impacted incisors after traction was shorter in the impaction group (approximately 2 mm) compared to the control group. Likewise, the thickness of the alveolar bone varied among different studies. Some authors noted that the treatment group had a smaller thickness (about 0.5 mm) compared to the control group (P < 0.05), while other authors found similar thickness after treatment.

Conclusions

Although there are few reported studies with a low risk of bias, it is clear that it is possible to successfully treat labially inverted impacted maxillary central incisors with apparently few side effects. Following traction, the clinical crown height of these incisors increased, while the root length was shorter than their normally erupted contralateral teeth.

Objectives

The purpose of this study was to evaluate the accuracy and cost-effectiveness of the dental models 3D printed in vertical and horizontal orientation as compared to the conventional plaster and digital models.

Methods

This study involved scanning 50 plaster models using Maestro 3D Desktop Scanner (AGE Solutions, Pisa, Italy). The STL file obtained from the scanner was processed and three-dimensionally (3D) printed in the horizontal and vertical orientation using a PolyJet 3D printer (Objet 30 prime, Stratasys Ltd., Eden Prairie, Minnesota, United States). The accuracy of the rapid-prototyped (3D printed) models was measured from the pre-determined landmarks and was compared among the groups. In addition, determining the cost-effectiveness of the 3D printed models in different orientations was based on the amount of material (resin) utilized during the 3D printing process. ANOVA was used to determine the accuracy of the models.

Results

There were statistically insignificant differences (P > 0.05) among rapid-prototyped models (≤ 0.06 mm) compared to plaster models and digital models for the linear measurements made in all three planes of space. The dental models printed in the horizontal orientation were found to be more cost-effective than those printed in a vertical orientation in terms of the amount of material (resin) utilized and printing time during the 3D printing process.

Conclusions

The accuracy of rapid-prototyped models 3D printed in the horizontal and vertical orientations was comparable to the plaster models and digital models for clinical applications. Horizontally printed models were more cost-effective than vertically printed models.

Background and purpose

The aim of this study was to evaluate the physico-mechanical, anti-bacterial, and anti-demineralization properties of orthodontic resin composite containing photoactivated zinc oxide nanoparticles (ZnONPs) on Streptococcus mutans biofilm around ceramic and metal brackets.

Material and methods

Following the minimum inhibitory concentration (MIC) determination for ZnONPs, shear bond strength (SBS) was tested for composites containing different concentrations of ZnONPs. The chosen concentration was used to evaluate the microleakage, anti-bacterial, and anti-demineralization properties.

Results

Adding 50 μg/mL of ZnONPs to the orthodontic composite did not negatively affect its physico-mechanical properties. ZnONPs (50 μg/mL)-mediated aPDT and 0.2% chlorhexidine significantly (P = 0.000) reduced S. mutans biofilms compared to the phosphate-buffered saline (PBS) groups (metal/PBS = 7.47 ± 0.7 × 10⁶, and ceramic/PBS = 7.47 ± 0.7 × 10⁶), with the lowest colony count observed in these groups (metal/chlorhexidine = 1.06 ± 0.4 × 10⁵, ceramic/chlorhexidine = 1 ± 0.2 × 10⁵, metal/ZnONPs-mediated aPDT = 1.33 ± 0.3 × 10⁵, and ceramic/ZnONPs-mediated aPDT = 1.2 ± 0.3 × 10⁵). Sodium fluoride varnish and ZnONPs-mediated aPDT showed the highest efficacy in anti-demineralization and significantly improving the enamel surface microhardness compared to the artificial saliva, especially in ceramic bracket groups (524.17 ± 42.78 N and 441.00 ± 29.48 N, 394.17 ± 46.83 N, P = 0.000, and P = 0.003, respectively).

Conclusion

ZnONPs (50 μg/mL)-mediated aPDT effectively inhibited S. mutans biofilm and promoted anti-demineralization without adverse effects on the physico-mechanical properties of the composite resin. These results suggest the potential of this method in preventing white spot lesions during orthodontic treatment.

Introduction

Wire syndrome (WS) refers to dental displacements that can be described as aberrant, inaccurate, unexplained, or excessive, on teeth still contained by an intact bonded retainer, without detachment or fracture, leading to evolving dental and periodontal, aesthetic and/or functional consequences. The objective of this study was to define the prevalence rate of mandibular WS and the associated risk factors.

Methods

Participants were dental students who had undergone orthodontic treatment and were wearing an intact fixed mandibular retainer. They completed a 20-item questionnaire, after which an extraoral and intraoral clinical examination was conducted. Participants were assigned to either the non-wire syndrome group or the wire syndrome group by two independent practitioners. Univariate and multivariate logistic regression models were used to investigate potential risk factors.

Results

A total of 59 students (23.4 years ± 1.7 years) were included. Among these, 9 students presented with mandibular WS, resulting in a prevalence rate of 15.25% (95% CI: 6.08%–24.43%). Univariate analysis revealed a significant association between a deep labio-mental fold, a concave profile, and a multi-strand round wire, and an excess risk of WS. The odds ratios were 16.5 (95% CI: 1.9–146.8, P = 0.01), 6.4 (95% CI: 1.0–41.0, P = 0.05), and 9.0 (95% CI: 1.7–48.7, P = 0.01), respectively. Multivariate analysis confirmed these significant associations, except for the concave profile.

Conclusions

The prevalence rate of wire syndrome was 15.25%. Two risk factors associated with WS were identified: a deep labio-mental fold and a multi-strand round wire retainer.