Incidence of white spot lesions during orthodontic clear aligner therapy

Effect of attachment flash on clear aligner force delivery: an in vitro study

BACKGROUND

The introduction of auxiliaries such as composite attachment has improved the force delivery of clear aligner (CA) therapy. However, the placement of the attachment may give rise to a flash, defined as excess resin around the attachment which may affect CA force delivery. This in vitro study aims to determine the differences in the force generated by the attachment in the presence or absence of flash in CA.

MATERIALS AND METHODS

Tristar Trubalance aligner sheets were used to fabricate the CAs. Thirty-four resin models were 3D printed and 17 each, were bonded with ellipsoidal or rectangular attachments on maxillary right central incisors. Fuji Prescale pressure film was used to measure the force generated by the attachment of CA. The images of colour density produced on the films were processed using a calibrated pressure mapping system utilising image processing techniques and topographical force mapping to quantify the force. The force measurement process was repeated after the flash was removed from the attachment using tungsten-carbide bur on a slow-speed handpiece.

RESULTS

The intraclass correlation coefficient showed excellent reliability (ICC = 0.96, 95% CI = 0.92-0.98). The average mean force exerted by ellipsoidal attachments with flash was 8.05 ± 0.16 N, while 8.11 ± 0.18 N was without flash. As for rectangular attachments, the average mean force with flash was 8.48 ± 0.27 N, while 8.53 ± 0.13 N was without flash. Paired t-test revealed no statistically significant difference in the mean force exerted by CA in the presence or absence of flash for both ellipsoidal (p = 0.07) and rectangular attachments (p = 0.41). Rectangular attachments generated statistically significantly (p < 0.001) higher mean force than ellipsoidal attachments for flash and without flash.

CONCLUSION

Although rectangular attachment generated a significantly higher force than ellipsoidal attachment, the force generated by both attachments in the presence or absence of flash is similar (p > 0.05).

Bioceramic micro-fillers reinforce antibiofilm and remineralization properties of clear aligner attachment materials

Introduction: Clear aligners, while offering a more hygienic alternative to fixed appliances, are still associated with challenges including plaque accumulation and enamel demineralization. The aim of the present study was to investigate the antibiofilm and remineralization effectiveness of innovative flowable composite attachments containing bioceramic micro-fillers. Methods: Four experimental attachments were formulated and bonded to human enamel specimens: 3M Filtek Supreme flowable composite (Filtek SF) + 10% bioactive glass 45S5 (BAG), Filtek SF + 30% BAG, Filtek SF + 10% Bredigite (BRT), Filtek SF + 30% BRT. Plaque biofilms were grown on the bonded enamel using a standardized protocol and the biofilm-killing effect was assessed by confocal laser scanning microscopy and scanning electron microscopy. Vickers microhardness was measured to evaluate the remineralization effect of the attachments containing bioceramic fillers after acid challenge. Shear bond test was performed to assess the bonding strength. Results: Attachments with bioceramic fillers significantly inhibited plaque biofilm growth in 3 weeks on enamel, contributing over 20% bacterial cell killing in 10% filler groups and over 30% killing in 30% filler groups. All four experimental groups demonstrated significantly higher microhardness values than the control group without fillers on the attachment side. The shear bonding strength was not compromised in the attachments with micro-fillers. Discussion: Proper incorporation of bioceramic micro-fillers in attachments provides an innovative approach for clear aligner therapy with reinforced antibiofilm and remineralization effects without weakening shear bonding strength.

Evaluation of the effects of different composite materials and surface roughening techniques in bonding attachments of clear aligner on monolithic zirconia

OBJECTIVE

The aim of this study is to evaluate the bond strengths of two different composite types used in the production of clear aligner attachments on monolithic zirconia with three different surface roughening processes.

MATERIALS AND METHODS

Packable composite Filtek Z250 was used in one group (PC-G) and flowable composite Filtek Supreme Ultra Flowable was used in the other group (FC-G). PC-G and FC-G groups were also divided into three subgroups as diamond bur+silane (Group 1), 50 μm aluminium oxide (Al2 O3 ) sandblasting+silane (Group 2) and 110 μm Al2 O3 sandblasting+silane (Group 3). Scanning electron microscopy (SEM) analysis was performed. Clear aligner attachments were bonded to the monolithic zirconia specimens. Shear bond strength (SBS) values were measured. Statistical analysis was performed using two-way ANOVA and post-hoc Tukey's tests (P < .05).

RESULTS

The highest SBS value was found in PC-G sandblasted with 110 μm Al2 O3 (P ≤ .001). The etching method with 110 μm sandblasting showed high SBS values in both composite types. The lowest SBS value gave FC-G in diamond bur roughening (P ≤ .001).

CONCLUSIONS

For the bonding of clear aligner attachments on monolithic zirconia, roughening with 110 μm particle size sandblasting and the choice of packable composite could be recommended in terms of retention.

Impact of Clear Aligners on Oral Health and Oral Microbiome During Orthodontic Treatment

The demand for clear aligners has risen over the past decade because they satisfy patients' desire for less noticeable and more comfortable orthodontic appliances. Because clear aligners are increasingly used in orthodontics, there is a big push to learn more about the physiologic and microbial changes that occur during treatment. The present work highlighted further links between clear aligners and changes in oral health and the oral microbiome and provided plaque control methods for clear aligner trays. Existing literature revealed that clear aligners have no significant influence on the structure of the oral microbiome during orthodontic therapy. Clear aligner treatment demonstrated promising results in terms of controlling plaque index, gingival health, and the prevalence of white spot lesions. Nevertheless, grooves, ridges, microcracks, and abrasions on the aligner surface would provide a prime environment for bacterial adherence and the development of plaque biofilms. A combination of mechanical and chemical methods seems to be a successful approach for removing plaque biofilm from aligners whilst also preventing pigment adsorption.

White spot lesions, plaque accumulation and salivary caries-associated bacteria in clear aligners compared to fixed orthodontic treatment. A systematic review and meta- analysis

OBJECTIVE

To analyse the available evidence regarding the incidence and severity of white spot lesions (WSLs), plaque accumulation and salivary caries-associated bacteria(SCB) in clear aligners (CA) verses conventional fixed (CF) orthodontic appliances.

METHODS

Electronic searches of MEDLINE, Scopus, Embase, Google Scholar, Clinical trial registry, OpenGrey and ProQuest were done for all relevant studies. Eligibility criteria were; Randomized Controlled Trials and Non-Randomized Studies that compared the incidence and severity of WSLs, plaque accumulation and SCB between CA and CF appliances in patients undergoing orthodontic treatment. The risk of bias(ROB) and certainty of evidence was assessed independently by two reviewers using Cochrane's ROB and GRADEpro, respectively. Standardized mean difference (SMD) was used to estimate the effect size using STATA 17 software.

RESULTS

A total of 14 studies met the eligibility criteria, and eight were suitable for meta-analysis. The qualitative results showed lower incidence and severity of WSLs, plaque accumulation, and SCB in CA group compared to CF appliances. The pooled results showed significantly lower plaque accumulation(SMD - 1.58;95%CI:-2.57,0.58;p = 0.002) in CA compared to CF appliances.

CONCLUSIONS

A moderate-quality evidence reveals less plaque accumulation and less SCB in CA, which might be related to the reduced incidence and severity of WSLs associated with CA when compared with CF appliances. However, the results of the present study should be interpreted with caution given the high ROB among some of the included studies as well as the marked heterogeneity across the studies.

CLINICAL RELEVANCE

For patients who can be treated with either CA or CF appliances, CA may be a better choice concerning oral health.

REGISTRATION

Open Science Framework (DOI: https://doi.org/10.17605/osf.io/kcpvb ).

Integrated Multiplex Sensing Clear Aligner for In Situ Monitoring of Dental Enamel Demineralization

Clear aligners have become one of the most important tools in orthodontic treatment. However, over a lengthy period of orthodontic treatment, enamel demineralization or even dental caries could be susceptible for occurrence. Therefore, early diagnosis of enamel demineralization has been widely investigated. Nevertheless, for reasons including bulky monitoring equipment and complexity of operation, few techniques reported to date possessed clinical utility. The combination of flexible electronics and electrochemical sensing technology presented a promising strategy. Herein, an integrated multiplex sensing clear aligner (IMSCA) system, including a clear aligner with a multiplex sensor array patch, was developed for in situ monitoring of Ca²⁺, pH, and PO₄^3- in the oral environment to provide a foundation for early diagnosis of enamel demineralization. The IMSCA exhibited a broad linear response range, great selectivity, temporal stability, reproducibility, and biological safety. Results of enamel demineralization simulating experiments and human permanent tooth demineralization experiments validate the capability of the IMSCA to indicate the occurrence of enamel demineralization. All results ultimately point to the promising clinical utility of the IMSCA, which facilitates the quantitative characterization of enamel demineralization in complex oral environments. This study provides a novel strategy in the early diagnosis of enamel demineralization.

Clear Aligners in Patients with Amelogenesis and Dentinogenesis Imperfecta

Dentinogenesis imperfecta (DI) and amelogenesis imperfecta (AI) are hereditary abnormalities of dental hard tissues. Dental abnormalities may also be accompanied by symptoms of disorders such as osteogenesis imperfecta. AI and DI have a significant burden on socializing, function, and comfort; therefore, frequent screening and accurate diagnosis is the cornerstone of managing such conditions. Both AI and DI could be treated with many strategies, including restorative, prosthetic, periodontal, surgical, and orthodontics treatment. The interdisciplinary combination of orthodontic, prosthodontic, and periodontic treatment has been proven to improve the prognosis of AI and DI. Regarding orthodontic treatment, the most difficult element of orthodontic therapy may be maintaining a high level of motivation for what might be a prolonged form of treatment spanning several years. There are many forms of orthodontic management for AI and DI, including removable appliances, functional appliances, and fixed appliances. Clear aligner therapy (CAT) contains a broad range of equipment that works in different ways, has different construction processes, and is compatible with different malocclusion procedures. The application of CAT in patients with AI and DI is favorable over the fixed applicants. However, the available evidence regarding the application of CAT in AI is weak and heterogeneous. In this review, we discussed the current evidence regarding the application of clear CAT in patients with AI and DI.

Prevalence of white spot lesions during clear aligner therapy: a systematic review

Objectives: To determine if an association exists between the prevalence of white spot lesions (WSLs) and orthodontic treatment using clear aligners.

Methods: Electronic databases were searched with no restrictions on year. Article selection criteria included human clear aligner studies conducted during the permanent dentition and with a full description of the applied technique and oral hygiene status.

Results: The search strategy resulted in a total of 4177 articles. After title and abstract screening, 156 relevant articles were identified from which five remained after the application of the exclusion criteria. The articles were mostly classified as having a low risk of bias.

Conclusions: Clear aligner therapy induces a lower development rate of new WSLs than orthodontic treatment by fixed appliances. In patients who have poor oral hygiene and/or existing WSLs, clear aligner treatment could be recommended.

Orthodontic treatment with clear aligners and enamel remineralization in adolescents

Relevance. The effectiveness of the new remineralizing agent PRESIDENT®PROFI REM "MINERALS GEL" was assessed at different stages of clear aligner orthodontic treatment in adolescents with reduced enamel resistance.Materials and methods. PRESIDENT®PROFI REM "MINERALS GEL" was evaluated in a one-month open, single center, non-comparative study where 20 adolescents took part (mean age 14.9 ± 1.1 years).Results. OHI-S decreased by 24.75%, PMA and ERT reduced by 44.33% and 17.11% respectively, after one month of the orthodontic treatment with clear aligners and simultaneous use of the remineralizing gel. The pH in the mixed saliva increased from 6.97 ± 0.16 to 7.69 ± 0.11, calcium went up by 48.5%, and the total antioxidant activity decreased by 29.36% (according to the mixed saliva biochemical parameters). The OHIP-14 questionnaire revealed that the quality of life decreased in 75% of adolescent patients during the orthodontic treatment with aligners due to "communication problems". The quality of life was significantly higher during the aligner treatment with simultaneous remineralizing therapy than during the conventional treatment with fixed appliances (4.25 ± 0.86 points in the aligner group versus 7.05 ± 1.16 points – the brackets group).Conclusions. The remineralizing gel PRESIDENT®PROFI REM "MINERALS GEL" has an anti-plaque and mineralizing effect. The quality of life is significantly higher during the clear aligner treatment with simultaneous remineralizing therapy than during the conventional treatment with fixed appliances.

Risk Factors of Composite Attachment Loss in Orthodontic Patients during Orthodontic Clear Aligner Therapy: A Prospective Study

BACKGROUND

The composite attachment loss during orthodontic clear aligner therapy is an adverse event that commonly happens in our daily practice. However, there is a lack of related statistical analysis and studies analyzing the related risk factors. Therefore, the aim of this study is to assess the incidence of attachment loss during orthodontic clear aligner therapy and to identify rick factors that may predict such event.

MATERIALS AND METHODS

The demographics and clinical variables of 94 patients undergoing clear aligner therapy (27 males and 67 females; average age: 27.60 ± 0.86 years) were recorded. Both patient-related and tooth-related attachment loss was recorded. The chi-squared test and logistic regressive analysis were applied to identify the potential risk factors. SPSS for Mac (version 23.0, IBM, USA) was used for statistical analyses. P < 0.05 was considered statistically significant.

RESULTS

Our study suggested that the risk factors for attachment loss include frequent aligner removal (≥ 5 times a day) (losing rate = 60.0%, P = 0.005), aligner wear time less than 18 hours a day (losing rate = 50.8%, P = 0.014), eating without aligners inserted (losing rate = 47.9%, P = 0.034), utilizing aligner tray seaters (losing rate = 48.2%, P = 0.006), and unilateral mastication (losing rate = 52.1%, P = 0.002). The multivariable logistic regression analysis indicates that aligner wear time less than 18 hours a day (P = 0.020, B = 0.925), using aligner tray seaters (P = 0.007, B = 1.168), and unilateral mastication (P = 0.034, B = -0.458) were considered independent factors that can predict the composite attachment loss in orthodontic clear aligner therapy.

CONCLUSION

Wearing aligner less than 18 hours a day, using aligner tray seaters, and unilateral mastication may contribute to increased incidence of composite attachment loss during orthodontic clear aligner therapy.