Halitosis, oral health and quality of life during treatment with Invisalign(®) and the effect of a low-dose chlorhexidine solution

Side effects and short effects of using three common mouthwashes on oral health and quality of life: A quasi-experimental study

BACKGROUND

Antiseptic mouthwashes are useful adjuncts to daily brushing and flossing for the control of dental plaque and gingivitis. The objective of the present study was to compare the effect of three mouthwashes: chlorhexidine, essential oils and cetylpyridinium chloride on oral health-related quality of life, gingival health, tongue coating and also to compare their potential side effects after 2-week consumption.

METHODS

Sixty participants were enrolled in this study and were divided into four groups (three mouthwash groups plus no mouthwash group). At the beginning, scaling and cleaning were performed and the following parameters were recorded: oral health impact profile (OHIP-5) questionnaire, tongue coating index, modified gingival index, calculus surface index, modified Lobene stain index and a questionnaire for side effects. Each group has followed up in 2 weeks. Data were analysed using paired t-test, ANOVA, Fisher's exact test and Pearson chi-square.

RESULTS

At the end of second week, all three mouthwashes significantly improved OHIP-5 score and reduced modified gingival index whereas essential oils and cetylpyridinium chloride significantly reduced tongue coating index when compared to control group (p < 0.05). The differences between four groups were significant for calculus formation, dental staining and reported burning sensation and changes of taste sensation and perception (p < 0.05).

CONCLUSION

The use of all three mouthwashes has been effective in controlling and reducing gingivitis and tongue coating; however, it appeared that essential oils has the minimum and Chlorhexidine has the maximum side effects. Moreover, the use of all three mouthwashes has been examined to improve the quality of life. Overall, essential oils mouthwash has the best performance among these three mouthwashes.

In vitro evaluation of a novel fluoride-coated clear aligner with antibacterial and enamel remineralization abilities

OBJECTIVE

To investigate the antibacterial and enamel remineralization performances as well as physicochemical properties and biocompatibility of a fluoride-coated clear aligner plastic (FCAP).

MATERIALS AND METHODS

FCAP and normal clear aligner plastic (CAP) was bought from the manufacturer (Angelalign Technology Inc, China). The FCAP was observed under scanning electron microscopy. Its element composition, resistance to separation, contact angle, and protein adhesion performance were characterized. Colony-forming unit (CFU) count and 3-(4,5)-dimethylthiazol(-z-y1)-3,5-diphenyltetrazolium bromide (MTT) assay were used to evaluate the antibacterial ability of Streptococcus mutans. Fluoride release-recharge patterns were obtained. Apatite formation was evaluated after immersing FCAP in artificial saliva. Enamel remineralization capability was evaluated in the demineralization model (immersing samples in demineralization solution for 36 h) and pH cycling model (immersing samples in demineralization solution and remineralization solution in turns for 14 days). Cell Counting Kit-8 (CCK-8) and live/dead cell staining kits were used for cytotoxicity assay.

RESULTS

The FCAP showed uniformly distributed fluoride and did not compromise protein adhesion performance. CFU count (5.47 ± 0.55 for CAP, 3.63 ± 0.38 for FCAP) and MTT assay (0.41 ± 0.025 for CAP, 0.28 ± 0.038) indicated that the FCAP had stronger antibacterial activity compared with normal CAP (P < 0.05 for both evaluations). The FCAP could release fluoride continuously for 14 days and could be recharged after immersing in NaF solution. The FCAP could induce the formation of hydroxyapatite in artificial saliva and could reduce the microhardness decrease, color change, and mineral loss of enamels in both two models (P < 0.05 for all evaluations). CCK-8 and live/dead cell staining analyses showed that the coating did not compromise the biocompatibility of the clear aligner (P > 0.05 for CCK-8 evaluation).

CONCLUSIONS

The FCAP had antibacterial, fluoride recharge, and enamel remineralization abilities while it did not compromise physicochemical properties and biocompatibility.

CLINICAL RELEVANCE

The FCAP has the potential to prevent enamel demineralization during clear aligner treatment.

ORGANOLEPTIC AND HALITOMETRIC ASSESSMENTS DO NOT CORRELATE WELL IN INTRA-ORAL HALITOSIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

The gold standard method for diagnosing oral halitosis is the subjective organoleptic measurement. Device-supported methods are also widespread worldwide. The challenges and safety concerns around performing organoleptic measurements during pandemics and the diversity of measuring device alternatives raised our clinical question: which halitometer is the most suitable for diagnosing halitosis?

METHODS

This systematic review was registered in PROSPERO (ID CRD42022320024). The search was performed on March 23, 2022 in the following electronic databases: MEDLINE, Embase, Scopus, Web of Science, and CENTRAL. Adult populations with or without halitosis were included, and patients with systemic diseases were excluded. Organoleptic (subjective) measurement and the device-supported (objective) methods were compared; the primary outcome was the correlation coefficient, and the secondary was the specificity and sensitivity of the devices. QUADAS-2 and QUADAS-C were used to evaluate the risk of bias in the studies. Random-effects meta analyses were performed on the outcomes, and the secondary outcomes were plotted on a common ROC plot.

RESULTS

A total of 1231 records were found in the 5 databases. After the selection process, 76 articles were eligible for the systematic review, and 14,635 patients were involved in the qualitative analysis. The pooled Spearman's correlation coefficient (c.c.) for sulfide monitors was 0.65; 95% CIs: [0.53-0.74]; I2 = 95%, P < .01. The pooled Spearman's c.c. for portable gas chromatographs was 0.69; 95% CIs: [0.63-0.74]; I2 = 12%, P < .01. The pooled Spearman's c.c. for gas chromatographs was 0.76; 95% CIs: [0.67-0.83]; I2 = 0%, P < .01.

DISCUSSION

None of the most commonly used halitometers proved to be significantly superior to the others. Halimeter and OralChroma measurements did not correlate well with the organoleptic level of oral halitosis in adults. Therefore, better halitometers need to be developed as an alternative to organoleptic measurements.

Aligner therapy in adolescents: first-year results on the impact of therapy on oral health-related quality of life and oral hygiene

OBJECTIVES

The aim of this multicenter clinical study was to examine the oral health-related quality of life and oral hygiene in adolescents before and during aligner therapy.

MATERIALS AND METHODS

Forty subjects (18 ♀, 22 ♂; mean age: 13.6 years) scheduled for aligner therapy (Invisalign® Teen) were given oral health-related quality of life questionnaires, Oral Health Impact Profile (OHIP-G14) and Psychosocial Impact of Dental Aesthetic Questionnaire (PIDAQ), to complete within their treatment (visit 1: 0 start of therapy; visit 2: 0 + 4 weeks; visit 3: 0 + 10 weeks; visit 4: 0 + 6 months; visit 5: 0 + 1 year). To assess oral hygiene, a questionnaire to take home was used, and plaque level was evaluated with the Quigley-Hein Plaque Index (TMQH) modified by Turesky et al. RESULTS: The OHIP-G14 mean score before aligner therapy was 3.3 ± 3.2, and 4.9 ± 5.4 after 1 year. The PIDAQ showed a positive psychological change in the well-being, as well as a more effective at-home oral hygiene regime. On average, the TMQH remained at a low level (grade 2 of 0-5). The initial insertion of the aligners caused the most significant changes in all parameters (except TMQH).

CONCLUSION

Oral health-related quality of life is only slightly affected during the first year of aligner therapy in adolescents. Oral hygiene at home is intensified and there is no increased dental plaque accumulation.

CLINICAL RELEVANCE

Dentofacial esthetics is a subset of the so-called Oral H-Related Quality of Life (OHRQoL) which should be considered more during orthodontic therapy.

Cleaning and Disinfection Protocols for Clear Orthodontic Aligners: A Systematic Review

(1) Background: Clear orthodontic aligners support the development of oral biofilms, which could lead to interferences with the oral microbiota already existing and the deterioration of oral health, with the development of dental caries, periodontal disease and even systemic infections. Therefore, preventive oral health care requires a cleaning and disinfection procedure for aligners. (2) Methods: A systematic review of the literature was conducted across four databases following the PRISMA guidelines up to May 2021, combining an electronic and a manual search. Prospective studies, including randomized controlled trials (RCTs), crossover studies (COSs) and controlled clinical trials (CCTs), published in the English language without time restrictions, evaluating the efficacy of cleaning and disinfection protocols for clear orthodontic aligners by comparing them with a placebo or a negative control, were included. The article selection, data extraction and risk of bias assessment were performed by two independent blinded review authors. In case of disagreement, a third author was solicited throughout the selection process. (3) Results: Among the 221 articles screened in the search process, 4 studies were included in the review, all designed as crossover studies (single arm without randomization with the same sequence of different cleaning and disinfection protocols for each participant). Different cleaning and disinfection methods were studied such as mechanical methods (brushing with toothpaste or vibration), chemical methods/pharmaceutical products (chlorhexidine antibacterial substance, anionic or cationic detergents or effervescent tablets) or combinations of both. (4) Conclusion: Although the determination of the most remarkable method of cleaning and disinfection was impossible because no direct comparison was conducted between all these methods, a multi-step protocol, including the combination of a mechanical and a chemical method, seems to be the most effective approach. Further research is needed to define the most preventive oral health care protocol. Registration: PROSPERO CRD 42021278498.

Self-perceived halitosis among young adults undergoing orthodontic treatment

INTRODUCTION

Halitosis is a common oral health problem that significantly impacts the quality of life of the affected individuals. In most cases, poor oral hygiene is responsible for the problem. Orthodontic therapy aims to correct malocclusion using different devices. It has been suggested that orthodontic treatment can promote gingival health by facilitating daily oral hygiene measures. However, the treatment may harm gingival health as these appliances may lead to a more significant accumulation of plaque, increasing the microbial load in the subgingival environment leading to halitosis.

OBJECTIVE

The primary goal of this survey is to assess the prevalence of self-perceived halitosis in patients undergoing orthodontic treatment.

MATERIALS AND METHODS

An online questionnaire was randomly distributed to patients undergoing orthodontic treatment. A total of 289 subjects completed the questionnaire. It included questions about: demographic data, medical history, social habits, past dental treatment and oral hygiene habits. Descriptive statistics as frequency distributions and percentages were calculated for the study variables.

RESULTS

The prevalence of self-perceived halitosis was 41.5%. The majority of the participants started to notice this problem during and after orthodontic treatment (62.5%). A statistically significant correlation was found between the regular dental visits and halitosis in patients with fixed orthodontic appliances (p-value = 0.010). Also, those patients had a substantial increase in tongue coating formation (p- value = 0.010).

CONCLUSION

Self-perceived halitosis is a common problem in patients receiving orthodontic treatment.

Influence of Conventional or Invisalign Orthodontic Treatment on Mineral and Trace Element Salivary Levels: Longitudinal Study with Total Reflection X-ray Fluorescence

This work aimed to evaluate the salivary concentration of chemical elements in patients undergoing orthodontic treatment with fixed orthodontic appliances and removable aligners. Twelve Angle Class I and II orthodontic patients undergoing treatment with conventional fixed appliances and 15 patients treated with removable aligners provided unstimulated whole saliva samples before treatment (pre) and after 3 months of treatment (post). The concentration and secretion rate of chemical elements in saliva were determined by total reflection X-ray fluorescence. Differences from pre to post and between groups were determined with the paired T test or Wilcoxon test, and two-way ANOVA, considering P < 0.05. The concentrations of S, Cl, and K decreased, while Zn increased significantly (P < 0.05) between pre and post treatment with the fixed appliance treatment. The salivary secretion rate of S was decreased from pre to post in the fixed appliance group. No differences in the concentration and secretion rate of chemical elements were detected from pre to post in the Invisalign group. Fe secretion rate presented an interaction between time and treatment, with lower secretion at post (P = 0.02) in the Invisalign group. Increased Br secretion rate and decreased Rb, Fe, P, and K in Invisalign patients suggested a better salivary electrolyte profile regarding periodontal bone remodeling. No significant alterations in ions associated with metal corrosion and inflammatory reactions were detected in orthodontic patients under dental plaque control.

Oral Impacts Experienced by Orthodontic Patients Undergoing Fixed or Removable Appliances Therapy in Saudi Arabia: A Cross-Sectional Study

PURPOSE

The objective of this study is to compare the orthodontic patient's experiences with removable and fixed orthodontic appliances on daily activities, food consumption, and oral symptoms in Riyadh city, Saudi Arabia.

METHODS

This was a cross-sectional observational study carried out among orthodontic patients. A total of 150 adult patients, including 118 in the fixed orthodontic appliance group and 32 in the removable (Invisalign) orthodontic group, who met the inclusion criteria completed a validated and self-administered questionnaire. In addition, the study participants reported their experience in terms of daily routine, food consumption, and oral symptoms one week after appliance activation. Data were analyzed using the chi-square test and Fisher's exact tests for the categorical variables. In addition, Mann-Whitney U, Kruskal-Wallis, and Spearman's tests were also applied to the data.

RESULTS

The fixed orthodontic patients compared to the removable orthodontic cases showed significantly higher difficulty in sleeping (1.28±1.10 vs 0.94±0.88, p=0.024), sores on the tongue (0.97±1.00 vs 0.56±0.76, p=0.042) and cheeks (1.20±1.11 vs 0.72±0.81, p=0.027), and the presence of food debris under the appliance (1.53±1.16 vs.1.00±0.95, p=0.021). Moreover, the oral health impact score showed a significant positive correlation with the duration of the orthodontic treatment (r=0.339, p<0.001) and pain intensity (r=0.309, p<0.001).

CONCLUSION

The fixed orthodontic treatment compared to removable orthodontic treatment resulted in more severe pain, sleeping difficulty, sores on the tongue and cheeks, and food impaction after one week of appliance activation.

Relationship between oral health impacts and personality profiles among orthodontic patients treated with Invisalign clear aligners

This within subject clinical experiment assessed oral health impacts before and after Invisalign orthodontic treatment and their relationships with personality characteristics. 50 patients (26 females and 24 males; mean age = 27.62 ± 8.25 years, SE = 1.17, 95% CI = 24.71–29.89 years) were assessed before and after treatment with Invisalign orthodontic treatment. Treatment clinical success was evaluated according defined clinical guidelines. Oral health impacts before and after Invisalign orthodontic treatment were measured via the Oral Health Impact Profile (OHIP). Personality features were measured via the NEO Five-Factor Inventory (NEO-FFI). Probability of α = .05 was utilized to identify significant findings. Females scored less OHIP scores after treatment (had less negative impacts) in comparison to baseline OHIP scores (t = 3.782, df = 25, P = .001, 95% CI of mean difference = 2.750–9.327). Among males, openness scores (R² = .911, B = 5.235, 95% CI for B = 0.062–10.407, t = 2.601, P = .048) were able to predict OHIP scores before treatment; meanwhile, extraversion (R² = .959, B = − 8.224, 95% CI for B = − 14.605–1.843, t = − 3.313, P = .021), openness (R² = .959, B = 21.795, 95% CI for B = 10.737–32.853, t = 5.067, P = .004), and conscientiousness (R² = .959, B = 10.293, 95% CI for B = 4.796–15.790, t = 4.813, P = .005) scores were useful to predict OHIP scores after treatment (R² = .959, P < .05). NEO-FFI scores were not useful to predict OHIP scores before or after treatment among females (P > .05). These findings demonstrate that oral health impacts of Invisalign orthodontic treatment and personality profiles contribution to oral health impacts were different between genders.

Evaluation of effectiveness and stability of aligner treatments using the Peer Assessment Rating Index

AIMS

The aims of this study were to measure treatment effects of aligner treatments in adult patients directly after treatment and the stability of these effects after a short-term retention period using the Peer Assessment Rating (PAR) Index.

METHODS

This double-center trial consecutively screened 98 adult patients of whom 33 patients were treated according to predefined inclusion and exclusion criteria. The study sample was shown to be representative for adult orthodontic reality with regard to gender, age, and distribution of malocclusion type. Malocclusion severity was rated by using the PAR Index measured at baseline (T0), after finishing orthodontic treatment with Invisalign® (T1; Align Technology Inc., Santa Clara, CA, USA) and after a mean retention period of 10 months (T2). Furthermore, to better understand the observed treatment modality, specific treatment characteristics were recorded and analyzed.

RESULTS

The average PAR score at T0 was 22.18 (standard deviation [SD] ± 8.68). Posttreatment PAR score was 4.64 (SD ± 4.23) at T1 and was stable after a retention period of 10.07 months at T2 (SD ± 126.80 days; PAR 4.36, SD ± 3.93). All of the study cases showed a significant reduction of the total PAR score between T0 and T1 (p < 0.001), but no further difference between T1 and T2 (PAR 4.64 vs. 4.36). Cases were either classified 'improved' (n = 23) or 'greatly improved' (n = 10); no case was classified into the third PAR Index category 'worse or no different'. On average, 72 aligners (SD ± 22) with 12 attachments per treatment (SD ± 4) were used to align teeth. Six patients needed a case refinement with a mean of 23 (SD ± 8) further aligners. The maximum number of needed ClinCheck® (Align Technology Inc., Santa Clara, CA, USA) treatment plan revisions was 18 (mean 7, SD ± 4).

CONCLUSION

The detected improvement rate indicated a good standard of orthodontic treatment using aligners. Treatment effects were stable throughout a short-term retention period using a specific retention protocol. Effectiveness and stability were equally achieved in mild, moderate, and rather severe cases within this consecutive sample. A critical focus should be placed on accurate treatment planning in order to make tooth movements predictable, realistic, and stable.

Changes in mechanical properties, surface morphology, structure, and composition of Invisalign material in the oral environment

INTRODUCTION

The mechanical properties of Invisalign material have rarely been explored because of the inaccessibility of the patent-protected raw material. The purpose of this study was to systematically evaluate the Invisalign thermoformed aligner material before and after clinical application, including mechanical properties, surface morphology, internal structure, and chemical composition changes.

METHODS

Twenty sets of "as-received" (0-week) and retrieved (2-week; worn for 2 weeks, 20 ± 2 hours per day) Invisalign aligners were randomly collected from 4 different patients. Tensile tests, stress relaxation, and creep tests were carried out with a dynamic mechanical analyzer to characterize the changes in the mechanical properties of this material, Fourier transform infrared spectroscopy was used to capture the molecular changes on the surface of these aligners, scanning electron microscopy and transmission electron microscopy were used to observe the changes in surface morphology and internal structure, and scanning transmission electron microscopy-energy dispersive x-ray analysis was used to detect any changes in the chemical composition of this material before and after clinical application.

RESULTS

The elastic modulus of 0-week and 2-week samples were 842 ± 63 MPa and 806 ± 19 MPa, respectively, with no significant difference. In addition, the relative stress after stress relaxation of 2 hours was 19.89 ± 2.25% and 15.91 ± 6.04% for 0-week and 2-week groups, respectively, with no significant difference. Scanning electron microscopy observations showed voids and signs of delamination on the surface of the 2-week samples, and scanning transmission electron microscopy-energy dispersive x-ray analysis indicated the possible release of trace elements during clinical use, such as aluminum. Results of Fourier transform infrared spectroscopy analysis, and transmission electron microscopy observations were quite stable, indicating that the molecular structure on the surface and the internal structure of this material were relatively stable under the oral environment.

CONCLUSIONS

The surface morphology showed some defects after the clinical use of 2 weeks; however, there was no significant difference in mechanical properties. Trace elements may release out during clinical use and may pose a specific danger to allergic patients.

Comparison of Short-Term Oral Impacts Experienced by Patients Treated with Invisalign or Conventional Fixed Orthodontic Appliances

OBJECTIVES

Our objective was to test the hypothesis that thermoplastic clear aligners (Invisalign®; Align Technology, Santa Clara, CA, USA) are more pleasant for patients than conventional fixed orthodontic appliances.

SUBJECTS AND METHODS

This was an observational retrospective study in which subjects were matched for age, treatment modality, and the treating orthodontist. A total of 60 adult patients (30 in the Invisalign group and 30 in the conventional buccal fixed appliance group) who met the inclusion criteria completed a validated self-reporting questionnaire, rating their experience after appliance activation in regard to oral impact experience and satisfaction of both treatment modalities. Categorical variables were compared using the χ2 test, Fisher's exact test, and the Z test. Continuous variables such as pain level and age were analyzed using the 2-sample t test.

RESULTS

Patients on clear aligner therapy reported significantly more difficulty in speech (p = 0.035) necessitating change in speech delivery (p = 0.003). In addition, they reported better chewing ability (p < 0.001), no restrictions on amounts or types of food (p = 0.02), and less mucosal ulcerations (p = 0.01). Effects on daily routine, use of analgesics, and overall treatment satisfaction were not significantly different between the 2 groups.

CONCLUSION

Clear aligner therapy is not necessarily more pleasant, but it is more tolerable as it satisfies patient needs over food consumption and absence of mucosal ulcerations. However, clear aligners affect pronunciation and speech delivery in the short term.

Assessment of the effectiveness of invisible aligners compared with conventional appliance in aesthetic and functional orthodontic treatment: A systematic review

To seek scientific evidence to support the effectiveness of invisible aligners, in the aesthetic and functional aspects, compared with that of conventional braces. An electronic search was performed with a complementary grey literature search for in vivo research. No language restrictions were applied. Scopus, PubMed, Web of Science, Cochrane, ClinicalTrials and GreyLiterature databases were used. Studies were first selected by title and abstract; those potentially eligible were read in full. Non-randomized studies were assessed for risk of bias using the tools Methodological Index for Non-randomized Studies (MINORS) and Cochrane Collaboration Common Scheme for Bias as a function of the presence of randomization. The search found 559 studies, of which 55 were potentially eligible. A total of 4 articles were included in this systematic literature review: three non-randomized controlled studies and one randomized controlled study, three with low risk of bias (RoB) and one with moderate RoB. Three studies showed time of correction of dental crowding shorter or equal to that of the control group and only one study showed less time of correction using conventional braces. Invisible aligners were deficient with respect to anterior/posterior and vertical corrections compared with fixed orthodontic appliances. Invisible aligners are effective in promoting dental alignment, but present clinical limitations in relation to the conventional system.

Salivary levels of cariogenic bacterial species during orthodontic treatment with thermoplastic aligners or fixed appliances: a prospective cohort study

BACKGROUND

Fixed orthodontic appliances might be associated with intraoral adverse effects on enamel, due to plaque accumulation and their colonization by oral microbes. At the same time, the demand for esthetic alternatives to orthodontic treatment, like thermoplastic aligners, is growing. However, thermoplastic aligners may behave differently intraorally than fixed appliances in terms of bacterial colonization and biofilm formation. Therefore, the aim of this prospective cohort study was to assess the salivary prevalence of the cariogenic bacteria Streptococcus mutans, Lactobacillus acidophilus, and Streptococcus sanguinis among adolescents treated orthodontically with thermoplastic aligners or fixed appliances.

METHODS

Thirty adolescent patients (17 girls/13 boys; mean age 13.8 years old) were assigned to treatment with either (i) self-ligating fixed appliances with nickel-titanium archwires or (ii) aligners constructed from clear transparent polyethylenterephthalat-glycol copolyester (PET-G) thermoplastic sheets. Whole stimulated saliva was collected from each patient at three time points: at baseline (before bonding and initiation of orthodontic therapy or before insertion of the thermoplastic aligners), after 2 weeks, and after 1 month. A simplified plaque index, a simplified gingival index, and the decayed, missing, and filled teeth (DMFT) index were assessed from the clinical examination of the patients. Microbiological analysis of salivary bacteria was performed by quantitative polymerase chain reaction, followed by descriptive and inferential statistics at the 5% level.

RESULTS

Although patients treated with aligners had significantly lower plaque and gingivitis scores throughout treatment compared to patients treated with fixed appliances, no significant difference could be found between the S. mutans counts of the two groups at any time through treatment (P > 0.05). On the other hand, patients treated with aligners had significantly lower salivary S. sanguinis counts at all time points than patients treated with fixed appliances (P < 0.05). Finally, almost no L. acidophilus were identified in the collected saliva samples in either of the treated samples.

CONCLUSIONS

Within the limitations of this study, there were no differences in the salivary counts of S. mutans or L. acidophilus among adolescent patients treated for 1 month with thermoplastic aligners or self-ligating appliances. On the other hand, patients treated with aligners had lower salivary levels of S. sanguinis compared to those treated with self-ligating appliances.

Patient satisfaction and quality of life changes after Invisalign treatment

INTRODUCTION

Our objective was to assess patient satisfaction and changes in oral health-related quality of life immediately after orthodontic treatment using the Invisalign system (Align Technology, Santa Clara, Calif).

METHODS

Adult patients were recruited from private practices in Canada and surveyed using a combination of 2 validated questionnaires: Dental Impact of Daily Living and Patient Satisfaction Questionnaire. This 94-question assessment focused on various dimensions of satisfaction and changes in quality of life. Multivariate analysis of variance, regression analysis, and canonical correlation analysis were applied in the data analysis.

RESULTS

A total of 81 patients, 29.6% men and 70.4% women, exclusively treated with the Invisalign system participated. The most significant improvements were seen in the appearance and eating and chewing categories, with patients responding positively to more than 70% of the questions in those categories. Food packing between teeth, affecting 24% of the participants, and pain affecting 16% were the most common sources of dissatisfaction. However, these negative experiences were not strong enough to reduce the overall positive experience that patients reported. Appearance and dentofacial improvement were strongly correlated. Canonical correlation of the Patient Satisfaction Questionnaire factors showed that doctor-patient relationship had a significant correlation with situational aspects, dentofacial improvement, and the residual category. Phrases from the doctor-patient relationship category such as "the orthodontist treated me with respect" and "carefully explained what treatment would be like" were associated with higher patient satisfaction.

CONCLUSIONS

Although positive changes in appearance and eating categories were linked with patient satisfaction, doctor-patient relationship was the factor that correlated better with multiple aspects of patient satisfaction.

Reliability, Accuracy, and Use Frequency of Evaluation Methods for Amount of Tongue Coating

OBJECTIVE

To classify the evaluation methods for amount of tongue coating (TC) and investigate their reliability, accuracy, and frequency of use.

METHODS

Articles published from 1985 to 2015 were searched for evaluation methods for the amount of TC in PubMed and the Cochrane Library. Only clinical researches were included except protocol articles. The methods were classified according to their characteristics.

RESULTS

Finally, 113 articles were selected. The evaluation method for the amount of TC from the articles was classified into 4 types: intuitive, specificative, computerized, and weighing TC. The reliability in the intuitive and specificative methods (κ =0.33-0.92) showed varying levels among the studies. In general, the amount of TC calculated by the specificative method (Spearman's r=0.68-0.80) was more strongly related to the directly measured value than to the value estimated by the computerized method (Pearson's r=0.442). The number of articles published on this topic has increased consistently, and the specificative method was the most frequently used. Despite the higher reliability of the computerized method, it has not been widely used.

CONCLUSIONS

The high prevalence of the specificative method would continue in clinical practice because of its convenience and accuracy. However, to establish higher reliability, the limitation of the subjectivity of the assessors should be overcome through calibration training. In the computerized method, novel algorithms are needed to obtain a higher accuracy so that it can help the practitioners confidently estimate the amount of TC.

Comparative SEM analysis of nine F22 aligner cleaning strategies

Background

The orthodontics industry has paid great attention to the aesthetics of orthodontic appliances, seeking to make them as invisible as possible. There are several advantages to clear aligner systems, including aesthetics, comfort, chairside time reduction, and the fact that they can be removed for meals and oral hygiene procedures.

Methods

Five patients were each given a series of F22 aligners, each to be worn for 14 days and nights, with the exception of meal and brushing times. Patients were instructed to clean each aligner using a prescribed strategy, and sections of the used aligners were observed under SEM. One grey-scale SEM image was saved per aligner in JPEG format with an 8-bit colour depth, and a total of 45 measurements on the grey scale (“Value” variable) were made. This dataset was analysed statistically via repeated measures ANOVA to determine the effect of each of the nine cleaning strategies in each of the five patients.

Results

A statistically significant difference in the efficacy of the cleaning strategies was detected. Specifically, rinsing with water alone was significantly less efficacious, and a combination of cationic detergent solution and ultrasonication was significantly more efficacious than the other methods (p < 0.05).

Conclusions

Of the nine cleaning strategies examined, only that involving 5 min of ultrasonication at 42 k Hz combined with a 0.3% germicidal cationic detergent was observed to be statistically effective at removing the bacterial biofilm from the surface of F22 aligners.

Periodontal health in teenagers treated with removable aligners and fixed orthodontic appliances

OBJECTIVES

The purpose of this study was to explore the microbiological and periodontal changes occurring in adolescents during 12 months of orthodontic therapy with removable aligners and with fixed appliances.

MATERIAL AND METHODS

During the years 2012-2013, 50 teenagers aged 10-18 years with similar initial orthodontic conditions participated in this trial in a university clinic in northern Italy. After receiving professional oral hygiene and instructions on a standardized oral hygiene protocol, the adolescents were randomly assigned to either orthodontic treatment with traditional fixed brackets (n = 25) or to treatment with Invisalign® aligners (n = 25). Subgingival microbiological samples, probing depth (PD), plaque index (PI), and bleeding on probing (BOP) were obtained and documented from the mesiovestibular subgingival sulcus of the upper right first molar and left central incisor at the beginning of treatment and 3, 6, and 12 months later. Compliance with oral hygiene procedures, full mouth plaque score (FMPS), and full mouth bleeding score (FMBS) were assessed at the beginning of treatment and 12 months later. Two sample independent t-tests and the χ(2) test were used to study whether the indices of periodontal health differed in the teenagers due to the experimental conditions.

RESULTS

None of the patients was positive for the periodontal anaerobes analyzed. The PI, PD, BOP, FMPS, and FMBS scores were significantly lower and compliance with oral hygiene was significantly higher in the group treated with Invisalign® than in the group treated with fixed brackets.

CONCLUSION

Teenagers treated with removable appliances display better compliance with oral hygiene, less plaque, and fewer gingival inflammatory reactions than their peers with fixed appliances.

Changes in force associated with the amount of aligner activation and lingual bodily movement of the maxillary central incisor

Objective

The purposes of this study were to measure the orthodontic forces generated by thermoplastic aligners and investigate the possible influences of different activations for lingual bodily movements on orthodontic forces, and their attenuation.

Methods

Thermoplastic material of 1.0-mm in thickness was used to manufacture aligners for 0.2, 0.3, 0.4, 0.5, and 0.6 mm activations for lingual bodily movements of the maxillary central incisor. The orthodontic force in the lingual direction delivered by the thermoplastic aligners was measured using a micro-stress sensor system for the invisible orthodontic technique, and was monitored for 2 weeks.

Results

Orthodontic force increased with the amount of activation of the aligner in the initial measurements. The attenuation speed in the 0.6 mm group was faster than that of the other groups (p < 0.05). All aligners demonstrated rapid relaxation in the first 8 hours, which then decreased slowly and plateaued on day 4 or 5.

Conclusions

The amount of activation had a substantial influence on the orthodontic force imparted by the aligners. The results suggest that the activation of lingual bodily movement of the maxillary central incisor should not exceed 0.5 mm. The initial 4 or 5 days is important with respect to orthodontic treatment incorporating an aligner.

Finite element method analysis of the periodontal ligament in mandibular canine movement with transparent tooth correction treatment

Background

This study used the 3D finite element method to investigate canine’s displacements and stresses in the canine’s periodontal ligament (PDL) during canine’s translation, inclination, and rotation with transparent tooth correction treatment.

Methods

Finite element models were developed to simulate dynamic orthodontic treatments of the translation, inclination, and rotation of the left mandibular canine with transparent tooth correction system. Piecewise static simulations were performed to replicate the dynamic process of orthodontic treatments. The distribution and change trends of canine’s displacements and stresses in the canine’s PDL during the three types of tooth movements were obtained.

Results

Maximum displacements were observed at the crown and middle part in the translation case, at the crown in the inclination case, and at the crown and root part in the rotation case. The relative maximum von Mises and principal stresses were mainly found at the cervix of the PDL in the translation and inclination cases. In the translation case, tensile stress was mainly observed on the mesial and distal surfaces near the lingual side and compressive stress was located at the bottom of the labial surface. In the inclination case, tensile stress was mainly observed at the labial cervix and lingual apex and compressive stress was located at the lingual cervix and labial apex. In the rotation case, von Mises stress was mainly located at the cervix and inside the lingual surface, tensile stress was located on the distal surface, and compressive stress was detected on the mesial surface. The stress and displacement value rapidly decreased in the first few steps and then reached a plateau.

Conclusions

Canine’s movement type significantly influences the distribution of canine’s displacement and stresses in the canine’s PDL. Changes in canine’s displacement and stresses in the canine’s PDL were exponential in transparent tooth correction treatment.

INFLUENCE OF FRICTION IN TRANSPARENT TOOTH CORRECTION TREATMENT: FINITE ELEMENT METHOD

Objective: The objective was to evaluate the effect of frictional forces on the canine's translation and rotation in transparent tooth correction treatment. Materials and Methods: Based on computed tomography (CT) images of the teeth and their supporting tissues, solid models were used to build finite-element models. One canine was simulated translation and rotation in the buccolingual direction by aligners with different friction coefficients. Results: The change of the canine's rotation centers and periodontal ligament (PDL) stress with an increase of the friction coefficient in the two movement types were obtained. Conclusions: Friction coefficient has little effect on the canine's translation movement. While in rotation cases, the small friction coefficient seems to be helpful to gain the body movement type.