Periodontal health of anterior teeth with two types of fixed retainers

Periodontal indexes of two types of 3 x 3 retainers: 0.032-in SS V-loop versus 0.0215-in SS coaxial - a randomized crossover trial

OBJECTIVE

This randomized crossover trial evaluated periodontal indexes of two types of 3 x 3 retainers (a modified 0.032-in SS V-loop retainer and a conventional 0.0215-in SS coaxial wire retainer) after bonded for six months. Also, bonded failure rate, and a questionnaire about comfort, ease of cleaning and overall preference were recorded.

MATERIAL AND METHODS

15 patients were enrolled in this study who used both retainers for six months each, having a 15-day wash-out interval between each bonded retainer usage. The following periodontal index were recorded: Plaque Index (PI), Calculus Index (CI) and Gingival Index (GI). Patients answered a questionnaire to assess comfort, ease of cleaning and overall retainer-type preference. Rate of bonding failure was also evaluated.

RESULTS

V-Loop retainer showed higher PI (P<0.05) as compared to conventional 0.0215-in coaxial wire retainer. However, CI and GI presented no statistically significant differences between both types of retainers. The conventional 0.0215-in coaxial wire retainer was chosen as the most comfortable (p<0.05), although no statistically significant differences were found for all other questionnaire answers. Bonding failure events were more observed in the 3x3 V-Loop retainer (p<0.002), as compared to the conventional 0.0215-in coaxial retainer.

CONCLUSION

V-Loop retainer showed higher PI (p<0.05), higher bonding failure rate and less comfortable, as compared to conventional 0.0215-in coaxial wire.

Risk factors for gingival recessions after orthodontic treatment: a systematic review

BACKGROUND/OBJECTIVES

To systematically review the available evidence concerning the risk factors for gingival recessions (GR) after orthodontic treatment (OT).

DATA COLLECTION AND ANALYSIS

Data was obtained and collected by systematically searching 3 data bases: Pubmed, EMBASE, and Web of Science until 20 April 2023. Controlled trials, cohort, case-control or cross-sectional studies describing GR or clinical crown height (CCH) after OT were included. The risk of bias in the selected studies was evaluated with the methodological index for non-randomized studies.

RESULTS

Forty-eight articles were included, investigating the following six risk factors for GR: 1. OT (n = 21), 2. Type of orthodontic intervention (n = 32), 3. Patient's baseline occlusal and skeletal characteristics (n = 14), 4. Mucogingival characteristics (n = 10), 5. Oral hygiene (n = 9), and 6. Others (n = 12). Significantly higher prevalence, severity and extent of GR were found in orthodontic patients by 10/15, 4/10, and 2/2 articles respectively. 10/16 articles reported significantly more GR and increased CCH in patients where orthodontic incisor proclination was performed. The evidence surrounding maxillary expansion and orthodontic retention was too heterogeneous to allow for? definitive conclusions. Pre-treatment angle classification, ANB, overjet, overbite, arch width and mandibular divergence were found not to be associated with GR (9/14), while pre-treatment crossbite, symphysis height and width were (5/7 studies). A thin gingival biotype, presence of previous GR, baseline width of keratinized gingiva and facial gingival margin thickness were correlated with increased risk of GR after OT by nine articles, while pocket depth was not. Oral hygiene, sex, treatment duration, and oral piercings were found not to be linked with GR in orthodontic patients, while GR was reported to increase with age in orthodontic patients by 50 per cent of the articles investigating this factor. The mean risk of bias for comparative and not comparative studies was 14.17/24 and 9.12/16.

LIMITATIONS

The selected studies were quite heterogeneous regarding study settings, variables reported and included very limited sample sizes.

CONCLUSION

Although studies regarding the risk factors for GR are relatively abundant, they are very heterogeneous concerning design, studied factors, methodology and reporting, which often leads to contradictory results. Uniform reporting guidelines are urgently needed for future research.

PROSPERO REGISTRATION

CRD42020181661.

FUNDING

This research received no funding.

Orthodontist and periodontist's knowledge, attitudes and aspects of clinical practice, regarding fixed lower orthodontic retainers

OBJECTIVE

This study aimed to assess the knowledge, attitudes, and aspects of the clinical practice of orthodontists and periodontists, regarding lower fixed orthodontic retainers.

METHODS

The orthodontists (n=502) and periodontists (n=269) who participated in this cross-sectional observational study received, via e-mail, questions related to the type of lower fixed retainer, dental biofilm accumulation, oral hygiene, and potential periodontal changes. The data were subjected to chi-square and Fisher's exact tests, at 5% significance level.

RESULTS

Both orthodontists (72.3%) and periodontists (58.7%) reported that hygienic retainers accumulate more dental biofilm (p< 0.05), and 64.1% of orthodontists and 58.7% of periodontists considered that modified retainers may lead to periodontal changes (p< 0.05). There was no significant difference between the dental specialties, regarding the type of lower fixed retainer considered the easiest for the patient to perform hygiene (p> 0.05), whereas 48.6% of professionals chose the modified type.

CONCLUSION

The modified retainer accumulates a greater amount of dental biofilm and, in the perception of orthodontists and periodontists, it may cause periodontal changes.

Microbiological Changes during Orthodontic Aligner Therapy: A Prospective Clinical Trial

The purpose of this study is to assess the variations induced by Clear Aligner Treatment (CAT) on the periodontal status and microbiological composition of oral microbiota. A total of 20 orthodontic patients were submitted to professional oral hygiene and, subsequently, underwent CAT (Group one, trials). A total of 20 non orthodontic patients (Group two, controls) remained untreated after oral hygiene. At T0 (baseline) and T1 (after 2 months), the participants were clinically examined for Probing Pocket Depth (PPD), Bleeding on Probing (BOP) and Plaque Index (PI), and microbiological tests were performed to detect bacteria of the red and orange complexes as well as the presence of Aggregatibacter actinomycetemcomitans. No significant inter- or intra-group differences were shown neither for PPD, PI and BOP (p > 0.05), nor for bacteria expressed in copies/microlitre or in percentages (p > 0.05). The only significant difference was assessed from T0 (baseline) to T1 (2 months) in both groups and is related to the total bacteria count increase. However, this parameter encompasses all the bacteria of the common oral microbiota, thus, not representing a significant result from a clinical point of view. Despite the limitations of this study, CAT does not significantly affect periodontal and microbiological parameters with respect to untreated patients for the first two months of therapy.

Side effects of twistflex retainers-3D evaluation of tooth movement after retainer debonding

PURPOSE

Evaluation of tooth movement after retainer debonding in retainer-associated misalignment cases.

METHODS

This pilot study is based on a retrospective data analysis. Adult patients (age 25.5 ± 4.9 years) wearing fixed twistflex retainers and having visible retainer-associated misalignment were included and examined for tooth movement after retainer debonding. Orthodontic study models were taken at retainer debonding (t0) and 14 (±1) weeks later (t1). They were digitally superimposed using 2D/3D dental imaging software and tooth movement was analyzed in all three dimensions.

RESULTS

A total of 23 teeth (12 upper teeth: 10 incisors, 2 canines; 11 lower teeth: 7 incisors, 4 canines) were analyzed. Mean overall tipping was 1.11 ± 0.82° in the mesial/distal direction (angulation, x‑axis), 2.02 ± 1.9° in the buccal/lingual direction (inclination, y‑axis) and 1.28 ± 0.99° around the tooth axis (z-axis). Mean overall bodily movement was 0.30 ± 0.31 mm in the mesial/distal direction (angulation, x‑axis), 0.10 ± 0.13 mm in the buccal/lingual direction (inclination, y‑axis), and mean in- or extrusion 0.22 ± 0.24 mm (z-axis). Mean tipping and bodily movement were more pronounced in the upper jaw.

CONCLUSION

The present data shows that tooth movement after debonding of twistflex retainers can be expected in misalignment cases.

The effects of fixed orthodontic retainers on periodontal health: A systematic review

INTRODUCTION

The objective of this systematic review was to assess the available evidence in the literature for the effects of fixed orthodontic retainers on periodontal health.

METHODS

The following databases were searched up to August 31, 2019: Medline, EMBASE, the Cochrane Oral Health Group's Trials Register, CENTRAL, ClinicalTrials.gov, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. Randomized controlled trials (RCTs), controlled clinical trials, cohort studies of prospective and retrospective design, and cross-sectional studies reporting on periodontal measurements of patients who received fixed retention after orthodontic treatment were eligible for inclusion. The quality of the included RCTs was assessed per the revised Cochrane risk of bias tool for randomized trials (RoB 2.0), whereas the risk of bias of the included cohort studies was assessed using the Risk Of Bias In Nonrandomized Studies of Interventions tool. A modified version of the Newcastle-Ottawa scale was used for cross-sectional studies.

RESULTS

Eleven RCTs, 4 prospective cohort studies, 1 retrospective cohort study, and 13 cross-sectional studies fulfilled the inclusion criteria. The quality of evidence was low for most of the included studies. In contrast to the general consensus, 2 RCTs, 1 prospective cohort study, and 2 cross-sectional studies reported poorer periodontal conditions in the presence of a fixed retainer. The results of the included studies comparing different types of fixed retainers were heterogeneous.

CONCLUSIONS

According to the currently available literature, orthodontic fixed retainers seem to be a retention strategy rather compatible with periodontal health, or at least not related to severe detrimental effects on the periodontium.

Lower fixed retainers: bonded on all teeth or only on canines? A systematic review

OBJECTIVE

To evaluate the stability after orthodontic treatment between two types of lower fixed retainers: those bonded onto all anterior teeth or those bonded only onto the canines.

MATERIALS AND METHODS

The following electronic databases were consulted: PubMed, Scopus, Web of Science, Cochrane Library, Lilacs, OpenGrey, ClinicalTrials, and Google Scholar. No restriction of language or year were applied. After selection of studies, risk-of-bias evaluation and qualitative synthesis of the included studies were performed using The Cochrane Collaboration's tool for randomized studies and the "Risk of Bias in Non-randomized Studies of Interventions" (ROBINS-I) tool for nonrandomized studies, and a summary of the overall strength of evidence was presented using the "Grading of recommendations, assessment, development and evaluation" tool.

RESULTS

Among the 180 studies retrieved from the searches, five were included in this review. Three of them showed a low risk of bias, while two presented a high risk of bias. With regard to stability, two studies reported better stability for retainers bonded to all six teeth, while the other three showed no difference. The retainer bonded to all teeth presented a higher breakage rate in one study.

CONCLUSIONS

Stability seems better with lower fixed retainers bonded on all anterior teeth. The breakage rate may not change according to the bonding. However, studies with greater methodological soundness are necessary to reach a more reliable conclusion.

Fixed Orthodontic Retainers: A Review

Orthodontic retention is defined as maintaining teeth in optimal aesthetic and functional position after treatment. Despite the necessity of retention phase and the factors influencing the stability of the teeth after orthodontic treatment was discussed by the orthodontist for a long time, it is accepted that a retention phase is essential for stability of orthodontic treatment results nowadays. Therefore, the application of a suitable retention method is important both for prevention of relapse after orthodontic treatment and for increasing patient satisfaction. Removable appliances had been used for many years for retention purposes. Later, fixed retainers were introduced to prevent relapse as having a number of advantages, such as better aesthetics, no need for patient cooperation, effectiveness, and suitability for lifelong retention. However, their need for precise bonding technique, fragility, and tendency to cause periodontal problems by weakening oral hygiene are some of their disadvantages.

Papilla reconstruction: Interdisciplinary consideration for clinical success

One of the most difficult achievements in the periodontal therapy is the reconstruction of interdental papilla that has been lost by periodontal disease. The poor esthetic appearance caused by the "black triangle," especially in the maxillary anterior region has been a concern for both patients and professionals. However, when the papilla destruction is followed by loss of contact point, the use of different specialties is usually necessary to restore the interproximal embrasure. This clinical case report describes an interdisciplinary (periodontic-orthodontic-restorative) approach for the treatment of a patient with severe case of papilla destruction in an esthetic zone. The patient's esthetic expectations for the anterior maxilla were met through phase I treatment, including the surgical reconstruction of the papillary complex and the orthodontic movement to restore the contact point. However, after the initial treatment was successfully concluded, the long-term stability of the result was compromised as the intercommunication among the specialists was not coordinated. CLINICAL SIGNIFICANCE: The treatment plan that involves interdisciplinary teamwork should be followed by an understanding about the principles of the specialties as well the intercommunication among specialists.

Effects of vacuum-formed retainers on periodontal status and their retention efficiency

INTRODUCTION

The stability of treatment results is a major concern in orthodontics. Numerous retention regimens to maintain stability have been introduced. The objectives of this study were to evaluate the effects of vacuum-formed retainers (VFRs) on periodontal tissues and the retention efficiency of VFRs.

METHODS

Forty patients were included in this study. Clinical effectiveness of VFRs for nighttime use only over a 12-month period was assessed by using the American Board of Orthodontics' Objective Grading System. Periodontal measurements and indexes were recorded and evaluated immediately after removal of the braces and after 1, 6, and 12 months of VFR use.

RESULTS

There was no significant change in the total Objective Grading System score between the end of the active treatment period and the end of the 12-month retention period. However, regarding periodontal measurements, the plaque and gingival indexes decreased, whereas the bleeding on probing, probing depth, calculus index, and clinical attachment loss increased between the evaluated periods.

CONCLUSIONS

In terms of periodontal health, the use of VFRs resulted in a slight periodontal attachment loss that seemed to be clinically insignificant, without gingival inflammation or recession. In terms of stability, VFRs were found to be effective in orthodontic retention.

Gingival condition associated with two types of orthodontic fixed retainers: a meta-analysis

Background

The maintenance of gingival health around orthodontic fixed retainers (FRs) is difficult and different designs have been proposed.

Objective

The goal of this systematic review was to analyse whether FR designs that allow unobstructed interproximal flossing, compared with the ones that do not, improve gingival parameters.

Search methods

Detailed individual database search strategies for Cochrane Library, 'Latin' American and 'Caribbean' Health Sciences Literature, PubMed, Scopus, and Web of Science were developed. Grey literature was also considered.

Selection criteria

Clinical trials and cross-sectional studies that compared two types of FRs (plain and waved) were included and evaluated.

Data collection and analysis

Study selection, data extraction, and risk of bias (RoB) assessment were performed individually and in duplicate. The methodology quality was assessed using the MAStARI RoB tool.

Results

Four studies met the inclusion criteria, and all presented moderate RoB. While two of those studies found a statistically significant difference in gingival parameters, the other two did not report differences. A meta-analysis was conducted based on two of the selected studies, which performed evaluations of plaque index (PI) and calculus index (CI). The results revealed no differences on PI between wave FR and plain FR of 0.46 (0.24 to 0.69) and no differences on CI of 0.12 (-0.10 to 0.33). Regarding comfort, no clear differences were identified.

Conclusions

There is not enough scientific evidence to support or not an association between FR design and gingival health, flossing frequency, or patient comfort.

Registration

PROSPERO - CRD42016030059.

Long-term influence of fixed lingual retainers on the development of gingival recession: A retrospective, longitudinal cohort study

OBJECTIVE

To investigate the long-term influence of fixed lingual retainers on the development of mandibular gingival recession and to compare the prevalence with untreated individuals.

MATERIALS AND METHODS

The material consisted of 144 subjects: 96 orthodontically treated patients followed for 5 years after therapy and 48 untreated age-matched subjects. The treated patients were divided in two groups: one receiving a fixed mandibular retainer (n = 48) and one receiving no form of retention in the mandible (n = 48). The presence or absence of gingival recession and calculus accumulation were scored before treatment (T0), after debonding (T1), and 5 years after debonding (T5) for each tooth in the mandibular intercanine region using plaster models and intraoral photographs. The chi-square test, one-way ANOVA, and Cochran's Q test were used to evaluate inter- and intragroup differences.

RESULTS

The prevalence of patients with recession increased gradually and significantly throughout the observation periods in all groups, but the intergroup differences at T5 were not significant. Significantly more calculus accumulation was observed at T5 in the retainer group compared with the group without retainers.

CONCLUSIONS

Long-term presence of fixed lingual retainers does not seem to increase the development of mandibular gingival recession, but does increase calculus accumulation.

Effects of different orthodontic retention protocols on the periodontal health of mandibular incisors

OBJECTIVES

To test the following two hypotheses: 1) different types of retainers result in distinct levels of biomarkers in gingival crevicular fluid (GCF) and 2) the retainer bonded to all mandibular anterior teeth induces more detrimental outcomes to the periodontium.

SETTING AND SAMPLE POPULATION

The Department of Orthodontics at the University of Florida. The population consisted of individuals in the retention phase of orthodontic treatment.

MATERIAL AND METHODS

This was a cross-sectional study that enrolled 36 individuals. Subjects in group 1 had retainers bonded to the mandibular canines only. Group 2 consisted of individuals having retainers bonded to all mandibular anterior teeth. Group 3 included patients using mandibular removable retainers. After clinical examination, GCF was collected from the mandibular incisor and biomarker levels were compared between the groups.

RESULTS

Plaque accumulation and gingivitis differed significantly among groups, with the highest median values in group 2 subjects. Pairwise comparison of the groups with respect to gingivitis showed significant differences between groups 1 and 2. Significant differences among groups were detected for RANKL, OPG, OPN, M-CSF, MMP-3, and MMP-9. The ratio RANKL/OPG was significantly higher in group 2 subjects, with pairwise comparisons indicating that groups 1 and 2 differed from group 3.

CONCLUSION

An association was found between orthodontic retention groups and GCF biomarker levels, which should be further explored in longitudinal studies. The presence of retainers bonded to all anterior teeth seems to increase plaque accumulation and gingivitis.

CAD based design sensitivity analysis and shape optimization of scaffolds for bio-root regeneration in swine

Tooth root supports dental crown and bears occlusal force. While proper root shape and size render the force being evenly delivered and dispersed into jawbone. Yet it remains unclear what shape and size of a biological tooth root (bio-root), which is mostly determined by the scaffold geometric design, is suitable for stress distributing and mastication performing. Therefore, this study hypothesized scaffold fabricated in proper shape and size is better for regeneration of tooth root with approving biomechanical functional features. In this study, we optimized shape and size of scaffolds for bio-root regeneration using computer aided design (CAD) modeling and finite element analysis (FEA). Statical structural analysis showed the total deformation (TD) and equivalent von-mises stress (EQV) of the restored tooth model mainly concentrated on the scaffold and the post, in accordance with the condition in a natural post restored tooth. Design sensitivity analysis showed increasing the height and upper diameter of the scaffold can tremendously reduce the TD and EQV of the model, while increasing the bottom diameter of scaffold can, to some extent, reduce the EQV in post. However, increase on post height had little influence on the whole model, only slightly increased the native EQV stress in post. Through response surface based optimization, we successfully screened out the optimal shape of the scaffold used in tissue engineering of tooth root. The optimal scaffold adopted a slightly tapered shape with the upper diameter of 4.9 mm, bottom diameter of 3.4 mm; the length of the optimized scaffold shape was 9.4 mm. While the analysis also suggested a height of about 9 mm for a metal post with a diameter of 1.4 mm suitable for crown restoration in bio-root regeneration. In order to validate the physiological function of the shape optimized scaffold in vivo, we transplanted the shape optimized treated dentin matrix (TDM) scaffold, seeding with dental stem cells, into alveolar bone of swine and further installed porcelain crown. Results showed that tooth root has not only been successfully regenerated histologically but also performed masticatory function and maintained stable for three months after crown restoration. Our results suggested that TDM scaffold with 9.4 mm in length and 4.9 mm/3.4 mm in upper/bottom diameter is a suitable biological scaffold for tooth root regeneration. These results also provided a recommendable design protocol for fabricating other scaffolds in tooth root reconstruction.