Comparative evaluation of salivary microbial levels and periodontal status of patients wearing fixed and removable orthodontic retainers

Poly-Ether-Ether-Ketone versus dead-soft coaxial bonded retainers: a randomized clinical trial. Part 2: periodontal health and microbial biofilm assessment

BACKGROUND

Retainers have the potential to detrimentally impact periodontal health and contribute to tooth decay.

OBJECTIVES

To investigate periodontal health and bacterial biofilm related to Poly-Ether-Ether-Ketone (PEEK) fixed retainers as compared to Dead-soft coaxial fixed retainer (DSC).

TRIAL DESIGN

A two-arm parallel groups single-centre randomized clinical trial.

METHODS

The trial included patients whose orthodontic treatment was completed and required retainers. Participants were randomly assigned into two retainer groups: PEEK retainers, prepared by computer-aided design and manufacturing into 0.8 mm wire form, and DSC retainers. The objectives included assessing periodontal health through plaque accumulation index (PI), bleeding on probing (BOP), periodontal pocket depth (PPD), gingival index (GI), calculus index (CI), and alveolar bone height (ABH) assessment. Biofilm assessment involved bacteriological screening of aerobic, facultative anaerobic, mutans streptococci, and lactobacilli. The periodontal indices and microbiological screening as well as were assessed at the debonding stage (T0), 1-month (T1), 3-month (T3), and 6-month (T6) after the commencement of the trial, except for the ABH, which was recorded using periapical radiograph at T0 and T6.

BLINDING

Single blinding of participants in addition to the bacteriological specialist.

RESULTS

Initially, the trial enrolled 46 participants, aged between 12 and 28 years, and were randomly assigned to two groups, with 23 participants in each group. Subsequently, one participant withdrew from the trial, resulting in a total of 45 participants whose data were analysed. Assessment of the periodontal indices, excluding the CI (P = .480), revealed statistically but not clinically significant differences between groups after 6-month of retention (P = .016 of PI, P = .020 of BOP, P = .05 of PPD, and P = .01 of GI). There was slight plaque accumulation, normal PPD (approximately 1 mm), healthy to mild gingivitis with a GI of less than 1 and BOP was around 10%. Concerning the ABH, there was a noticeable reduction in its score after 6 months, particularly in the PEEK group, although the difference was not statistically significant (P = .102). Furthermore, the bacteriological viable count did not show any significant difference between the groups during the recall visits.

HARMS

There have been no reported negative consequences.

LIMITATIONS

Blinding the assessor of periodontal indices was not feasible due to the nature of the intervention. The trial follow-up duration was limited.

CONCLUSIONS

Both the PEEK and DSC retainers have comparable impacts on periodontal health and bacterial accumulation and composition during the retention period.

TRIAL REGISTRATION

NCT05557136.

The Influence of Orthodontic Treatment on Periodontal Health between Challenge and Synergy: A Narrative Review

By correctly repositioning teeth, orthodontic therapy improves both the function and appearance of an occlusion. The relationship between teeth and the tissues that surround and support them significantly influences these alterations. With ever more adults seeking orthodontic care, orthodontists are increasingly seeing patients with periodontal issues. Concerns about the patient's appearance, such as uneven gingival margins or functional issues caused by inflammatory periodontal diseases, should be accounted for when designing orthodontic treatment plans. Furthermore, orthodontics may increase the chances of saving and recovering a degraded dentition in cases of severe periodontitis. Today, general dentists, dontists, and orthodontists play integrative roles that enable them to achieve the best possible results for their patients. This review will improve the results of interdisciplinary treatments and increase cooperation between dental specialists by drawing attention to the essential connection between orthodontics and periodontics in regular clinical practice.

Comparison of efficacy of thermoplastic retainer with round and rectangular bonded lingual wire retainer in the mandible two years after orthodontic treatment: a randomised controlled trial

OBJECTIVE

To analyse three protocols in maintaining the stability of orthodontic therapy results and their effect on gingival health.

MATERIALS AND METHODS

Sixty-six subjects (pre-therapeutic age 11-18 years; 68% female) randomly allocated into three retention groups of equal size were analysed. The first group had a 0.673 × 0.268 mm (0.027 × 0.011 inches) rectangular braided steel retention wire bonded to the lingual surfaces of all mandibular teeth from canine to canine, and the second group had a 0.406 mm (0.016 inches) round twisted steel wire. The third group was the control, without wires, and only with vacuum-formed retainers. All three groups had vacuum-formed removable retainers in the maxilla. The frequency of wire detachment/breakage/loss of retainer, the occurrence of crowding of mandibular incisors, and changes in intercanine width and gingival health were monitored.

RESULTS

Incidence and severity of relapse differed between groups (p = 0.001 and 0.049) being most common in the removable retainer group (incidence 68.2%; severity 0.7 ± 1.0 mm), followed by the round wire group (36.4%; 0.5 ± 1.2 mm) and rectangular wire group (13.6%; 0.1 ± 0.1 mm). The intercanine width decreased more without a bonded retainer (incidence 68.2%; severity 0.5 ± 0.7 mm) and with the round wire more (45.5%; 0.5 ± 0.7 mm) than with the rectangular (27.3%; 0.1 ± 0.3 mm). The difference was significant for incidence (p = 0.025), but not severity. Detaching of the wires/breakage/loss of retainer was similar. There were no significant differences in the accumulation of biofilm, calculus and gingivitis between appliances.

CONCLUSION

A rectangular wire is the most effective in retention, and the impact of retention appliances on gingival health is similar.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05121220. Registered 02 October 2021 - Retrospectively registered.

CLINICAL RELEVANCE

Studying guidelines for reducing relapse, proper use of materials and appliances, the behavior of retention wires according to their profile in the retention phase, and possibilities of maintaining oral health will contribute to improving the stability of orthodontic therapy results.

Results of microbiological study of dental biofilm in generalized periodontitis against the background of different body reactivity

OBJECTIVE

Aim: To study the spectrum, frequency of isolation and level of colonization of dental biofilm with microorganisms in generalized periodontitis against the background of different body reactivity.

PATIENTS AND METHODS

Materials and Methods: 216 people with the diagnosis of generalized periodontitis. Depending on the state of reactivity of the organism, the patients were divided into 3 groups: with normo-, hyper- and with hyporeaction. The patients underwent patch surgery. After the surgery, dental biofilm was taken. Microbiological studies included the isolation and species identification of dental biofilm microorganisms, the results of quantitative studies of microflora: the level of colonization was expressed in colony-forming units per 1 ml (CFU/ml); the frequency of microorganisms isolation was expressed in absolute numbers. Statistical processing of the obtained digital data was performed using the computer program Statistica 8.0.

RESULTS

Results: The studies have shown that in different states of the body's reactivityi n patients with generalized periodontitis after flap surgery, different quantitative and qualitative composition of the microflora of the dental biofilm is determined. In case of normal body reactivity, there are predominantly aerobic-anaerobic associations with a wide range and quantitative predominance of aerobic microflora; in case of impaired (hyper- and hypo-) reactivity, there are predominantly aerobic-anaerobic associations with an expansion of the spectrum, frequency of isolation and level of colonization of facultative and obligate anaerobes.

CONCLUSION

Conclusions: The identified differences in the quantitative and qualitative composition of the microflora of the dental biofilm indicate the key role of the body's reactivity in the studied processes.

Retention procedures for stabilising tooth position after treatment with orthodontic braces

BACKGROUND

Without a phase of retention after successful orthodontic treatment, teeth tend to 'relapse', that is, to return to their initial position. Retention is achieved by fitting fixed or removable retainers to provide stability to the teeth while avoiding damage to teeth and gums. Removable retainers can be worn full- or part-time. Retainers vary in shape, material, and the way they are made. Adjunctive procedures are sometimes used to try to improve retention, for example, reshaping teeth where they contact ('interproximal reduction'), or cutting fibres around teeth ('percision'). This review is an update of one originally published in 2004 and last updated in 2016.

OBJECTIVES

To evaluate the effects of different retainers and retention strategies used to stabilise tooth position after orthodontic braces.

SEARCH METHODS

An information specialist searched Cochrane Oral Health Trials Register, CENTRAL, MEDLINE, Embase and OpenGrey up to 27 April 2022 and used additional search methods to identify published, unpublished and ongoing studies.  SELECTION CRITERIA: Randomised controlled trials (RCTs) involving children and adults who had retainers fitted or adjunctive procedures undertaken to prevent relapse following orthodontic treatment with braces. We excluded studies with aligners.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened eligible studies, assessed risk of bias and extracted data. Outcomes were stability or relapse of tooth position, retainer failure (i.e. broken, detached, worn out, ill-fitting or lost), adverse effects on teeth and gums (i.e. plaque, gingival and bleeding indices), and participant satisfaction. We calculated mean differences (MD) for continuous data, risk ratios (RR) or risk differences (RD) for dichotomous data, and hazard ratios (HR) for survival data, all with 95% confidence intervals (CI). We conducted meta-analyses when similar studies reported outcomes at the same time point; otherwise results were reported as mean ranges. We prioritised reporting of Little's Irregularity Index (crookedness of anterior teeth) to measure relapse, judging the minimum important difference to be 1 mm.

MAIN RESULTS

We included 47 studies, with 4377 participants. The studies evaluated: removable versus fixed retainers (8 studies); different types of fixed retainers (22 studies) or bonding materials (3 studies); and different types of removable retainers (16 studies). Four studies evaluated more than one comparison. We judged 28 studies to have high risk of bias, 11 to have low risk, and eight studies as unclear.  We focused on 12-month follow-up.  The evidence is low or very low certainty. Most comparisons and outcomes were evaluated in only one study at high risk of bias, and most studies measured outcomes after less than a year. Removable versus fixed retainers Removable (part-time) versus fixed   One study reported that participants wearing clear plastic retainers part-time in the lower arch had more relapse than participants with multistrand fixed retainers, but the amount was not clinically significant (Little's Irregularity Index (LII) MD 0.92 mm, 95% CI 0.23 to 1.61; 56 participants). Removable retainers were more likely to cause discomfort (RR 12.22; 95% CI 1.69 to 88.52; 57 participants), but were associated with less retainer failure (RR 0.44, 95% CI 0.20 to 0.98; 57 participants) and better periodontal health (Gingival Index (GI) MD -0.34, 95% CI -0.66 to -0.02; 59 participants). Removable (full-time) versus fixed   One study reported that removable clear plastic retainers worn full-time in the lower arch did not provide any clinically significant benefit for tooth stability over fixed retainers (LII MD 0.60 mm, 95% CI 0.17 to 1.03; 84 participants). Participants with clear plastic retainers had better periodontal health (gingival bleeding RR 0.53, 95% CI 0.31 to 0.88; 84 participants), but higher risk of retainer failure (RR 3.42, 95% CI 1.38 to 8.47; 77 participants). The study found no difference between retainers for caries.  Different types of fixed retainers Computer-aided design/computer-aided manufacturing (CAD/CAM) nitinol versus conventional/analogue multistrand One study reported that CAD/CAM nitinol fixed retainers were better for tooth stability, but the difference was not clinically significant (LII MD -0.46 mm, 95% CI -0.72 to -0.21; 66 participants). There was no evidence of a difference between retainers for periodontal health (GI MD 0.00, 95% CI -0.16 to 0.16; 2 studies, 107 participants), or retainer survival (RR 1.29, 95% CI 0.67 to 2.49; 1 study, 41 participants). Fibre-reinforced composite versus conventional multistrand/spiral wire  One study reported that fibre-reinforced composite fixed retainers provided better stability than multistrand retainers, but this was not of a clinically significant amount (LII MD -0.70 mm, 95% CI -1.17 to -0.23; 52 participants). The fibre-reinforced retainers had better patient satisfaction with aesthetics (MD 1.49 cm on a visual analogue scale, 95% CI 0.76 to 2.22; 1 study, 32 participants), and similar retainer survival rates (RR 1.01, 95% CI 0.84 to 1.21; 7 studies; 1337 participants) at 12 months. However, failures occurred earlier (MD -1.48 months, 95% CI -1.88 to -1.08; 2 studies, 103 participants; 24-month follow-up) and more gingival inflammation at six months, though bleeding on probing (BoP) was similar (GI MD 0.59, 95% CI 0.13 to 1.05; BoP MD 0.33, 95% CI -0.13 to 0.79; 1 study, 40 participants). Different types of removable retainers Clear plastic versus Hawley When worn in the lower arch for six months full-time and six months part-time, clear plastic provided similar stability to Hawley retainers (LII MD 0.01 mm, 95% CI -0.65 to 0.67; 1 study, 30 participants). Hawley retainers had lower risk of failure (RR 0.60, 95% CI 0.43 to 0.83; 1 study, 111 participants), but were less comfortable at six months (VAS MD -1.86 cm, 95% CI -2.19 to -1.53; 1 study, 86 participants). Part-time versus full-time wear of Hawley There was no evidence of a difference in stability between part-time and full-time use of Hawley retainers (MD 0.20 mm, 95% CI -0.28 to 0.68; 1 study, 52 participants).

AUTHORS' CONCLUSIONS

The evidence is low to very low certainty, so we cannot draw firm conclusions about any one approach to retention over another. More high-quality studies are needed that measure tooth stability over at least two years, and measure how long retainers last, patient satisfaction and negative side effects from wearing retainers, such as tooth decay and gum disease.

Effect of splinting material type and location on resistance against deflection force of splinted periodontally compromised teeth with hypermobility

This study aimed to evaluate the effect of splinting material type and material location on the force resistance of splinted periodontally compromised teeth with hypermobility. Extracted teeth including the target tooth (maxillary second premolar) and its adjacent teeth were placed into the alveolar sockets of a dental arch model via artificial periodontal ligaments made of elastic impression material. Three different experimental models with varied target tooth mobility including Periotest® values (PTVs) of 20, 30, and 40 were fabricated (named models #20, #30, and #40, respectively). For each experimental model, the force resistance of tooth splinting was tested using the following four materials: everStick PERIO (glass fiber reinforcement: GFR), FORESTAFLEX (braided stainless steel: BSS), Ortho-FlexTech (stainless steel chain: SSC), and Super-Bond (MMA-based resin cement: MRC). The evaluated measures were the PTV after tooth splinting and the required load to cause tooth displacements of 0.05 mm and 0.10 mm in the vertical and lateral directions, respectively. The splinting material type and material location as well as the original PTV of target the tooth significantly affected all the evaluated measures (p < 0.001). MRC revealed the significantly highest force resistance of tooth splinting regardless of material location in each experimental model and was followed by GFR. The PTVs of splinted teeth were comparable to those of adjacent anchor teeth in models #20 and #30 when using GFR, while that was comparable in model #40 when using MRC. Meanwhile, the load causing certain tooth displacement showed a similar tendency to previous-reported data with healthy teeth in model #20 when using GFR, while that showed a similar tendency in models #30 and #40 when using MRC. Overall results concluded that splinting material type and location play a role in the resistance against the deflection force of splinted periodontally compromised hypermobile tooth. It was noted that MRC provided the highest resistance against the deflection force of splinted teeth regardless of material location whereas GFR maintained the physiologically considered tooth mobility.

Direct 3D-Printed Orthodontic Retainers. A Systematic Review

Three-dimensional (3D) printing technology has shed light on many fields in medicine and dentistry, including orthodontics. Direct 3D-printed prosthetics, implants or surgical devices are well-documented. The fabrication of orthodontic retainers using CAD technology and additive manufacturing is an emerging trend but the available data are scarce. The research approach of the present review included keywords in Medline, Scopus, Cochrane Library and Google Scholar up to December 2022. The searching process concluded with five studies eligible for our project. Three of them investigated directly 3D-printed clear retainers in vitro. The other two studies investigated directly 3D-printed fixed retainers. Among them, one study was in vitro and the second was a prospective clinical trial. Directly 3D-printed retainers can be evolved over time as a good alternative to all the conventional materials for retention. Devices that are 3D-printed are more time and cost efficient, offer more comfortable procedures for both practitioners and patients and the materials used in additive manufacturing can solve aesthetic problems, periodontal issues or problems with the interference of these materials with magnetic resonance imaging (MRI). More well-designed prospective clinical trials are necessary for more evaluable results.

Microbial adherence on vacuum-formed retainers with different surface roughness as constructed from conventional stone models and 3D printed models: a randomized controlled clinical trial

OBJECTIVE

This single center parallel, randomized controlled trial aimed to determine the propensity of microbial adherence on vacuum-formed retainers (VFRs) with different surface roughness imprints.

MATERIALS AND METHODS

Thirty-six patients debonded from fixed appliances at a teaching institution were allocated by block randomization stratified for gender to three groups [VFRs fabricated on conventional, fused deposition modeling (FDM) or stereolithography apparatus (SLA) working models]. Participants wore the VFRs for three months full-time followed by three months part-time. VFRs were collected after each follow-up for Streptococcus and yeast counts. Surface roughness was measured indirectly on the working models using a 3D optical surface texture analyzer. Blinding was not feasible due to appliance appearance. The trial was registered [NCT03844425 ( ClinicalTrials.gov )] and funded by the Universiti Malaya Dental Postgraduate Research Grant (DPRG/14/19).

RESULTS

Thirty participants (eleven conventional, ten FDM, and nine SLA) were analyzed after six dropped out. No harms were reported. Microbial counts between the groups were not significantly different. There were more microbes in the lower VFRs than upper VFRs (total count: p<0.05; effect size, 0.5 during full-time wear and 0.4 during part-time wear). SLA had significantly (p<0.05) smoother surface than FDM (effect size, 0.3) and conventional models (effect size, 0.5). Microbial adherence was not associated with working model surface roughness.

CONCLUSION

Microbial adherence on VFRs was not influenced by degree of surface roughness imprints from working models.

CLINICAL RELEVANCE

3D printed models can be used to make VFRs. Lower VFRs tended to accumulate oral microbes, potentially increasing the oral health risk in the lower arch.

Enamel Evaluation after Debonding of Fixed Retention and Polishing Treatment with Three Different Methods

Lack of standardization of the retention phase has led to many studies of stability of movements and characteristic of retainers, disregarding the enamel repercussions of fixed retention on this phase. This study aimed to analyze different methods of enamel polishing after detachment of orthodontic retainers. Forty-five healthy premolars were divided into three groups according to the polishing bur after debonding, and four specimens without intervention were used as control. A 0.038 × 0.015 inches gold chain was bonded between the premolars and then removed. The adhesive remnant was removed with three types of burs according to the study groups (Group 1: white stone at high speed; Group 2: high-speed handpiece with a 30-blade tungsten carbide bur; Group 3: low-speed handpiece and a 30-blade tungsten bur). After debonding and polishing, all samples were analyzed with a confocal microscopy on surface roughness parameters: Sa: Arithmetic mean of the height of the surface. Rq: Square mean of the height of the surface and Sz: Maximum surface height. Mechanical tests were carried out to determine the bonding stress of the retention adhered to the teeth using an electromechanical testing machine. The adhesion stress was 8.23 MPa (±0.87). The quality of the refinement of the enamel after debonding is essential in order to preserve its integrity. The use of the 30-blade tungsten carbide bur provides a smooth enamel surface after polishing.

Orthodontic Retainers-A Critical Review

The achievement of aesthetic, functional occlusion should not mark the end of the orthodontic intervention. To prevent relapse, retention needs advance planning, and may vary in duration. This review aims to present and comment on the available means of retention. The ever-popular, passive Hawley-like removable appliances are credible in maintaining the desired occlusion. Modifications are the removable appliance Wrap Around, having the labial archwire extending to the premolars; the translucent retainer, Astics, a unique aesthetic Hawley-type device; and the reinforced removable retainer, which features a metallic grid reinforcing the acrylic base. Vacuum-formed retainers are easy to fabricate and are readily prescribed. By contrast, fixed retainers are made of orthodontic wire and composite resin bonded on the lingual or palatal surfaces of the anterior teeth. Patient-related variables need evaluation to select the appropriate retainer, while patients ought to realize the importance of retention and comply with offered guidance. Overall, the orthodontist is responsible for keeping the patient informed on the properties and the duration of retention, even before starting active orthodontic treatment.

Orthodontic Retainers-A Critical Review

The achievement of aesthetic, functional occlusion should not mark the end of the orthodontic intervention. To prevent relapse, retention needs advance planning, and may vary in duration. This review aims to present and comment on the available means of retention. The ever-popular, passive Hawley-like removable appliances are credible in maintaining the desired occlusion. Modifications are the removable appliance Wrap Around, having the labial archwire extending to the premolars; the translucent retainer, Astics, a unique aesthetic Hawley-type device; and the reinforced removable retainer, which features a metallic grid reinforcing the acrylic base. Vacuum-formed retainers are easy to fabricate and are readily prescribed. By contrast, fixed retainers are made of orthodontic wire and composite resin bonded on the lingual or palatal surfaces of the anterior teeth. Patient-related variables need evaluation to select the appropriate retainer, while patients ought to realize the importance of retention and comply with offered guidance. Overall, the orthodontist is responsible for keeping the patient informed on the properties and the duration of retention, even before starting active orthodontic treatment.

Oral Microbiome in Orthodontic Acrylic Retainer

The oral microbiome can be shifted if the patients wear the acrylic retainers for a lengthy period. It is essential to understand the components of the plaque in order to forestall the development of dental caries and gingivitis. The aim of this study is to report the bacterial communities that adhere to the acrylic retainers by full-length nanopore 16S sequencing. Six healthy participants were allocated into 2 groups (chemical tablet and brushing groups). Plaque samples were collected from the acrylic retainer surfaces before and after cleaning. The bacterial communities were reported using full-length nanopore 16S sequencing. The results showed that 7 distinct phyla were identified by sequencing. The most prevalent of these was the Firmicutes. We found a total of 72 genera. The most common microorganism across all samples was Streptococcus, followed by Neisseria, Rothia, and Gemella. The beta diversity showed a significant difference between before and after cleaning (p < 0.05). This study revealed the novel finding that a combination of chemical and mechanical cleaning methods was the most effective method of eliminating retainer biofilms. Moreover, retainer cleaning tablets did not alter the homeostatic balance of the bacterial communities adhering to the acrylic retainers.

Metal versus Fiberglass Post-Orthodontic Retainers Short-Term Effects on Plaque Index and Microbial Colonization: An Observational Study

In orthodontics, post-treatment retention phase is crucial for maintaining the obtained clinical results. In cases of crowding, a bonded fixed retainer is often chosen to maintain teeth alignment in the anterior sector of the lower dental arch. A fixed retainer can remain in the mouth for years. Therefore, it is important that it is applied with harmless materials for the level of plaque control. The present study aimed to investigate the salivary concentrations of Streptococcus mutans (S. mutans) and Lactobacilli, and the Sillness and Loe plaque index, in patients wearing metal wire versus fiberglass orthodontic retainers. Forty post-orthodontic patients were included in the sample: in 20 subjects a metal wire retainer was applied (MR), while in the others a fiberglass retainer was applied (FR). The variables were recorded at baseline (T0), after 1 month (T1), and after 2 months (T2) of follow-up. The percentage of patients with a level of S. mutans and Lactobacilli colonization > 105 increased over time in the FR group (T0 = 0%, T1 = 5%, T2 = 35%), compared with the MR group. PI increased in the FR group (T0 = 0, T1 = 14, T2 = 27), and remained almost the same in the MR group (T0 = 3, T1 = 0, T2 = 2). From the present results it appears that the metal wire retainer is better than the fiberglass retainer for the level of plaque control performed by the patients.

Screening of biochemical parameters in the orthodontic treatment with the fixed appliances: A follow-up study

The aim of this study was to assess the changes in vital salivary parameters such as calcium, phosphorous, alkaline phosphatase, buffering capacity, pH, flow-rate and Oral Hygiene Index (OHI) in fixed orthodontic treatment patients during the retention period. In this study, saliva samples were collected from 35 patients before de-bonding (T₀) and after 4 to 5 weeks of de-bonding or on retention period (T₁). The biochemical parameters such as calcium, phosphorous and alkaline phosphatase levels were measured with saliva samples. Additionally, flow-rate, buffering capacity, pH and OHI levels was also measured. The current study results showed reduction in calcium, alkaline phosphatase, pH, flow-rate and OHI levels during T₁ (p < 0.05). However, phosphorous and buffering capacity levels were increased at T₁. The phosphorous levels showed non statistically significant difference when compared between T₀ and T₁ (p = 0.42). The remaining salivary parameters showed statistically significant difference when compared between T₀ and T₁ (p < 0.05). The present study concludes that there was a statistically significant decrease in the calcium, alkaline phosphatase, pH, flow rate and OHI values a month after de-bonding and increased in the buffering capacity values.

Real time polymerase chain reaction analysis in the patients treated with fixed appliances after the orthodontic treatment: A follow-up study

This study aimed to compare the changes in the salivary cariogenic bacteria levels using qPCR and oral hygiene status after orthodontic treatment with fixed appliances during the retention phase concerning the patient and treatment variables. In this study, saliva samples were collected from 35 patients before debonding (T₀) and after five weeks of debonding on retention (T₁). The saliva samples were collected to extract the genomic DNA, and using specific probes and primers using real-time polymerase chain reaction was performed to analyze the changes in S. mutants, S. sobrinus, L. Casei after orthodontic treatment with fixed appliances. Additionally, OHI levels were also measured. The current study confirms the statistical association between T0 and T1 groups of S. mutants (p = 0.028) and S. sobrinus (p = 0.049). However, a lack of association was observed with L. Casei (p > 0.05). The number of bacteria was decreased from the T₀ group and increased in the T₁ group in Streptococcus mutants (S. mutants) and Streptococcus Sobrinus (S. sobrinus) while in Lactobacillus Casei (L. Casei) it was vice versa between T₀ and T₁ groups. The Oral Hygiene Levels (OHI) levels were also found to be statistically associated (p = 0.003). This study concludes that comparing the salivary cariogenic bacterial levels at T₀ (before debonding of fixed orthodontic appliances), with T1 (Five weeks after the debonding), and despite better oral hygiene, there was increase in salivary S mutants and S sobrinus levels. The current study suggested that orthodontic patients need careful hygienic procedures during the retention period. Future studies are recommended with additional follow-up and a large sample size.

Assessment of the effect of vacuum-formed retainers and Hawley retainers on periodontal health: A systematic review and meta-analysis

Background

Recently, increasing attention has been paid to the periodontal health of orthodontic patients in the maintenance stage in clinical practice. The focus of this meta-analysis was to compare the effects of vacuum-formed retainers (VFR) and Hawley retainers (HR) on periodontal health, in order to provide a reference for clinical selection.

Methods

From the establishment of the database until November 2020, a large number of databases were searched to find relevant randomized control trials, including the Cochrane Library databases, Embase, PubMed, Medline via Ovi, Web of Science, Scopus, Grey Literature in Europe, Google Scholar and CNKI. Related literature was manually searched and included in the analysis. Two researchers screened the literature according to relevant criteria. The size of the effect was determined using RevMan5.3 software, and the mean difference and 95% confidence intervals (CI) were used to estimate the results using a random effects model.

Results

This meta-analysis included six randomized controlled trials involving 304 patients. The results of the meta-analysis showed that there was no statistical difference in sulcus probing depth status between the VFR group and the HR group, including at 1, 3, and 6 months. Compared with the VFR group, the HR group showed a lower gingival index at 1 month (mean difference = 0.12, 95%CI: 0.06 to 0.19) and 3 months (mean difference = 0.11, 95%CI: 0.06 to 0.17), while there was no statistically significant difference at 6 months (mean difference = 0.10, 95%CI: -0.07 to 0.27). The plaque index of the HR group also showed a good state at 1 month (mean difference = 0.06, 95%CI: 0.01 to 0.12), 3 months (mean difference = 0.12, 95%CI: 0.08 to 0.16), and 6 months (mean difference = 0.19, 95%CI: 0.09 to 0.29). Subgroup analysis of PLI showed that when all teeth were measured, PLI status was lower in the HR group at 6 months (mean difference = 0.32, 95%CI: 0.18 to 0.46). PLI status was also low for the other teeth group (mean difference = 0.15, 95%CI: 0.08 to 0.22).

Conclusion

Our meta-analysis showed that patients using the Hawley retainer had better periodontal health compared with those using vacuum-formed retainers. However, more research is needed to look at the periodontal health of patients using these two retainers.

Removable orthodontic retainers: practical considerations

This article provides an overview of removable orthodontic retainers, discussing their history and the different types available, and compares the two most popular removable retainers. Practical information on consent and the clinical steps involved in the provision of removable retainers, as well as suggested wear and care instructions, are also presented.

A Case of Mandibular Prognathism with Generalized Aggressive Periodontitis and Crowding

Aggressive periodontitis during adolescence has a poor prognosis due to rapid alveolar bone resorption. Few studies have investigated long-term follow-up after surgical orthodontic treatment performed in conjunction with that for invasive periodontitis. Here, we report a case of mandibular prognathism accompanied by generalized aggressive periodontitis and crowding. A 31-year-old woman was referred to our department for treatment of masticatory dysfunction due to reverse overjet. The patient exhibited a class III molar relationship, protrusion of the ANB of －6.0°, and severe maxillary crowding. Initial periodontal examination revealed deep periodontal pockets and extensive inflammation. Mandibular prognathism accompanied by generalized aggressive periodontitis and crowding was diagnosed. Therefore, it was necessary to adopt an interdisciplinary approach involving surgical, orthodontic, and periodontal treatment. Prior to commencement of orthodontic treatment, plaque control, scaling, and root planing of all teeth were performed by a periodontist to suppress inflammation and reduce probing depth. During pre-surgical orthodontic treatment, the maxillary first premolars were extracted to reduce crowding of the maxillary incisors. To correct the mandibular prognathism, the mandible was repositioned by sagittal split ramus osteotomy. Proper occlusion of the incisors and maximum intercuspation were achieved by post-surgical orthodontic treatment. After completion of active orthodontic treatment, acceleration of inflammation was observed together with aggravated resorption of the alveolar bone surrounding the molars. However, reduction of probing depth and inflammation were observed after scaling and root planing. The surgical-orthodontic treatment time was 1 year and 11 months, which was followed by a 2-year retention period. There was no tooth loss due to periodontitis, and an overall satisfactory outcome was achieved.

Clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients: a retrospective study

PURPOSE

The aim of this study was to evaluate clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients.

METHODS

In total, 52 patients with at least 2 years of follow-up after periodontal and orthodontic treatment were included in this study. After scaling and root planing, orthodontic treatment with fixed appliances or clear aligners was performed. Fixed retainers with twist-flex stainless steel wires were bonded to the palatal or lingual sides of anterior teeth. Changes in clinical parameters, including the plaque index, gingival index, calculus index (CI), probing pocket depth, and radiographic bone levels, were evaluated before bonding of fixed retainers and at a 12-month follow-up. Cumulative survival rates (CSRs) for retainer failure were evaluated according to sex, site, CI, stage of periodontitis, and the severity of the irregularity with the log-rank test and hazard ratios (HRs).

RESULTS

Twelve months after bonding of fixed retainers, improvements were observed in all clinical parameters except CI and radiographic bone gain. The overall CSR of the retainers with a CI <1 at the 12-month follow-up after bonding of fixed retainers was significantly higher than that of the retainers with a CI ≥1 at the 12-month follow-up (log-rank test; P<0.001). Patients with stage III (grade B or C) periodontitis had a higher multivariate HR for retainer failure (5.4; 95% confidence interval, 1.22-23.91; P=0.026) than patients with stage I (grade A or B) periodontitis.

CONCLUSIONS

Although fixed retainers were bonded in periodontitis patients, periodontal health was well maintained if supportive periodontal treatment with repeated oral hygiene education was provided. Nonetheless, fixed retainer failure occurred more frequently in patients who had stage III (grade B or C) periodontitis or a CI ≥1 at 12-month follow-up after bonding of fixed retainers.

The periodontal status of removable appliances vs fixed appliances: A comparative meta-analysis

BACKGROUND

Although several researchers have analyzed the dental identity of patients experience with corrective methods using fixed and removable appliances, the consequences stay debatable. This meta-analysis intended to verify whether the periodontal status of removable appliances is similar to that of the conventional fixed appliances.

METHODS

Relevant literature was retrieved from the database of Cochrane library, PubMed, EMBASE, and CNKI until December 2019, without time or language restrictions. Comparative clinical studies assessing periodontal conditions between removable appliances and fixed appliances were included for analysis. The data was analyzed using the Stata 12.0 software.

RESULTS

A total of 13 articles involving 598 subjects were selected for this meta-analysis. We found that the plaque index (PLI) identity of the removable appliances group was significantly lower compared to the fixed appliances group at 3 months (OR = -0.57, 95% CI: -0.98 to -0.16, P = .006) and 6 months (OR = -1.10, 95% CI: -1.60 to -0.61, P = .000). The gingival index (GI) of the removable appliances group was lower at 6 months (OR = -1.14, 95% CI: -1.95 to -0.34, P = .005), but the difference was not statistically significant at 3 months (OR = -0.20, 95% CI: -0.50 to 0.10, P = .185) when compared with that of the fixed appliances group. The sulcus probing depth (SPD) of the removable appliances group was lower compared to the fixed appliances group at 3 months (OR = -0.26, 95% CI: -0.52 to -0.01, P = .047) and 6 months (OR = -0.42, 95% CI: -0.83 to -0.01, P = .045). The shape of the funnel plot was symmetrical, indicating no obvious publication bias in the Begg test (P = .174); the Egger test also indicated no obvious publication bias (P = .1).

CONCLUSION

Our meta-analysis demonstrated that malocclusion patients treated with the removable appliances demonstrated a better periodontal status as compared with those treated with fixed orthodontic appliances. However, the analyses of more numbers of clinical trials are warranted to confirm this conclusion.

Assessment of surface roughness changes on orthodontic acrylic resins by all-in-one spray disinfectant solutions

Background. The disinfection of orthodontic acrylic resins might change the physical and mechanical properties of these materials. We aimed to investigate the impact of four different commercially available disinfectants on the surface roughness of acrylic resins used for orthodontic appliances.

Methods. Four disinfectant solutions (BirexSE, Opti-Cide3, COEfect MinuteSpray, and CaviCide Spray) were used to disinfect orthodontic acrylic resins using the spraying method. The resins were subjected to repeated disinfection protocols. Distilled water, also applied via spraying method, was used as a control. Surface roughness was scrutinized to examine the extent of surface topography changes by stylus profilometry. Data normality was evaluated via the Shapiro–Wilk test, followed by the Wilcoxon Signed-Rank test for non-parametric data or paired Student’s t-test for parametric data to compare intra-group differences in roughness before and after the use of the disinfectant solutions.

Results. Some of the disinfectants (BirexSE and CaviCide) resulted in significant changes in surface roughness values before and after the disinfection compared to the controls (P<0.05). The groups that were in contact with distilled water, Opti-Cide, and Coeffect did not exhibit significant differences in surface roughness before and after the intervention (P>0.05). However, from a clinical perspective, the resulting variations in surface roughness (<%0.15) induced by these solutions might not reflect clinically significant differences.

Conclusion. The use of disinfectant solutions is unlikely to harm the surface of orthodontic acrylic resins. Oral care providers need to be attentive to the interpretation and implementation of clinically significant changes in their evidence-based approach regarding potential material damages by disinfection sprays.