A split-mouth randomized controlled trial to compare the rate of canine retraction after a soft tissue procedure compared against a corticotomy procedure for accelerated tooth movement

Background and Aim

Various methods to accelerate the orthodontic tooth movement have been used, among which corticotomy is considered to be the most common one. The suggested reasoning for such acceleration was the regional acceleratory phenomenon (RAP). Since the RAP is a property of both the hard and soft tissues, we designed a soft tissue flap procedure to compare the effects with the conventional corticotomy procedure. A split-mouth study was conducted where the two procedures were assessed in a single participant.

Patients and Methods

The total sample size was calculated to be 40 with 20 participants in each group. The rate of tooth movement was the primary outcome measure, and the secondary outcomes were dentoalveolar changes, which were studied in both the conventional corticotomy and the flap-only procedure based on a cone-beam computed tomography (CBCT) wherein the alveolar bone density (BD) around canines, tipping, and rotational changes in canines, premolars, and molars were assessed.

Results

Corticotomy resulted in greater canine angulation, lesser canine rotation and premolar rotation, and greater molar rotation compared with flap elevation, but these differences were statistically insignificant.

Conclusion

Though the corticotomy resulted in higher BD, the differences were statistically insignificant. There was no significant difference in the rate of space closure assessed by the two techniques compared.

Sulfate-Reducing Bacteria in Patients Undergoing Fixed Orthodontic Treatment

OBJECTIVES

The oral microbiological environment may be implicated in the corrosion of orthodontic metals. This study aimed to examine the prevalence of sulfate-reducing bacteria (SRB) in orthodontic patients undergoing fixed appliance treatment.

METHODS

Sixty-nine orthodontic and 69 healthy non-orthodontic participants were enrolled in the study. Supragingival and subgingivaloral biofilm were collected and tested for the presence of SRB. The DNA extraction, polymerase chain reaction (PCR), and 16sRNA Sanger sequencing method was performed from the SRB-positive samples. The sequenced PCR products were analysed and compared with databases to identify the bacterial genus.

RESULTS

Amongst 69 orthodontic patients, characteristic black precipitates developed in 14, indicating the presence of iron sulfides which demonstrates the likelihood of SRB. Alternatively, 2 out of 69 showed the presence of SRB in healthy non-orthodontic participants (controls). Desulfovibrio spp was confirmed by analyses of 16sRNA sequencing, which revealed that the SRB prevalence was 20% in the examined participants with orthodontic appliances.

CONCLUSIONS

The prevalence of SRB was found to be significantly higher amongst orthodontic patients compared to non-orthodontic participants. Presence of stainless steel in the oral environment may have facilitated the colonisation of SRB.

Assessing the cytotoxic effect and antimicrobial activity of Moringa oleifera aqueous and ethanolic extract against oral pathogens extracted from periodontal and orthodontic patients

Background: Periodontitis is the result of inflammation caused due to the activity of microorganisms. The prevalence of anaerobic organisms is more when it comes to periodontal pockets and orthodontic patients. Plants with phytochemicals that could exert antimicrobial effects could aid in host modulation for management of periodontitis caused by these bacteria in periodontal and orthodontic patients Aim: To assess the antimicrobial effect of aqueous extract of Moringa oleifera Lam (MOL) and cytotoxic effect of aqueous and ethanol extracts of MOL. Materials and methods: Moringa oleifera Lam. extracts were prepared by maceration. Subgingival plaque samples were collected and microorganisms were cultured in anaerobic environment. The microorganisms were treated with the extracts and minimum inhibitory concentration and minimum bactericidal concentration was assessed. The cytotoxic effects were assessed by brine shrimp assay. Results: Aqueous extract showed antimicrobial effect in dose and time dependent manner and both extracts exhibited cytotoxic effects in a dose and time dependent manner Summary and Conclusion: The antimicrobial effect of MOL could be utilized to develop a nature derived local drug delivery system for treating plaque induced periodontitis in different clinical situations.

In-Vitro Assessment of the Corrosion Potential of an Oral Strain of Sulfate-Reducing Bacteria on Metallic Orthodontic Materials

AIM

Orthodontic literature is scant when it comes to microbial corrosion. The oral prevalence of many bacteria which are capable of causing microbial corrosion is reported in the dental literature. The aim of this study is to experimentally determine the corrosive potential of an oral strain of Sulfate-reducing bacteria.

MATERIALS AND METHODS

Stainless steel (SS) bracket, stainless steel archwire, NiTi archwire, Titanium molybdenum (TMA) archwire, and titanium miniscrew were immersed in five media which included Artificial saliva (group I), Sulfate rich artificial saliva (group II), API agar medium specific for SRB (group III), AS + API medium+ bacterial strain (group IV), SRAS+ API medium+ bacterial strain (group V). The materials were then subjected to Scanning electron microscopy and energy-dispersive X-ray analysis (EDX).

RESULTS

Materials in groups I, II, and III did not show any surface changes whereas materials in groups IV and V which contained the bacteria showed surface changes which were erosive patches suggestive of corrosion. EDX analyses were in line with similar findings.

CONCLUSION

This in vitro study suggested that the oral strain of Sulfate-reducing bacteria was able to induce corrosive changes in the experimental setup.

Bibliometric analysis on microbial corrosion in dentistry

Abstract: Aim: The present bibliometric analysis was conducted to find the evidence regarding microbial corrosion in dentistry since corrosion by whatever means affect the intraoral performance of the metallic appliances. Materials and methods: Material and methods: Dimensions software was used to search for published literature pertaining to the keywords “microbial corrosion” AND “dentistry”. Two reviewers assessed the articles in terms of year of publication, authors, country of origin, journal of publication, and the affiliated institutions of the authors as well as their collaborations and the most cited publications. Results: The search revealed a total of 3,118 articles between the years 2000 to 2022. The number of publications was on the rising pattern with a spike between 2004-2007, again with a small spike between 2014 and 2016 and then a steep increase from 2017 onwards.  The publications were almost equally split between Engineering science and Medical Sciences. United States topped the list of countries with 378 documents with total link strength of 106224. Sao Paulo University topped the list in terms of organizations with total link strength of 12722. The journal of Anatomia Histologia Embryologia topped with 136 publications followed by Materials with 94 publications. Valentim from Brazil topped the authors with 22 publications. Conclusion: Microbial corrosion is needs equal concentration as any other forms of intraoral corrosion given that oral cavity is loaded with huge varieties of microorganisms with some of them known to cause microbial corrosion like sulfate reducing bacteria. The recent decline in research and publications in this field especially in 2022 is concerning. More studies are needed to learn more on microbial corrosion and its effects in dentistry.  Keywords: microbial corrosion, dentistry, sulfate reducing bacteria  

Microbial Corrosion in Orthodontics

Even with the exponential popularity of the contemporary clear aligners, the main stream of orthodontic practice still remains to be metal braces especially in adolescent age-group.¹ Along with the advantages of metal braces such as lower cost, reduced friction, etc., there goes the disadvantages such as corrosion possibility, reduced esthetics, etc. Corrosion of orthodontic appliances is a widely researched topic.^2-5 It is surprising to learn that microbially induced corrosion (MIC) has not been addressed in orthodontic literature till date. Microbial corrosion is an interesting arena which requires knowledge of both corrosion science and microbiology. The microorganisms capable of corrosion include various bacteria, fungi, and algae. The most common among them which has been widely indicated in MIC are the bacteria belonging to the sulfur cycle especially the sulfate-reducing bacteria (SRB). The connecting knot with orthodontics is the reported prevalence of these SRB in the oral cavity. SRB is prevalent in healthy individuals,^6,7 patients associated with periodontitis^6-11 and patients with gastrointestinal issues.^12-14 The prevalence of SRB in the oral cavity has a greater clinical implication since the SRB have been proven to cause corrosion of stainless steel.^15-24 There is literature attributing SRB as a potential cause in periodontal diseases^7-11 as well as gastrointestinal diseases such as ulcerative colitis, inflammatory bowel diseases, and Crohn's disease.¹² With its presence in the healthy oral environment already reported in the previous studies,^6,7,25,26 it further emphasizes the absolute need to be researching on its corrosion possibility in the intra oral environment. The genus generally found intraorally was Desulfovibrio and Desulfobacter¹⁰ which is commonly regarded as the most "opportunistic" and ubiquitous group of sulfate reducers.^6,7 There is an interesting literature on the inhibition of Desulfovibrio spp. by human saliva, the reason being quoted as salivary nitrate and nitrite.¹⁴ The mechanism behind the antimicrobial action of nitrate and nitrite is that they increase the oxidative stress on the bacteria.²⁷ However, concentrations of salivary nitrate vary depending on the food intake, endogenous production, and salivary flow rate.^28,29 Despite there exist natural inhibitors, the prevalence in oral cavity is high, 22% in healthy and 86% in patients associated with periodontitis.⁷ There is a predilection for the bacteria to grow when favorable conditions exist. Biofilms is one such favorable medium for the growth of SRB. Paster et al.²⁶ identified SRB in biofilms of patients associated with refractory periodontitis, periodontitis, acute necrotizing ulcerative gingivitis (ANUG), and also in healthy subjects. Biofilm is a surface film composed of organic and inorganic saliva components that are colonized with microorganisms in extracellular polymeric substances adsorbed on all surfaces in the oral cavity.³⁰ The oral biofilm formation is a complex process involving interspecies aggregation, which is surrounded by a cohesive matrix, forms a complex structure which in turn facilitates anaerobic growth. It is the intrinsic nature of oral biofilms which make the survival of facultative anaerobes such as SRB in the oral cavity possible. Literatures^31-35 report that there are increased biofilm formations in orthodontic patients due to increased retentive areas caused by the brackets, ligatures, wires, mini implants, force components, and archwires. Bacteria in dental plaque function as a metabolically, functionally, and physically integrated community.³⁶ The study by Mystkowska et al.³⁷ mentioned that biofilm per se play a critical role in corrosion process by forming corrosive microcells. With time-dependent association, the microbes in the biofilm, along with saliva acting as an electrolyte and components from food, causes a decreased pH in the areas immediately under the biofilms. The decreased pH along with a change of oxygenation releases metal oxides and hydroxides from the metal surface ultimately leading to the corrosion of metallic structures.^37-41 The initial roughness also acts in a vicious form promoting more biofilm adherence and the process repeats causing more corrosion. With the biofilm itself serving to initiate and propagate corrosion, the increased prevalence of SRB in patients associated with orthodontics treatment all the more increases the possibility of MIC of orthodontic materials.

Effect of Fluoridated Mouthwashes on Corrosion Property of Orthodontic Appliances: A Narrative Review

OBJECTIVE

To analyze the effects of various fluoride agents on metallic orthodontic materials.

DESIGN

PubMed, Google Scholar, and Embase were searched using keyword combinations such as fluoride mouthwash and orthodontic appliance and corrosion, fluoride and fixed appliance, and metal degradation.

RESULTS

Of 315 articles, 20 were selected for inclusion in the review. All types of fluoride agents, especially the acidulated form of fluoride, seemed to influence the corrosion of orthodontic metallic appliances.

CONCLUSION

Since most of the studies reported suggest that fluoride ions are capable of causing corrosion of metallic orthodontic appliances, attention should be paid while prescribing fluoride agents for orthodontic patients. The degree of corrosion seems to be directly correlated with the acidity of the medium and the concentration of fluoride ions. Co-Cr brackets are resistant to corrosion by fluoride while stainless steel and Ti brackets are susceptible.

CLINICAL SIGNIFICANCE

It allows making the right choice while choosing the orthodontic brackets in relation to their susceptibility to corrosion by fluoride ions.

Assessing the Potential Association Between Microbes and Corrosion of Intra-Oral Metallic Alloy-Based Dental Appliances Through a Systematic Review of the Literature

Objective: Systematic review assessing the association between oral microorganisms and corrosion of intra-oral metallic alloy-based dental appliances.

Design: PubMed, Scopus, and Web of Science were searched using keyword combinations such as microbes and oral and corrosion; microbes and dental and corrosion; microorganisms and oral and corrosion; microorganisms and dental and corrosion.

Results: Out of 141 articles, only 25 satisfied the selection criteria. Lactobacillus reuteri, Streptococcus mutans, Streptococcus sanguis, Streptococcus mitis, Streptococcus sobrinus, Streptococcus salivarius, sulfate-reducing bacteria, sulfate oxidizing bacteria, Veilonella, Actinomyces, Candida albicans were found to have a potential association with corrosion of intraoral metallic alloys such as stainless steel, titanium, nickel, cobalt-chromium, neodymium-iron-boron magnets, zirconia, amalgam, copper aluminum, and precious metal alloys.

Conclusion: The included studies inferred an association between oral microorganisms and intra-oral metallic alloys-based dental appliances, although, it is vital to acknowledge that most studies in the review employed an in-vitro simulation of the intra-oral condition.

Is the Stability of a Standard Stable Reference Stable Enough?

The dogmatic approach of following the past principles has made many significant features of science go unnoticed and unquestioned. One such is the concept of immutability of the anterior contour of the sella turcica. For many decades, we have been using the anterior contour of sella turcica as a stable reference structure to study the growth of the craniofacial skeleton.¹ This was based on the usage by Björk and Skieller. But on analyzing the various studies on the growth and disease of the pituitary gland and its influence on the size and morphology of sella turcica, it seems that the anterior contour of the sella turcica may not be a stable parameter of reference. This article is an attempt to throw light on the intricacies of the association between pituitary gland and sella turcica.

Assessment of the dental and skeletal effects of fan-type rapid maxillary expansion screw and Hyrax screw on craniofacial structures

Aims and Objectives:

The purpose of the study was to assess the skeletal and dental effects of fan-type rapid maxillary expansion (RME) appliance and Hyrax RME appliance on the craniofacial structures.

Materials and Methods:

The sample of the study included 12 patients with constricted maxillary arches. Acrylic bonded type of attachment was used for both groups. Changes in sagittal, vertical, and transverse relationship were assessed with lateral and frontal cephalograms, respectively. Intercanine and intermolar widths were measured with stone models. Pre- and immediate post-treatment records were statistically analyzed with Wilcoxon signed-rank test. The differences between the groups were evaluated using Mann–Whitney U-test. Since the data pertaining to intercanine width and intermolar width were normally distributed, parametric test of significance (unpaired t-test) was used to compare them.

Results:

Results showed that Hyrax presented with significantly greater increments for both nasal cavity width and maxillary width when compared to fan-type RME. Both groups had retroclination of incisors. The increase in the intercanine width was almost similar in both groups.

Conclusion:

Fan-type RME caused only minimal expansion of the intermolar width when compared to the Hyrax. The ratio between the intercanine and intermolar width expansion was nearly 4:1 in the fan-type RME and 0.75:1 in Hyrax.

Sotrastaurin in calcineurin inhibitor-free regimen using everolimus in de novo kidney transplant recipients

Sotrastaurin, a novel selective protein-kinase-C inhibitor, inhibits early T cell activation via a calcineurin-independent pathway. Efficacy and safety of sotrastaurin in a calcineurin inhibitor-free regimen were evaluated in this two-stage Phase II study of de novo kidney transplant recipients. Stage 1 randomized 131 patients (2:1) to sotrastaurin 300 mg or cyclosporine A (CsA). Stage 2 randomized 180 patients (1:1:1) to sotrastaurin 300 or 200 mg or CsA. All patients received basiliximab, everolimus (EVR) and prednisone. Primary endpoint was composite efficacy failure rate of treated biopsy-proven acute rejection, graft loss, death or lost to follow-up. Main safety assessment was estimated glomerular filtration rate (eGFR) by MDRD-4 at Month 12. Composite efficacy failure rates at 12 months were higher in sotrastaurin arms (Stage 1: 16.5% and 10.9% for sotrastaurin 300 mg and CsA; Stage 2: 27.2%, 34.5% and 19.4% for sotrastaurin 200 mg, 300 mg and CsA). eGFR was significantly better in sotrastaurin groups versus CsA at most time points, except at 12 months. Gastrointestinal and cardiac adverse events were more frequent with sotrastaurin. Higher treatment discontinuation, deaths and graft losses occurred with sotrastaurin 300 mg. Sotrastaurin combined with EVR showed higher efficacy failure rates and some improvement in renal allograft function compared to a CsA-based therapy.