Effective Parameters for Orthodontic Tooth Movement Acceleration with Photobiomodulation: An Umbrella Review.

Objective: To answer this research question: What are the effective wavelength, power, and energy density parameters for achieving dental movement acceleration? Background Data: Photobiomodulation (PBM) has been clinically studied for its ability to accelerate dental movements in orthodontics. However, its effectiveness is dose dependent. Methods: The search was carried out in PubMed, SCOPUS, and ISI Web of Science. The quality of the included systematic reviews was performed using the AMSTAR 2 tool. The risk of bias was assessed using the ROBIS tool. Results: In total, 29 articles in PubMed, 75 in Scopus, and 61 in ISI Web of Science. Finally, only five systematic reviews were included. Conclusions: The results showed the range from 730 to 830 nm as the most effective range of wavelength to accelerate the orthodontic dental movement. A power range of 0.25-200 mW, with emphasis on the direct correlation between power, wavelength, and energy density. Energy density has not been adequately reported in the most randomized controlled clinical trials.

Photobiomodulation in Orthodontics: Mechanisms and Clinical Efficacy for Faster Tooth Movement.

Accelerated orthodontics has revolutionized traditional dental practices by employing innovative techniques to expedite tooth movement and enhance treatment outcomes. Among these advancements, low-level laser therapy (LLLT) has emerged as a promising adjunctive method that offers a non-invasive and efficient approach to accelerate orthodontic tooth movement. By harnessing the power of low-level lasers, LLLT aims to stimulate cellular activity, promote bone remodeling, and reduce treatment duration, thereby revolutionizing the landscape of orthodontic care. In this review, we discuss the mechanism of action, methods, efficacy, advantages, limitations, and future scope of LLLT, uncovering its transformative impact on the field of accelerated orthodontics.

Is it possible to anchor a tooth with photobiomodulation?

During orthodontic treatment, we can achieve differential movements by using photobiomodulation (PBM) as an adjuvant before applying force. We can expect a greater bone density that initially resists movement while applying PBM to the other teeth to achieve an accelerating effect. The proposed protocol is to use an 810 nm laser at 0.1W power, applying between 4 and 6J per tooth for 22 s on the vestibular and lingual root surfaces, following the axial axis of the tooth. The energy density depends on the tip selected in the instrument. Normal bone remodeling cannot be avoided by applying high doses of PBM. PBM should be applied before orthodontic force to reduce tooth movement. In addition, PBM can be used during force application to teeth that require acceleration to achieve differential movement in orthodontic treatments. The protocol is the same in both scenarios.

The consequences of orthodontic extrusion on previously intruded permanent incisors-A retrospective study.

AIM: The aim of this study is to compare the adverse effects that occur after orthodontic extrusion of teeth that have been traumatically intruded with those of similar teeth that have not experienced any trauma. BACKGROUND: The outcome of incisors intrusion can be affected by the patient's age, extent of injury, root development, and malocclusion. Orthodontic extrusion is a potential solution, but it may also cause complications. MATERIALS AND METHODS: A retrospective study of the effects of extrusion of traumatically intruded teeth was carried out. The study group included 21 teeth in 14 patients. The control group included 32 teeth in 10 patients that underwent orthodontic extrusion with no history of trauma. Patients' age, gender, and stage of root development were recorded. The severity of the intrusion was classified as mild (<3 mm), moderate (3-6 mm), and severe (≥7 mm). A comparison of signs of pulp necrosis and root resorptions between the groups was made. RESULTS: The central incisor is the tooth that is most injured in 80.9% of cases. A majority of these incidents involve severe intrusion, which was found in 42.9% of cases. 90% of the traumatized teeth had already lost their vitality prior to orthodontic treatment. Various forms of root resorption were observed in the study group. In the control group, 31.2% of teeth showed signs of external root resorption, but no endodontic intervention was carried out during the follow-up period, as these teeth remained vital. CONCLUSIONS: Following intrusion, there is a high risk for root resorption and pulp necrosis. Orthodontic repositioning should be carried out with caution and mild force to prevent complications. Long-term follow-ups are required to ensure the best possible outcome.

Effectiveness of photobiomodulation with low-level lasers on the acceleration of orthodontic tooth movement: a systematic review and meta-analysis of split-mouth randomised clinical trials.

Although several studies have evaluated the effect of low-level laser therapy (LLLT) on orthodontic movement acceleration, results are still inconsistent. Such inconsistencies may be attributed to the differences in the LLLT application protocols, especially in terms of wavelength ranges. Objective: (i) to assess the clinical effects of LLLT on the acceleration of orthodontic movement and (ii) to establish the most effective LLLT wavelength to accelerate tooth movement during orthodontic treatments. MEDLINE (PubMed), Scopus, ScienceDirect, and LILACS were searched from inception to October 2022. Inclusion criteria: Split-mouth randomised clinical trials (RCTs) on systemically healthy patients reporting the effect of LLLT in accelerating orthodontic movements, specifically retraction of canines. The risk of bias was assessed using RoB-2. A random effect model was applied. Nineteen RCTs met the inclusion criteria for qualitative synthesis, and eighteen RCTs were included in the quantitative synthesis. Seventeen studies were rated as at some concerns of bias and two studies were classified as having a low risk of bias. In general terms, this systematic review and meta-analysis presents a moderate risk of bias. Findings of this systematic review and meta-analysis point to a tendency for faster orthodontic dental movement in the groups receiving LLLT treatment during the first (OR of 0.28 95% CI (0.07 to 0.48)), second (OR of 0.52 95% CI (0.31 to 0.73)), and third (OR of 0.41 95% CI (0.03 to 0.79)) month follow-up. Wavelengths ≤ 810 nm and energy density values ≤ 5.3 J/cm2 were associated with faster orthodontic tooth movement.

Long-Term Clinical and Radiographic Observation of Previously Regenerated Treated Incisors Subjected to Orthodontic Movement. A Case Series.

INTRODUCTION: With an increasing number of anterior traumatized teeth treated with regenerative endodontic procedures (REPs) nowadays, orthodontic movement of such teeth is expected to become a common scenario in everyday clinical practice. However, little is known about the clinical implications and the response capacity of regenerated tissues to orthodontic forces. METHODS: The aim of this clinical article was to report on 4 cases of REP-treated immature anterior permanent teeth subjected to orthodontic forces, and to describe the long-term response of the regenerated apical and intracanal tissues. RESULTS: Signs of orthodontic-induced external root resorption were observed in 2 of the 4 presented cases without, however, the presence of any associated adverse events. No other complications were observed, either clinically or radiographically, throughout the observation period. In the long-term, all 4 cases responded favorably to orthodontic forces, maintaining healthy apical tissues and structural integrity of both intracanal as well as apically regenerated tissues. CONCLUSIONS: The orthodontic movement of REP-treated teeth seems feasible, nevertheless, special care should be implemented. Lightly acting orthodontic forces, short duration of active movement, and close monitoring of the patient seem to be prerequisites to limit complications to a minimum and achieve a favorable healing of REP-treated teeth in the long-term following orthodontic treatment completion.

Cortical and Trabecular Bone Stress Assessment during Periodontal Breakdown-A Comparative Finite Element Analysis of Multiple Failure Criteria.

Background and Objectives: This numerical analysis investigated the biomechanical behavior of the mandibular bone as a structure subjected to 0.5 N of orthodontic force during periodontal breakdown. Additionally, the suitability of the five most used failure criteria (Von Mises (VM), Tresca (T), maximum principal (S1), minimum principal (S3), and hydrostatic pressure (HP)) for the study of bone was assessed, and a single criterion was identified for the study of teeth and the surrounding periodontium (by performing correlations with other FEA studies). Materials and Methods: The finite element analysis (FEA) employed 405 simulations over eighty-one mandibular models with variable levels of bone loss (0-8 mm) and five orthodontic movements (intrusion, extrusion, tipping, rotation, and translation). For the numerical analysis of bone, the ductile failure criteria are suitable (T and VM are adequate for the study of bone), with Tresca being more suited. S1, S3, and HP criteria, due to their distinctive design dedicated to brittle materials and liquids/gas, only occasionally correctly described the bone stress distribution. Results: Only T and VM displayed a coherent and correlated gradual stress increase pattern for all five movements and levels of the periodontal breakdown. The quantitative values provided by T and VM were the highest (for each movement and level of bone loss) among all five criteria. The MHP (maximum physiological hydrostatic pressure) was exceeded in all simulations since the mandibular bone is anatomically less vascularized, and the ischemic risks are reduced. Only T and VM displayed a correlated (both qualitative and quantitative) stress increase for all five movements. Both T and VM displayed rotation and translation, closely followed by tipping, as stressful movements, while intrusion and extrusion were less stressful for the mandibular bone. Conclusions: Based on correlations with earlier numerical studies on the same models and boundary conditions, T seems better suited as a single unitary failure criterion for the study of teeth and the surrounding periodontium.

Effective endodontically treated incisors with external root resorption during orthodontic movement: A case report.

This case report describes a 21-year-old orthodontic patient experienced the external apical root resorption of maxillary central incisors with pulpitis during the orthodontic movement. The active cooperation of orthodontists and endodontists demonstrated the satisfactory treatment outcome and prevented further apical root resorption. The etiology of external apical root resorption is comprehensive, orthodontists should be armed with an adequate training and scientific knowledge, and keep the treatment mechanism simple and precise to guard against it. Besides, we should know the right timing of endodontic treatment and applying orthodontic force when external apical root resorption occurs.

Assessment of the Best FEA Failure Criteria (Part II): Investigation of the Biomechanical Behavior of Dental Pulp and Apical-Neuro-Vascular Bundle in Intact and Reduced Periodontium.

The aim of this study was to biomechanically assess the behavior of apical neuro-vascular bundles (NVB) and dental pulp employing Tresca, Von Mises, Pressure, S1 and S3 failure criterions in a gradual periodontal breakdown under orthodontic movements. Additionally, it was to assess the accuracy of failure criteria, correlation with the maximum hydrostatic pressure (MHP), and the amount of force safe for reduced periodontium. Based on cone-beam computed tomography, 81 3D models of the second lower premolar were subjected to 0.5 N of intrusion, extrusion, rotation, tipping, and translation. A Finite Elements Analysis (FEA) was performed. In intact and reduced periodontium apical NVB, stress (predominant in all criteria) was significantly higher than dental pulp stress, but lower than MHP. VM and Tresca displayed identical results, with added pulpal stress in translation and rotation. S1, S3 and Pressure showed stress in the apical NVB area. 0.5 N seems safe up to 8 mm periodontal breakdown. A clear difference between failure criteria for dental pulp and apical NVB cannot be proved based only on the correlation quantitative results-MHP. Tresca and VM (adequate for ductile materials) showed equivalent results with the lowest amounts of stress. The employed failure criteria must be selected based on the type of material to be analyzed.

Assessment of the Best FEA Failure Criteria (Part I): Investigation of the Biomechanical Behavior of PDL in Intact and Reduced Periodontium.

The accuracy of five failure criterions employed in the study of periodontal ligaments (PDL) during periodontal breakdown under orthodontic movements was assessed. Based on cone-beam computed tomography (CBCT) examinations, nine 3D models of the second lower premolar with intact periodontium were created and individually subjected to various levels of horizontal bone loss. 0.5 N of intrusion, extrusion, rotation, tipping, and translation was applied. A finite Elements Analysis (FEA) was performed, and stresses were quantitatively and qualitatively analyzed. In intact periodontium, Tresca and Von Mises (VM) stresses were lower than maximum physiological hydrostatic pressure (MHP), while maximum principal stress S1, minimum principal stress S3, and pressure were higher. In reduced periodontium, Tresca and VM stresses were lower than MHP for intrusion, extrusion, and the apical third of the periodontal ligament for the other movements. 0.5 N of rotation, translation and tipping induced cervical third stress exceeding MHP. Only Tresca (quantitatively more accurate) and VM are adequate for the study of PDL (resemblance to ductile), being qualitatively similar. A 0.5 N force seems safe in the intact periodontium, and for intrusion and extrusion up to 8 mm bone loss. The amount of force should be reduced to 0.1-0.2 N for rotation, 0.15-0.3 N for translation and 0.2-0.4 N for tipping in 4-8 mm periodontal breakdown. S1, S3, and pressure criteria provided only qualitative results.

Matrix Metalloproteinases in Dental and Periodontal Tissues and Their Current Inhibitors: Developmental, Degradational and Pathological Aspects.

OBJECTIVES: This review article aims to describe some of the roles of Matrix metalloproteinases (MMPs) in enamel, dentine, dental caries, hybrid layer degradation, pulp and periodontal tissues, throwing light on their current inhibitors. The article addresses the potential of MMPs to serve as biomarkers with diagnostic and therapeutic value. DESIGN: The sections of this review discuss MMPs' involvement in developmental, remodeling, degradational and turnover aspects of dental and periodontal tissues as well as their signals in the pathogenesis, progress of different lesions and wound healing of these tissues. The literature was searched for original research articles, review articles and theses. The literature search was conducted in PubMed and MEDLINE for articles published in the last 20 years. RESULTS: 119 published papers, two textbooks and two doctoral theses were selected for preparing the current review. CONCLUSIONS: MMPs are significant proteases, of evident contribution in dental and periapical tissue development, health and disease processes, with promising potential for use as diagnostic and prognostic disease biomarkers. Continuing understanding of their role in pathogenesis and progress of different dental, periapical and periodontal lesions, as well as in dentine-pulp wound healing could be a keystone to future diagnostic and therapeutic regimens.

Do submerged roots hinder orthodontic treatment or the use of implants?

ABSTRACT Introduction: In clinical practice, submerged roots are found with high frequency, and their presence can change the planning of dental movements and implant placement. Objectives: To provide explanations of possible developments in the area involved, according to the evolutionary stage of the process, at the time of diagnosis. Discussion: After atrophy of the periodontal ligament and epithelial remnants of Malassez, ankylosis of the bone with the submerged root occurs, and initiates a process of replacement resorption. Until this process reaches the most advanced stage, this area represents an increased "bone" density, and if some care is not taken, this can generate resorption problems in the tooth to be moved. Whereas implants can be placed, despite the presence of the submerged root, irrespective of the stage of evolution. Conclusion: It is natural for the onset of alveolodental ankylosis and tooth replacement resorption to occur in submerged roots, and its stage of evolution will be decisive in the approach to be adopted in clinical planning.

RESUMO Introdução: A frequência, na prática clínica, das raízes submersas é elevada, e sua presença pode modificar o planejamento de movimentações osteodentárias e da instalação de implantes. Objetivo: Apresentar as explicações das possíveis evoluções na área envolvida, de acordo com o estágio evolutivo do processo, no momento do diagnóstico. Discussão: Depois da atrofia do ligamento periodontal e dos restos epiteliais de Malassez, o osso anquilosa-se com a raiz submersa, e se inicia a reabsorção por substituição. Até se chegar ao estágio mais avançado, essa área representa uma densidade "óssea" aumentada, o que pode gerar problemas reabsortivos no dente a ser movimentado, caso alguns cuidados não sejam tomados. Por outro lado, os implantes podem ser aplicados, apesar da presença da raiz submersa, independentemente da fase evolutiva. Conclusão: É natural que, em raízes submersas, se instale a anquilose alveolodentária e a reabsorção dentária por substituição, e o seu estágio evolutivo será determinante na conduta a ser adotada no planejamento clínico.

What changes in the biology of bone movement induced with mini-implants/miniplates is the synchronicity

ABSTRACT Introduction: Induced tooth-bone movement occurs by a synchronicity of dental and bone phenomena, thanks to the osteocytic network, which is a three-dimensional network that controls the bone shape or design. Objective: To describe the tooth-bone movement induced by enhanced anchorage, divided into three distinct moments: zero, start and stop. Question: From this description, the main question arises: with the use of mini-implants/miniplates, what changes in the biology of induced tooth-bone movement? The answer is: nothing changes, either biologically or microscopically. Conclusion: This technique optimizes the treatment time, and the range of therapeutic possibilities is broadened, thanks to the synchronicity of phenomena - which remain the same, in all teeth and bones, yet in a synchronized manner. Bone anchorage represents synchronicity in induced tooth-bone movement.

RESUMO Introdução: A movimentação osseodentária induzida ocorre meio de uma sincronicidade de fenômenos dentários e ósseos, graças à rede osteocítica, uma rede tridimensional de controle do formato ou design ósseo. Objetivo: Descrever a movimentação osseodentária induzida com ancoragem ampliada, dividindo-a em três momentos distintos: zero, start e stop. Questionamento: Dessa descrição origina-se a principal pergunta: com o uso de mini-implantes/miniplacas, o que muda na biologia da movimentação osseodentária induzida? A resposta é: não muda nada, nem biologicamente, nem microscopicamente. Conclusão: O que se otimiza, com essa técnica, é o tempo de tratamento, e se amplia o leque de possibilidades terapêuticas, graças à sincronicidade dos fenômenos - que continuam sendo os mesmos, em todos os dentes e nos ossos, só que de forma sincronizada. A ancoragem óssea representa a sincronicidade na movimentação osseodentária induzida.

Novo método de sobreposição mandibular usando o programa Autodesk Inventor® para avaliação da acurácia do protocolo G8 da Invisalign® / New mandibular superposition method using Autodesk Inventor® software to evaluate the accuracy of the Invisalign® G8 protocol

O uso de alinhadores transparentes tem se tornado um fenômeno mundial na clínica ortodôntica e muitos esforços e recursos têm sido consumidos para que o resultado do tratamento seja o mais acurado possível. Em 2021 a Invisalgn® lançou protocolo G8 prometendo melhor previsibilidade no tratamento. É através da sobreposição de imagens que estes resultados podem ser avaliados. Na literatura, encontram-se relatos de diversos métodos e softwares que buscam confiabilidade para sobreposição de modelos tridimensionais (3D), entretanto não há consenso sobre estes métodos. Desta forma, os objetivos deste estudo foram: (1) Desenvolver novo método de sobreposição de modelos 3D com Autodesk Inventor®, (2) avaliar a reprodutibilidade do Autodesk Inventor® utilizando o sistema de coordenadas universais (UCS) associado a único ponto para sobreposição de modelos ortodônticos 3D da mandíbula e maxila, (3) avaliar a reprodutibilidade do Autodesk Inventor® na sobreposição de modelo ortodôntico 3D da maxila e mandíbula, (4) Comparar a acurácia do protocolo G8 através do resultado previsto pelo ClinCheck® com o resultado real obtido nos movimentos de intrusão e expansão dentária posterior. Para responder os objetivos 1, 2 e 3, foram selecionados 11 pares de modelos em STL (estereolitografia) de ambos os arcos exportados pelo software My Itero® e tratados com Invisalign® em dois tempos: início (T0) e refinamento (T1). As sobreposições foram realizadas utilizando os softwares Slicer® (versão 4.1) e Autodesk Inventor® usando como referência os planos dos 3 eixos cartesianos UCS (X, Y e Z) associado a um ponto na segunda ruga palatina na maxila e, na mandíbula, um ponto na linha muco gengival lingual. Após a sobreposição os movimentos de translação buco-lingual dos caninos, pré-molares e molares superiores e inferiores, intrusão, rotação dos caninos e incisivos mandibulares foram analisados por dois examinadores calibrados. Para responder o objetivo 4, a acurácia foi comparada nos movimentos alcançados e previstos pelo ClinCheck® entre três casos em que o protocolo G8 foi ativado e 8 casos em que não foi ativado para a expansão posterior maxila e mandíbula, intrusão de caninos e incisivos inferiores. Os resultados do objetivo 1, 2 e 3 foram coeficientes de correlação intraclasse (ICC) maior que 0,90 em todas as medidas, não foi observado erro sistemático avaliado pela fórmula de Dahlberg. Nos resultados do objetivo 4 não foram observadas diferenças estatísticas significativas entre os grupos. A acurácia no grupo G8 quando comparada ao grupo não G8 para expansão posterior na mandíbula e maxila aumentou 12.7% e 7,8% respectivamente, mas não houve diferenças estatísticas significante. Para o movimento de intrusão, a acurácia do grupo G8 foi 7,7% maior que a do grupo não G8 sem diferença estatística entre eles. Não foram observadas diferenças estatísticas significativas nos movimentos dos dentes dos grupos G8 e não G8. Concluiu-se que o método desenvolvido se mostrou reprodutível para sobreposição de modelos tridimensionais. O protocolo G8, quando ativado, não apresenta maior acurácia para o tratamento com Invisalign®.

The use of clear aligners has become a worldwide phenomenon in orthodontic practice and much effort and resources have been expended to ensure that the treatment outcome is as accurate as possible. In 2021 Invisalgn® released the G8 protocol promises better treatment predictability. It is through image superimposition that these results can be evaluated. In the literature, there are reports of various methods and software that seek reliability for superimposing three-dimensional (3D) models, but there is no consensus on these methods. Thus, the objectives of this study were: (1) Develop a new method for superimposing 3D models with Autodesk Inventor®, (2) evaluate the reproducibility of Autodesk Inventor® using the universal coordinate system (UCS) associated with a single point for superimposing 3D orthodontic models of the mandible and maxilla (3) Evaluate the reproducibility of Autodesk Inventor® in superimposing orthodontic 3D models of the maxilla and mandible, (4) Compare the accuracy of the G8 protocol through the result predicted by ClinCheck® with the actual result obtained in intrusion movements and posterior dental expansion. To answer the objectives 1, 2 and 3, 11 pairs of STL (Stereo- lithography) models of both arches exported by My Itero® software and treated with Invisalign® were selected at two times: initial (T0) and refinement (T1). The superpositions were performed using the Slicer® (version 4.1) and Autodesk Inventor® software using as reference the planes of the three Cartesian axes (X, Y and Z) associated with a point on the second palatal crease in the maxilla and, in the mandible, a point on the lingual mucous gingival line. After superimposition, the bucco-lingual translation movements of the canines, premolars and upper and lower molars, intrusion, rotation of the canines and mandibular incisors were analyzed by two calibrated examiners. To answer the objective 4, the accuracy was compared in the movements achieved and predicted by ClinCheck® between three cases in which the G8 protocol was activated and 8 cases in which it was not activated for maxillary and mandibular posterior expansion, canine and mandibular incisor intrusion. The results of objectives 1, 2 and 3 were intraclass correlation coefficients (ICC) greater than 0.90 in all measurements, no systematic error evaluated by the Dahlberg formula was observed. In the results of objective 4, no statistically significant differences were observed between the groups. The accuracy in the G8 group when compared to the non-G8 group for posterior expansion in the mandible and maxilla increased by 12.7% and 7.8% respectively but without statistically significant differences. For intrusion movement, the accuracy of the G8 group was 7.7% higher than the non G8 group with no statistical difference between groups. No statistically significant differences were observed in the tooth movements of the G8 and non-G8 groups. It was concluded that the developed method proved reproducible for three- dimensional model superimposition. The G8 protocol, when activated, does not present greater accuracy for treatment with Invisalign®

Do orthodontic tooth movements induce pulp necrosis? A systematic review.

BACKGROUND: Orthodontic tooth movements are performed by applying forces on teeth, which may cause alterations within the dental pulp. Previously published systematic reviews on the subject only included a small number of studies that assessed pulp status through reliable diagnostic methods. Since then, new evidence has been published, and a further systematic review on the subject is necessary. OBJECTIVES: To evaluate whether there is scientific evidence to support the possibility that orthodontic tooth movements could induce pulp necrosis. METHODS: A systematic search of articles published until June 2020 was performed using MeSH and free terms in the PubMed, Cochrane Library, LILACS, SciELO, Web of Science, EMBASE, Open Grey and Grey Literature databases. Randomized clinical trials (RCTs), nonrandomized clinical trials (nRCTs) and longitudinal (prospective or retrospective) studies that evaluated the pulp status of teeth subjected to orthodontic movements using laser Doppler flowmetry or pulse oximetry were included. The revised Cochrane risk of bias tools for randomized trials (RoB 2) and nonrandomized interventions (ROBINS-I) were used to assess the quality of the included studies. Relevant findings were summarized and evaluated. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. RESULTS: Initial screening of databases resulted in 353 studies. In total, 285 studies were excluded because they were duplicates. Of 68 eligible papers, fourteen met the inclusion criteria and were selected for full-text reading. Two studies were excluded due to the methods used to evaluate pulp status. Twelve studies (five RCTs, one nRCT and six prospective) were included. Four RCTs were classified as having an unclear risk of bias and one as having a high risk of bias. The nRCT was classified as having a low risk of bias. Two prospective studies were classified as having a moderate risk of bias and four as having a serious risk of bias. The GRADE analysis demonstrated a low to very low quality of evidence. DISCUSSION: Significant limitations regarding the randomization processes within the included RCTs and a lack of control of confounders on most nonrandomized and longitudinal studies were verified. CONCLUSIONS: This systematic review indicates that orthodontic movements do not induce loss of pulp vitality with low to very low certainty of evidence.

Effects of diabetes on oxidative stress, periodontal ligament fiber orientation, and matrix metalloproteinase 8 and 9 expressions during orthodontic tooth movement.

OBJECTIVES: To evaluate the influence of diabetes on oxidative stress, periodontal ligament (PDL) orientation, and matrix metalloproteinase (MMP) 8 and 9 expressions during orthodontic tooth movement in a rat model. MATERIALS AND METHODS: An orthodontic appliance was placed in 60 Sprague-Dawley rats divided into three groups: normoglycemics (n = 20) and two streptozotocin-induced diabetic groups, one untreated (n = 20) and one insulin-treated (n = 20). At 24, 48, and 72 h and 1 week, rats were sacrificed. At each time point, myeloperoxidase (MPO) and malondialdehyde (MDA) were quantified by spectrophotometry, tooth movement was evaluated by micro-CT analysis, and hematoxylin and eosin staining was used to evaluate PDL fiber orientation and immunohistochemistry staining with semi-quantitative H-score analysis of MMP-8 and MMP-9 was performed.. RESULTS: At 24 h, MPO activity was significantly higher in untreated-diabetics than normoglycemics. At 24 and 48 h, the MDA level in untreated-diabetic rats was significantly higher than in normoglycemics and insulin-treated animals. At 72 h and 1 week, PDL fibers were oriented significantly more irregularly in untreated-diabetics than in normoglycemics. At all time points, MMP-8 and MMP-9 expressions were significantly higher in both diabetic groups than in the normoglycemic group. After the second day, tooth movement was significantly greater in untreated-diabetics than in the insulin-treated and normoglycemic groups. CONCLUSIONS: Mechanical stress in untreated-diabetic rats produces more inflammatory response, oxidative stress, tooth movement, PDL disorganization, and MMP-8 and MMP-9 expressions than among normoglycemics. Insulin reverses these effects, favoring the reorganization of periodontal ligament. CLINICAL RELEVANCE: Our results suggest that the application of orthodontic force in diabetic patients would increase inflammation and delay periodontal restructuring. Insulin would partly reverse this situation although glycemic decompensation episodes may occur. For these reasons, the periods between fixed orthodontic appliance activations should be of sufficient duration to allow adequate tissue recovery.

Previsibilidade de movimentos dentários com alinhadores estéticos ­ acelerando a curva de aprendizagem / Predictability of orthodontic movement with aesthetic aligners ­ accelerating the learning curve

Resumo A utilização correta dos alinhadores transparentes está diretamente ligada com a velocidade da curva de aprendizagem pela qual passam os profissionais. As maiores dificuldades parecem ser a indicação correta dos casos, o gerenciamento do fluxo digital e o manejo clínico, que estão intrinsecamente ligados ao conhecimento do funcionamento da técnica, ou seja, das propriedades de liberação de forças (propriedades mecânicas dos materiais termoplásticos), quando utilizadas em um contexto de customização por meio de sistemas CAD/CAM. Para um melhor entendimento do tema em relação aos tipos de movimentos dentários, esse artigo estabelece uma classificação de dificuldade em três categorias, variando de acordo com a quantidade de alinhadores necessários: até 10 fases (placas) para casos simples (movimentos pontuais), até 20 fases para os casos moderados e acima de 20 alinhadores para casos complexos computando-se sempre por arcada dentária (AU)

Abstract The correct use of clear aligners is directly linked to the speed of the learning curve that professionals go through. The biggest difficulties seem to be the correct indication of the cases, the management of the digital workflow and the clinical management, which are intrinsically linked to the knowledge of the technique's details, that is, the force-delivery properties (mechanical properties of thermoplastic materials), when used in a context of CAD/CAM systems customization. For a better understanding of the topic in relation to the types of tooth movement when using aligners, this article establishes a classification of difficulty into three categories, varying according to the number of aligners needed: up to 10 phases for simple cases, up to 20 phases for moderate cases, and above 20 aligners for more complex cases, always computing the aligner's number by each dental arch. (AU)

Láser de baja potencia y aceleración de movimientos dentarios en ortodoncia: revisión sistemática / Low-level laser accelerating dental movements in orthodontics: systematic review

Según la literatura científica, ¿El láser de baja potencia propicia la aceleración de los movimientos dentarios durante el tratamiento ortodóntico? El objetivo de este trabajo buscasistematizar sobre la capacidad del láser de baja potencia en la aceleración de los movimientos dentarios durante el tratamiento ortodóncico. Para ello, se realizó una revisión sistemática, una búsqueda empleando buscadores booleanos en la plataforma de PubMed. Las palabras clave empleadas para fueron: orthodontic movement, orthodontic tooth movement, orthodontic, orthodontic treatment, low level laser therapy, low level laser,laser therapy y la combinación entre ellos. Las investigaciones incluidas trataron el tema de la aceleración del movimiento dentario durante el tratamiento de ortodoncia empleando láser de baja potencia. Se incluyeron en este estudio publicaciones de revistas indexadas en PubMed, ensayos clínicos, en idioma inglés y que correspondieran a artículos publicados desde el año 2000 a la fecha. A si también,se realizó evaluación del riesgo de sesgo. Las variables analizadas fueron: autor principal, título, año, tipo de artículo, revista, país de investigación y si los artículos demuestran que el láser de baja potencia aumenta el movimiento dentario durante el tratamiento ortodóncico. Los resultados arrojaron que el 60% de los estudios incluidos concluyen que el láser de baja potencia acelera el movimiento dentario durante el tratamiento de ortodoncia; el 30% de estos no encontraron cambios significativos con relación a los grupos estudiados con los de control y un 10% resultó en conclusiones dudosas. Por lo tanto, a pesar de que los resultados son alentadores por la tendencia en que el láser de baja potencia si acelera los movimientos ortodónticos, sería necesaria la presencia de un número superior de estudios clínicos aleatorizados para un esclarecimiento específico de las bondades que aporta esta terapia al sector.

According to scientific literature, does low-power laser promote acceleration of tooth movements during orthodontic treatment? The objective for this work seeksto systematize the ability of the low-power laser to accelerate tooth movements during orthodontic treatment.For this,a systematic review was carried out, a search using Boolean search engines on the PubMed platform. The keywords used for were: orthodontic movement, orthodontic tooth movement, orthodontic, orthodontic treatment, low level laser therapy, low level laser, laser therapy and the combination between them. The included investigations dealt with the issue of acceleration of tooth movement during orthodontic treatment using low-power laser, were from journals indexed in PubMed, clinical trials, in English, and corresponded to articles published since 2000 to date. Assessment of risk of bias was performed. The variables analyzed were: main author, title, year, type of article, journal, country of research, and whether the articles show that low-power laser increases tooth movement during orthodontic treatment.The results showed that 60% of the included studies conclude that the low-power laser accelerates tooth movement during orthodontic treatment, 30% of these did not find significant changes in relation to the groups studied with those of control and 10% resulted in dubious conclusions. Thus, although the results are encouraging due to the trend in which the low-power laser does accelerate orthodontic movements, the presence of a higher number of randomized clinical studies would be necessary for a specific clarification of the benefits that this therapy brings to the patient. sector.

A systematic review of the effective laser wavelength range in delivering photobiomodulation for pain relief in active orthodontic treatment.

OBJECTIVE: This systematic review aimed to establish an effective wavelength range for PhotoBioModulation (PBM) to relieve pain in orthodontic treatments. MATERIAL AND METHODS: The electronic literature search was carried out in the following databases: PubMed, ISI Web of Science, Scopus, and Cochrane. In the initial search, 255 papers were obtained. Deleting duplicates in the search left 180 items. One manually searched study was included for a total of 181 studies. According to PRISMA guidelines and a thorough analysis of their methodology, the final sample was composed of 13 RCTs. The final statistical analysis was performed in 11 studies. The statistical analysis sought to strengthen the collected data, determining the correlation coefficient (r) for the same time interval (24h) using a scale equivalent to the standard value (0-10cm). Aiming to reduce the effect of heterogeneity, the difference in cm between control group (GC) and experimental group (EG) averages was considered the outcome. This difference was correlated with the wavelength in nm, calculating the Pearson linear correlation coefficient, and calculating a logarithmic correlation. RESULTS: The dispersion of the data obtained in the experimental groups at each given wavelength showed that the most significant number of studies were in the ranges of 780-830nm. The correlation between the wavelength and the difference between the control and experimental group averages, either linear (R2=0.0564, r=0.237) or logarithmic (R2=0.0688, r=0.262) was not significant (P>0.90). Therefore, pain reduction after 24h is not significantly dependent of wavelength. CONCLUSION: The majority of RCTs related to pain relief in orthodontic treatment showed 780-830nm as the most effective photobiomodulation wavelength range for orthodontic pain relief. However, pain reduction after 24h is not significantly dependent of wavelength. The protocol was registered in PROSPERO (CRD42019119799).

Changes in clinical and microbiological parameters of the periodontium during initial stages of orthodontic movement in patients with treated severe periodontitis: A longitudinal site-level analysis.

Applying orthodontic braces makes oral hygiene difficult and increases plaque accumulation, frequently resulting in gingival inflammation. In patients with previous severe periodontitis, this inflammation overlaps with the pre-existing inflammatory challenge and can lead to further progression of periodontal attachment loss. The aim of this study was to assess longitudinal site-level changes as mirrored by clinical and microbiological parameters during the initial remodeling of alveolar bone and the periodontal ligament, produced as an effect of light orthodontic forces in adult patients with severe periodontal disease that underwent standard (non-surgical and conventional surgical) periodontal therapy. Thirteen patients with previously treated severe generalized periodontitis were given fixed orthodontic appliances for re-alignment of teeth misaligned or displaced during the course of periodontitis. Before insertion of orthodontic appliances and at 2, 4, and 6 months of treatment, periodontal clinical parameters were recorded in the same deepest residual pocket of at least 3 mm in each patient. The same pocket was sampled at baseline and after 6 months of orthodontic treatment for the frequency of positive detection of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tanerella forsythia (Tf), Treponema denticola (Td). An average reduction in Pocket Depth by 0.2 mm at the end of the assessment period was identified. The only clinical parameter with statistically significant improvement was bleeding on probing. The frequency of detection of Aa, Pg, Pi, and Tf was not significantly different between baseline and 6 months of treatment, while a marginally significant increase of Td was found. There were no significant differences in the clinical parameters or microflora in the initial phase of orthodontic treatment in patients with reduced periodontal support. By correlating clinical and microbiological data, we concluded that the presence of periopathogens do not negatively influence periodontal health during orthodontic treatment in adult patients treated for severe periodontitis.