Traumatic compressive stress inhibits osteoblast differentiation through long chain non-coding RNA Dancr.

BACKGROUND: Occlusal trauma is an important local contributing factor aggravating periodontal pocket and alveolar bone absorption in periodontal diseases. Our previous studies have found that occlusal trauma inhibited osteogenic differentiation through nuclear factor (NF)-κB signaling. To further investigate the underlying mechanism, the aim of this study was to explore the role of long chain non-coding differentiation antagonizing non-protein coding RNA (Dancr) in the inhibitory effect of traumatic stress on osteoblast differentiation. METHODS: We took the MC3T3-E1 cells as object in vitro research and stimulated cells with simple stress load, Dancr-siRNA + stress load, Dancr overexpression-plasmid + stress load. Quantitative real-time polymerase chain reaction was used to detect the RNA expression levels of Dancr, alkaline phosphatase (Alp) and Runt-related transcription factor 2 (Runx2). The protein expressions of Alp and Runx2 were tested by Western blot and the activity of Alp was qualitatively demonstrated by Alp staining. In addition, Western blot was performed to investigate the role of Dancr in affecting NF-κB signaling pathway. RESULTS: Traumatic compressive stress inhibited the expressions of Alp, Runx2, andDancr in MC3T3-E1 cells. Stress-induced inhibition of osteoblast differentiation was promoted after silencing Dancr. Overexpression of Dancr could alleviate the inhibitory effect of traumatic force on osteoblast differentiation to some extent. Furthermore, NF-κB signaling was activated after silencing Dancr, and the activated effect of traumatic force on NF-κB signaling could be alleviated through overexpression of Dancr to some extent. CONCLUSION: Traumatic compressive stress can indirectly activate the NF-κB signaling through downregulation of Dancr, thereby inhibiting osteogenic differentiation.

Falha no Tratamento da Avulsão Dentária Infantil: Relato de Caso / Failure in child tooth avulsion treatment: a case report

Objetivo: este artigo tem como objetivo demonstrar a abordagem de um trauma alveolar dentário no qual o reimplante dentário foi realizado no Sistema Único de Saúde (SUS) e encaminhado para acompanhamento a longo prazo em uma Clínica Odontológica da Universidade do Nordeste do Brasil. Relato de caso: paciente do sexo masculino, 7 anos, encaminhado à Clínica Odontológica da Universidade Tiradentes para acompanhamento em longo prazo de um reimplante dentário do elemento 11. Durante o exame clínico, observa-se um grau severo de mobilidade dentária, além da presença de fístula na linha do muco gengival do dente. Radiograficamente, observou-se espessamento do ligamento periodontal e áreas de extensa reabsorção externa. O acompanhamento do caso durou aproximadamente 1 ano. Conclusão: portanto, é essencial que o profissional cirurgião-dentista tenha conhecimento para o correto diagnóstico e agilidade neste tratamento urgente, a fim de preservar o órgão dentário na cavidade oral por mais tempo

Introduction: dental trauma is an injury that mainly affects children and adolescents. Tooth avulsion is one of the most common causes of trauma, which is the expulsion of the alveolar tooth. The prognosis is due to pulp and support tissue repair, however, it is associated with complications such as functional, aesthetic and psychological problems, and is doubtful and dependent on rapid behavior. Objective: this article aims to demonstrate the approach of a dental alveolar trauma in which dental reimplantation was performed in the Unified Health System (SUS) and referred for long-term follow-up in a University Dental Clinic of Northeast Brazil. Case report: a 7-year-old male patient, referred to the Dental Clinic of Universidade Tiradentes for long-term follow-up of a dental reimplantation of element 11. During the clinical examination, a severe degree of tooth mobility can be observed, in addition to presence of fistula in the gingival mucus line of the tooth. Radiographically, thickening of the periodontal ligament and areas of extensive external resorption were observed. The follow-up of the case lasted approximately 1 year. Conclusion: thus, it is essential that the dental surgeon professional has knowledge for the correct diagnosis and agility in this urgent treatment, in order to preserve the dental organ in the oral cavity for a longer time.

Orthodontic Management of a Migrated Maxillary Central Incisor With a Secondary Occlusal Trauma.

INTRODUCTION: Normal or excessive occlusal forces exerted on teeth with a reduced periodontal support might result in a secondary occlusal trauma. This type of injury is diagnosed based on histological changes in the periodontium. Multiple clinical and radiographic indicators are, therefore, required as surrogates to assist the presumptive diagnosis of a (secondary) occlusal trauma. CASE PRESENTATION: In this case report, the diagnosis, management, and the 1-year follow-up of a secondary occlusal trauma of a maxillary central incisor are described. The occlusal relationship was rehabilitated with fixed orthodontic appliances and was further stabilized with both fixed and removable retainers. CONCLUSIONS: A combined periodontal-orthodontic approach for a secondary occlusal trauma allows the rehabilitation of periodontal, occlusal, and esthetic parameters. Twelve months after the end of the active orthodontic treatment, a combination of fixed and removable retainers showed to be effective in retaining the treatment outcome.

Occlusal trauma inhibits osteoblast differentiation and bone formation through IKK-NF-κB signaling.

BACKGROUND: Occlusal trauma is an important factor promoting bone loss caused by periodontal diseases. Although there are reports of traumatic force promoting bone resorption in periodontal diseases, no studies examining the inhibition of bone formation by traumatic force and the underlying mechanism have been reported. The aim of this study was to investigate the mechanism whereby traumatic force inhibits bone formation. METHODS: MC3T3-E1 cells were induced to undergo osteogenic differentiation and subjected to cyclic uniaxial compressive stress with or without stimulation with Pg. LPS. The expression of osteoblast markers and the activation of IKK-NF-κB signaling were evaluated in vitro. Then, MC3T3-E1 cells were induced to undergo osteogenic differentiation and subjected to cyclic uniaxial compressive stress with or without IKK-2 Inhibitor VI. The expression of osteoblast markers was determined. Then, the classic Wnt signaling pathway (ß-catenin, Gsk3ß, p-Gsk3ß, and Dkk1) was further evaluated in vitro. Finally, occlusal trauma was induced in Wistar rats with or without the injection of IKK-2 Inhibitor VI, to evaluate changes in bone mass and IKK-NF-κB and Wnt/ß-catenin signaling in vivo. RESULTS: After stimulation with Pg. LPS and traumatic force, IKK-NF-κB signaling was significantly activated in vitro. The expression of osteoblast markers and the activity of alkaline phosphatase in MC3T3-E1 cells declined after traumatic force loading and were rescued when IKK-NF-κB signaling was blocked. Wnt/ß-catenin signaling was accordingly inhibited upon force loading, but this inhibition was reversed when IKK-NF-κB was antagonized in vitro. X-ray and Micro-CT analysis of the mandibles of the rats as well as HE and TRAP staining showed that bone loss induced by occlusal trauma declined after IKK-NF-κB was inhibited. The expression of p65 and IκBα was increased when occlusal trauma was induced in Wistar rats, whereas ß-catenin, OCN, and Runx2 levels were decreased. After blocking IKK-NF-κB, significant upregulation of ß-catenin, OCN, and Runx2 was observed in rats suffering from occlusal trauma. CONCLUSIONS: IKK-NF-κB signaling could be activated by traumatic force or occlusal trauma. Its activation promoted the degradation of ß-catenin, ultimately inhibiting osteogenic differentiation in vitro and bone formation in vivo.

Influência da oclusão traumática no processo de reparo do periodonto em dentes submetidos à subluxação / The influence of traumatic occlusion on the repair process in teeth subjected to subluxation

A subluxação caracteriza-se pelo dano ao ligamento periodontal (LP) com sangramento e mobilidade anormal do dente; e a presença de edema na região apical do dente pode provocar discreta extrusão. O objetivo desse estudo foi avaliar a influência da oclusão traumática (OT) no processo de reparo do periodonto em dentes submetidos à subluxação, por meio de análises histomorfométricas e imunoistoquímica. Para este estudo, 90 ratos Wistar com 12 semanas de idade; foram distribuídos em três grupos: controle (C), subluxação (S) e subluxação com oclusão traumática (S+OT); nos períodos experimentais de 7 e 21 dias. A subluxação foi induzida pela aplicação de uma força de 900cN no sentido ocluso-gengival na superfície oclusal do 1ºMSD calibrada por um tensiômetro e a OT foi induzida por uma restauração de resina composta na superfície oclusal do primeiro molar superior direito (1°MSD). Para comparação estatística entre os grupos e períodos foi usado o teste de Kruskal-Wallis com Dunn post hoc teste. No período de 7 dias, houve um aumento significativo da espessura do LP (S34% e S+OT-80%), da substância fundamental amorfa (S-84% e S+OT-148%) e uma redução significativa da área óssea (S-60,8% e S+OT-81,8%) em relação ao grupo controle. Aos 21 dias houve um aumento da espessura do ligamento periodontal significativo no grupo S+OT e na porcentagem de fibras colágenas (S-86%) no grupo S, mas não no grupo S+OT. A porcentagem de substância fundamental amorfa permaneceu proporcionalmente aumentada nos dois grupos experimentais e o perfil nuclear mostrou um aumento significativo no grupo S quando comparada ao período de 7 dias. Nos 2 grupos experimentais também houve um aumento do número de células TRAP positivas tanto no LP (4x) quanto no osso do septo alveolar (16x). O grupo S apresentou um pequeno aumento na porcentagem da área óssea do septo alveolar, enquanto no grupo S+OT houve redução de 52% da área óssea quando comparada ao mesmo grupo no período de 7 dias. A subluxação com ou sem a OT provocou apenas reabsorções radiculares superficiais e a OT foi capaz de prejudicar o reparo das áreas radiculares reabsorvidas após a subluxação no período de 21 dias. Assim conclui-se que a oclusão traumática agravou os danos no ligamento periodontal, no osso alveolar e na superfície radicular gerados após a subluxação, bem como atrasou o processo de reparo dos mesmos(AU)

Subluxation is characterised by damage to the periodontal ligament (PDL), accompanied by bleeding and abnormal tooth mobility. The presence of edema in the apical region of the tooth can provoke discrete extrusion. The aim of this study was to assess the influence of traumatic occlusion (TO) on the periodontal repair process in teeth submitted to subluxation, by means of histomorphometrical and immunohistochemical analyses. For this study, 90 Wistar rats aged 12 weeks were divided into three groups: control (C), subluxation (S) and subluxation with traumatic occlusion (S+TO); with experimental periods of 7 and 21 days. Subluxation was induced by applying a 900cN force in the occlusal-gingival sense on the occlusal surface of the 1st SRM calibrated by a tensiometer. TO was induced by a composed resin restoration on the occlusal surface of the first superior right molar (1st SRM). The Kruskal-Wallis with Dunn post-hoc test was used for group and period comparison. At 7 days, there was a significant increase in PDL width (S-34% and S+TO-80%), amorphous fundamental substance (S-84% and S+TO-148%), and a significant reduction of bone surface (S-60.8% and S+TO-81.8%), in comparison to the control group. After 21 days, there was a significant increase in the periodontal ligament width in group S+TO and in the percentage of collagen fibres in group S (86%), but not in group S+TO. The percentage of amorphous fundamental substance remained proportionally increased in the two experimental groups, and the nuclear profile showed a significant increase in group S, compared to the 7 days period. In the two experimental groups an increase in positive TRAP cells was also observed, in the PDL (4x) as well as in the bone area of the alveolar septum (16x). Group S presented a small increase in the alveolar septum's bone area, whereas group S+TO showed a 52% bone area reduction compared to the same group at 7 days. The subluxation with or without TO caused only superficial root resorption. The TO was able to damage the repair processo of reabsorbed root areas after 21 days of subluxation. It can be concluded that traumatic occlusion aggravates post-subluxation damage to the periodontal ligament, the alveolar bone and the radicular surface, and has a delaying effect on the repair process(AU)

Influence of the occlusal interference time on masticatory muscle mechanical hyperal-gesia in rats / 北京大学学报(医学版)

Objective:To investigate the relationship between the removal time of 0.2 mm occlusal in-terference and the recovery of masticatory muscle mechanical hyperalgesia in rats.Methods:Forty male Sprague-Dawley rats (200-220 g)were randomly assigned to eight groups,with five rats in each group:(1 )nave group:these rats were anesthetized and their mouths were forced open for about 5 min (the same duration as the other groups),but restorations were not applied;(2 )sham-occlusal interference control group:bands were bonded to the right maxillary first molars which did not interfere with occlu-sion;(3 )occlusal interference group:0.2 mm thick crowns were bonded to the right maxillary first molars;(4)2,3,4,5,and 6 d removal of occlusal interference groups:0.2 mm thick crowns were bonded to the right maxillary first molars and removed on days 2,3,4,5,and 6.The nave group and sham-occlusal interference control group were control groups.The other groups were experimental groups. Bilateral masticatory muscle mechanical withdrawal thresholds were tested on pre-application days 1 ,2, and 3,and on post-application days 1 ,3,5,7,1 0,1 4,21 and 28.The rats were weighed on pre-application day 1 and on post-application days 1 ,2,3,4,5,6,and 7.Results:Between the nave group and the sham-occlusal interference control group,there was no significant difference in the mastica-tory muscle mechanical withdrawal threshold of bilateral temporalis and masseters at each time point.No significant difference was detected between the contralateral side and ipsilateral side in experimental groups (P>0.05 ).In the 2,3,4,and 5 d removal of occlusal interference groups,the masticatory muscle mechanical withdrawal thresholds decreased after occlusal interference and increased after removal of the crowns and recovered to the baseline on days 7,1 0,1 4,and 1 4,respectively [the masticatory muscle mechanical withdrawal thresholds of right masseter muscle were (1 37.46 ±2.08)g,(1 39.02 ± 2.1 1 )g,(1 40.40 ±0.98)g,(1 38.95 ±0.98)g,respectively].In the 6 d removal of occlusal inter-ference group,the masticatory muscle mechanical withdrawal threshold increased after removal of the crowns and became stable since day 1 4.There was a significant difference between the 6 d removal of oc-clusal interference group and the sham-occlusal interference group on day 28(P<0.05),the masticatory muscle mechanical withdrawal thresholds of right masseter muscle were (1 31 .24 ±0.76 ) g and (1 41 .34 ±1 .43)g,respectively.Conclusion:After removal of the 0.2 mm thick crown within 5 days, the mechanical hyperalgesia of the rats could reverse completely.The mechanical hyperalgesia of the rats could only be relieved,but not reverse completely after removal of the 0.2 mm thick crown on day 6.As the time went on,even minor occlusal interference could cause irreversible mechanical hyperalgesia of masticatory muscles.This study suggested that occlusal interference caused by dental treatment should be eliminated as soon as possible,to avoid irreversible orofacial pain.

Traumatismo dentario. Presentación de un caso / Dental Trauma. A Case Report

Los traumas dentarios en niños y niñas son frecuentes, razón por la cual el estomatólogo debe estar capacitado para darles solución. En el presente trabajo se expone el diagnóstico, tratamiento y evolución del caso de un niño con resalte de 12 mm, hábito de respiración bucal y cierre bilabial incompetente, que sufrió trauma severo en el diente 11, lo que le causó movilidad de este. Se aplicó una férula al diente afectado y posteriormente se realizó tratamiento pulporadicular, todo ello con una evolución satisfactoria. Aunque estos traumas son comunes, la presentación de este caso es de interés, por su utilidad en el contexto docente.

Dental traumas in children are common; therefore the dentist should be trained to solve them. This paper presents the diagnosis, treatment and outcome of a child with a 12 mm overjet, mouth breathing habit and bilabial incompetence who suffered a severe trauma to tooth number 11, causing its mobility. A splint was applied to the affected tooth and subsequently, a root canal filling was performed, all with a satisfactory outcome. Although these traumas are common, the presentation of this case is important due to its use in the teaching context.

Considerations about the relation between occlusal trauma and periodontal: peri-implant disease / Considerações sobre a relação entre trauma oclusal e doença periodontal: peri-implantar

O trauma oclusal é uma injúria ao aparato de inserção como resultado de força oclusal excessiva, e sua interação com a doença periodontal/peri-implantar permanece um tema muito discutido na literatura. O objetivo neste artigo foi realizar uma revisão de literatura acerca da relação entre trauma oclusal e doença periodontal/peri-implantar, por meio de uma análise de estudos experimentais em humanos e animais, bem como de revisões sistemáticas que discutiram o papel do fator oclusal como etiológico ou agravante da doença periodontal/peri-implantar. Concluiu-se que apesar de não ser considerado fator etiológico para o desenvolvimento de periodontite e peri-implantite, o trauma oclusal pode agravar a perda óssea ao redor de dentes ou implantes. Além disso, a diversidade das metodologias nos estudos sobre o assunto pode contribuir para os resultados conflitantes disponíveis, destacando-se a importância da padronização e maior detalhamento dos critérios de pesquisa.

The occlusal trauma is an injury to the insertion apparatus as a result of excessive occlusal force, and its interaction with periodontal/peri-implant disease remains controversial topic in the literature. The aim of this study was to review the literature about the relationship between occlusal trauma and periodontal/peri-implant disease, through an analysis of experimental studies in humans and animals, as well as systematic reviews that discussed the role of occlusal factor as etiological or aggravating periodontal/periplant disease. It was concluded that, although not considered a cause for the development of periodontitis and periimplantitis, occlusal trauma may exacerbate bone loss around the teeth or implants. Moreover, the diversity of methodologies in studies on the subject might contribute to the conflicting results available, highlighting the importance of standardization and more detailed research criteria.

Traumatic dental injuries among 12-15-year-old-school children in panchkula.

BACKGROUND: Traumatic dental injury (TDI) in children and adolescents has become one of the most serious dental public health problems. Despite such a high prevalence of dental trauma, very less attention has been paid to TDI, its etiology, and prevention. OBJECTIVES: To determine the prevalence of anterior tooth traumatic dental injuries in 12-15-year-old school children of Panchkula district, India, and to find any correlation with the cause, gender, extent of overbite as well as over-jet, and previous treatment. PATIENTS AND METHODS: A multistage sample of 12-15-year-old school children (n = 810) in Panchkula district, Haryana, was selected. The children were screened using WHO criteria for oral examination and a trained dental surgeon examined the children. Those with clinical TDI were examined further for the type of traumatic injuries using Elis classification modified by Holland. Overjet and overbite were recorded. After examination, questions regarding the cause of trauma and its treatment were asked. Data were subjected to statistical analysis using the Chi square and Mantel-Haenszel tests by SPSS version 20.0. RESULTS: The results showed that out of 810 children, 86 (10.2 %) had TDI. Males had higher prevalence of trauma than females (P < 0.05). The common cause of trauma was fall (51.11%) followed by sports injuries (41.86%). Enamel-dentin fracture without pulpal involvement was the most common type of trauma and the most frequent involved teeth were maxillary central incisors. A significant association was observed between overjet and overbite and trauma. Only 3.5% of the children affected with trauma had received treatment. CONCLUSIONS: The prevalence of traumatic injuries to permanent incisors in 12-15-year-old Panchkula school children was relatively high. TDI was associated with gender, overjet, and lip competence. There was a great unmet treatment need.

Tratamento de perda óssea por trauma oclusal primário. Relato de caso / Treatment of bone loss by occlusal trauma. Case report

A distribuição correta de forças oclusais deve ser uma preocupação constante para os profissionais da odontologia, isto para que propicie a manutenção do equilíbrio entre os elementos do sistema estomatognático. Quando as forças oclusais excedem o limite fisiológico dos tecidos, pode ocorrer injúria nos tecidos periodontais decorrente do trauma oclusal. A paciente MLC, branca do sexo feminino 53 anos compareceu à pesquisa de oclusão e dor orofacial da Faculdade de Odontologia da UFG com quadro clínico de mobilidade no primeiro pré-molar inferior esquerdo, hipersensibilidade ao toque no mesmo e reabsorção óssea na região face mesial. Ao exame clínico observou-se desvio da mandíbula para a esquerda, devido a interferência na vertente mesial da cúspide mésio palatina do primeiro molar superior esquerdo, a referida interferência projetava a mandíbula para anterior e para a esquerda resultando em trauma oclusal no segundo pré-molar inferior esquerdo. O dente sob trauma não apresentava bolsa periodontal e respondeu positivamente ao teste de vitalidade pulpar. Observou-se que a dor e a mobilidade foram causadas pela interferência, caracterizando trauma oclusal primário. Para eliminar o contato prematuro, o tratamento indicado foi o ajuste oclusal por desgaste seletivo, num total de cinco sessões. Após quatro meses de acompanhamento verificou-se ao exame radiográfico neoformação óssea na região mesial do referido dente, com desaparecimento da mobilidade e de toda sintomatologia associada. Concluindo, assim, o ajuste oclusal por desgaste seletivo pode ser indicado em casos de trauma oclusal, desde que este seja o fator tiológico.

The correct distribution of occlusal forces should be a constant concern for dental professionals, to ensure that conducive to maintaining the equilibrium between the elements of the stomatognathic system. When occlusal forces exceed the physiological limit tissue, injury can occur in periodontal tissues resulting from occlusal trauma. The patient MLC, white female 53 years old attended the search occlusion and orofacial pain, School of Dentistry of UFG with clinical mobility in the first premolar left, hypersensitivity to touch and even bone reabsorption in the mesial region. On clinical examination there was deviation of the jaw to the left, because interference in mesial aspect mesial palatal cusp of the maxillary first molar left, the interference projected the mandibular anterior and to the left resulting in injury in the second premolar left . The tooth under trauma showed no periodontal pocket and responded positively to the test pulp vitality. It was observed that the pain and mobility were caused by interference, characterizing primary occlusal trauma. To eliminate premature contact, the indicated treatment was occlusal adjustment by selective grinding. After four months of follow-up was found to radiographic bone formation in the region of the mesial said tooth, with disappearance of mobility and all associated symptoms. In conclusion, therefore, occlusal adjustment by selective grinding can be used in cases of occlusal trauma, since this is the etiologic factor.

O efeito da carga oclusal no processo de reparo do ligamento periodontal após reimplante imediato em molar de ratos: avaliação histológica e imunoistoquímica / The effect of occlusal load on the repair process of the periodontal ligament after immediate replantation in rat molars: histological and immunohistochemical assessment

Busca-se ainda encontrar o melhor tratamento para os casos de reimplantes imediatos ou tardios, visto que estes seriam considerados os tratamentos ideais em caso de avulsão. Fatores como período extra-alveolar, meios de conservação, contaminação, fase de rizogênese dental, uso de contenção e trauma oclusal podem interferir no prognóstico dos reimplantes. A função oclusal favorável é um estímulo mecânico necessário para a manutenção da homeostasia dos tecidos periodontais, já a falta ou o excesso de carga oclusal resulta na desarmonia do funcionamento dos tecidos periodontais. O objetivo deste estudo foi avaliar o efeito da carga oclusal após o processo de reparo de reimplante imediato em molares de ratos. Foram utilizados 280 ratos wistars divididos em três grupos experimentais(oclusão normal, infraoclusão e supraoclusão) e um grupo controle total, os mesmos foram divididos em nove períodos. As análises qualitativas e quantitativas foram realizadas em cortes histológicos corados pelo método da hematoxilina e eosina, e imunorreatividade para apoptose celular. Os dados foram comparados através da análise de variância (ANOVA), Kruskal-Wallis e Bonferroni como teste post-hoc, considerando p<0,05 como significante. No período inicial (1 a 3 ou 5 dias) a espessura do espaço do LPD (ligamento periodontal) do terço cervical dos dentes reimplantados, apresentou um aumento estatisticamente significante da espessura em todos os grupos experimentais quando comparados ao grupo controle total. O grupo oclusão normal e infraoclusão apresentaram uma redução na porcentagem da área de vasos, perfil celular e espessura do espaço do LPD, na maioria dos períodos estudados. O grupo supraoclusão apresentou uma maior reabsorção radicular, seguido dos grupos oclusão normal e infra-oclusão. Concluiu-se que a carga oclusal recebida pelos dentes reimplantados modifica o padrão do processo de reparo do ligamento periodontal; e que o trauma oclusal acelera significativamente a reabsorção...

An ideal protocol treatment for cases of immediate or delayed tooth replantation hasn’t been developed yet, although tooth replantation is considered the best treatment in cases of tooth avulsion. Factors like extra-alveolar time, storage, contamination, dental rizogenesis phase, use of a splint, and occlusal trauma can interfere in the replantation prognosis. The normal occlusal function is a mechanical stimulus that is necessary for the maintenance of the homeostasis of periodontal tissue, whereas the absence or excess of occlusal load results in a disharmonic functioning of periodontal tissues. The aim of this study is to assess the influence of occlusal load during the repair process of immediate and delayed replantation of rat molars. They used 280 Wistar rats divided into three groups (normal occlusion, and infraocclusion supraoclusão) and a control group total, they were divided into nine periods. Qualitative and quantitative analysis will be performed in histological cuts, using the hematoxylin eosin staining protocol, and cells that display immunoreactivity to cellular apoptosis. The data will be submitted to variance analysis A or Kruskal-Wallis), using SPSS 16.0 at a significance level of p<0.05. In the initial period the thickness of the cervical third of the PDL of replanted teeth showed a statistically significant increase in all test groups, compared to the control group. A percentage reduction of blood vessel area, cell profile and PDL thickness was observed in the majority of studied periods. The supra-occlusal group showed a higher level of radicular resorption, followed by the normal and infra-occlusion groups. In face of the limitations of this study, it was concluded that the occlusal load absorbed by replanted teeth modifies the repair process of the PDL. Occlusal trauma accelerates the radicular resorption of replanted teeth significantly

Parameter on Occlusal Traumatism in Patients With Chronic Periodontitis.

The American Academy of Periodontology has developed the following parameter on occlusal traumatism in patients with chronic periodontitis. Occlusal therapy is an integral part of periodontal therapy. Patients should be informed about the occlusal problem, therapeutic alternatives, potential complications, expected results, and their responsibility in treatment. Consequences of no treatment should be explained. Failure to treat occlusal traumatism appropriately in patients with chronic periodontitis may result in progressive loss of bone and an adverse change in prognosis, and could result in tooth loss. Given this information, patients should then be able to make informed decisions regarding their periodontal therapy. J Periodontol 2000;71:873-875.