Treatment outcomes of pulp revascularization in traumatized immature teeth using calcium hydroxide and 2% chlorhexidine gel as intracanal medication

Abstract Objective Pulp revascularization is an effective treatment for immature necrotic teeth. Calcium hydroxide has been used in pulp revascularization as an intracanal medication due to its antimicrobial action and the non-exhibition of crown discoloration and cytotoxicity for stem cells from the apical papilla. Our study aimed to investigate the clinical success and quantitative radiographic changes of root development in immature traumatized teeth using calcium hydroxide plus 2% chlorhexidine gel as intracanal medication. Methodology In this retrospective study, 16 patients were treated with a standardized pulp revascularization protocol. Calcium hydroxide and 2% chlorhexidine gel were manipulated in a 1:1 (v/v) ratio and inserted into root canals with Lentulo spirals (Dentsply Maillefer, Baillaigues, Switzerland). Patients were followed up for a period from 9 to 36 months for the evaluation of clinical and radiological data. Radiographic measurements of root length, root width, apical diameter, and MTA placement from the apex were quantified using software ImageJ. Wilcoxon test and t-test were used, according to nonparametric or parametric data, respectively, for changes over time in root length, root width, and apical diameter. Results Fifteen teeth survived during the follow-up period (93.75%) and met the criteria for clinical success. Although the changes seem to be very small in many cases, significant increases in the average root length (14.28%, p<0.0001), root width (8.12%, p=0.0196), and decrease in apical diameter (48.37%, p=0.0007) were observed. MTA placement from the apex and age at the time of treatment was not significantly associated with the quantitative radiographic outcomes. Conclusions Pulp revascularization in traumatized immature teeth treated with calcium hydroxide plus 2% chlorhexidine gel as intracanal medication had high success and survival rates, showing periodontal healing and resolution of signs and symptoms. However, concerning the continued root development, the outcomes can still be considered unpredictable.

Pulp analysis of teeth submitted to different types of forces: a histological study in rats

Abstract Objective: The purpose of this study was to histologically evaluate pulp and dentin under induced tooth movement (ITM) with different types of forces. Material and Methods: The maxillary right first molars of rats were submitted to movement with continuous (CF), continuous interrupted (CIF) and intermittent (IF) forces during 5, 7 and 9 days with nickel-titanium (NiTi) closed-coil springs exerting 50cN force magnitude. The groups were histologically evaluated as for cellularity pattern, presence of dystrophic, hemodynamic alterations in the pulp as well dentin alterations. The main observed alterations were related to hemodynamic pulp characteristics, such as presence of thrombosis, vascular congestion and hemorrhages. The hemodynamic alterations were statistically evaluated by Shapiro-Wilk normality test and analysis of variance by the Kruskall-Wallis test. Results: There was no significant differences observed between groups in the different types of applied forces and duration of ITM (vascular congestion, p=1.000; hemorrhage, p=0.305; thrombosis, p=1.000). Conclusions: Pulp tissue alterations resulting from ITM were limited to hemodynamic events, without progressing to irreversible degeneration, regardless of the type of force applied.

Clinical study on autologus platelet-rich fibrin aided revascularization of immature permanent teeth / 北京大学学报(医学版)

OBJECTIVE@#To compare the clinical treatment efficiency of platelet-rich fibrin (PRF) assisted revascularization and traditional revascularization in immature permanent teeth.@*METHODS@#Eighteen non-vital immature permanent teeth of sixteen patients which were diagnosed as necrotic pulpitis with (or without) periapical inflammations were treated with PRF assisted revascularization. Twenty-two teeth non-vital immature permanent teeth of twenty patients which were diagnosed as necrotic pulpitis with (or without) periapical inflammations were treated with traditional revascularization. All the cases were accorded with inclusive criteria and were treated at Pediatric Dentistry of Peking University School and Hospital of Stomatology. The cases were followed up clinically and radiographically at regular intervals. Clinical examinations and periapical radiographs were recorded and analyzed. Clinical success rate was evaluated based on the clinical and radiographic findings. The changes of root length, dentine wall thickness and apical foramen width of the teeth from the two groups were measured and compared according to the preoperative and by recalling the periapical radiographs.@*RESULTS@#The cases were followed up for 6-16 months. Clinically, totally 17 out of the 18 teeth in PRF group and 21 out of the 22 teeth in traditional group were asymptomatic with no sensitivity to percussion or palpation. PRF group tended to be more effective than traditional group clinically without significant differences (P=0.446). Radiographically, 15 out of the 18 teeth in PRF group and 15 out of the 22 teeth in traditional group displayed that the roots developed, showing that root length and dentine wall thickness increased and apical foramen closed. There was a marked difference in dentine wall thickening in PRF group in comparison with traditional group (P=0.039). However, the changes of root length increasing (P=0.411) and apical foramen width closure (P=0.737) were comparable in both groups. The result in electric pulp test (P=0.517), root canal calcification (P=0.324) and crown discolor (P=0.386) were also comparable in the two groups.@*CONCLUSION@#PRF assisted revascularization and traditional revascularization in non-vital immature permanent teeth which were diagnosed as necrotic pulpitis with (or without) periapical inflammations resulted in similar clinical outcomes. Both methods showed good prognosis. PRF revascularization seemed to have better effect on dentine wall thickening than traditional method.

In-office bleaching effects on the pulp flow and tooth sensitivity – case series

Laser Doppler flowmetry (LDF) is a noninvasive method capable of evaluating variations in pulp blood flow (PBF) and pulp vitality. This method has thus far not been used to assess changes in blood flow after in-office bleaching. The aim of this case series report was to measure changes in PBF by LDF in the upper central incisor of three patients submitted to in-office bleaching. The buccal surfaces of the upper arch were bleached with a single session of 35% hydrogen peroxide gel with three 15-min applications. The color was recorded using a value-oriented Vita shade guide before in-office bleaching and one week after the procedure. The tooth sensitivity (TS) in a verbal scale was reported, and PBF was assessed by LDF before, immediately, and one week after the bleaching session. The lower arch was submitted to dental bleaching but not used for data assessment. A whitening degree of 3 to 4 shade guide units was detected. All participants experienced moderate to considerable TS after the procedure. The PBF readings reduced 20% to 40% immediately after bleaching. One week post-bleaching, TS and PBF were shown to be equal to baseline values. A reversible decrease of PBF was detected immediately after bleaching, which recovered to the baseline values or showed a slight increase sooner than one week post-bleaching. The LDF method allows detection of pulp blood changes in teeth submitted to in-office bleaching, but further studies are still required.

Estudo da resposta pulpar em pacientes portadores de neoplasias malignas de cabeça e pescoço submetidos à radioterapia / Evaluation of pulp response in patients undergone radiation therapy for treatment of head and neck cancer

Introdução: a radioterapia promove alterações na cavidade oral e na polpa dental que conduzem a mudanças na sensibilidade frente a estímulos em contato com a superfície dental. Torna-se necessário investigar a ocorrência dessas alterações e estabelecer o diagnóstico pulpar e perirradicular dos elementos remanescentes em áreas submetidas à irradiação ionizante, com o intuito de prevenirem-se os processos patológicos periapicais, descritos como fatores precipitadores de osteorradionecrose. Objetivo: avaliar as respostas pulpares ao teste de vitalidade com gás refrigerante tetrafluoroetano, em pacientes, submetidos à radioterapia e em um grupo de controle, em três agrupamentos dentários distintos (incisivos inferiores, incisivos superiores e caninos). Casuística e método: foram testados 91 dentes hígidos de pacientes de ambos os gêneros submetidos à radioterapia para o tratamento de neoplasias malignas de cabeça e pescoço e 103 dentes de pacientes do grupo de controle. Resultados: verificou-se que a diferença significativa (p<.05) entre os dois grupos com relação às respostas negativas apresentadas; não houve diferença entre os agrupamentos dentários avaliados. Conclusão: os pacientes submetidos à radioterapia de cabeça e pescoço apresentam amior número de elementos dentais com resposta negativa ao teste de vitalidade pulpar quando comparados com um grupo de controle

Introduction: alterations promoted by radiation therapy in the oral cavity and in dental pulp leads to sensitiveness changes in enamel surface when in contact with some external stimuli. The investigation of these changes and the establishment of the pulpal and perapicaql diagnosis of the elements remained in irradiated sites, in order to prevent pathological process that have been described as osteoradionecrosis developing factors, is mandatory. Objective: to evaluate the pulp response obtained by tetrafluoroethane in patients under gone radiation therapy and in a control group, in three dental groups (maxillary incisors, mandibular incisors and canines). Patients and methods: 91 teeth were tested in patients in both genders submitted to radiation therapy for head and neck malignances and 103 teeth in a control group. Results: the results showed sifnificant difference (p<.05) between the groups evaluated related to negative responses, despite no difference between the dental groups. Conclusion: patients undergoing radiation therapy in tghe head and neck present a greater number of teeth with negative response to the vitality test in comparison to the control group

Initial pulp changes during orthodontic movement: histomorphological evaluation

This study evaluated pulp changes in molars of rats submitted to tooth movement by application of a 0.4 N force. Twenty-five adult male Wistar rats (Rattus norvegicus, albinus) were randomly assigned to 5 groups (n=5), being one control group not submitted to force application, and four study groups of 6, 12, 24 and 72 h of force application. The study groups received a 5-mm long nickel-titanium closed coil spring, placed from the right maxillary first molar to the maxillary incisors of each animal. The coil spring was used for mesial inclination of the first molar. After the specific period of tooth movement of each study group, the animals were sacrificed and specimens containing the teeth submitted to movement were processed and stained with hematoxylin and eosin for histological analysis under light microscopy. The results demonstrated alteration of the odontoblastic layer, with hypertrophy of odontoblasts especially at the mesial area of the coronal pulp, edema of the pulp connective tissue in the central area of the pulp, and vascular alteration with accumulation of erythrocytes and leukocytes inside the vessels, especially at the mesial root of the moved teeth. These changes were less remarkable for the 72-h period. Thus, it may be concluded that tooth movement yielded pulpal tissue alterations compatible with an inflammatory process, which are reversible if the aggression is not more intense than the physiological limit of tissue tolerance.

Este estudo avaliou alterações pulpares em molares de ratos movimentados com amplitude de força de 0,4 N. Vinte e cinco ratos machos adultos Wistar (Rattus norvegicus, albinus) foram aleatoriamente alocados em 5 grupos (n=5), sendo 1 grupo controle não submetido à aplicação de força, e 4 grupos teste submetidos a 6, 12, 24 e 72 h de aplicação de força. Os grupos teste receberam uma mola fechada tipo coil spring de níquel-titânio com 5 mm de comprimento, fixada do primeiro molar superior direito até os incisos superiores do animal. A mola tipo coil spring foi utilizada para mesialização do primeiro molar. Após o período específico de movimentação de cada grupo experimental, os animais foram sacrificados e as peças contendo o dente movimentado e o seu tecido pulpar foram processadas e coradas com hematoxilina e eosina para análise histológica em microscopia de luz. Os resultados mostraram alteração da camada de odontoblastos com hipertrofia dessas células, principalmente na região mesial da polpa coronária; edema no tecido conjuntivo pulpar, evidenciado na região central da polpa; alteração vascular, com acúmulo de eritrócitos e leucócitos dentro da luz dos vasos, principalmente na raiz mesial do dente movimentado. Essas alterações foram menos evidentes no período de 72 h. Dessa forma, conclui-se que o movimento dentário provoca alterações pulpares teciduais compatíveis com processo inflamatório, as quais são reversíveis se a agressão não ultrapassar o limite de tolerância do tecido.

Assessment of the efficacy of an indigeniously developed pulse oximeter dental sensor holder for pulp vitality testing.

Current routine methods of assessment of pulp vitality rely on stimulation of nerve fibres and give no direct indication of blood flow within the pulp. Pulse oximeter is a proven, atraumatic method of measuring vascular status, by evaluating oxygen saturation. This study explores the use of customized dental pulse oximeter sensor holder to assess pulpal vascular oxygen saturation in permanent teeth. Pulse oximeter readily differentiated between known vital and nonvital teeth. Vital teeth consistently provided oxygen saturation values that were lower than the values recorded on the patient's fingers. Pulse oximeter is an accurate, atraumatic clinical alternative to the present electrical and thermal methods of assessing pulp vitality in teeth.

Circulação pulpar, metabolismo dentinário e cárie dentária / Pulpal blood circulation, dentin metabolism and dental caries

Este trabalho enfoca com bastante realce o papel que a circulação sanguínea pulpar e o metabolismo dentinário exercem sobre a suscetibilidade do dente à carie dentária. O acúmulo de ácido láctico dentinário é o fator mais importante da condição de isquemia pulpar e da alteração do metabolismo dentinário. Em condições onde existe um acúmulo de ácido láctico dentinário e um aumento da pressão osmótica salivar, a difusão de ácido láctico da dentina para o esmalte pode estar muito aumentada. Nesta situação, a passagem de ácido láctico pelo esmalte, se em quantidade suficiente, pode provocar a descalcificação dos cristais de hidroxiapatita localizados na sua trajetória, aumentando, assim, a permeabilidade do esmalte e, conseqüentemente, a sua suscetibilidade à cárie

Efeito da isquemia sobre a atividade glicolítica dentinária de molares de ratos / Effect of ischemia on the dentin glycolytic activity of rats molar teeth

Uma avaliaçäo da atividade glicolítica dentinária foi feita em dentes molares de ratos em condiçöes de isquemia tendo em vista que a circulaçäo pulpar é importante na manutençäo da resistência dentinária à carie dentária. Coroas dentárias dos dentes molares de ratos controles e isquêmicos foram trituradas em um gral de porcelana contendo água ou KOH 1N, centrifugadas e nos sobrenadantes dosados ácido láctico, fosfato inorgânico, glicose e glicogênio, respectivamente. Os resultados demonstram que o estado isquêmico provoca um aumento da atividade glicolítica dentinária de forma semelhante ao dos tecidos moles, isto é, aumento do conteúdo de ácido e fosfato inorgânico e diminuiçäo de glicose e glicogênio