Wound-healing Processes After Pulpotomy in the Pulp Tissue of Type 1 Diabetes Mellitus Model Rats.

INTRODUCTION: Patients with type 1 diabetes mellitus (DM1) tend to have delayed wound healing, even in the pulp tissue. We hypothesized that hyperglycemia affects odontoblast-like cell (OLC) differentiation and is involved in macrophage polarization. Accordingly, we evaluated dental pulp stem cell differentiation and macrophage phenotypes after pulpotomy. METHODS: After modifying DM1 rat models by streptozotocin, 8-week-old rats' upper left first molars were pulpotomized with mineral trioxide aggregate. Meanwhile, the control group was administered saline. Immunohistochemical localization of nestin, osteopontin, α-smooth muscles (α-SMAs), and CD68 (pan-macrophage marker) was conducted 7 days after pulpotomy. The OLC differentiation stage was determined using double immunofluorescence of nestin and α-SMA. Double immunofluorescence of CD68 and iNOS was counted as M1 macrophages and CD68 and CD206 as M2 macrophages. Proliferating cell nuclear antigen and Thy-1 (CD90) were evaluated by immunofluorescence. RESULTS: In DM1 rats, the reparative dentin bridge was not complete; however, the osteopontin-positive area did not differ significantly from that in controls. Proliferating cell nuclear antigen, indicative of cell proliferation, increased in positive cells in DM1 rats compared with controls. Double-positive cells for α-SMA and nestin indicated many immature OLCs in DM1. CD90 was positive only in controls. CD68-positive cells, especially M1 macrophages, were increased in DM1 rats, allowing the inflammatory stage to continue 7 days after pulpotomy. CONCLUSIONS: The condition of DM1 model rats can interfere at various stages of the wound healing process, altering OLC differentiation and macrophage polarization. These findings highlight the importance of normal blood glucose concentrations during pulp wound healing.

Multimodal Imaging of Dental Pulp Healing Patterns Following Tooth Autotransplantation and Regenerative Endodontic Treatment.

INTRODUCTION: Understanding the healing process of dental pulp after tooth autotransplantation (TAT) and regenerative endodontic treatment (RET) of immature teeth is important both clinically and scientifically. This study aimed to characterize the pattern of dental pulp healing in human teeth that underwent TAT and RET using state-of-the-art imaging techniques. MATERIALS AND METHODS: This study examined 4 human teeth, 2 premolars that underwent TAT, and 2 central incisors that received RET. The premolars were extracted after 1 year (case 1) and 2 years (case 2) due to ankylosis, while the central incisors were extracted after 3 years (cases 3 and 4) for orthodontic reasons. Nanofocus x-ray computed tomography was used to image the samples before being processed for histological and immunohistochemical analysis. Laser scanning confocal second harmonic generation imaging (SHG) was used to examine the patterns of collagen deposition. A maturity-matched premolar was included as a negative control for the histological and SHG analysis. RESULTS: Analysis of the 4 cases revealed different patterns of dental pulp healing. Similarities were observed in the progressive obliteration of the root canal space. However, a striking loss of typical pulpal architecture was observed in the TAT cases, while a pulp-like tissue was observed in one of the RET cases. Odontoblast-like cells were observed in cases 1 and 3. CONCLUSIONS: This study provided insights into the patterns of dental pulp healing after TAT and RET. The SHG imaging sheds light on the patterns of collagen deposition during reparative dentin formation.

The outcomes of auto-transplanted premolars in the anterior maxilla following traumatic dental injuries.

BACKGROUND/AIMS: Tooth auto-transplantation is a treatment option, which is often not considered to replace anterior maxillary incisors in children and adolescents. There are multiple prognostic factors that may influence the outcomes of premolar auto-transplantation, but there is limited evidence from human studies. The aim of this study was to report the outcomes of auto-transplanted premolars in the anterior maxilla following traumatic dental injuries (TDIs) and to identify their prognostic factors. MATERIALS AND METHODS: The clinical records of patients who had premolars transplanted in the anterior maxilla following TDI, with appropriate radiographs and a minimal of 1-year follow-up, were reviewed retrospectively. A specific data extraction form was developed, tested and used to collect information for the prognostic factors and outcomes. RESULTS: The cohort included 120 patients with 144 auto-transplanted premolars. The mean age was 12.2 years (±2.0), and the mean observation period was 3.7 years (±1.8). The success rate was 80%, and the survival rate was 93%. Unfavourable outcomes included external replacement resorption in 12.5%, uncontrolled external inflammatory resorption in 2.7%, and both resorption types in 4.9% of teeth. Periodontal healing was significantly associated with donor tooth root maturity, graft handling at the time of surgery including ease of donor tooth extraction and placement at the recipient sites, recipient site alveolar bone status, and post-operative transplant mobility. Seventy-four teeth (53.4%) were immature at the time of transplantation where pulp revascularisation was anticipated, and 52 (70%) of those had radiographic and clinical signs of pulp healing. Pulp healing was significantly related to donor tooth eruption stage, ease of extraction of donor tooth, and ease of placement in the recipient site. CONCLUSIONS: Good outcomes were observed for premolar teeth auto-transplanted in the anterior maxilla. The main prognostic factors were ease of extraction of donor tooth and ease of placement in the recipient sites and donor tooth root maturity.

Prognóstico pulpar após lesões por luxação em dentes permanentes: uma análise de riscos competitivos / A retrospective cohort study of pulp prognosis in luxated permanent teeth: a competing risk analysis

As lesões por luxação representam o grupo de lesões traumáticas dento-alveolares (LTDA) caracterizadas pelo dano simultâneo ao feixe vásculo-nervoso periapical e estruturas de sustentação dentária, em diferentes graus de complexidade, dependendo da força e direção do impacto. A patogenia das alterações pulpares decorrentes das luxações é resultado da extensão da lesão do feixe vásculo-nervoso apical e de sua capacidade de reparo, que determinam os seguintes desfechos para a polpa: manutenção da vitalidade pulpar, manutenção da vitalidade pulpar com obliteração da cavidade pulpar (OCP) ou a necrose pulpar. Entretanto, o processo de reparo pulpar pode envolver fenômenos intermediários cujos sinais e sintomas se modificam ao longo do período de acompanhamento até um diagnóstico definitivo. Sendo assim, do ponto de vista clinico, o tempo até a observação destas respostas, bem como seus fatores determinantes, representa uma informação tão importante quanto o próprio desfecho, pois tem influência direta na tomada de decisão sobre as condutas clinicas mais adequadas. A presente pesquisa consistiu num estudo clínico longitudinal retrospectivo com o objetivo de avaliar o prognóstico pulpar de dentes permanentes portadores de lesões por luxação, seu padrão cronológico e fatores determinantes, entre os pacientes atendidos na Clínica de Traumatismos Dentários da Faculdade de Odontologia da Universidade Federal de Minas Gerais no período de 2014 a 2022. Foram analisados prontuários de 224 pacientes com 427 dentes permanentes portadores de luxações, acompanhados por um período mediano de 1,4 anos (variação de 11 dias a 6,9 anos). O padrão de resposta pulpar foi classificado como manutenção da vitalidade pulpar, OCP e necrose pulpar através da avaliação clínica e radiográfica. Uma análise de sobrevivência utilizando-se o modelo de riscos competitivos foi realizada e curvas de função de incidência acumulada (FIA) foram construídas para se avaliar as taxas de cada um dos desfechos pulpares utilizando-se o estimador de Aalen-Johansen. O efeito de variáveis independentes, incluindo sexo, idade do paciente no momento do trauma, estágio de desenvolvimento radicular, grupo dentário, tipo de luxação, presença de fratura coronária concomitante e prescrição de antibioticoterapia sistêmica (ATS), foi avaliado utilizando-se um modelo multivariado de Cox causa-específico. Os dados foram analisados no programa estatístico R (versão 4.0.4, Viena, Áustria, 2021). Os resultados demonstraram manutenção da vitalidade pulpar em 38,2% da amostra (163 dentes), necrose pulpar em 28,1% (120 dentes) e OCP em 12,9% da amostra (55 dentes). O tempo mediano para o diagnóstico de necrose pulpar foi de 3 meses, enquanto o tempo para vitalidade pulpar foi de 8 meses e para OCP foi de 16 meses A probabilidade de manutenção de vitalidade pulpar diminuiu significativamente com a ocorrência de fraturas coronárias de esmalte e dentina concomitantes (HR 0,38 IC 95% [0,2 ­ 0,8] p = 0,006). A taxa de necrose pulpar foi significativamente menor em dentes com forame apical amplo (HR 0,62 IC 95% [0,4 ­ 0,96] p = 0,03) mas aumentou significativamente em dentes com luxações associadas às fraturas coronárias (HR 4,0 IC 95% [2,6 - 6,1] p = 0,001) e em dentes portadores de luxações intrusivas (HR 2,3 IC 95% [1,2 - 4,1] p = 0,007). Dentes portadores de luxações laterais ou extrusivas (HR 3,0 IC 95% [1,3 ­ 6,9] p = 0,001) ou com forame amplo (HR 2,4 IC 95% [1,2 ­ 4,7] p=0.01) apresentaram as maiores taxas de OCP.

Luxation injuries are a group of traumatic dental injuries (TDI) that involve damage to both the pulp and periodontium, with different degrees of complexity. Pulp damage results from injury to the apical neuro-vascular bundle and, depending on the repair potential, may result in the following outcomes: maintenance of pulp vitality, maintenance of pulp vitality with pulp canal obliteration (PCO) or pulp necrosis. However, the pulp healing process may involve intermediate and reversible phenomena whose signs and symptoms mimic pulp necrosis, rendering the timing of these events critical for decision-making during the follow-up period. The present study consisted in a retrospective cohort to evaluate the pulpal prognosis of luxated permanent teeth, its chronological pattern and predictive factors, among patients treated at the Dental Trauma Clinic of the Federal University of Minas Gerais, from 2014 to 2021. Records of 224 patients with 427 permanent teeth with luxations, followed up for a median period of 1.4 years (ranging from 11 days to 6.9 years) were analysed. Pulp outcomes - maintenance of pulp vitality, PCO and pulp necrosis were defined trough clinical and radiographic evaluation. A competing risk survival analysis was performed and cumulative incidence function (CIF) curves were build using the Aalen-Johansen estimator to assess the rates of each of the pulp outcomes during the follow-up period. The effect of independent variables including patient's gender and age at the time of trauma, tooth group and stage of root development, type of luxation, concomitant injuries, systemic antibiotic therapy (SAT) prescription, was evaluated using a cause-specific Cox regression model. Data were analysed in the R statistical program (version 4.0.4, Vienna, Austria, 2021). The results showed maintenance of pulp vitality in 38.2% of the sample (163 teeth), pulp necrosis in 28.1% (120 teeth) and OCP in 12.9% of the sample (55 teeth). The median time for the diagnosis of pulp necrosis was 3 months, while the time for pulp vitality was 8 months and for PCO was 16 months. The hazards of pulp vitality significantly decreased with the occurrence of concomitant coronal fractures (HR 0 .38 95% CI [0.2 ­ 0.8] p = 0.006). The hazards of pulp necrosis was significantly lower in teeth with a wide apical foramen (HR 0.62 95% CI [0.4 ­ 0.96] p = 0.03) but increased significantly in teeth with luxations associated with crown fractures (HR 4.0 CI 95% [2.6 - 6.1] p = 0.001) and in teeth with intrusive displacement (HR 2.3 CI 95% [1.2 - 4.1] p = 0.007). Teeth with lateral or extrusive luxations (HR 3.0 CI 95% [1.3 ­ 6.9] p = 0.001) or with a wide foramen (HR 2.4 CI 95% [1.2 ­ 4.7] p =0.01) showed the highest rates of PCO.

Cicatrização e prognóstico no longo prazo de fraturas radiculares transversais pós-traumáticas: estudo clínico longitudinal / Healing and long-term prognosis of root fractured permanent teeth: a retrospective longitudinal study

Fraturas radiculares são lesões traumáticas dento-alveiolares (LTDA) complexas que afetam dentina, cemento, polpa e o ligamento periodontal, sendo frequente a ocorrência de lesões concomitantes ao fragmento coronário. São lesões relativamente raras com frequências relatadas variando entre 1,2% e 7% das LTDA na dentição permanente, sendo mais comuns em dentes com completo desenvolvimento radicular. O presente estudo consistiu em um levantamento clínico longitudinal retrospectivo para avaliar dados de 87 pacientes, portadores de 104 dentes permanentes com fraturas radiculares transversais, atendidos na Clínica de Traumatismos Dentários da Faculdade de Odontologia da UFMG, durante o período de 1995 a 2022. Com base na análise dos prontuários, avaliou-se o padrão radiográfico de cicatrização na linha de fratura, seguindo os critérios estabelecidos por Andreasen e Hjorting-Hansen (1967), em dois momentos: no período inicial após o trauma e ao final do período de acompanhamento. Uma análise de sobrevivência de risco competitivo foi realizada para estimar as taxas dos eventos de cicatrização no período inicial após o trauma, bem como o efeito das variáveis demográficas, clínicas e relacionadas ao tratamento. Os resultados demonstraram um percentual de 51,9% de cicatrização no curto prazo, diagnosticada em até 5 meses após o trauma. A não cicatrização com interposição de tecido de granulação na linha de fratura foi fortemente influenciada pela presença e tipo de lesão concomitante no fragmento coronário. Dentes com fraturas de esmalte e dentina (sHR 24,38, IC 95% [3,16 - 188,3], p = 0,0022), luxações com deslocamentos (sHR 10,58, IC 95% [1,37 - 81,9], p = 0,0240) e subluxações (HR 9,66, IC 95% [1,14 - 81,7], p = 0,0370) apresentaram as maiores taxas de não cicatrização das fraturas radiculares no curto prazo. A taxa de cicatrização no longo prazo foi de 70,1%, a maioria delas com interposição de osso e tecido conjuntivo. A estatística Kappa demonstrou uma concordância global de 67,1% entre as modalidades de cicatrização no período inicial e no longo prazo, especialmente para os padrões tecido mineralizado e tecido conjuntivo/osso.

Root fractures are complex traumatic dental injuries (TDI) affecting dentin, cementum, pulp and supporting tissues, generally associated to concurrent injuries to the coronal fragment. They are uncommon injuries with reported frequencies varying between 1.2% and 7% of all TDI in permanent teeth, being more frequent in teeth with complete root development. In the present study we retrospectively evaluated data from 87 patients with104 root-fractured permanent teeth treated at the Dental Trauma Clinic from the Federal University of Minas Gerais, during the period from 1995 to 2022. Clinical dan radiographic data was collected from patient's records to establish healing patterns in the fracture line, following the criteria established by Andreasen & Hjorting-Hansen (1967), at two moments: in the initial period after the trauma and at the end of the follow-up period. A competing risk survival analysis was performed to estimate rates of healing events in the early period after trauma as well as the effect of demographic, clinical, and treatment-related variables. The results showed a rate of 51.9% of healing in the short term, diagnosed in a maximum median period of 5 months after trauma. Non-healing with interposition of granulation tissue at the fracture line was strongly influenced by the presence and type of concomitant lesion in the coronal fragment. Teeth with associated enamel -dentin fractures (sHR 24.38, 95% CI [3.16 - 188.3], p = 0.0022), luxations with dislocations (sHR 10.58, 95% CI [1.37 - 81.9], p = 0.0240) and subluxations (HR 9.66, 95% CI [1.14 - 81.7], p = 0.0370) had the highest rates of non-healing of root fractures in the short term. The long-term healing rate was 70.1%, most of them with interposition of bone and connective tissue. Kappa statistics demonstrated an overall agreement of 67.1% between short and long-term healing patterns, in special HT and CT+ Bone modalities.

The role of angiogenesis and pulpal healing in tooth replantation and allograft transplantation.

Tooth transplantation is one of the treatment options for extracted teeth that can be considered before dental implantation. Although the success rate of tooth transplantation is lower than that of implantation, tooth replantation and transplantation have the great advantage of using natural teeth. Tooth replantation might be considered a promising option in some cases. In present study, the expression patterns of revascularization and pulpal healing, which are the most important for the pulp viability, were analyzed after tooth replantation and allograft in mice. The inflammatory response and root dentin resorption were observed and not different between replantation and allograft in initiation of healing process. However, bonelike tissue formation, pulp revascularization and pulp healing were faster in replantation. The difference of healing patterns between tooth replantation and allograft found in present study will be helpful to select the treatment option and to understand healing mechanism.

Glucose Transporter 2 and 4 Are Involved in Glucose Supply during Pulpal Wound Healing after Pulpotomy with Mineral Trioxide Aggregate in Rat Molars.

INTRODUCTION: Pulp capping materials allow healing of injured pulp with a layer of reparative dentin. Glucose is needed to cure the injured area. Glucose is transported by glucose transporter (Glut) 2 and Glut4, which are transmembrane proteins that act as gatekeepers. We hypothesized that the transport of glucose via Glut2/Glut4 might contribute to the production of a dentin bridge during wound healing. Therefore, we explored Glut2 and Glut4 expression during reparative dentinogenesis after mineral trioxide aggregate capping. METHODS: The upper left first molar of 8-week-old Wistar rats underwent pulpotomy with mineral trioxide aggregate. At 1, 3, 5, 7, and 14 days after treatment, localization and colocalization of Glut2, Glut4, nestin (odontoblast marker), and antiendothelial cell antigen 1 (RECA-1; endothelial cell marker) were analyzed with immunohistochemical staining. Messenger RNA expression levels of Slc2a2 (encoding Glut2), Slc2a4 (encoding Glut4), Igf-1r (encoding insulinlike growth factor 1 receptor), and nestin were analyzed in the extracted teeth using real-time polymerase chain reaction. RESULTS: Glut2 and Glut4 were localized within odontoblasts and endothelial cells in normal control teeth. Three days after pulpotomy, Glut2- and Glut4-positive cells were detected; 7 days after pulpotomy, immunoreactivity for Glut2 and Glut4 was confined to newly differentiated odontoblastlike cells arranged beneath reparative dentin. Messenger RNA expression levels of Slc2a2 and Slc2a4 were significantly up-regulated after pulpotomy. CONCLUSIONS: Glut2 and Glut4 regulate glucose transport during wound healing beneath the injured area. This may contribute to the development of new vital pulp therapy for patients with deep caries.

Photobiomodulation in Pediatric Dentistry: A Current State-of-the-Art.

Objective: Given the tremendous progress in biophotonics applications in biology and engineering, we sought to examine the evidence for the use of low-dose biophotonics treatments, termed photobiomodulation (PBM) therapy, in pediatric dentistry. Background: PBM therapy has been noted to alleviate pain and inflammation while promoting tissue healing and regeneration. These basic processes contribute to the fundamental etiopathogenesis of various oral diseases, and hence, there is now a growing list of potential clinical applications with PBM therapy in children. Materials and methods: An exhaustive literature search was conducted for PBM studies in pediatric dentistry that includes patients up to 21 years of age. An analysis of the quality of the included studies was also performed to evaluate the rigor of the evidence. Specific emphasis was placed on the treatment efficacy on the relevant specified outcomes for individual applications. Results: From a total of over 420 initial hits, 19 studies were deemed suitable for inclusion in this review. Among them, PBM therapy has been used in pediatric dentistry for prevention and treatment of oral mucositis associated with oncotherapy (chemotherapy, radiation, and transplants), for postsurgical oral pain and for pulpotomies. Overall, all studies reported therapeutic benefits, and no adverse effects were reported. Conclusions: This review noted that PBM therapy is a safe and effective treatment modality for various clinical applications in pediatric dentistry. Despite potential positive publication bias, there appears to be clear evidence of clinical benefit with this treatment, and we recommend well-designed randomized, placebo-controlled human clinical trial be pursued.

A retrospective study of survival of 196 replanted permanent teeth in children.

BACKGROUND/AIM: The extra-alveolar period and storage medium are important for the survival of replanted teeth. The aim of this study was to evaluate factors affecting the survival of replanted teeth in children. MATERIAL AND METHODS: Complete dental records of avulsed teeth including age, gender, extra-alveolar time, storage type and period, stage of root development, crown fracture, gingival laceration, alveolar fracture, antibiotics, and splint type and period were obtained. Kaplan-Meier, Cox regression and chi-square tests were used to analyse the risk factors affecting survival (P < 0.05). RESULTS: The study included 196 replanted teeth with a mean follow-up period of 4.0 years. Forty-two (21.4%), 45 (23.0%), and 109 teeth (55.6%) showed functional healing, inflammatory resorption and replacement resorption. The root resorption incidence of teeth with extra-alveolar time longer than 30 minutes was higher vs teeth with a time of less than 30 minutes (P = 0.010). Physiologically stored replanted teeth showed lower incidence of root resorption (19/31, 61.3%) than those stored in non-physiologic media (94/114, 82.5%) (P = 0.025). Root resorption incidence of teeth stored non-physiologically within 30 minutes and then transferred to physiologic media (25/33, 75.8%) was similar to that of teeth stored physiologically (P = 0.127). Teeth stored non-physiologically for longer than 30 minutes had a significantly higher root resorption incidence (99/113, 87.6%) than teeth stored non-physiologically within 30 minutes (55/83, 66.3%) (odds ratio = 1.726, P = 0.001). Pulp canal obliteration occurred in five of the 56 immature teeth (8.9%) but two of them were later extracted because of replacement resorption. The survival of mature teeth (111/140, 79.3%) was significantly higher than that of immature teeth (39/56, 69.6%) (P = 0.007). CONCLUSIONS: This study suggested that non-physiologic storage within 30 minutes was critical for the periodontal healing of replanted teeth. Replanted immature teeth had lower survival rates than mature teeth.

Tricalcium Silicate Capping Materials Modulate Pulp Healing and Inflammatory Activity In Vitro.

INTRODUCTION: On stimulation by lipoteichoic acid or by a physical injury, fibroblasts have been shown to play a major role in the initiation of the pulp inflammatory reaction and healing through secretion of complement proteins and growth factors. The application of direct pulp-capping materials on these cells may interfere with the inflammatory and the healing processes within the pulp's inextensible environment. This work was designed to study in vitro the effects of silicate-based materials on pulp fibroblast modulation of the initial steps of pulp inflammation and healing. METHODS: The effects of Biodentine, TheraCal, and Xeno III eluates were studied on lipoteichoic acid-stimulated and physically injured fibroblasts. Cytokine secretion (interleukin 6, vascular endothelial growth factor, fibroblast growth factor-2, and transforming growth factor-ß1) was quantified by enzyme-linked immunosorbent assay. Inflammatory THP-1 adhesion to endothelial cells and their migration and activation were studied in vitro. Human pulp fibroblast proliferation was investigated with the MTT test, and their migration to the injury site was studied with the scratch healing assay. RESULTS: Interleukin 6 and vascular endothelial growth factor secretion increased with all materials but to a lesser extent with Biodentine. Fibroblast growth factor-2 and transforming growth factor-ß1 secretion was significantly higher with Biodentine than with all other materials. THP-1 cell adhesion to endothelial cells and their activation were reduced by Biodentine and TheraCal. However, their migration decreased only with Biodentine. Fibroblast proliferation significantly increased with Biodentine but significantly decreased with Xeno III after day 6. Finally, only Biodentine induced fibroblast migration to the injury site in the scratch assay. CONCLUSIONS: These results confirm that pulp-capping materials affect the early steps of pulp inflammation and healing. They show that Biodentine had the highest pulp healing and anti-inflammatory potential when compared with the resin-containing materials. This highlights the interest of the material choice for direct pulp-capping.

Factors Affecting the Pulp and Root Healing of Root Fractures in Immature Permanent Teeth / 대한소아치과학회지

The aim of this study was to evaluate the factors affecting the healing of root fracture in immature permanent teeth and the prognosis of root fracture by statistically analyzing the relationship with the pulp and root healing.The radiographs of 51 root-fractured maxillary anterior permanent teeth were collected. In radiograph, locations of root fracture, apical foramen width and width of diastasis between the fragments were measured. The value of the studied parameters were compared by independent t-test and rogistic regression test.In conclusion, there was no difference in the prognosis of pulp healing according to the location of root fracture. However, root healing occurs well as the root fracture is located at the root apex (p < 0.05). Lastly, the smaller the width of diastasis between the fragments after reduction, the better the pulp healing was (p < 0.05).

Outcomes and prognostic factors that influence the success of tooth autotransplantation in children and adolescents.

BACKGROUND/AIM: Tooth autotransplantation has been advocated for replacement of missing teeth or teeth that are unsuitable for restoration. The aim of this study was to investigate the outcomes and prognostic factors that influenced the success of tooth transplantation in a paediatric population. MATERIALS AND METHODS: Data were extracted from the records of 75 patients (89 teeth). Demographic and prognostic factors were recorded and analysed for the clinical and radiographic outcomes for periodontal ligament (PDL) and pulp healing of transplanted teeth. RESULTS: The mean age at transplant was 13.2 years, and the mean follow-up observation period was 2.6±1.8 years with a range of 12.0 months to 9.9 years. The main reason for transplantation was to replace upper central incisors lost or missing due to dental trauma, hypodontia and dilaceration. Of the 45 teeth that were monitored for pulp revascularization, 75.6% showed clinical and radiographic signs of pulp healing and 24.4% showed signs of pulp necrosis and infection. Pulp healing was significantly related to the stage of root development of the transplant. Favourable PDL healing was observed in 87.6% of the transplants, while 13.5% showed signs of replacement resorption. PDL healing was significantly related to the stage of root formation of the transplanted tooth at the time of the surgery, the ease of handling and placement of the tooth, and the status of the alveolar bone at the recipient site at the time of the surgery. Overall success of tooth transplantation was 87.6%, and the survival rate was 94.4%. CONCLUSIONS: Tooth transplantation carried out in children and adolescents demonstrated high success and survival, with the stage of root development influencing both the pulp and PDL healing of the transplanted teeth.

Characterization of Dental Pulp Myofibroblasts in Rat Molars after Pulpotomy.

INTRODUCTION: Myofibroblasts express alpha smooth muscle actin (α-SMA) and play a critical role in wound healing. Myofibroblast differentiation is controlled by the joint actions of transforming growth factor beta 1 (TGF-ß1) and the extradomain A fibronectin splice variant (EDA-FN). Currently, the contribution of myofibroblasts to dental pulp healing is unknown. Therefore, we analyzed expressional characteristics of α-SMA-positive cells and investigated TGF-ß1, EDA-FN, and α-SMA expression levels after pulpotomy to better understand dental pulp healing. METHODS: The maxillary first molars of 8-week-old Wistar rats were pulpotomized with mineral trioxide aggregate. After 1 to 14 days, localization and colocalization of α-SMA, rat endothelial cell antigen-1 (as a marker of endothelial cells), neuron-glial antigen 2 (as a marker of perivascular cells), prolyl-4-hydroxylase (P4H, as an additional marker of myofibroblasts), and EDA-FN were analyzed using immunohistochemistry and double immunofluorescence. Time-course changes in the messenger RNA expression levels of TGF-ß1, EDA-FN, and α-SMA were evaluated using quantitative real-time polymerase chain reaction analysis. RESULTS: Spindle-shaped α-SMA-positive cells transiently appeared after pulpotomy. These cells initially emerged in the pulp core on day 3 and then accumulated at the wound site by day 5. These cells were isolated from rat endothelial cell antigen-1 positive cells and did not express neuron-glial antigen 2 but did express P4H. The messenger RNA levels of TGF-ß1, EDA-FN, and α-SMA were significantly up-regulated after pulpotomy. EDA-FN and α-SMA were colocalized at the wound sites on day 5. CONCLUSIONS: In association with up-regulation of TGF-ß1 and EDA-FN expression, α-SMA and P4H double-positive cells accumulated at the wound sites after pulpotomy. This suggests that myofibroblasts participate in dental pulp healing.

Biocompatibility of biomaterials - Lessons learned and considerations for the design of novel materials.

OBJECTIVES: Biocompatibility of dental materials has gained increasing interest during recent decades. Meanwhile, legal regulations and standard test procedures are available to evaluate biocompatibility. Herein, these developments will be exemplarily outlined and some considerations for the development of novel materials will be provided. METHODS: Different aspects including test selection, release of substances, barriers, tissue healing, antibacterial substances, nanoparticles and environmental aspects will be covered. The provided information is mainly based on a review of the relevant literature in international peer reviewed journals, on regulatory documents and on ISO standards. RESULTS: Today, a structured and systematic approach for demonstrating biocompatibility from both a scientific and regulatory point of view is based on a clinical risk assessment in an early stage of material development. This includes the analysis of eluted substances and relevant barriers like dentin or epithelium. ISO standards 14971, 10993, and 7405 specify the modes for clinical risk assessment, test selection and test performance. In contact with breached tissues, materials must not impair the healing process. Antibacterial effects should be based on timely controllable substances or on repellant surfaces. Nanoparticles are produced by intraoral grinding irrespective of the content of nanoparticles in the material, but apparently at low concentrations. Concerns regarding environmental aspects of mercury from amalgam can be met by amalgam separating devices. The status for other materials (e.g. bisphenol-A in resin composites) needs to be evaluated. Finally, the public interest for biocompatibility issues calls for a suitable strategy of risk communication. SIGNIFICANCE: A wise use of the new tools, especially the clinical risk assessment should aim at preventing the patients, professionals and the environment from harm but should not block the development of novel materials. However, biocompatibility must always be weighed against the beneficial effects of materials in curing/preventing oral diseases.

Responses of the pulp, periradicular and soft tissues following trauma to the permanent teeth.

Trauma to the permanent teeth involves not only the teeth but also the pulp, the periodontal ligament, alveolar bone, gingiva and other associated structures. There are many variations in the types of injuries with varying severity and often a tooth may sustain more than one injury at the same time. In more severe trauma cases, there are many different cellular systems of mineralized hard and unmineralized soft tissues involved, each with varying potential for healing. Furthermore, the responses of the different tissues may be interrelated and dependent on each other. Hence, healing subsequent to dental trauma has long been known to be very complex. Because of this complexity, tissue responses and the consequences following dental trauma have been confusing and puzzling for many clinicians. In this review, the tissue responses are described under the tissue compartments typically involved following dental trauma: the pulp, periradicular and associated soft tissues. The factors involved in the mechanisms of trauma are analysed for their effects on the tissue responses. A thorough understanding of the possible tissue responses is imperative for clinicians to overcome the confusion and manage dental trauma adequately and conservatively in order to minimize the consequences following trauma.

Histology of dental pulp healing after tooth replantation in rats / 대한치과보존학회지

The objective of this study was to observe the histology of dental pulp healing after tooth replantation in rats. The maxillary right first molars of 4-week-old rat were extracted, and then the teeth were repositioned in the original socket. At 3 days after replantation, there was localized inflammatory reaction. But, pulp revasculization and healing had already begun in the root area. At 5 days after replantation, odontoblast-like cells were observed. Tertiary dentin deposition was observed beneath the pulp-dentin border from 1 week after replantation. And tertiary dentin was increased at 2 weeks after replantation. The presence of odontoblast-like cells and the formation of tertiary dentin were continued to 4 weeks after replantation. At 4 weeks after replantation, the deposition of bone-like tissues and cementum-like tissues was observed. This results show that there is a possibility of pulp healing after tooth replantation in rats and the mineralization of tooth can progress. The mineralization of tooth after replantation was initially occurred by the deposition of tertiary dentin, but as time passed, the deposition of bone-like tissues and cementum-like tissues was begun and increased.

Autotransplantation of immature third molars; Pulp healing, periodontal healing and root development

PURPOSES: The aim of this study was to evaluate pulp healing, periodontal healing, root development of autotransplantation of immature third molars and show its viability in treatment of early loss of tooth in young patients MATERIALS AND METHODS: In this article we performed a retrospective study with 41 transplanted teeth in 36 patients. The Mean age at the time of surgery was 17 years(range 13-24 years) and mean postoperative follow up period was 2.4 years(range 1-6 years) We evaluated the survival rate, pulp healing, periodontal healing, root development of the above teeth RESULTS: At the last examination 40 teeth among 41 transplants were still present so survival rate was 97.6%. The pulpal healing was found in 38 teeth of 41 transplants. The periodontal healing was found in 38 transplants. The continuous root development was seen in 38 transplants. CONCLUSIONS: From the above results, the autotransplantation of immature third molars was found to be a useful and reliable treatment method for early loss of teeth in adolescents and young adults.