Apical Negative Pressure irrigation presents tissue compatibility in immature teeth

Aim: To compare the apical negative pressure irrigation (ANP) with conventional irrigation in the teeth of immature dogs with apical periodontitis. Methods: Fifty-two immature pre-molar root canals were randomly assigned into 4 groups: ANP (n=15); conventional irrigation (n=17); healthy teeth (control) (n = 10); and teeth with untreated apical periodontitis (control) (n=10). After induction of apical periodontitis, teeth were instrumented using EndoVac® (apical negative pressure irrigation) or conventional irrigation. The animals were euthanized after 90 days. The sections were stained by HE and analyzed under conventional and fluorescence microscopy. TRAP histoenzymology was also performed. Statistical analyses were performed with the significance level set at 5%. Results: There was difference in the histopathological parameters between ANP and conventional groups (p;0.05). However, a lower number of osteoclasts was observed in the ANP group (

Bacterial endotoxin adhesion to different types of orthodontic adhesives

Bacterial endotoxin (LPS) adhesion to orthodontic brackets is a known contributing factor to inflammation of the adjacent gingival tissues. Objective The aim of this study was to assess whether LPS adheres to orthodontic adhesive systems, comparing two commercial brands. Material and Methods Forty specimens were fabricated from Transbond XT and Light Bond composite and bonding agent components (n=10/component), then contaminated by immersion in a bacterial endotoxin solution. Contaminated and non-contaminated acrylic resin samples were used as positive and negative control groups, respectively. LPS quantification was performed by the Limulus Amebocyte Lysate QCL-1000™ test. Data obtained were scored and subjected to the Chi-square test using a significance level of 5%. Results There was endotoxin adhesion to all materials (p;0.05). There was no significant difference (p>;0.05) among commercial brands. Affinity of endotoxin was significantly greater for the bonding agents (p=0.0025). Conclusions LPS adhered to both orthodontic adhesive systems. Regardless of the brand, the endotoxin had higher affinity for the bonding agents than for the composites. There is no previous study assessing the affinity of LPS for orthodontic adhesive systems. This study revealed that LPS adheres to orthodontic adhesive systems. Therefore, additional care is recommended to orthodontic applications of these materials

Comparison of digital and conventional radiographic techniques

This study aimed to evaluate the correlation between conventional and digital radiographic methods in the measurement of periapical lesions in primary molars and compares the time used to obtain the radiographic images betweenboth methods. Material and methods: This crossover study included children between 4 to 8-year-old with periapical lesion in primary mandibular molars. Fifteen molars were randomly assigned firstly to receive conventional or digital periapical radiograph during the steps of endodontic treatment. The time to obtain the radiographic image was evaluated in seconds and compared by the Mann-Whitney test. The periapical lesions measurement (mm2) were performed by the Image J software and the degree of correlation of measurement between both techniques was evaluated by the Spearman correlation test. Data was analyzed using the GraphPad Prism software (α = 0.05). Results: A strong positive correlation between the measurement of lesions occurred on conventional methods in comparison with the measurement on digital methods (r2=0.778; p<0.0006); however, the time to obtain the radiographic images was shorter in the digital method (p<0.0001). Conclusion: The digital method had a shorter amount of time to obtain the images and strong correlation for the lesions measurement in comparison to the conventional method. Therefore, the digital radiograph method is preferable for use in children

Root canal irrigation systems: radiographic, histopathological, histomicrobiological and histoenzymological evaluation in dogs\' teeth with apical periodontitis

O fundamento do sucesso da terapia endodôntica é baseado no controle da contaminação microbiana presente no sistema de canais radiculares. Com essa finalidade, novos sistemas de irrigação têm sido desenvolvidos, demonstrando maior eficácia e segurança, destacando-se a irrigação por Pressão Apical Negativa (ANP) e a Irrigação Ultrassônica Passiva (PUI). O presente estudo in vivo teve como objetivo comparar a ANP e a PUI no reparo apical e periapical de dentes de cães com lesão periapical crônica, tendo como controle a irrigação convencional por Pressão Positiva (PP). Um total de 60 canais radiculares de pré-molares, com lesões periapicais experimentalmente induzidas, foram submetidos ao tratamento endodôntico em sessão única. Radiografias periapicais foram realizadas após a indução das lesões periapicais. Os dentes foram aleatoriamente divididos em 3 grupos: Grupo I - Irrigação por Pressão Apical Negativa (n=20 canais radiculares); Grupo II - Irrigação Ultrassônica Passiva (n=20 canais radiculares) e Grupo III - Irrigação por Pressão Positiva (controle) (n=20 canais radiculares). Após 180 dias, os animais foram eutanasiados, as peças removidas e submetidas ao processamento histotécnico para a análise histopatológica morfológica e morfométrica, em cortes corados com HE, sob microscopia convencional e de fluorescência. A análise radiográfica do tamanho das lesões periapicais foi realizada através da comparação das medidas das áreas das lesões antes e 180 dias após o tratamento endodôntico. Também foi realizada a histoenzimologia para a Fosfatase Ácida Resistente ao Tartarato (TRAP), para a marcação de osteoclastos, e a coloração de Brown e Brenn, para avaliar a presença de bactérias e sua localização. Os resultados obtidos foram submetidos à análise estatística por meio do teste de Kruskal-Wallis. O nível de significância adotado foi de 5%. Observou-se que não houve diferença estatisticamente significante entre os grupos com relação à resposta radiográfica (p=0,91). Na comparação dos parâmetros histopatológicos, o grupo I apresentou resultados mais homogêneos. Houve diferença estatisticamente significante entre os grupos I e III, com infiltrado inflamatório mais suave no grupo I (p=0,02), enquanto o grupo II foi semelhante aos grupos I e III. Na comparação das variáveis numéricas (morfometria em microscopia de fluorescência e TRAP), não foi possível observar diferença significativa entre os grupos (p>0,05). Os resultados deste estudo in vivo demonstraram que a irrigação por ANP resultou em resposta inflamatória mais suave, em comparação ao grupo controle, porém, semelhante à PUI. Nos demais aspectos, a resposta dos tecidos apicais e periapicais, após irrigação por ANP ou PUI, foi semelhante à irrigação convencional por PP.A successful endodontic therapy relies on the control of microbial contamination of the root canal system. For this purpose, new irrigation systems with greater efficacy and safety have been developed, standing out the apical negative pressure (ANP) and the passive ultrasonic (PUI) irrigation systems. The aim of this in vivo study was to compare apical positive pressure irrigation (PP - conventional irrigation), ANP and PUI in the apical and periapical repair of dogs teeth with chronic periapical lesion. Sixty root canals of premolars with experimentally induced periapical lesions were subjected to a single-session endodontic treatment. Periapical radiographs were taken after inducing the periapical lesions. The teeth were randomly assigned to three groups: Group I: ANP with EndoVac (n=20 root canals); Group II: PUI (n=20 root canals) and Group III: apical positive pressure irrigation (PP - conventional irrigation - control) (n=20 root canals). After 180 days, the animals were euthanized, and the anatomic pieces were removed and subjected to histotechnical processing for histopathological, morphological and morphometric analyses of HE-stained sections under conventional and fluorescence microscopy. The radiographic analysis of the size of periapical lesions was performed by measuring the lesions before and 180 days after the endodontic treatment. Tartrate-resistant acid phosphatase (TRAP) histoenzymology for identification of osteoclasts and Brown and Brenn staining for identification and localization of bacteria were also performed. Data were analyzed statistically by the Kruskal-Wallis test a significance level of 5%. There were no statistically significant differences among the groups regarding the radiographic response (p=0.91). In the comparison of histopathological parameters, Group I presented more homogeneous results. There was a statistically significant difference between Groups I and III, with milder infiltrate inflammatory in Group I (p=0.02). Group II was similar to Groups I and III. Comparing the numerical variables (morphometric analysis under fluorescence microscopy and TRAP), no statistically significant difference could be found among the groups (p>0.05). The results of this in vivo study revealed that ANP caused milder inflammatory response than PP (control group), but similar to PUI. In the other aspects, the response of apical and periapical to ANP and PUI was similar to tissue response to PP

Evaluation of maxillary bones and apical periodontitis induced in ovariectomized rats subjected or not to treatment with bisphosphonate or cathepsin K inhibitor

O objetivo do presente estudo foi avaliar ossos maxilares e lesões periapicais induzidas em ratas ovariectomizadas submetidas ou não ao tratamento com bisfosfonato (Alendronato - ALD) ou com inibidor da catepsina K (Odanacatib - ODN). Foram utilizadas 45 ratas, divididas em 6 grupos: I sham (cirurgia de ovariectomia fictícia); II sham e lesão periapical (LP); III - ovariectomia (OVX) sem LP; IV OVX e LP; V OVX, LP e ALD; e Grupo VI - OVX, LP e ODN. Um dia após a realização da OVX ou da cirurgia fictícia, os animais dos grupos V e VI começaram a receber ALD ou ODN, via gavagem. Decorridas 9 semanas da realização da OVX, os primeiros molares dos grupos II, IV, V e VI foram submetidos à indução de LP por 3 semanas. Decorrido este período, foi realizada colheita microbiológica dos canais radiculares para a quantificação de micro-organismos e os animais foram submetidos à eutanásia. Fêmures foram analisados por meio de densitômetro, para registro da densidade mineral óssea (BMD). As maxilas foram analisadas por meio de microtomografia computadorizada (micro-CT) para avaliação da microarquitetura e BMD do osso interradicular e as mandíbulas para avaliação do volume das LP. Os primeiros molares inferiores foram submetidos ao processamento histotécnico, sendo os cortes corados com hematoxilina e eosina (HE) e analisados em microscopia convencional. Paralelamente, foi realizada a análise morfométrica da área das lesões periapicais, em microscopia de fluorescência e histoenzimologia para a atividade da TRAP. Os primeiros molares superiores foram submetidos à detecção da expressão gênica de citocinas, marcadores da osteoclastogênese e de metaloproteinases da matriz. Os resultados obtidos foram submetidos à análise estatística apropriada, com nível de significância de 5%. A OVX afetou a BMD do fêmur e da maxila e a microarquitetura apenas do fêmur. O ALD recuperou a BMD dos ossos avaliados. A OVX não foi capaz de influenciar nos níveis de contaminação microbiana do canal radicular. As LP dos animais do grupo IV apresentaram expressão aumentada de RANK, RANKL, IL-1&beta;, IL-6, TNF-&alpha;, MMP-8 e 13, enquanto o tratamento com ALD (grupo V) foi capaz de reduzir a expressão de IL-6 e MMP-8, ao mesmo nível que nas LP do grupo II. Além disso, as LP do grupo IV foram maiores (área e volume), em comparação às dos grupos II e V. O ODN, na dose e frequência de administração aplicada, não foi capaz de promover alterações significantes. A OVX e os tratamentos antirreabsortivos não influenciaram no número de osteoclastos ao redor da LP. Assim, concluiu-se que a condição hipoestrogênica induzida pela OVX foi capaz de diminuir a BMD do fêmur e da maxila e alterou a microarquitetura do fêmur. Apenas o ALD foi capaz de recuperar o fenótipo da BMD, ou seja, retorno aos níveis observados nos animais saudáveis. Ainda, a OVX agravou o processo de reabsorção, a inflamação e a expressão de MMPs, provocando lesões periapicais maiores. O ALD e o ODN proporcionaram uma melhora da resposta periapical. Entretanto, apenas o tratamento com ALD recuperou o fenótipo, fazendo com que as lesões periapicais fossem similares às lesões dos animais saudáveis.The aim of this study was to evaluate maxillary bones and apical periodontitis induced in ovariectomized rats treated or not with bisphosphonate (Alendronate - ALD) or cathepsin K inhibitor (Odanacatib - ODN). Forty-five female rats were divided into 6 groups: I sham surgery; II - sham and apical periodontitis (AP); III - ovariectomy (OVX) without AP; IV - OVX and AP; V - OVX, AP and ALD; and Group VI - OVX, AP and ODN. One day after OVX or sham surgery, the animals in groups V and VI started receiving ALD or ODN, by gavage. After 9 weeks, the first molars of the rats in groups II, IV, V and VI were subjected to induction of AP for 3 weeks. Microbiological root canal sampling was collected for quantification of microorganisms and the animals were euthanized. Bone mineral density (BMD) of the femurs was analyzed by bone densitometry. The maxillas were analyzed by microcomputed tomography (micro-CT) to determine the microarchitecture and BMD of the interradicular bone while the mandibles were analyzed to determined AP volume. The mandibular first molars were subjected to histotechnical processing and hematoxylin and eosin-stained histological sections were examined with conventional microscopy. In addition, a morphometric analysis of AP area was performed using fluorescence microscopy and tartrate-resistant acid phosphatase (TRAP) histoenzymology. The maxillary first molars were used to evaluate the gene expression of cytokines, osteoclastogenesis markers and matrix metalloproteinases (MMP) using RT-PCR. The results were subjected to appropriate statistical analysis with 5% significance level. OVX affected femoral and maxillary BMD and femoral microarchitecture. ALD recovered the BMD of both types of bones. OVX was not able to influence the microbial levels of the root canal. In group IV, AP showed increased expression of RANK, RANKL, IL-1&beta;, IL-6, TNF-&alpha;, MMP-8 and MMP-13, while ALD treatment (group V) reduced IL-6 and MMP-8 expression to the same level as the AP in group II. In group IV, AP area and volume were larger than in groups II and V. ODN, in the dosage and frequency of administration applied, was not able to promote significant changes. OVX and antiresorptive treatments did not influence the number of osteoclasts around the AP region. In conclusion, the hypoestrogenic condition induced by OVX was able to decrease the BMD of femur and maxilla and only the microarchitecture of the femur. ALD was able to recover the BMD phenotype, i.e., return to the levels observed in healthy animals. Furthermore, OVX exacerbated resorption, inflammation and MMP expression, inducing larger lesions. Treatment with ALD and ODN resulted in an improvement of the periapical response. However, only ALD recovered the phenotype, with AP similar to that of healthy animals

Apical Negative Pressure irrigation presents tissue compatibility in immature teeth

Abstract Aim: To compare the apical negative pressure irrigation (ANP) with conventional irrigation in the teeth of immature dogs with apical periodontitis. Methods: Fifty-two immature pre-molar root canals were randomly assigned into 4 groups: ANP (n=15); conventional irrigation (n=17); healthy teeth (control) (n = 10); and teeth with untreated apical periodontitis (control) (n=10). After induction of apical periodontitis, teeth were instrumented using EndoVac® (apical negative pressure irrigation) or conventional irrigation. The animals were euthanized after 90 days. The sections were stained by HE and analyzed under conventional and fluorescence microscopy. TRAP histoenzymology was also performed. Statistical analyses were performed with the significance level set at 5%. Results: There was difference in the histopathological parameters between ANP and conventional groups (p0.05). However, a lower number of osteoclasts was observed in the ANP group (p<0.05). Conclusion: The EndoVac® irrigation system presented better biological results and more advanced repair process in immature teeth with apical periodontitis than the conventional irrigation system, confirming the hypothesis

Bacterial endotoxin adhesion to different types of orthodontic adhesives

Abstract Bacterial endotoxin (LPS) adhesion to orthodontic brackets is a known contributing factor to inflammation of the adjacent gingival tissues. Objective The aim of this study was to assess whether LPS adheres to orthodontic adhesive systems, comparing two commercial brands. Material and Methods Forty specimens were fabricated from Transbond XT and Light Bond composite and bonding agent components (n=10/component), then contaminated by immersion in a bacterial endotoxin solution. Contaminated and non-contaminated acrylic resin samples were used as positive and negative control groups, respectively. LPS quantification was performed by the Limulus Amebocyte Lysate QCL-1000™ test. Data obtained were scored and subjected to the Chi-square test using a significance level of 5%. Results There was endotoxin adhesion to all materials (p0.05). There was no significant difference (p>0.05) among commercial brands. Affinity of endotoxin was significantly greater for the bonding agents (p=0.0025). Conclusions LPS adhered to both orthodontic adhesive systems. Regardless of the brand, the endotoxin had higher affinity for the bonding agents than for the composites. There is no previous study assessing the affinity of LPS for orthodontic adhesive systems. This study revealed that LPS adheres to orthodontic adhesive systems. Therefore, additional care is recommended to orthodontic applications of these materials

Apical Negative Pressure irrigation presents tissue compatibility in immature teeth

<div><p>Abstract Aim: To compare the apical negative pressure irrigation (ANP) with conventional irrigation in the teeth of immature dogs with apical periodontitis. Methods: Fifty-two immature pre-molar root canals were randomly assigned into 4 groups: ANP (n=15); conventional irrigation (n=17); healthy teeth (control) (n = 10); and teeth with untreated apical periodontitis (control) (n=10). After induction of apical periodontitis, teeth were instrumented using EndoVac® (apical negative pressure irrigation) or conventional irrigation. The animals were euthanized after 90 days. The sections were stained by HE and analyzed under conventional and fluorescence microscopy. TRAP histoenzymology was also performed. Statistical analyses were performed with the significance level set at 5%. Results: There was difference in the histopathological parameters between ANP and conventional groups (p<0.05). The ANP group showed a predominance of low magnitude inflammatory infiltrate, a smaller periodontal ligament, and lower mineralized tissue resorption. There were no differences in the periapical lesion extensions between the ANP and conventional groups (p>0.05). However, a lower number of osteoclasts was observed in the ANP group (p<0.05). Conclusion: The EndoVac® irrigation system presented better biological results and more advanced repair process in immature teeth with apical periodontitis than the conventional irrigation system, confirming the hypothesis.</p></div

Effect of ovariectomy on maxilla and mandible dimensions of female rats

Objective The role of oestrogen in craniofacial growth still remains unclear. Therefore, the present study aimed to assess the effect of oestrogen deficiency on maxilla and mandible dimensions. Setting and Sample Population The study was conducted at the Department of Pediatric Dentistry at the School of Dentistry of Ribeirao Preto, University of Sao Paulo, and used forty female Wistar rats. Material and Methods Ovariectomy (OVX) and placebo surgery (Sham) were performed when animals were twenty-one days old (prepubertal stage). Dimensions of the maxilla and mandible were assessed by craniometric analysis using radiographs, during and after puberty of the animals (45 and 63 days old, respectively). Quantitative real-time PCR and immunohistochemical analyses were performed to determine the expression and localization, respectively, of oestrogen receptor alpha (ER alpha) and oestrogen receptor beta (ER beta) in different growth sites of the evaluated structures at puberty. The differences between the groups for each outcome were evaluated using the t test with an established alpha error of 5%. Results There were significant differences between the OVX and Sham groups for horizontal and vertical linear measurements in the maxilla and the mandible at both pubertal and post-pubertal stages (P .05). Immunohistochemical analyses revealed the presence of both oestrogen receptors in osteoblasts and chondrocytes in the midpalatal suture and mandibular condyle, respectively, in the OVX and Sham groups. Conclusion Our results suggest that oestrogen deficiency from the prepubertal stage might increase the growth of the maxilla and mandible in female rats

Effect of ovariectomy on maxilla and mandible dimensions of female rats

Objective The role of oestrogen in craniofacial growth still remains unclear. Therefore, the present study aimed to assess the effect of oestrogen deficiency on maxilla and mandible dimensions. Setting and Sample Population The study was conducted at the Department of Pediatric Dentistry at the School of Dentistry of Ribeirao Preto, University of Sao Paulo, and used forty female Wistar rats. Material and Methods Ovariectomy (OVX) and placebo surgery (Sham) were performed when animals were twenty-one days old (prepubertal stage). Dimensions of the maxilla and mandible were assessed by craniometric analysis using radiographs, during and after puberty of the animals (45 and 63 days old, respectively). Quantitative real-time PCR and immunohistochemical analyses were performed to determine the expression and localization, respectively, of oestrogen receptor alpha (ER alpha) and oestrogen receptor beta (ER beta) in different growth sites of the evaluated structures at puberty. The differences between the groups for each outcome were evaluated using the t test with an established alpha error of 5%. Results There were significant differences between the OVX and Sham groups for horizontal and vertical linear measurements in the maxilla and the mandible at both pubertal and post-pubertal stages (P .05). Immunohistochemical analyses revealed the presence of both oestrogen receptors in osteoblasts and chondrocytes in the midpalatal suture and mandibular condyle, respectively, in the OVX and Sham groups. Conclusion Our results suggest that oestrogen deficiency from the prepubertal stage might increase the growth of the maxilla and mandible in female rats