Assessment of Deviations of Implants Installed with Prototyped Surgical Guide and Conventional Guide: In Vitro Study.

OBJECTIVE: The study aimed to assess the angular and linear deviations of implants installed in mannequins aided by surgical guides produced with the techniques of dual tomography (DT), model-based tomography (MT), and nonprototyped guide. MATERIALS AND METHODS: Implants were installed in mannequins of a partially edentulous maxilla and divided into three groups: Group C (n = 20), implants installed using the conventional technique with flap opening and conventional guide; Group DT (n = 20), implants installed using guided surgery with the dual tomography technique; and Group MT (n = 20), implants installed using the model-based tomography technique. After implant installation, the mannequin was subjected to a computed tomography (CT) to measure the linear and angular deviations of implant positioning relative to the initial planning on both sides. RESULTS: There was a higher mean angular deviation in group C (4.61 ± 1.21, p ≤ 0.001) than in groups DT (2.13 ± 0.62) and MT (1.87 ± 0.94), which were statistically similar between each other. Similarly, the linear deviations showed group C with the greatest discrepancy in relation to the other groups in the crown (2.17 ± 0.82, p = 0.007), central (2.2 ± 0.77, p = 0.004), and apical (2.34 ± 0.8, p = 0.001) regions. CONCLUSION: The techniques of DT and MT presented smaller angular and linear deviations than the conventional technique with the nonprototyped guide. There was no difference between the two-guided surgery techniques.

Evaluation of deviation in implants placed at different depths with a prototype surgical guide: an in vitro study.

The aim of this study was to measure the angular and linear deviations between planned and placed dental implant positions at different depths in an in vitro model. Ten dental manikins of a maxilla without the central and lateral incisors were used. The implants were placed in the tooth positions using a prototype guide based on computed tomographic scans of dental casts. The groups consisted of implants placed at varying depths according to tooth position: 1 mm deep for the right lateral incisor, 2 mm deep for the right central incisor, 3 mm deep for the left central incisor, and 4 mm deep for the left lateral incisor (n = 10 per group). After implant placement, the manikin was scanned again to compare the positioning of the implants to the planned positions. Statistical analysis evaluated the linear deviations between planned and placed implant positions at 3 points (coronal, central, and apical) as well as the angular discrepancies. The analysis showed that the depth of the implant placement proportionally affected the linear deviation of the actual position from the planned position; thus, the deeper implants showed significantly greater linear deviations (P < 0.05; 1-way analysis of variance and Tukey test). There were no statistically significant differences in the mean angular deviations of the groups. Thus, the results suggest that implants placed at greater depths present greater linear deviations than implants placed at shallower depths, but the angular deviation is not affected by implant depth.

Um novo conceito na obtenção do guia prototipado em Implantodontia ­ relato de caso / A newconcept in prototyped guide obtaining in implantology - case report

A tomografia computadorizada (TC) em Implantodontia permite planejar virtualmente a posição ideal do implante dentário considerando as características anatômicas e restauradoras. Através desse planejamento, o guia cirúrgico prototipado pode ser confeccionado possibilitando a integração dos determinantes protéticos no posicionamento dos implantes. Nesse contexto, a "técnica da tomografia do molde" para obtenção do guia prototipado consiste na realização da TC do molde do paciente que será vazado virtualmente para a obtenção de um modelo 3D, capaz de reproduzir tecidos moles e elementos dentais. Posteriormente, essa imagem é virtualmente sobreposta à tomografia da boca do paciente, permitindo uma avaliação óssea conjunta com o tecido mole e elementos dentais ausentes. O relato de caso descreve a reabilitação oral com implantes osseointegráveis utilizando um guia prototipado confeccionado através da "técnica da tomografia do molde". Paciente apresentava ausência dos dentes 17, 16, 14, 12, 11, 21, 22 e 26. Devido à presença de qualidade e quantidade óssea adequadas, foi planejada a reabilitação das áreas edêntulas com implantes dentários posicionados utilizando guia prototipado confeccionado pela "técnica da tomografia do molde". Após a obtenção do guia, os implantes dentários foram posicionados. Com a instalação dos provisórios, após 4 meses de osseointegração, constatou-se que a realização da cirurgia guiada com a utilização do guia prototipado obtido através da "técnica da tomografia do molde" garantiu previsibilidade no posicionamento dos implantes dentários trazendo facilidade na execução das próteses, além de sucesso estético/funcional no tratamento restaurador e maior comodidade ao paciente do início ao final do tratamento (AU).

The computed tomography (CT) in implant Dentistry allows virtually plan of the dental implant ideal position considering restorative and anatomical characteristics. Through this planning, a surgical guide can be prototyped for integrate prosthetic aspects in the positioning of the implants. In this context, the "mold tomography technique" for obtaining prototyped guide consists in use the CT of the patient mold to be poured virtually for obtaining a 3D model capable of reproducing soft tissues and dental elements. Then, this image is superimposed on the virtual scan of the patient's mouth, allowing a complete evaluation of bone and soft tissues. This case report describes the oral rehabilitation with dental implants using a prototyped guide made by "mold tomography technique." Patient had no 17, 16, 14, 12, 11, 21, 22, and 26 teeth. Due to the presence of quality and adequate bone quantity, it was planned rehabilitation of edentulous areas with dental implants positioned using prototyped guide made by "mold tomography technique." After obtaining the guide, dental implants were positioned. After 4 months of osseointegration, the final restaurations have been installed. With the installation of the provisory, after 4 months of osseointegration, it has noted that the realization of guided surgery using the guide prototyped obtained by "mold tomography technique" guaranteed predictability in the placement of dental implants bringing ease of application of the prosthesis beyond aesthetic / functional success in restorative treatment and convenience to the patient from beginning to end of treatment (AU).

Functional Haplotypes in Interleukin 4 Gene Associated with Periodontitis.

Chronic periodontitis (CP) is an infectious inflammatory disease that affects tooth-supporting structures and in which dental plaque bacteria, immune mechanisms and genetic predisposition play important roles. Interleukin 4 (IL-4) is a key anti-inflammatory cytokine with relevant action in imbalances in inflamed periodontal tissue. Individuals carrying the TCI/CCI genotype (S-haplotype) of the IL-4 gene are 5 times more susceptible to CP, whereas the CTI/TTD genotype (P-haplotype) confers protection against CP. Compared with the S-haplotype, subjects with the P-haplotype produce higher levels of the IL-4 protein after non-surgical periodontal therapy. The present in vitro study aimed to investigate the functionality of IL-4 haplotypes in immune cells to obtain insight into the influence of these genetic variations in regulating immune responses to CP-associated bacteria. Peripheral blood was collected from 6 subjects carrying each haplotype, and their immune cells were challenged with periodontopathogens to compare responses of the different haplotypes with regard to gene expression, protein secretion and the immunophenotype of T helper responses. We found higher IL-4 mRNA and protein levels in the P-haplotype, which also presented higher levels of anti-inflammatory cytokines. In contrast, cells from S-haplotype subjects responded with higher levels of pro-inflammatory cytokines. S-haplotype individuals exhibited significantly greater polarization toward the Th1 phenotype, whereas the P-haplotype was associated with an attenuated response to periodontopathogens, with suggestive skewing toward Th2/M2 phenotypes. In conclusion, IL-4 genetic variations associated with susceptibility to or protection against chronic periodontitis are directly associated with influencing the response of immune cells to periodontopathogens.

Long-term evaluation of oral gavage with periodontopathogens or ligature induction of experimental periodontal disease in mice.

OBJECTIVE: To evaluate in long-term periods the destruction of periodontal tissues and bacterial colonization induced by oral gavage with periodontopathogens or ligature experimental periodontal disease models. MATERIAL AND METHODS: Forty-eight C57BL/6 J mice were divided into four groups: group C: negative control; group L: ligature; group G-Pg: oral gavage with Porphyromonas gingivalis; and group G-PgFn: oral gavage with Porphyromonas gingivalis associated with Fusobacterium nucleatum. Mice were infected by oral gavage five times in 2-day intervals. After 45 and 60 days, animals were sacrificed and the immune-inflammatory response in the periodontal tissue was assessed by stereometric analysis. The alveolar bone loss was evaluated by live microcomputed tomography and histometric analysis. qPCR was used to confirm the bacterial colonization in all the groups. Data were analyzed using the Kruskal-Wallis, Wilcoxon, and ANOVA tests, at 5 % of significance level. RESULTS: Ligature model induced inflammation and bone resorption characterized by increased number of inflammatory cells and decreased number of fibroblasts, followed by advanced alveolar bone loss at 45 and 60 days (p < 0.05). Bacterial colonization in groups G-Pg and G-PgFn was confirmed by qPCR but inflammation and bone resorption were not observed (p < 0.05). CONCLUSIONS: The ligature model but not the oral gavage models were effective to induce inflammation and bone loss in long-term periods. Pg colonization was observed in all models of experimental periodontal disease induction, independent of tissue alterations. These mice models of periodontitis validates, compliments, and enhances published PD models that utilize ligature or oral gavage and supports the importance of a successful colonization of a susceptible host, a bacterial invasion into vulnerable tissue, and host-bacterial interactions that lead to tissue destruction. CLINICAL RELEVANCE: The ligature model was an effective approach to induce inflammation and bone loss similar to human periodontitis, but the oral gavage models were not efficient in inducing periodontal inflammation and tissue destruction in the conditions studied. Ligature models can provide a basis for future interventional studies that contribute to the understanding of the disease pathogenesis and the complex host response to microbial challenge.

Dentinogenesis imperfecta type II: approach for dental treatment / Dentinogênese imperfeita tipo II: abordagem de tratamento odontológico

Introduction: Dentinogenesis imperfecta (DI) is a hereditary dentin development disorder that affects both primary and permanent dentitions. The DI characteristics are discolored and translucent teeth ranging from gray to brownish-blue or amber. The enamel may split readily from the dentin when subjected to occlusal stress. Radiographically there are evident of cervical constrictions, short root and pulp chambers, and the root canals are smaller than normal or completely obliterated. The dental treatment choice can be decided on a case-by case-basis, considering the degree of dental tissue loss, and child age and cooperation. Objective: The aim of this case report was to describe the early dental treatment performed in a child affected by DI type II. Case Report: The treatment involved basic preventive procedures. Primary molars were worn to such an extent that the remained tooth structure was covered with composite resin to protect the exposed dentin. Resin-based sealant was applied in all first permanent molars. Posterior cross bite was treated with the expansion of the upper arch. Conclusion: The early treatment restored the patient´s vertical dimension resulting in acceptable esthetics and function for the permanent teeth to complete their eruption.

Introdução: A dentinogênese imperfeita (DI) é uma desordem hereditária no desenvolvimento da dentina, que afeta tanto a dentição decídua quanto a permanente. A DI apresenta como características dentes escurecidos e translúcidos que vão do cinza ao marrom ou âmbar. O esmalte pode se separar facilmente da dentina quando submetido ao estresse oclusal. Radiograficamente há evidencias de constrição cervical, raiz curta e polpas reduzidas, sendo os canais menores do que o comum ou completamente obliterados. A escolha do tratamento pode ser decidida com base no caso, considerando-se a idade da criança, grau de perda de tecido dentário e de cooperação do paciente. Objetivo: O objetivo deste relato de caso foi descrever o tratamento odontológico precoce realizado em uma criança afetada pela DI tipo II. Relato do Caso: O tratamento envolveu procedimentos básicos de prevenção. Molares decíduos foram desgastados, de tal forma que a estrutura remanescente do dente foi coberta com resina composta para proteger a dentina exposta. Selante resinoso foi aplicado em todos os primeiros molares permanentes. Mordida cruzada posterior foi tratada com a expansão do arco superior. Conclusão: O tratamento precoce restaurou a dimensão vertical do paciente resultando em estética e função aceitáveis para os dentes permanentes completarem sua erupção.

Effect of long-term water immersion on the fracture toughness of denture base and reline resins.

PURPOSE: This study evaluated the fracture toughness (FT) of one denture base (Lucitone 550 - L) and four hard reline resins [Ufi Gel Hard (UH), Tokuyama Rebase II (TR), New Truliner (NT) and Kooliner (K)], and the effect of long-term water storage on this property. MATERIALS AND METHODS: Forty specimens (40 × 8 × 4 mm) of each material were made, and FT was assessed after polymerisation (control of reliners), after 48 ± 2 h in water at 37°C (control of denture base resin) and after storage in water at 37°C for 7, 90 or 180 days (all materials). Data (MPa.m(1/2) ) were analysed by two-way anova and Games-Howell test (p = 0.05). RESULTS: Resin L exhibited the highest FT mean values. After 180 days of storage, FT mean values of L (3.37), UH (1.53) and K (1.20) were higher than those of the other periods. FT mean values of NT decreased from control (1.63) to 7 days (1.30) and then remained constant. FT mean values of TR (1.13) were similar in all periods of analysis. CONCLUSION: The denture base resin L showed higher FT mean values than the reline resins. Long-term water storage increased the FT of L, UH and K, reduced the FT of NT and did not influence the FT of TR.

Evidências da associação entre periodontite e câncer bucal / Evidences of the association between periodontitis and oral cancer

Introdução: a periodontite constitui um foco inflamatório crônico em resposta ao biofilme dental que pode estar envolvida no desenvolvimento de câncer bucal. Objetivo: o objetivo desta revisão narrativa da literatura foi compreender e verificar as evidências de associação entre periodontite e câncer bucal. Revisão da literatura: foram buscados artigos que avaliassem a relação entre periodontite - e seus fatores associados - e câncer bucal. Conclusão: frente à indisponibilidade de dados caracterizando casos reais de periodontite e as dificuldades metodológicas, concluiu-se que é fraco o nível de evidência científica relacionando a periodontite com o câncer bucal

Introduction: Periodontitis represents a chronic inflammatory site in response to oral biofilm which may be involved in oral cancer development. Objective: The objective of this narrative literature review was to comprehend and assess the evidences of association between periodontitis and oral cancer. Literature review: Articles which assessed the relationship between periodontitis -and its associated factors - and oral cancer were searched. Conclusion: Due to unavailable data representing real periodontitis cases and methodological difficulties, it was concluded that the level of evidence relating periodontitis with oral cancer is weak.

Investigação comparativa de dados clínicos e microbiológicos entre indivíduos geneticamente suscetíveis e não suscetíveis à periodontite / Clinical and microbiological data investigation from individuals genetically susceptible and non-susceptible to periodontitis

A Doença Periodontal (DP) tem caráter multifatorial, com influência da presença de microrganismos periodontopatogênicos, suscetibilidade genética do hospedeiro, entre outros. O tecido periodontal inflamado produz dentre outras citocinas, a Interleucina 8 (IL-8). Na literatura científica há informações conflitantes acerca dos níveis de IL-8 em fluido crevicular gengival de pacientes com e sem DP. Estudos prévios realizados por nosso grupo identificaram que pacientes carregando o haplótipo ATC/TTC no gene IL8 foram 2 vezes mais suscetíveis à DP e que esses pacientes mesmo com menor desafio microbiano, pareciam desenvolver a DP mais exacerbadamente comparados aos indivíduos considerados não suscetíveis à DP pela ausência daquele haplótipo. Como esses resultados foram obtidos de um estudo clínico, estudos in vitro se mostraram necessários para investigar a funcionalidade dos haplótipos no gene IL8. O objetivo deste trabalho foi verificar na literatura científica se os níveis de IL-8 estão aumentados ou não mediante a presença da DP e se, por meio de ensaios in vitro controlados, os mencionados haplótipos no gene IL8 podem influenciar a funcionalidade e expressão deste e outros genes importantes para a resposta imune. Realizamos uma criteriosa revisão sistemática da literatura seguida de meta-análise enfocando a quantificação de mRNA e proteína IL-8 em tecido gengival, saliva e fluido crevicular gengival (FCG) de pacientes com DP comparados a indivíduos periodontalmente saudáveis. Verificamos maior expressão gênica de IL8 e da proteína IL-8 nos tecidos gengivais de pacientes com DP, enquanto níveis proteicos de IL-8 mostraram níveis variáveis na saliva e FCG. Também investigamos em células isoladas do sangue periférico de pacientes carregando diferentes haplótipos no gene IL8, a possível influência destes na expressão de genes do sistema imune. A funcionalidade destes haplótipos no gene IL8 foi também investigada após edição genética em linhagem celular por meio do sistema CRISPR-CAS9 seguida de recombinação homóloga. Conjuntamente observamos que perante estímulos microbianos o haplótipo ATC/TCC foi associado à maior expressão gênica e funcionalidade do gene IL8 em comparação ao outro haplótipo ATT/TCC. Como conclusão geral notou-se que em tecido gengival há concordância na literatura sobre maiores níveis de mRNA e proteicos de IL-8 associados à DP, e que o haplótipo no gene IL8 previamente associado com suscetibilidade à DP mostrou-se funcional influenciando a expressão gênica

Periodontal disease (PD) is a multifactorial disease, influenced by the periodontopathogenic microorganisms' presence, host genetic susceptibility, among others. The inflamed periodontal tissue produces amongst other cytokines the Interleukin8 (IL-8). In the scientific literature there are conflicting information about the IL-8 levels in gingival crevicular fluid of patients with and without DP. Previous studies of our group found that patients carrying the haplotype ATC/TTC in IL8 gene were 2 times more susceptible to PD and these same patients with lower microbial challenge develop PD more exaggeratedly compared to individuals considered not susceptible to PD by absence of that haplotype. As these results were obtained from a clinical study, in vitro studies are necessary to investigate the functionality of the IL8 gene haplotypes. The objective of this study was to investigate whether IL-8 levels are increased or not by the presence of PD and, through controlled in vitro assays, the aforementioned haplotypes in IL8 gene can influence the functionality and expression of this and other important genes to the immune response. We conducted a rigorous literature systematic review followed by meta-analysis focusing on the mRNA and IL-8 protein quantification in gingival tissue, saliva and gingival crevicular fluid (GCF) of patients with PD compared to periodontally healthy individuals. We found a higher IL8 gene expression and IL-8 protein in the gingival tissues of PD patients, whereas protein levels of IL-8 showed varying levels in GCF and saliva. We also investigated cells from the patient's peripheral blood carrying different haplotypes in IL8 gene, their possible influence on the expression genes of the immune system. The functionality of these haplotypes in IL8 gene was also investigated after genetic edition in cell line using CRISPR-CAS9 followed by homologous recombination system. It was observed that against microbial stimuli the ATC/TTC haplotype was associated with increased gene expression and function of the IL8 gene compared to the ATT/TCC haplotype. As a general conclusion it was noted that in gingival tissue there is an agreement in the literature on higher levels of mRNA and protein for IL-8 associated with PD, and that the IL8 haplotype previously associated with susceptibility to chronic periodontitis proved functional, influencing gene expression

Achados clínicos, genéticos e microbiológicos de uma família com Periodontite Agressiva em Maceió / Clinical, microbiological and genetics findings of a family with Aggressive Periodontitis from Maceio

O presente estudo relata achados clínicos, genéticos e microbiológicos de indivíduos de uma família com periodontite agressiva (PA) residente em Maceió - AL, Brasil. Quatorze membros da família foram submetidos a exames clínicos periodontais, coleta de células da mucosa oral para extração de DNA e coleta de fluido subgengival para detecção de cinco espécies de periodontopatógenos por meio da PCR (Reação em Cadeia da Polimerase). Polimorfismos nos genes Interleucina 4 e 10 (IL4 e IL10) foram investigados em cada indivíduo por meio da PCR-RFLP (Polimorfismo por Comprimento de Fragmento de Restrição). Seis membros da família apresentaram PA generalizada e oito foram considerados não afetados pela PA. Não houve associação de alelos, genótipos e haplótipos nos genes IL10 e IL4 com a presença de PA na família estudada. Treponema denticola (T.d.) foi o patógeno prevalente, seguido por Tannerella forsythia (T.f.). Houve correlação dos parâmetros clínicos investigados (perda de inserção clínica, sangramento à sondagem e profundidade de sondagem) com a presença de T.d., enquanto que para T.f. houve associação deste com o sangramento à sondagem. Conclui-se que, apesar de os polimorfismos investigados não terem relação com a suscetibilidade à PA, a presença de periodontopatógenos está associada a piores índices clínicos periodontais.

The present study reports clinical, microbiological and genetic findings in members of a family with Aggressive Periodontitis (AgP) from Maceió - AL, Brazil. After periodontal exams in fourteen members of the family, DNA was obtained from epithelial buccal cells and microbiological samples were collected from subgingival plaque to detect five species of periodontopathogens by Polymerase Chain Reaction (PCR). PCR-RFLP (Restriction Fragment Length Polymorphism) was used to investigate human polymorphisms in interleukin genes (IL4, IL10). Six members of the family showed Generalized AgP and eight were considered unaffected by the AgP. There was no association of alleles, genotypes and haplotypes in the IL10 and IL4 genes with the AgP in the studied family. Treponema denticola (T.d.) was the prevalent pathogen, followed by the Tannerella forsythia (T.f.). There was correlation between clinical findings (clinical attachment loss, bleeding on probing and probing depth) with the presence of T.d., while T.f. was correlated with bleeding on probing. In conclusion, although the investigated polimorphisms were not associated with the susceptibility to AgP, the presence of periodontopathogens is related to worse periodontal clinical parameters.