Comparison of three methods for establishing rat peri-implantitis model / 北京大学学报(医学版)

OBJECTIVE@#To compare the efficiency and effect of establishing rat peri-implantitis model by traditional cotton thread ligation and local injection of Porphyromonas gingivalis lipopolysaccharide (LPS) around the implant, as well as the combination of the two methods.@*METHODS@#Left side maxillary first molars of 39 male SD rats were extracted, and titanium implants were implanted after four weeks of healing. After 4 weeks of implant osseointegration, 39 rats were randomly divided into 4 groups. Cotton thread ligation (n=12), local injection of LPS around the implant (n=12), and the two methods combined (n=12) were used to induce peri-implantitis, the rest 3 rats were untreated as control group. All procedures were conducted under 5% isoflurane inhalation anesthesia. The rats were sacrificed 2 weeks and 4 weeks after induction through carbon dioxide asphyxiation method. The maxilla of the rats in the test groups were collected and marginal bone loss was observed by micro-CT. The gingival tissues around the implants were collected for further real time quantitative PCR (RT-qPCR) analysis, specifically the expression of tumor necrosis factor-alpha (TNF-α) as well as interleukin-1β (IL-1β). The probing depth (PD), bleeding on probing (BOP) and gingival index (GI) of each rat in the experimental group were recorded before induction of inflammation and before death.@*RESULTS@#After 4 weeks of implantation, the osseointegration of implants were confirmed. All the three test groups showed red and swollen gums, obvious marginal bone loss around implants. After 2 weeks and 4 weeks of inflammation induction, PD, GI and BOP of the three test groups increased compared with those before induction, but only BOP was statistically significant among the three test groups (P < 0.05). At the end of 2 weeks of inflammation induction, marginal bone loss was observed at each site in the cotton thread ligation group and the combined group. At each site, the bone resorption in the combined group was greater than that in the cotton thread ligation group, but the difference was not statistically significant (P > 0.05), bone resorption was observed at some sites of some implants in LPS local injection group. At the end of 4 weeks of inflammation induction, marginal bone loss was observed at all sites in each group. The marginal bone loss in the cotton thread ligation group and the combined group was greater than that in the LPS local injection group, and the difference was statistically significant (P < 0.05). At the end of 2 weeks and 4 weeks of induction, the expression of TNF-α and IL-1β in the test groups were higher than those in the control group (P < 0.05).@*CONCLUSION@#Compared with local injection of LPS around the implant, cotton thread ligature and the two methods combined can induce peri-implantitis in rats better and faster.

Mucina y Enfermedad Periodontal / Mucin and periodontal disease

La enfermedad periodontal (EP) es una patología que afecta principalmente los tejidos que rodean a la pieza dentaria (PD) y se caracteriza, en la mayoría de los casos, por una exposición bacteriana que favorece una respuesta destructiva e inflamatoria del huésped, que conduce a la pérdida de inserción periodontal de la PD, provocando una marcada reabsorción ósea y la posible pérdida de las PD. El diagnóstico de EP implica evaluaciones clínicas y radiográficas, en la actualidad se están realizando diversas investigaciones para evaluar posibles compuestos en los fluidos orales a través de lo cual puede ser posible evaluar la presencia y gravedad de estas enfermedades, como así también el riesgo en los pacientes. Hay evidencias de la interacción de macromoléculas salivales, como las mucinas, con microorganismos específicos. De esta manera las mucinas, junto con otros productos de la saliva, ayudan a modular tanto el número como el tipo de proliferación de ciertos organismos y provocar la disminución de otros. La revisión de la literatura actual concluye que las mucinas salivales pueden servir como un parámetro bioquímico de la inflamación del periodonto (AU)

Periodontal disease (PD) is a pathology that mainly affects the tissues surrounding the tooth (PD) and is characterized, in most cases, by a bacterial exposure that favors a destructive and inflammatory response of the host, which leads to the loss of periodontal insertion of the PD, causing a marked bone resorption and the possible loss of the PD. The diagnosis of PD involves clinical and radiographic evaluations, at present several investigations are being carried out to evaluate possible compounds in oral fluids through which it may be possible to evaluate the presence and severity of these diseases, as well as the risk in patients. There is evidence of the interaction of salivary macromolecules, such as mucins, with specific microorganisms. In this way, mucins, together with other saliva products, help modulate both the number and type of proliferation of certain organisms and cause the decrease of others. The review of the current literature concludes that salivary mucins can serve as a biochemical parameter of inflammation of the periodontium (AU)

Granuloma piógeno oral recurrente con pérdida ósea alveolar y movilidad dentaria: Reporte de un caso inusual / Granuloma piogênico oral recorrente com perda óssea alveolar e mobilidade dental: Relato de um caso incomum / Recurrent oral pyogenic granuloma with alveolar bone loss and tooth mobility: report of an unusual case

Resumen El granuloma piógeno oral es una lesión benigna multifactorial, caracterizada por presentarse como un agrandamiento gingival muy vascularizado. Se puede localizar en cualquier área de la cavidad oral, con más frecuencia en la encía marginal vestibular. Se presenta con mayor incidencia en mujeres adultas y en niños varones. No suele comprometer tejido óseo ni dientes y su tratamiento más seguro es la exéresis quirúrgica, siendo el riesgo de recurrencia alto. El objetivo del presente estudio es reportar el caso de una paciente de 9 años de edad, que fue sometida a la exéresis de un granuloma piogénico oral en el hueso maxilar y al año siguiente presentó una recurrencia de la lesión con pérdida ósea alveolar y movilidad de un diente adyacente. Se le realizó una biopsia y un curetaje minucioso, confirmándose el diagnostico de granuloma piogénico oral.

Resumo O granuloma piogênico oral é uma lesão multifatorial benigna, caracterizada por apresentarse como um aumento gengival altamente vascularizado. Pode estar localizado em qualquer área da cavidade oral, mais frequentemente na gengiva marginal vestibular. Ocorre com maior incidência em mulheres adultas e em crianças do sexo masculino. Geralmente não compromete o tecido ósseo ou os dentes e seu tratamento mais seguro é a escisão cirúrgica, sendo alto o risco de recorrência. O objetivo do presente estudo é relatar o caso de uma paciente de 9 anos de idade, submetida a escisão de granuloma piogênico oral no maxilar e no ano seguinte apresentou uma recorrência da lesão com perda óssea alveolar e a mobilidade de umo de seus dentes adjacentes. Uma biópsia e uma curetagem completa foram realizadas, confirmando o diagnóstico de granuloma piogênico oral.

Abstract Oral pyogenic granuloma is a benign multifactorial lesion that appears as a highly vascular gingival enlargement. It can be located anywhere in the oral cavity, most often in the vestibular marginal gingiva. It occurs most frequently in adult women and male children. It does not usually compromise bone tissue or teeth; its safest treatment is surgical excision, with a high recurrence risk. This study aims to report the case of a 9-year-old female patient who underwent oral pyogenic granuloma excision in the maxilla. The following year, she presented a possible lesion recurrence with alveolar bone loss and the mobility of an adjacent tooth. A biopsy and thorough curettage were performed, confirming the diagnosis of oral pyogenic granuloma.

Effect of Obesity and/or Ligature-induced Periodontitis on Aortic Wall Thickness in Wistar Rats / Efeito da obesidade e/ou periodontite induzida por ligadura na espessura da parede da aorta em ratos wistar

ABSTRACT The purpose of this study was to evaluate aortic wall thickness after periodontal disease and/or obesity induction in a Wistar rat model. Sixty male Wistar rats were randomly divided into four groups: control (CT), periodontal disease (PD), obesity (OB), and obesity plus periodontal disease (OB+PD). Groups OB and OB+PD received cafeteria diet for 17 weeks. After they had acquired obesity (week 12), periodontal disease was induced by placing a silk ligature on the maxillary right second molar of groups PD and OB+PD. During the experimental period, body weight and Lee index were assessed. Mean alveolar bone loss (ABL) was evaluated, and aortas were prepared for histometric analysis of the aortic wall by ImageJ software. Body weight and Lee index increased in rats exposed to cafeteria diet. Mean ABL was higher in Groups PD and OB+PD than in control and OB (p<0.05). ABL was 18% higher in Group OB+PD than in Group PD, with statistically significant difference (p<0.001). Aortas were thicker in Groups OB and OB+PD than in control and PD groups, respectively (2.31mm ± 0.28 and 2.33 ± 0.29 vs. 2.18 ± 0.26 and 2.14 ± 0.27). Group OB differed significantly from the control group (p=0.036), and OB+PD and OB differed significantly from PD (p=0.004 and p= 0.001, respectively). Obesity alters aortic wall thickness in Wistar rats. However, the presence of periodontal disease did not affect the aortic wall thickness under the conditions of the present study.

RESUMO O objetivo deste estudo foi avaliar a espessura da parede da aorta após modelos de indução de doença periodontal e/ou obesidade em ratos Wistar. Sessenta ratos Wistar machos foram aleatoria mente divididos em quatro grupos: controle (CT), doença periodontal (DP), obesidade (OB), obesidade mais doença periodontal (OB+DP). Os grupos OB e OB+DP rece beram dieta de cafeteria por 17 semanas. Após de adquirirem obesidade, (semana 12), doença periodontal foi induzido pela colocação de ligaduras de seda no segundo molar superior direito dos grupos DP e OB+DP. Durante o período experi mental, o peso corporal e índice de Lee foram obtidos. Média de perda óssea alveolar (POA) foi avaliada e as aortas preparadas para análise histométrica da parede aórtica (em mm) pelo software ImageJ. Ratos expostos a dieta de cafeteria demonstraram um aumento do peso corporal e do índice de Lee. Uma POA media maior foi observada nos grupos DP e OB+DP comparado aos grupos controle e OB (p<0.05). O grupo OB+DP, quando comparado ao grupo DP, apresentou POA 18% maior e essa diferença foi estatisticamente significativa (p<0.001). Os grupos OB e OB+DP exibiram uma espessura de aorta maior comparado aos grupos DP e controle, respectivamente (2.31 ± 0.28 e 2.33 ± 0.29 vs. 2.18 ± 0.26 e 2.14 ± 0.27). Diferenças significativas foram observadas nas comparações dos grupos OB e controle (p=0,036), e OB+DP e OB comparado ao grupo DP (p=0.004 e p= 0.001, respectivamente). A obesidade parece afetar a espessura da parede da aorta em ratos Wistar. Entretanto, a presença de doença periodontal não afetou a espessura da parede da aorta sob as condições do presente estudo.

Pam2CSK4 (TLR2 agonist) induces periodontal destruction in mice

Abstract Lipoproteins are important bacterial immunostimulating molecules capable of inducing receptor activator of nuclear factor-κB (RANKL) and osteoclast formation in vitro and in vivo . Although these molecules are present in periodontopathogenic bacteria, their role in periodontitis is not known. In this study, we used Pam2CSK4 (PAM2), a synthetic molecule that mimics bacterial lipoprotein, to investigate the effects of lipoproteins on periodontitis in mice. C57BL/6 male mice were randomly divided into three experimental groups: 1) Negative control group: animals received vehicle injection; 2) Positive control group: animals received injection of Escherichia coli lipopolysaccharide (LPS); 3) PAM2 group: animals received PAM2 injection. All the injections were performed bilaterally every other day into the palatal mucosa between first and second molars. After twenty-four days, the animals were euthanized to assess alveolar bone volume (micro-CT), cellular and extracellular composition in the gingiva (stereometric analysis), and osteoclast numbers (TRAP staining). Treatment with either PAM2 or LPS induced gingival inflammation, as demonstrated by increased infiltration of inflammatory cells and enhanced angiogenesis, associated with a smaller number of fibroblasts and decreased extracellular matrix. Importantly, treatment not only with LPS but also with PAM2 resulted in a larger number of TRAP+ multinucleated osteoclasts and significant loss of alveolar bone. Collectively, our data demonstrate that PAM2 can induce gingival inflammation and bone loss in mice, broadening the avenues of investigation into the role of lipoproteins in the pathogenesis of periodontal disease.

Pam2CSK4 (TLR2 agonist) induces periodontal destruction in mice

Abstract Lipoproteins are important bacterial immunostimulating molecules capable of inducing receptor activator of nuclear factor-κB (RANKL) and osteoclast formation in vitro and in vivo . Although these molecules are present in periodontopathogenic bacteria, their role in periodontitis is not known. In this study, we used Pam2CSK4 (PAM2), a synthetic molecule that mimics bacterial lipoprotein, to investigate the effects of lipoproteins on periodontitis in mice. C57BL/6 male mice were randomly divided into three experimental groups: 1) Negative control group: animals received vehicle injection; 2) Positive control group: animals received injection of Escherichia coli lipopolysaccharide (LPS); 3) PAM2 group: animals received PAM2 injection. All the injections were performed bilaterally every other day into the palatal mucosa between first and second molars. After twenty-four days, the animals were euthanized to assess alveolar bone volume (micro-CT), cellular and extracellular composition in the gingiva (stereometric analysis), and osteoclast numbers (TRAP staining). Treatment with either PAM2 or LPS induced gingival inflammation, as demonstrated by increased infiltration of inflammatory cells and enhanced angiogenesis, associated with a smaller number of fibroblasts and decreased extracellular matrix. Importantly, treatment not only with LPS but also with PAM2 resulted in a larger number of TRAP+ multinucleated osteoclasts and significant loss of alveolar bone. Collectively, our data demonstrate that PAM2 can induce gingival inflammation and bone loss in mice, broadening the avenues of investigation into the role of lipoproteins in the pathogenesis of periodontal disease.

H2S in periodontal immune-inflammatory response and bone loss: a study in rats / Influência do H2S na resposta imunoinflamatória e perda óssea periodontal: um estudo em ratos

ABSTRACT Halitosis is highly prevalent in periodontitis and attributed mainly to the presence of volatile sulfur compounds (VSC), where hydrogen sulfide (H2S) is the chief culprit in the characteristic malodor of periodontitis and thus may play an active role in its pathogenesis. The aim of this study was to evaluate the effect of H2S in the acute, intermediate and chronic immuneinflammatory host response and alveolar bone loss in vivo by using an animal model of induced periodontal disease. Thirtysix rats were divided into 2 groups: test group (n = 18), rats exposed to H2S (NaHS H2S donor molecule) and control group (n = 18), rats treated with saline only (Ctrl). All animals had one of their lower second molars ligated to induce periodontal disease (PD). The sound contralateral molar was used as control (H). Each group was subdivided into 3 (n = 6), according to followup time (3h, 5 days and 14 days). The gingival tissue was used for mRNA expression analysis (IL1, IL6, RANKL, OPG and SOFAT) by realtime PCR and the mandibles were analyzed morphometrically. Data analysis showed that the ligature promoted alveolar bone loss, observed mainly at 14 days, both in the group exposed to H2S and in the Ctrl group. H2S administration did not result in additional bone loss. Gene expression showed a significant increase in IL1, IL6, RANKL and SOFAT only in the CtrlPD group (p<0.05). A significant downregulation in OPG expression was observed over time in the CtrlPD group (p<0.05). In conclusion, H2S had no effect on alveolar bone loss in the absence of a ligature. In the presence of a ligature, however, exposure to H2S had an immunoregulatory effect on the expression of proinflammatory and proresorptive cytokines.

RESUMO A halitose é altamente prevalente na periodontite e é atribuída principalmente à presença de compostos sulforosos voláteis (CSV), sendo o sulfeto de hidrogênio (H2S) o principal gás relacionado ao mau odor e que pode estar envolvido na patogênese da doença periodontal. O objetivo deste estudo foi avaliar o efeito agudo, intermediário e crônico do H2S na resposta imunoinflamatória e na perda óssea alveolar em ratos, com e sem doença periodontal induzida. Trinta e seis ratos foram divididos em 2 grupos: teste (n = 18), ratos expostos ao H2S (NaHS molécula doadora de H2S) e grupo controle (n = 18), ratos tratados apenas com solução salina (Ctrl). Todos os animais tiveram um dos seus segundos molares inferiores submetidos à colocação de uma ligadura para o desenvolvimento da doença periodontal (DP), em comparação com o dente contralateral saudável (H). Cada grupo foi subdividido em 3 (n = 6), de acordo com o tempo de eutanásia (3h, 5 dias e 14 dias). Os tecidos gengivais foram utilizados para a análise da expressão gênica (IL1, IL6, RANKL, OPG e SOFAT) por PCR em tempo real e as mandíbulas foram analisadas morfometricamente. Análise dos dados demonstrou que a ligadura promoveu perda óssea alveolar, observada principalmente aos 14 dias, tanto no grupo exposto ao H2S quanto no grupo Ctrl. A administração de H2S não resultou em perda óssea adicional. A expressão gênica demonstrou aumento significativo de IL1, IL6, RANKL e SOFAT apenas no grupo CtrlPD (p <0,05). Uma significativa regulação negativa na expressão de OPG foi observada ao longo do tempo no grupo CtrlPD (p <0,05). Podese concluir que o H2S não teve efeito adicional na perda óssea alveolar, na ausência de ligadura. Entretanto, na presença de ligadura, a exposição ao H2S teve um efeito imunorregulatório na expressão de citocinas próinflamatórias e próreabsortivas.

Osteonecrosis por bifosfonatos: presentación de un caso clínico / Osteonecrosis of the jaws: report of a clinical case

La osteonecrosis de los maxilares asociada a bifosfonatosfuedefinida como «Área de hueso expuesto en la región máxilo facial que permanece expuesta al menos por 8 semanas, siempre que los pacientes hayan sido prescriptos con bifosfonatos, y en ausencia de terapia radiante¼. (1) En la actualidad se agregó "hueso expuesto o hueso que se puede sondear a través de una fistula intra o extra oral" (2). Presentamos un caso clínico de una paciente femenina de 70 años de edad, diagnosticada con cáncer de hueso (osteosarcoma) con foco en la pelvis, historia de consumo de bifosfonatosvía endovenosa durante tres años, zolendronato 70mg, semanalmente. Al momento de la consulta, se encontraba en periodo de remisión de la enfermedad de base y sin consumo de medicación antiresortiva desde hace un año (AU)

Osteonecrosis of the jaws associated with bisphosphonates was defined as «Area of exposed bone in the maxillofacial region that remains exposed for at least 8 weeks, provided that patients have been prescribed with bisphosphonates, and in the absence of radiant therapy¼. (1) At present, "exposed bone or bone that can be probed through an intra or extra oral fistula" was added (2). We present a clinical case of a 70-year-old female patient, diagnosed with bone cancer (osteosarcoma) with a focus on the pelvis, history of consumption of bisphosphonates intravenously for three years, zolendronate 70 mg, weekly. At the time of the consultation, he was in the period of remission of the underlying disease and without consumption of antiresortive medication for a year (AU)

Alveolar bone pattern and salivary leptin levels among premenopausal obese women / Padrão ósseo alveolar e níveis salivares de leptina entre mulheres obesas na pré-menopausa

ABSTRACT Background: Systemic bone loss may lead to more severe periodontal destruction, decreasing local bone mineral density. Aim: A cross-sectional designed was performed to study associations among alveolar bone pattern, salivary leptin concentrations, and clinical periodontal status in premenopausal obese and eutrophic women. Methods: Thirty morbid obese (G1) and 30 normal-weight (G2) women were included. Anthropometric and periodontal measurements (probing depth - PD, clinical attachment levels - CAL, presence of calculus, bleeding on probing -BOP, and plaque accumulation) were assessed. OHIP-14 was used for assessment of oral health impact on quality of life. Panoramic radiography was used to obtain the panoramic mandibular index (PMI), mandibular cortical index (MCI), and mental index (MI). Intraoral periapical (PA) radiography was taken to measure the total trabecular bone volume. Leptin was measured in saliva of fasted overnight women. Results: Groups 1 and 2 differed in all anthropometric aspects, but height. Pocket depth, calculus, BOP, and plaque index were worse in G1. No differences between groups were found considering OHIP. Normal-weight subjects showed higher proportion of dense bone trabeculae than obese subjects for pre-molars, but not for molars. Mental and panoramic mandibular indexes did not differ and were in normal level. Leptin concentration was dependent only on BMI. Conclusion: Obesity affected the periodontal conditions, the alveolar bone pattern, and the salivary leptin concentration.

RESUMO Racional: A perda óssea sistêmica pode levar à destruição periodontal mais severa, diminuindo a densidade mineral óssea local. Objetivo: Investigar as associações entre padrão ósseo alveolar, concentrações de leptina salivar e estado periodontal em mulheres obesas na pré-menopausa e eutróficas. Métodos: Foram avaliadas 30 mulheres com obesidade mórbida (G1) e 30 com peso normal (G2). Foram analisadas as medidas antropométricas e periodontais (profundidade de sondagem - PS, nível clínico de inserção - NCI, presença de cálculo, sangramento à sondagem - SS e acúmulo de placa). O impacto da saúde bucal na qualidade de vida foi mensurado por meio do questionário OHIP-14. Radiografia panorâmica foi utilizada para obter o índice mandibular panorâmico (PMI), índice cortical mandibular (MCI) e índice mental (MI); já a radiografia periapical intraoral (AF) para medir o volume ósseo trabecular total. A leptina salivar foi coletada no período da manhã com a paciente em jejum. Resultados: Os grupos 1 e 2 diferiram em todos os aspectos antropométricos, exceto em estatura. Profundidade de bolsa, cálculo, SS e índice de placa foram piores no G1. Não foram encontradas diferenças entre os grupos considerando o OHIP. Indivíduos com peso normal apresentaram maior proporção de trabéculas ósseas densas do que os obesos para pré-molares, mas não para molares. Índices radiomorfométricos não diferiram entre os grupos e estavam dentro de valores normais. A concentração de leptina esteve associada ao IMC. Conclusão: A obesidade afetou as condições periodontais, o padrão ósseo alveolar e a concentração de leptina salivar.

Does the implant-abutment interface interfere on marginal bone loss? A systematic review and meta-analysis

Abstract The objective of this systematic review was to compare the conical internal connection (IC) with the external hexagonal connection (EH) on the occurrence of marginal bone loss (ΔMBL). Different databases were used to carry out the selection of the elected studies. The studies were judged according to the risk of bias as "high", "low" and "unclear" risk. For the meta-analysis we included only studies that could extract the data of ΔMBL, survival rate (SR) and probing depth (PD). No statistically significant differences were found for ΔMBL data at one, three- and five-year survival rates between implant connections (p <0.05), however statistically significant differences were found for PD between EH and IC implants (1-year follow-up) -0.53 [95%CI -0.82 to -0.24, p = 0.0004]. This present systematic review demonstrated that there are no significant differences between IC and EH implants for both ΔMBL and SR at 1, 3 e 5 years after functional loading, although better PD values were observed for implants pertaining to the IC connections. Considering the high heterogeneity, more well-delineated, randomized clinical trials should be conducted.

Does traumatic occlusal forces lead to peri-implant bone loss? A systematic review

Abstract Observational studies have indicated that crestal bone level changes at implants are typically associated with clinical signs of inflammation, but still mechanical overload has been described as possible factor leading to hard-tissue deficiencies at implant sites without mucosal inflammation. The aim of this paper was systematically review the literature regarding the possible effect of traumatic occlusal forces on the peri-implant bone levels. Literature search was conducted using PubMed, Scielo and Lilacs, including the following terms: oral OR dental AND implant$ AND (load OR overload OR excessive load OR force$ OR bruxism) AND (bone loss OR bone resorption OR implant failure$). Databases were searched for the past 10 years of publications, including: clinical human studies, either randomized or not, cohort studies, case control studies, case series and animal research. Exclusion criteria were review articles, guidelines and in vitro and in silico (finite element analysis) research, as well as retrospective studies. The PICO questions formulated was: "does traumatic occlusal forces lead to peri-implant bone loss?" The database searches as well as additional hand searching, resulted in 807 potentially relevant titles. After inclusion/exclusion criteria assessment 2 clinical and 4 animal studies were considered relevant to the topic. The included animal studies did not reveal an association between overload and peri-implant bone loss when lower overloads were applied, whereas in the presence of excessive overload it seemed to generate peri-implant bone loss, even in the absence of inflammation. The effect of traumatic occlusal forces in peri-implant bone loss is poorly reported and provides little evidence to support a cause-and-effect relationship in humans, considering the strength of a clinically relevant traumatic occlusal force.

Treatment of peri-implant soft tissue defects: a narrative review

Abstract Soft tissue defects around dental implants, such as papilla or volume loss, peri-implant recession and alterations of the ridge color and/or texture, lead to esthetic and functional complaints. Treatments of these defects in implants are more demanding than in teeth because peri-implant tissue exhibits different anatomical and histological characteristics. This narrative review discusses the proposed treatments for soft tissue defects around implants in the current literature. Several clinical and pre-clinical studies addressed methods to augment the quantity of the peri-implant keratinized mucosa. Autogenous grafts performed better than soft tissue substitutes in the treatment of soft tissue defects, but there is no clinical consensus on the more appropriate donor area for connective tissue grafts. Treatment for facial volume loss, alterations on the mucosa color or texture and shallow peri-implant recessions are more predictable than deep recessions and sites that present loss of papilla. Correction of peri-implant soft tissue defects may be challenging, especially in areas that exhibit larger defects and interproximal loss. Therefore, the regeneration of soft and hard tissues during implant treatment is important to prevent the occurrence of these alterations.

Decoronation followed by dental implants placement: fundamentals, applications and explanations

ABSTRACT Dental arches areas with teeth presenting dentoalveolar ankylosis and replacement root resorption can be considered as presenting normal bone, in full physiological remodeling process; and osseointegrated implants can be successfully placed. Bone remodeling will promote osseointegration, regardless of presenting ankylosis and/or replacement root resorption. After 1 to 10 years, all dental tissues will have been replaced by bone. The site, angulation and ideal positioning in the space to place the implant should be dictated exclusively by the clinical convenience, associated with previous planning. One of the advantages of decoronation followed by dental implants placement in ankylosed teeth with replacement resorption is the maintenance of bone volume in the region, both vertical and horizontal. If possible, the buccal part of the root, even if thin, should be preserved in the preparation of the cavity for the implant, as this will maintain gingival tissues looking fully normal for long periods. In the selection of cases for decoronation, the absence of microbial contamination in the region - represented by chronic periapical lesions, presence of fistula, old unconsolidated root fractures and active advanced periodontal disease - is important. Such situations are contraindications to decoronation. However, the occurrence of dentoalveolar ankylosis and replacement resorption without contamination should neither change the planning for implant installation, nor the criteria for choosing the type and brand of dental implant to be used. Failure to decoronate and use dental implants has never been reported.

RESUMO Áreas dos maxilares com dentes em anquilose alveolodentária e reabsorção dentária por substituição podem ser consideradas como portadoras de osso normal, em pleno processo fisiológico contínuo de remodelação; e os implantes osseointegráveis podem ser aplicados com sucesso. A remodelação óssea promoverá sua osseointegração, independentemente de haver raízes em anquilose e/ou em reabsorção por substituição. Após 1 a 10 anos, todos os tecidos dentários terão sido substituídos por osso. O local, a angulação e o posicionamento ideal no espaço para se colocar o implante devem ser ditados pela conveniência clínica associada, exclusivamente, ao planejamento prévio. Uma das vantagens da decoronação com colocação imediata de implantes em dentes anquilosados e com reabsorção por substituição é a manutenção do volume ósseo na região, tanto vertical quanto horizontalmente. Se possível, deve-se preservar, na preparação da cavidade para o implante, a parte vestibular da raiz, mesmo que fina; isso deixará os tecidos gengivais com aspecto de plena normalidade por longos períodos. O importante na seleção de casos para a decoronação é a ausência de contaminação microbiana na região, representada por lesões periapicais crônicas, presença de fístula, fraturas radiculares antigas não consolidadas e doença periodontal avançada ativa. Essas situações são contraindicações para a decoronação. A ocorrência de anquilose alveolodentária e reabsorção por substituição sem contaminação não deve mudar o planejamento para instalação de implantes, nem mesmo os critérios de escolha do tipo e marca de implante dentário a ser utilizado. Nunca foi relatado fracasso na decoronação e uso de implantes dentários.

Prosthetic, orthodontic and implant-supported rehabilitation of five maxillary anterior teeth with alveolar bone loss

ABSTRACT Introduction: Treatment of maxillofacial injuries is complex and requires the establishment of a comprehensive and accurate diagnosis and correct treatment planning. Objective: The objective of this case report was to describe the re-treatment of a 27-year-old woman who was involved in a severe car accident that resulted in the loss of five anterior teeth and alveolar bone, and whose previous orthodontic and surgical treatments had been unsuccessful. Case report: In this case, the space for the missing mandibular molar was reopened to allow for rehabilitation. The positions of the mandibular incisors were improved. The right mandibular canine was moved to the mesial, allowing for correction of the Class II canine relationship on that side, and implants were placed to replace the maxillary anterior teeth. Conclusion: Anterior aesthetic and functional rehabilitation using a multidisciplinary approach was essential to improve the patient's facial aesthetics, to obtain great improvement in function and to achieve occlusal stability after 2 years of follow-up.

RESUMO Introdução: o tratamento de danos bucomaxilofaciais é complexo e requer diagnóstico abrangente e preciso, além de um correto plano de tratamento. Objetivo: o objetivo deste relato de caso foi descrever o retratamento de uma paciente do sexo feminino, 27 anos de idade, envolvida em acidente automobilístico grave, que resultou na perda de cinco dentes, além de perda óssea alveolar na região anterior. Relato de caso: a paciente apresentava histórico de insucesso de tratamento ortodôntico e cirúrgico. No caso apresentado, o espaço referente aos molares inferiores ausentes foi reaberto, para possibilitar a reabilitação. Houve melhora no posicionamento dos incisivos inferiores. O canino inferior direito foi deslocado para mesial, possibilitando a correção da relação de Classe II intercaninos do mesmo lado. Implantes foram inseridos a fim de substituir os dentes superiores da região anterior. Conclusão: a reabilitação estética e funcional da região anterior, realizada por meio de uma abordagem multidisciplinar, foi fundamental para valorizar a estética facial da paciente, melhorar a função e promover estabilidade oclusal após dois anos de acompanhamento.

Stability and bone loss around submerged and non-submerged implants in diabetic and non-diabetic patients: a 7-year follow-up

Abstract To evaluate peri-implant bone loss (PIBL) and stability around submerged and non-submerged dental implants in patients with and without type 2 diabetes mellitus (T2DM). Thirty-five T2DM and non-diabetic (NT2DM) patients were included in this study. Demographic data were recorded using a questionnaire and PIBL was measured on digital radiographs. Resonance frequency analysis (RFA) was carried out for each implant at the time of fixture placement and at 3 months in both groups. P values less than 0.05 were considered statistically significant. One hundred and eighteen dental implants with a mean height of 10 to 12 mm and 3.3 to 4.1 mm in diameter were placed. The comparison of the mean RFA values at baseline and at 3 months was statistically significant (p = 0.008) in T2DM patients. The inter-group mean RFA values at baseline and at 3 months were not significant (p > 0.05). PIBL was significantly high in T2DM as compared to NT2DM patients at each follow-up (p < 0.05). At 2, 3, and 7 years, non-submerged dental implants showed significantly high PIBL in T2DM patients as compared to NT2DM individuals (p<0.05). The results of the present clinical study demonstrate increased PIBL around non-submerged single-tooth implant-supported restorations in T2DM patients, which may be due to the immune inflammatory status.

Maxillary sinus floor pneumatization and alveolar ridge resorption after tooth loss: a cross-sectional study

Abstract This is a cross-sectional study that aimed to estimate maxillary sinus floor (MSF) pneumatization in single missing tooth of posterior maxilla, by using cone-beam computed tomography (CBCT). CBCT images were analyzed bilaterally and divided into 2 groups: edentulous site (EdS) - edentulous single region of upper second premolar, first or second molars; Tooth site (TS) - contralateral region homologous to the EdS region, with tooth present. Variables evaluated were: sinus height (SH), estimated sinus pneumatization (eSP: ∆ EdS - TS), healed ridge height (HR) and presence of localized sinus pneumatization (LSP) in molars teeth at TS. HR were categorized according to therapeutic option for posterior maxilla. 183 CBCT scans were included and it was observed that EdS presented a higher SH than the TS (p < 0.001) showing an eSP of 0.9 ± 2.93 mm. First molars presented the highest SH for both sides, although significant differences were detected when compared to second molars. First molars were mostly affected by LSP at TS (36 out of 43). Individuals with LSP at TS presented lower HR than the ones without LSP (p < 0.05). 54% of the cases presenting LSP obtained HR < 5 mm, which indicates sinus lift surgery. The present study showed that tooth loss in posterior maxilla favors sinus pneumatization and the identification of LSP at molar roots seems to indicate a greater necessity for sinus lift surgeries.

Short implants versus longer implants with maxillary sinus lift. A systematic review and meta-analysis

Abstract This study compared the survival rate of dental implants, amount of marginal bone loss, and rates of complications (biological and prosthetic) between short implants and long implants placed after maxillary sinus augmentation. This systematic review has been registered at PROSPERO under the number (CRD42017073929). Two reviewers searched the PubMed/MEDLINE, Embase, LILACS, and Cochrane Library databases. Eligibility criteria included randomized controlled trials, comparisons between short implants and long implants placed after maxillary sinus augmentation in the same study, and follow-up for >6 months. The Cochrane Collaboration's tool for assessing the risk of bias in randomized trials was used to assess the quality and risk of bias of the included studies. The search identified 1366 references. After applying the inclusion criteria, 11 trials including 420 patients who received 911 dental implants were considered eligible. No significant difference was observed in the survival rate [p = 0.86; risk ratio (RR): 1.08; 95% confidence interval (CI): 0.46-2.52] or in the amount of marginal bone loss (p = 0.08; RR: −0.05; 95%CI: −0.10 to 0.01). However, higher rates of biological complications for long implants associated with maxillary sinus augmentation were observed (p < 0.00001; RR: 0.21; 95%CI: 0.10-0.41), whereas a higher prosthetic complication rate for short implants was noted (p = 0.010; RR: 3.15; 95%CI: 1.32-7.51). Short implant placement is an effective alternative because of fewer biological complications and similar survival and marginal bone loss than long implant placement with maxillary sinus augmentation. However, the risk of mechanical complications associated with the prostheses fitted on short implants should be considered.

Agreement, correlation, and kinetics of the alveolar bone-loss measurement methodologies in a ligature-induced periodontitis animal model

Abstract Periodontal research involves the use of animal models to better understand the biological processes of periodontal diseases and the potential of new or existing therapies. Currently, ligature-induced periodontitis in rats is the main model used in periodontal research, in this model, alveolar bone loss (ABL) is the main parameter evaluated by radiographic, morphometric, and histological techniques. Interestingly, although these methodologies are widely used, it is not totally clarified neither the kinetics of ABL over the induction time nor the agreement degree (repeatability and reproducibility) of these techniques. Objective: To characterize ABL kinetics at 0, 3, 7, 15, 30, and 60 days after ABL induction by ligature and to evaluate the intra- (repeatability) and inter-examiner (reproducibility) agreement and the correlation among the radiographic, morphometric, and histological methodologies. Material and Methods: 60 male Wistar rats with induced ABL were randomly divided into 6 experimental groups (n = 10 animals/group). After 0, 3, 7, 15, 30, and 60 days, the animals were euthanized and their hemimandibles were removed for ABL determination using radiographic, morphometric and histological techniques. Results: Radiographic and morphometric/linear techniques allowed the detection of statistically significant ABL on the third day, while histological and morphometric/area techniques could only detect ABL after the seventh day (ANOVA/Tukey, p<0.05). After the fifteenth day, except for histological analysis, the ABL was stabilized. Concerning the agreement of the methodologies, Bland Altman's test (intra and inter-examiner evaluations) showed no difference among the measurements (p>0.05). In addition, high correlations (Pearson's test, r2>0.9, p<0.05) were observed. Conclusion: The results indicated that the minimum time for ABL induction could vary from 3 to 7 days, according to the chosen analysis methodology. Agreement and correlation data support the comparison of results between studies with same induction time.

Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: a long-term evaluation

Abstract Objective The aim of this retrospective study was to evaluate the long-term effects of orthodontic traction on root length and alveolar bone level in impacted canines and adjacent teeth. Material and Methods Sample consisted of 16 patients (nine males and seven females), mean initial age 11 years and 8 months presenting with unilaterally maxillary impacted canines, palatally displaced, treated with the same surgical and orthodontic approach. Teeth from the impacted-canine side were assigned as Group I (GI), and contralateral teeth as control, Group II (GII). The mean age of patients at the end of orthodontic treatment was 14 years and 2 months and the mean post-treatment time was 5 years and 11 months. Both contralateral erupted maxillary canines and adjacent teeth served as control. Root length and alveolar bone level (buccal and palatal) were evaluated on cone-beam computed tomography (CBCT) images. The comparison of root length and alveolar bone level changes between groups were assessed by applying paired t-test, at a significance level of 5% (p<0.05). Results There were no statistically significant differences in root length and buccal and palatal bone levels of canines and adjacent teeth among groups. Conclusions Impacted canine treatment by closed-eruption technique associated with canine crown perforation, has a minimal effect on root length and buccal and palatal alveolar bone level in both canine and adjacent teeth, demonstrating that this treatment protocol has a good long-term prognosis.

Different engagement of TLR2 and TLR4 in Porphyromonas gingivalis vs. ligature-induced periodontal bone loss

Abstract This study was conducted to investigate the roles of different Toll-like receptor (TLR) signaling in Porphyromonas gingivalis (P. gingivalis)-induced and ligature-induced experimental periodontal bone resorption in mice. Wild-type (WT), TLR2 knockout (KO), TLR4KO, and TLR2&4 KO mice with C57/BL6 background were divided into three groups: control, P. gingivalis infection, and ligation. Live P. gingivalis or silk ligatures were placed in the sulcus around maxillary second molars over a 2-week period. Images were captured by digital stereomicroscopy, and the bone resorption area was measured with ImageJ software. The protein expression level of gingival RANKL was measured by ELISA. The gingival mRNA levels of RANKL, IL-1β, TNF-α, and IL-10 were detected by RT-qPCR. The results showed that P. gingivalis induced significant periodontal bone resorption in WT mice and TLR2 KO mice but not in TLR4 KO mice or TLR2&4 KO mice. For all four types of mice, ligation induced significant bone loss compared with that in control groups, and this bone loss was significantly higher than that in the P. gingivalis infection group. RANKL protein expression was significantly increased in the ligation group compared with that in the control group for all four types of mice, and in the P. gingivalis infection group of WT, TLR2 KO, and TLR4 KO mice. Expression patterns of RANKL, IL-1β, TNF-α, and IL-10 mRNA were different in the P. gingivalis infection group and the ligation group in different types of mice. In summary, P. gingivalis-induced periodontal bone resorption is TLR4-dependent, whereas ligation-induced periodontal bone resorption is neither TLR2- nor TLR4-dependent.