Titanium micro-nano textured surface with strontium incorporation improves osseointegration: an in vivo and in vitro study*

Abstract Objectives This study aimed to investigate the osseointegration of titanium (Ti) implants with micro-nano textured surfaces functionalized with strontium additions (Sr) in a pre-clinical rat tibia model. Methodology Ti commercially pure (cp-Ti) implants were installed bilaterally in the tibia of 64 Holtzman rats, divided into four experimental groups (n=16/group): (1) Machined surface - control (C); (2) Micro-nano textured surface treatment (MN); (3) Micro-nano textured surface with Sr2+ addition (MNSr); and (4) Micro-nano textured surface with a higher complementary addition of Sr2+ (MNSr+). In total, two experimental euthanasia periods were assessed at 15 and 45 days (n=8/period). The tibia was subjected to micro-computed tomography (μ-CT), histomorphometry with the EXAKT system, removal torque (TR) testing, and gene expression analysis by PCR-Array of 84 osteogenic markers. Gene expression and protein production of bone markers were performed in an in vitro model with MC3T3-E1 cells. The surface characteristics of the implants were evaluated by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and laser scanning confocal microscopy. Results SEM, confocal, and EDS analyses demonstrated the formation of uniform micro-nano textured surfaces in the MN group and Sr addition in the MNSr and MNSr+ groups. TR test indicated greater osseointegration in the 45-day period for treated surfaces. Histological analysis highlighted the benefits of the treatments, especially in cortical bone, in which an increase in bone-implant contact was found in groups MN (15 days) and MNSr (45 days) compared to the control group. Gene expression analysis of osteogenic activity markers showed modulation of various osteogenesis-related genes. According to the in vitro model, RT-qPCR and ELISA demonstrated that the treatments favored gene expression and production of osteoblastic differentiation markers. Conclusions Micro-nano textured surface and Sr addition can effectively improve and accelerate implant osseointegration and is, therefore, an attractive approach to modifying titanium implant surfaces with significant potential in clinical practice.

Effect of electric, ultrasonic and manual toothbrushes on biofilm removal and gingivitis control: in vitro and parallel randomized controlled clinical trial study

Aim: To evaluate the effect of manual (M), electric (E) and ultrasonic (US) toothbrushes on the removal of oral biofilm and control of gingivitis. Also, the roughness and tooth wear production were evaluated in vitro. Methods: For the in vitro analyses, thirty bovine dentin specimens were submitted to a 3-month brushing simulation (9 minutes) with the three types of toothbrushes (n = 10). Subsequently, a randomized controlled clinical trial was performed with 36 patients divided into 3 groups according to the toothbrushes used (n = 12). Gingival index, visible plaque index and the volume of crevicular fluid were evaluated at baseline and 3 months after the beginning of the toothbrush use. Furthermore, the performance of the biofilm removal per brushing cycle of 1 and 3 minutes with each toothbrush was made monthly until the end of the experiment. Results: The US group had the highest dentin wear. Clinically, the US group had a lower plaque index at 3 months than the M group. The M group also showed less biofilm removal efficiency from the second month of follow-up and more worn bristles at the end of the 3 month period than the E and US groups. Conclusion: The ultrasonic, electric and manual toothbrushes showed no differences in gingivitis control in the present study. The ultrasonic and electric toothbrushes had a more significant effect on biofilm removal than a manual toothbrush, but the ultrasonic toothbrush promoted greater dentin tissue wear

Regulation of ghrelin receptor by microbial and inflammatory signals in human osteoblasts

Abstract: Recently, it has been suggested that the anti-inflammatory hormone ghrelin (GHRL) and its receptor GHS-R may play a pivotal role in periodontal health and diseases. However, their exact regulation and effects in periodontitis are not known. The aim of this in-vitro study was to investigate the effect of microbial and inflammatory insults on the GHS-R1a expression in human osteoblast-like cells. MG-63 cells were exposed to interleukin (IL)-1β and Fusobacterium nucleatum in the presence and absence of GHRL for up to 2 d. Subsequently, gene expressions of GHS-R1a, inflammatory mediators and matrix metalloproteinase were analyzed by real-time PCR. GHS-R protein synthesis and NF-κB p65 nuclear translocation were assessed by immunocytochemistry and immunofluorescence microscopy, respectively. IL-1β and F. nucleatum caused a significant upregulation of GHS-R1a expression and an increase in GHS-R1a protein. Pre-incubation with a MEK1/2 inhibitor diminished the IL-1β-induced GHS-R1a upregulation. IL-1β and F. nucleatum also enhanced the expressions of cyclooxygenase 2, CC-chemokine ligand 2, IL-6, IL-8, and matrix metalloproteinase 1, but these stimulatory effects were counteracted by GHRL. By contrast, the stimulatory actions of IL-1β and F. nucleatum on the GHS-R1a expression were further enhanced by GHRL. Our study provides original evidence that IL-1β and F. nucleatum regulate the GHS-R/GHRL system in osteoblast-like cells. Furthermore, we demonstrate for the first time that the proinflammatory and proteolytic actions of IL-1β and F. nucleatum on osteoblast-like cells are inhibited by GHRL. Our study suggests that microbial and inflammatory insults upregulate GHS-R1a, which may represent a protective negative feedback mechanism in human bone.

Suppressor of cytokine signaling 1 expression during LPS-induced inflammation and bone loss in rats

Abstract This study aimed to characterize the dynamics of suppressor of cytokine signaling (SOCS1) expression in a rat model of lipopolysaccharide-induced periodontitis. Wistar rats in the experimental groups were injected three times/week with LPS from Escherichia coli on the palatal aspect of the first molars, and control animals were injected with vehicle (phosphate-buffered saline). Animals were sacrificed 7, 15, and 30 days after the first injection to analyze inflammation (stereometric analysis), bone loss (macroscopic analysis), gene expression (qRT-PCR), and protein expression/activation (Western blotting). The severity of inflammation and bone loss associated with LPS-induced periodontitis increased from day 7 to day 15, and it was sustained through day 30. Significant (p < 0.05) increases in SOCS1, RANKL, OPG, and IFN-γ gene expression were observed in the experimental group versus the control group at day 15. SOCS1 protein expression and STAT1 and NF-κB activation were increased throughout the 30-day experimental period. Gingival tissues affected by experimental periodontitis express SOCS1, indicating that this protein may potentially downregulate signaling events involved in inflammatory reactions and bone loss and thus may play a relevant role in the development and progression of periodontal disease.

Modulation of host cell signaling pathways as a therapeutic approach in periodontal disease

Recently, new treatment approaches have been developed to target the host component of periodontal disease. This review aims at providing updated information on host-modulating therapies, focusing on treatment strategies for inhibiting signal transduction pathways involved in inflammation. Pharmacological inhibitors of MAPK, NFκB and JAK/STAT pathways are being developed to manage rheumatoid arthritis, periodontal disease and other inflammatory diseases. Through these agents, inflammatory mediators can be inhibited at cell signaling level, interfering on transcription factors activation and inflammatory gene expression. Although these drugs offer great potential to modulate host response, their main limitations are lack of specificity and developments of side effects. After overcoming these limitations, adjunctive host modulating drugs will provide new therapeutic strategies for periodontal treatment.

Morphometric study of the root anatomy in furcation area of mandibular first molars

Furcation involvement in periodontal disease has been a challenge for the dentist. OBJECTIVE: The aim of this study was to investigate root dimensions in the furcation area of 233 mandibular first molars. MATERIAL AND METHODS: Digital photomicrographs were used to obtain the following measurements on the buccal and lingual surfaces of each tooth: root trunk height (RT), horizontal interadicular distance obtained 1 mm (D1) and 2 mm (D2) below the fornix and interadicular angle (IA). RESULTS: Mean± standard deviation of buccal and lingual furcation measurements were, respectively, 1.37±0.78 mm and 2.04±0.89 mm for RT; 0.86±0.39 mm and 0.71±0.42 mm for D1; 1.50±0.48 mm and 1.38±0.48 mm for D2; 41.68±13.20° and 37.78±13.18° for IA. Statistically significant differences were found between all measured parameters for buccal and lingual sides (p<0.05, paired t test). CONCLUSIONS: In conclusion, the lingual furcation of mandibular first molars presented narrower entrance and longer root trunk than the buccal furcation, suggesting more limitation for instrumentation and worse prognosis to lingual furcation involvements in comparison to buccal lesions.

Combination of orthodontic movement and periodontal therapy for full root coverage in a miller class iii recession: a case report with 12 years of follow-up

One of the main purposes of mucogingival therapy is to obtain full root coverage. Several treatment modalities have been developed, but few techniques can provide complete root coverage in a class III Miller recession. Thus, the aim of this case report is to present a successful clinical case of a Miller class III gingival recession in which complete root coverage was obtained by means of a multidisciplinary approach. A 17-year-old Caucasian female was referred for treatment of a gingival recession on the mandibular left central incisor. The following procedures were planned for root coverage in this case: free gingival graft, orthodontic movement by means of alignment and leveling and coronally advanced flap (CAF). The case has been followed up for 12 years and the patient presents no recession, no abnormal probing depth and no bleeding on probing, with a wide attached gingiva band. A compromised tooth with poor prognosis, which would be indicated for extraction, can be treated by orthodontic movement and periodontal therapy, with possibility of 100% root coverage in some class III recessions.

Um dos principais objetivos da terapia mucogengival é atingir a cobertura completa da raiz. Diversas modalidades de tratamento têm sido desenvolvidas, mas poucas técnicas podem obter a cobertura total da raiz em uma recessão gengival classe III de Miller. Assim, o objetivo deste relato é apresentar um caso de sucesso clínico de uma recessão gengival classe III de Miller na qual foi obtida a cobertura completa da raiz por meio de uma abordagem multidisciplinar. Uma jovem de 17 anos sexo feminino, leucoderma, foi encaminhada para tratamento de uma recessão gengival no incisivo central inferior esquerdo. Para a cobertura radicular foi planejado: enxerto gengival livre, movimento ortodôntico por meio de alinhamento e nivelamento e retalho reposicionado coronariamente (CAF). Este caso tem sido acompanhado por 12 anos e o paciente apresenta ausência de recessão, sem profundidade de sondagem anormal e sem sangramento à sondagem com ampla faixa de gengiva inserida. Dentes comprometidos e com mau prognóstico, que seriam extraídos em muitos casos, podem ser tratados por meio de movimento ortodôntico e terapia periodontal. 100% de cobertura da raiz é possível e pode ser conseguida em alguns casos de recessão gengival classe III.

Aplicação de engenharia tecidual na elevação de seio maxilar: uma revisão sistemática da literatura / Tissue engineering application in sinus lifting procedures: a systematic literature review

O objetivo desta revisão de literatura é apresentar a aplicação da engenharia tecidual em cirurgias de elevação de assoalho do seio maxilar, relatando a influência dessas técnicas no aumento da altura e do volume ósseos no seio maxilar, e na osseointegração dos implantes instalados nas áreas enxertadas. A revisão foi realizada nas bases de dados PubMed e Scopus, utilizando-se as palavras-chave "scaffold" OR "tissue engineered" AND "sinus augmention" OR "sinus floor elevation". Na busca inicial, 463 artigos foram selecionados, dos quais 19 artigos para leituras dos abstracts, chegando ao final a nove artigos, que foram selecionados para avaliação da aplicação da engenharia tecidual em cirurgias de elevação do seio maxilar. Apesar dos resultados positivos da engenharia tecidual em procedimentos de elevação do seio maxilar relatados nos artigos selecionados, existe a necessidade de mais estudos, com melhor padronização de modelos experimentais e dos materiais utilizados, para que se chegue a conclusões convictas acerca do efeito da aplicação da engenharia tecidual na formação óssea em procedimentos de elevação de seio maxilar.

The purpose of this literature review is to present the state-of-the-art on the application of tissue engineering techniques in sinus lifts procedures, reporting the influence of these techniques in increasing bone height and volume in the maxillary sinus, and the osseointegration of the implants installed in the grafted areas. PubMed and Scopus databases were searched using the keywords "scaffold" OR "engineered tissue" AND "sinus augmention" OR "sinus floor elevation". In the initial search 463 articles were selected, of which 19 were selected abstracts reading, with nine papers selected by the end, for evaluation of the application of tissue engineering techniques in sinus lift procedures. Despite the positive results of tissue engineering procedures in sinus floor elevation reported in the selected articles, further studies are still needed, for a better standardization of experimental models and materials used, leading to definitive conclusions about the effects of the application of tissue engineering procedures on bone formation in maxillary sinus lifting procedures.

Burning mouth syndrome: a discussion about possible etiological factors and treatment modalities

Although several studies discuss the contributing factors associated with the burning mouth syndrome (BMS), there is still controversy with regard to its etiology. Therefore, in the majority of cases, the establishment of an adequate diagnosis and consequently the best treatment modality is complicated. In order to assist the clinician in the establishment of the correct diagnosis and management of BMS, this article reviews the literature, providing a discussion on the various etiologic factors involved in BMS, as well as the best treatment modalities for this condition that have showed to be the most effective ones in randomized clinical trials. In addition, the authors discuss some clinical characteristics in the differential diagnosis of BMS and other oral diseases. It is important for the clinician to understand that BMS should be diagnosed only after all other possible causes for the symptoms have been ruled out.