RESUMEN
The popularity of implants is increasing with the aging population requiring oral-dental rehabilitation. There are several critical steps in the implant workflow, including case selection, implant design, surgical procedure, biological tissue responses, and functional restoration. Among these steps, surgical osteotomy procedures are a crucial determinant of clinical success. This brief review was aimed at outlining the current state of the field in automation-assisted implant surgical osteotomy technologies. A broad search of the literature was performed to identify current literature. The results are outlined in three broad categories: semi-automated static (image-guided) or dynamic (navigation-assisted) systems, and fully-automated robotic systems. As well as the current mechanical rotary approaches, the literature supporting the use of lasers in further refinement of these approaches is reviewed. The advantages and limitations of adopting autonomous technologies in practical clinical dental practices are discussed. In summary, advances in clinical technologies enable improved precision and efficacious clinical outcomes with implant dentistry. Hard-tissue lasers offer further advancements in precision, improved biological responses, and favorable clinical outcomes that require further investigation.
RESUMEN
Insufficient nutrition exchange and limited transportation of blood supply in a porous only scaffold often hinder bone formation, even though the porous scaffold is loaded with cells or growth factors. To overcome these issues, we developed a cell- and growth factor-free approach to induce bone formation in a critical-size bone defect by using an interconnected porous beta-tricalcium phosphate (ß-TCP) scaffold with multiple channels. In vitro cell experimental results showed that multiple channels significantly promoted cell attachment and proliferation of human bone marrow mesenchymal stem cells, stimulated their alkaline phosphatase activity, and up-regulated the osteogenic gene expression. Multiple channels also considerably stimulated the expression of various mechanosensing markers of the cells, such as focal adhesion kinase, filamentous actin, and Yes-associated protein-1 at both static and dynamic culturing conditions. The in vivo bone defect implantation results demonstrated more bone formation inside multiple-channeled scaffolds compared to non-channeled scaffolds. Multiple channels prominently accelerated collagen type I, bone sialoprotein and osteocalcin protein expression. Fluorochrome images and angiogenic marker CD31 staining exhibited more mineral deposition and longer vasculature structures in multiple-channeled scaffolds, compared to non-channeled scaffolds. All the findings suggested that the creation of interconnected multiple channels in the porous ß-TCP scaffold is a very promising approach to promote bone tissue regeneration.
Asunto(s)
Sustitutos de Huesos , Cerámica , Regeneración Tisular Dirigida/métodos , Osteogénesis , Andamios del Tejido , Fosfatos de Calcio , Diferenciación Celular , Humanos , Mandíbula , Células Madre Mesenquimatosas/metabolismoRESUMEN
A new type of 2-D separation material was synthesized and studied. The material is suitable for 2-D chromatography utilizing both covalent and noncovalent interactions. The first dimension is boronate affinity chromatography, and the second dimension is RP chromatography (or vice versa). The polymeric media were prepared using p-vinylphenylboronic acid as the functional monomer. This monomer was selected due to the presence of the boronic acid group for the cis-diol/boronate interaction in boronate chromatography. Two crosslinkers were evaluated, namely ethylene glycol dimethacrylate and divinylbenzene. The crosslinker content was varied to maximize the polymer strength and the RP performance of the packed column. Several parameters were evaluated to define the optimum for polymer strength and column performance including crosslinker, porogen, initiator, and column-packing parameters. The polymer-based HPLC columns were successful in separating phenol, catechol, dimethylphthalate, and hydroquinone under RP conditions, and thus can be used as an RP HPLC column. The columns were also successful in separating catechol and adenosine under boronate chromatography conditions, and thus can be used as a boronate affinity column. Moreover, the two types of chromatography can be performed consecutively on the same column during one complete chromatographic run, making it a 2-D chromatography. Under these 2-D conditions, the catechol was separated from a mixture of phenol, catechol, dimethylphthalate, and hydroquinone; the adenosine ribonucleoside was separated from a mixture of adenosine ribonucleoside, adenosine deoxyribonucleoside, and uridine deoxyribonucleoside. This type of single-column 2-D HPLC eliminates the requirement of a complex and expensive multidimensional HPLC instrument and provides increased peak capacity for separation.
Asunto(s)
Cromatografía de Afinidad , Cromatografía Líquida de Alta Presión , Ácidos Borónicos/química , Cromatografía de Afinidad/instrumentación , Cromatografía de Afinidad/métodos , Cromatografía Líquida de Alta Presión/instrumentación , Cromatografía Líquida de Alta Presión/métodos , Ensayo de Materiales , Polímeros/química , PorosidadRESUMEN
Extra- and intracellular nucleases are predicted to decrease the in vivo efficiency of liposomal transfection. DNASE1 (D1) has been proposed as the main nuclease barrier, yet liposome-complexed DNA and in vitro lipofection are generally immune to D1. In contrast, medium conditioned by the macrophage enzyme DNASE1-like 3 (DNASE1L3 or D3) erects a potent in vitro barrier to liposomal transfection. Although homologous to D1 over its amino-terminal sequence, D3 has a distinct, highly basic carboxy terminus, which resembles polylysine stretches often found in polycationic liposomal reagents. If this domain is truncated from D3, the resulting enzyme has more nuclease activity against naked DNA ("free DNA"-nuclease activity), yet does not block transfection. C-terminal fusion of this domain to D1 forms a chimeric protein able to block transfection. D3 can be immunodetected in both serum and macrophage lysates. Macrophage-conditioned medium contains both "free DNA"-nuclease activity and the ability to block transfection, and by zymogram only a 28-kDa DNASE, consistent by size with D3, is present. Thus, medium containing D3 confers to cells an in vivo shield to the nuclear acquisition of exogenous DNA. Modulation and further elucidation of this activity are likely to have importance for both gene therapy and autoimmune disorders.