No abstract

CFR-PEEK (carbon fiber reforced-poly ether ether ketone) has been demonstrated to be excellent substitute titanium in orthopedic applications and can be manufactured with many physical, mechanical, and surface properties, in several shapes. The aim of this study was to compare, using the three-dimensional finite element method, the stress distribution in the peri-implant support bone of distinct models composed of PEEK components and implants reinforced with 30% carbon fiber (30% CFR-PEEK) or titanium. In simulations with a perfect bonding between the bone and the implant, the 30% CFR-PEEK presented higher stress concentration in the implant neck and the adjacent bone, due to the decreased stiffness and higher deformation in relation to the titanium. However, 30% CFR-PEEK implants and components did not exhibit any advantages in relation to the stress distribution compared to the titanium implants and components.

Bone allograft has become an alternative to autogenous bone due to its decreased operative trauma and the almost unlimited supply of reconstructive material. The aim of the present study was to histologically evaluate the suitability of fresh-frozen bone graft (test group) used in maxillary ridge augmentation, comparing it to autogenous bone (native maxilla: control group). During the re-entry procedures, 9 months after the fresh-frozen allogeneic bone blocks were placed in the atrophic maxillary ridges, bone cores were removed with a trephine bur from test and control treatments in the same patient. Routine histologic processing using hematoxylin and eosin and Picrosirius staining was performed. Mature and immature collagen area and density analysis were carried out for both groups under polarization. The results of Student's t test for paired samples (P > .05) showed no statistically significant difference in mature and immature collagen area or density percentage between test and control groups. Histologically similar bone formation patterns were observed in both groups. We concluded that fresh-frozen bone allograft is a biologically acceptable alternative for augmentation of the deficient alveolar ridge, showing a similar collagen pattern to that of autogenous bone.

No abstract

Dentigerous cyst is a common pathologic entity associated with an impacted tooth. The standard treatment for this lesion is enucleation and extraction of the involved tooth. Marsupialization of dentigerous cyst has also been advocated, once in many cases it can maintain the impacted tooth in its cavity and promotes its eruption. This report describes a case of a 13-year-old girl with a large dentigerous cyst associated with mandibular right second molar. The cyst was marsupialized and the patient was checked weekly. Two months after the surgical procedure the impacted tooth was completely erupted without orthodontic traction and therapy.