The aim of this article was to examine the research articles regarding biological and mechanical properties of cryopreserved teeth for potential use in tooth transplantation.
A systematic review of literatures was performed by Pubmed searching with assigned key words from January 1, 1990 to June 8, 2009. All articles were examined for inclusion criteria. Secondary search was conducted by hand‐search through references of included articles from primary search.
A total of 24 articles were obtained from both primary and secondary search and used as fundamental articles in this review. Periodontal ligament tissues of cryopreserved teeth were able to maintain their biological properties resulted in a satisfactory healing of periodontium. Dental pulp tissues, however, may be compromised by limitation of permeability of cryopreservative agent into pulp cavity. Therefore, an endodontic treatment of transplanted cryopreserved teeth was recommended. Cryopreserved teeth had comparable mechanical properties to those of normal teeth. Importantly, the success of cryopreserved tooth transplantation treatment in orthodontic patients was reported.
The cryopreserved teeth for tooth banking have a potential clinical application for treatment of missing teeth. Case selection, however, is critical for treatment success. More studies and data regarding masticatory function and periodontal healing of transplanted cryopreserved teeth are needed.
Dental biofilms are complex communities composed largely of harmless bacteria. Certain pathogenic species including Streptococcus mutans (S. mutans) can become predominant when host factors such as dietary sucrose intake imbalance the biofilm ecology. Current approaches to control S. mutans infection are not pathogen‐specific and eliminate the entire oral community along with any protective benefits provided. Here, we tested the hypothesis that removal of S. mutans from the oral community through targeted antimicrobial therapy achieves protection against subsequent S. mutans colonization.
Controlled amounts of S. mutans were mixed with S. mutans‐free saliva, grown into biofilms and visualized by antibody staining and cfu quantization. Two specifically‐targeted antimicrobial peptides (STAMPs) against S. mutans were tested for their ability to reduce S. mutans biofilm incorporation upon treatment of the inocula. The resulting biofilms were also evaluated for their ability to resist subsequent exogenous S. mutans colonization.
S. mutans colonization was considerably reduced (9 ± 0.4 fold reduction, P=0.01) when the surface was preoccupied with saliva‐derived biofilms. Furthermore, treatment with S. mutans‐specific STAMPs yielded S. mutans‐deficient biofilms with significant protection against further S. mutans colonization (5 minutes treatment: 38 ± 13 fold reduction P=0.01; 16 hours treatment: 96 ± 28 fold reduction P=0.07).
S. mutans infection is reduced by the presence of existing biofilms. Thus maintaining a healthy or “normal” biofilm through targeted antimicrobial therapy (such as the STAMPs) could represent an effective strategy for the treatment and prevention of S. mutans colonization in the oral cavity and caries progression.
Given the well‐known properties of Schwann cells in promoting nerve regeneration, transplanting Schwann cells into implant sockets might be an effective method to promote sensory responses of osseointegrated implants. The aim of this study was to evaluate the interaction between Schwann cells and osteoblasts.
Schwann cells derived from the sciatic nerves of neonatal rat were co‐culured with osteoblasts using Transwell inserts. The proliferation of Schwann cells in the co‐culture system was evaluated using methylthiazol tetrazolium (MTT) colorimetric method. Moreover, the secretions and mRNA levels of brain‐derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were measured by enzyme‐linked immunosorbent assay (ELISA) and quantitative real‐time PCR, respectively. In order to test the effect of Schwann cells on osteoblasts, alkaline phosphatase (ALP) staining and Alizerin red staining were performed as well.
Schwann cells, which were co‐cultured with the osteoblasts, showed an intact proliferation during the observation period. Moreover, the gene expression and synthesis of BDNF and NGF were not impaired by the osteoblasts. Meanwhile, co‐cultured osteoblasts exhibited a significant increase in the proliferation on day 3 and 6 (P< 0.05). Co‐culture of these two types of cells also led to a more intense staining of ALP and an elevated number of calcified nodules.
These findings demonstrate that, in the in vitro indirect co‐culture environment, Schwann cells can maintain their normal ability to synthesize neurotrophins, which then enhance the proliferation and differentiation of osteoblasts.
The objective of this study was to analyze the oral health among Japanese adults, with and without diabetes mellitus.
The subjects were 518 community residents aged 20 to 91 years in Japan, who participated in the “Akita health and nutrition survey” and the “Akita dental disease survey”, conducted in 2006. The surveys comprised a self‐administered questionnaire, along with medical and dental examinations.
Using the community periodontal index (CPI), the mean numbers of sextants presenting codes 0, 1 and 2 were significantly lower in diabetics than non‐diabetics among the 59 years or younger age group. Although the mean numbers of sextants with codes 0, 1 and 2 among the 60 to 69 years age group were lower, and sextants with a code X among the 59 years or younger age group were higher in diabetics than non‐diabetics, no statistically significant differences were detected. The tendency of lower mean numbers of natural teeth and functional tooth units in diabetics than non‐diabetics was observed, however no differences were statistically significant.
The outcome of periodontal disease seemed to be influenced by the diabetic state to some degree, but a clear association between diabetes and oral health status was not found.
Oral lichen planush (OLP) is a chronic inflammatory disease, and has been reported to have a correlation with hepatitis C virus (HCV) infection in some regional investigations. In this study, we investigated the prevalence of HCV in patients with oral lichen planus in an ethnic Chinese cohort.
The antibody of HCV infection was detected by using enzyme‐linked immunosorbent assay. Moreover, the clinical characteristics of whole the cohort have also been studied, such as the gender, age, clinical type, habits and social factors.
Of all 232 patients, the antibody of HCV infection was detected positive in 4 patients (1.72%) using enzyme‐linked immunosorbent assay. It was lower than that in control group of 2.5%, but not significant (P=0.309). The positive rate of HCV antibody in the erosive type ones (4.2%) was higher than that in the reticular type ones (1.0%), but this difference was proved to be not significant (P=0.389). The clinical characteristics of whole cohort, such as the gender, age, clinical type, habits and social factors, showed the outcome obtained in the present study were similar to thao of our previous study.
HCV may play no etiological role in oral lichen planus in ethnic Chinese OLP patients.
The purpose of this study was to conduct quantitative research on bone height and bone mineral density of palatal implant sites for implantation, and to provide reference sites for safe and stable palatal implants.
Three‐dimensional reformatting images were reconstructed by cone beam computed tomography (CBCT) in 34 patients, aged 18 to 35 years, using EZ Implant software. Bone height was measured at 20 sites of interest on the palate. Bone mineral density was measured at the 10 sites with the highest implantation rate, classified using K‐mean cluster analysis based on bone height and bone mineral density.
According to the cluster analysis, 10 sites were classified into three clusters. Significant differences in bone height and bone mineral density were detected between these three clusters (P<0.05). The greatest bone height was obtained in cluster 2, followed by cluster 1 and cluster 3. The highest bone mineral density was found in cluster 3, followed by cluster 1 and cluster 2.
CBCT plays an important role in pre‐surgical treatment planning. CBCT is helpful in identifying safe and stable implantation sites for palatal anchorage.
This paper deals with the treatment of an atrophied toothless mandible with a fixing bridge carried by two non‐standard implant systems.
Four bicortical screws were implanted into the frontal part of the mandible and one implant on each side was placed into the distal area of the mandible as a support for a fixing bridge.
During the years 2002 – 2007 the authors placed a total of 256 bicortical screw and 84 blade implants. During this period only four bicortical screws and one blade implant failed. The primary and secondary surgical success rate was therefore above 98%, while the prosthetic success rate was 100%. (Bridges which had to be re‐fabricated due to implant failure were not taken into account.)
This approach is recommended as a highly successful and affordable option for a wide range of patients.
Pyoderma gangrenosum (PG) is a rare, noninfectious neutrophilic dermatosis. Clinically, it begins with sterile pustules that rapidly progress into painful ulcers of variable depth and size with undermined violaceous borders. The diagnosis of PG is based on the history of an underlying disease, a typical clinical presentation, histopathology, and exclusion of other diseases. The peak incidence occurs between the ages of 20 to 50 years with women being more often affected than men. There have been very few reports of pyoderma gangrenosum with oral mucosal involvement. Oral lesions in previously reported cases have included ulcers of varying sizes from a few mm to several cm and have been reported to have been found on the tongue, soft and hard palate, buccal mucosa, and gingiva. Some of these oral lesions have been associated with ulcerative colitis, inflammatory bowel disease, and polycythemia rubra vera. A few cases were reported with biopsy findings, the histological picture being nonspecific, showing ulceration, and necrosis with inflammatory cell infiltrate. A peculiar case of pyoderma gangrenosum with an oral lesion is presented here, and the differential diagnosis is discussed.