The FT-IR and FT-Raman spectra of the calcium phosphates, hydroxyapatite $ rm (Ca sb{10}(PO sb4) sb6(OH) sb2),$ fluroapatite $ rm (Ca sb{10}(PO sb4) sb6F sb2),$ monocalcium phosphate monohydrate $ rm (Ca(H sb2PO sb4) sb2H sb2O),$ dicalcium phosphate dihydrate $ rm (CaHPO sb4 cdot 2H sb2O),$ anhydrous dicalcium phosphate $ rm (CaHPO sb4),$ have been recorded at ambient and high pressure ($<$50 kbar). Several pressure-induced phase transitions were detected. Some new information and general conclusions about the structure, chemical bonding and hydrogen bonding in these materials are presented. The high-pressure experimental method was improved. / The interactions between dentin, collagen and hydroxyapatite and the dental materials, 2-hydroxyethylmethacrylate and dipentaerythritol pentaacrylate phosphoric acid ester were explored by FT-IR, FT-Raman and NMR spectroscopy. Vibrational bonds were assigned for these materials. The results suggest that some hydrogen bonding or chemical reactions occur on the interface of dentin and dental materials. The interaction between dentin and 2-hydroxyethlmethacrylate mainly takes place between collagen and 2-hydroxyethylmethacrylate. On the other hand, the interaction between dentin and dipentaerythritol pentaacrylate phosphoric acid ester primarily occurs between hydroxyapatite and dipentaerythritol pentaacrylate phosphoric acid ester. The interaction of maleic acid with 2-hydroxyethylmethacrylate was studied by FT-Raman and NMR spectroscopy. The results show no evidence for a chemical reaction happening between these two compounds. The high-pressure FT-IR spectra of some restorative materials were also recorded and the results were interpreted.

<p> The temporomandibular joint (TMJ) complex consists of the condyle, articular eminence, and articular disc. This disc divides the intracapsular components of the joint into upper and lower joint spaces. Magnetic resonance imaging (MRI) is considered the reference standard for soft tissue diagnosis of the TMJ. One aim of the study was to identify if an association exists between arthralgia of the TMJ and MRI identified joint effusion.</p><p> The clinical significance of identifying the presence of TMJ effusion on MRI lies in its potential association with inflammation, clinically assessed as pain at the lateral TMJ pole or around the pole area. Unfortunately the literature has been divided in asserting whether pain in the joint area is associated with the presence of MRI assessed effusion. A systematic review of the literature was unable to provide conclusive evidence for or against an association between TMJ pain and effusion.</p><p> Materials and methods: Clinical and imaging findings from 336 joints were obtained from a historical cohort involving individuals with temporomandibular disorders. Two by two tables of association were used to determine if clinical signs associated with arthralgia were associated with the presence of ipsilateral effusion in the TMJ. These clinical signs included pain on range of motion (maximum unassisted and assisted opening as well as excursive movements), TMJ manipulation (compression and translation), and palpation of the lateral pole of the TMJ and around the TMJ pole. In addition, a total pain score (range 0-7) was created which represented the sum of positive responses to pain on any of the clinical range of motion tests. Statistical testing included the T-test to test for possible association of joint effusion with any pain to these clinical measures.</p><p> Results: Statistical tests of association between joint effusion and range of motion, excursions, protrusion, joint manipulation and palpation all had p values > .05.</p><p> Conclusion: The results suggest that there is no statistically significant association between an MRI diagnosis of joint effusion and TMJ arthralgia. </p>

Spirochetes are helical bacteria consisting of an outer sheath, a protoplasmic cylinder and periplasmic flagella. All oral anaerobic spirochetes (OAS) are species within the genus Treponema. They are important causative agents of periodontitis. This thesis examines some aspects of the physiology of OAS. As well, a novel symbiotic bacterium found in the blood of healthy humans was studied as a consequence of my work with OAS. / Our lab has been instrumental in rendering routine and reliable growth of OAS in vitro. An inexpensive medium which remains molten at 37°C and solidifies at 25°C was found for the enumeration of colony-forming units of OAS. New Oral Spirochete (NOS) medium with the addition of 0.5% gelatin-0.5% Noble agar met the above criteria. / Clinical isolates of spirochetes from the periodontal pocket need to be readily identified. Restriction fragment length polymorphism (RFLP) analysis was used on reference strains of Treponema denticola, T. vincentii, T. phagedenis, and T. socranskii as well as a number of clinical isolates in our laboratory collection. The banding patterns observed allowed discrimination between the different spirochete species. / Morphological variations such as spherical-shaped cells of T. denticola, termed "spherical bodies" are occasionally observed. The omission of the several individual components from NOS medium (brain heart infusion, yeast extract, rabbit serum, volatile fatty acids, or thiamine pyrophosphate), the age of the culture and the addition of lactic acid, enhanced the formation of these bodies. / J. Miklossy (NeuroReport, 1993) reported that spirochetes were found in blood, cerebral cortex and cerebral spinal fluid in autopsied Alzheimer's Disease (AD) subjects. It was suggested by her that spirochetes could be a causative factor in AD. Our laboratory attempted to duplicate these results and found spirochetes in the blood of only one late stage AD patient suggesting that spirochetes are not one of the causes of AD. / During the examination of blood by darkfield microscopy, we observed pleomorphic microorganisms. Blood of a healthy human is a sterile environment. Evidence for the existence of bacteria in blood includes light and electron micrographs of their morphology, and molecular analysis of their 16S ribosomal RNA and their gyrB gene.

Spirochetes are markedly prevalent in periodontal disease but are not included as predominant cultivable organisms because of the inability to quantify them by viable count. A successful method was developed for enumerating viable oral spirochetes in pure culture as colony-forming units (CFU) in new oral spirochete (NOS) medium with 0.7% agarose and using small tissue-culture flasks. Three species of oral spirochetes in log-phase growth in NOS broth were used for evaluation of the method. Reliable, consistent and reproducible viable counts of pure spirochete cultures were obtained. / This method was extended to enumerate viable oral spirochetes from periodontal pockets. The antibiotic rifampin (20 $ mu$g/ml) was found to be an excellent selective agent for such a count when added to NOS-agarose medium. Counts of cultivable oral spirochetes from 10 subgingival plaque samples ranged from 12.5% to 28.2% of the total cultivable anaerobic bacteria. In addition, by the use of this method thirteen new oral spirochetes were isolated. / The viable count technique was modified and employed to study the locomotion of spirochetes. Migration of oral spirochetes out of NOS-Bacto agar medium into NOS-agarose medium was observed and two locomotory phenotypes of oral spirochetes were detected.

Thesis (Ph.D.)--Pacific Graduate School of Psychology, 1998. / Source: Dissertation Abstracts International, Volume: 59-04, Section: B, page: 1918.

Thesis (Ph.D.)--University of California, San Francisco, 2006. / Source: Dissertation Abstracts International, Volume: 67-05, Section: B, page: 2455. Adviser: Daniel Fried.

Up to 70% of modern humans experience problems with their third molars, whether it is failure of proper eruption (impaction) or not erupting at all (agenesis). Thus, it is a commonly used example for explaining why humans are still evolving and the relevance of evolutionary medicine. Agenesis dates back to at least early Homo erectus, and is seen with greater frequency during the evolution of later Homo. However, there are currently few data that support any of the three hypotheses (agenesis as selection against impaction, developmental delay, and the probable mutation effect) proposed to explain the evolution of agenesis and impaction. Furthermore, while most researchers associate changes in the physical properties of food with an increased frequency of third molar pathologies, it is unclear whether these changes took place during the advent of agriculture, the beginning of industrialization or both. Considerable variation exists among modern human populations in the rate of agenesis and impaction, but there are inconsistencies in reports of how modern variation partitions among sex, population, and morphological traits. Thus, this study first aims to explain modern variance in agenesis and impaction, then to use morphological data to assess how the third molar pathologies of four different populations from Serbia, Egypt, Japan and SE USA changed with the adoption of agriculture and the beginnings of industry. This will lead to an understanding of the evolution of third molar agenesis and impaction that will help understand the evolutionary origins of an important condition affecting modern humans. First, we aimed to consolidate all available data on worldwide third molar agenesis frequencies, with a particular emphasis on exploring the factors leading authors to find contradictory results for the demographic and morphological predictors of this anomaly. A total of 12,376 studies were originally identified, then narrowed down to 1,312 for title/abstract screening. Based on our inclusion and exclusion criteria, we selected 92 studies, containing 100 effect sizes and 63,314 subjects, for systematic review and meta-regression. The worldwide rate of agenesis was found to be 22.63% (95% CI: 20.64%-24.76%), though the estimates ranged from 5.32% to 56.0%. Our subgroup analyses revealed that females are 14% more likely to have agenesis of one or more third molars than males and that maxillary agenesis was 36% more likely than mandibular agenesis in both sexes. Further, we found that having agenesis of one or two molars was most common, while agenesis of three molars was least common. Finally, we found large differences among agenesis frequency depending on geographic region. This information is expected to be of use not only to clinicians and patients but also to policy makers, given the implications for third molar extraction protocols. Next, we performed a meta-analysis to synthesize the abundant existing literature on third molar impaction frequencies worldwide. A total of 7,936 records were originally identified, then narrowed down to 864 for title/abstract screening. Based on our inclusion and exclusion criteria, we selected 49 studies, containing 83,484 subjects, for systematic review and meta-regression. The worldwide rate of impaction was found to be 24.40% (95%CI: 18.97%-30.80%), though the estimates ranged from 3.08% to 68.60%. Our subgroup analyses revealed that mandibular impaction was 57.58% more likely than maxillary impaction, while we did not detect any difference in impaction frequency between males and females. In addition, we found that mesioangular impaction was most common, followed by vertical impaction, with distoangular and horizontal impaction less frequent. Further, we found that having impaction of one or two third molars was most common, while impaction of three or four third molars was least common. Finally, we found small differences among impaction frequency depending on geographic region. Given the rich debate surrounding third molar treatment policy, understanding demographic and morphological differences in impaction rates is an important first step in assessing appropriate treatment protocols. Finally, we applied the results of these analyses to explore the evolutionary origins of third molar agenesis and impaction. Humans are unique in having high frequencies of pathological third molars, including impacted molars that fail to erupt and agenesis, or missing, molars. Many researchers attribute an increased prevalence of third molar agenesis and impaction to highly processed modern diets. Three competing hypotheses exist to explain the evolution of third molar agenesis: 1) agenesis as the result of selection against impaction, 2) agenesis as developmental delay, and 3) the probable mutation effect. These hypotheses, however, remain untested. Here we test these hypotheses using data from four populations sampled before, during and after the transitions to agriculture and two populations before, during, and after the transition to industry. We found the selection against impaction hypothesis contributed to the rise in third molar agenesis at the end of the industrial transition, but impaction remained at such low frequencies during the agricultural transition that this mechanism is unlikely to have been a causative force. Furthermore, we found a negative relationship between dental arch space and third molar agenesis in the industrial transition, but a positive relationship between these two variables in the agricultural transition. Overall, these data suggest that two different mechanisms influenced the prevalence of human third molar agenesis: one operating since the time of Homo erectus and one with much more recent origins. / Human Evolutionary Biology

Objective: This project aimed to determine whether single tooth implant restorations fabricated with CAD/CAM zirconia abutments/porcelain fused to zirconia crowns reveal different biological and esthetic outcomes compared with prefabricated anatomic titanium abutments/porcelain fused to metal crowns in the esthetic zone. Materials and Methods: Thirty patients who needed a single implant restoration in the esthetic zone were included in the study. Twenty-nine patients completed screening, baseline, crown insertion, one-month, six-month and one-year follow-up visits. At the screening visit, the patients were randomly allocated into two groups: the prefabricated anatomic titanium abutments/ porcelain fused to metal crown (Ti) group and the CAD/CAM zirconia abutments/ porcelain fused to zirconia crowns (Zr) group. Plaque and bleeding scores, microbial profiles, probing depth, width of keratinized tissue, vertical bone changes, pink and white esthetic scores, papilla height, and clinical crown height were evaluated through several study time points. Furthermore, patients’ self-esteem, satisfaction, and esthetic evaluations were assessed using visual analog scores (VAS). A simple scale called subjective and objective esthetic classification (SOE) was created to assess the esthetic success of treatment. Statistical analyses were performed using the Mann Whitney U test, Chi-square test and a generalized linear mixed model. Results: All implants were successfully osseointegrated with a 100% survival rate over one year. Biologically, both groups had comparable outcomes except that the mean prevalence of the bacteria in the Zr group was significantly greater than in the Ti group at the final visits for Streptococcus intermedius (p< 0.0001). Also, the Treponema denticola DNA probe signal was lower in the Zr group than the in Ti group at the final visits (p= 0.0007). In addition, the mean of probing depth of the mesial tooth at the mesio-lingual site (p= 0.02) was less in the Zr group. All the esthetic parameters showed no statistically significant differences between both groups. Patients’ self-esteem, satisfaction, and esthetic evaluations did not differ between groups. Conclusion: After one year of clinical performance, the Zr group showed comparable results to the Ti group. This indicated that good clinical, biological and esthetic outcomes could be achieved by either treatment option. Further observations and follow-up are required to evaluate long-term results.

Porphyromonas gingivalis, a key pathogen in periodontal disease, promotes atherosclerosis in apolipoprotein E null (apoe-/-) mice, a well characterized mouse model of the disease. Previous studies have provided indirect evidence that P gingivalis is capable of activating the enzyme caspase-1 in vitro, while preliminary studies conducted by our laboratory have outlined a role for caspase-1 in atherosclerosis in apoe-/- mice. The present study provides direct evidence that P gingivalis is capable of activating caspase-1, and that P gingivalis is capable of gaining access to, and localizing at, sites of lesion development following an oral challenge. Oral infection with P gingivalis exacerbated the development of atherosclerosis in the aortic root of male mice competent for caspase-1 as compared to those deficient in the enzyme. Infected animals also displayed evidence of alveolar bone loss, a hallmark of periodontal disease. Our findings reveal that oral infection with P gingivalis accelerates atherosclerotic lesion development in male apoe-/- mice through the activation of caspase-1.

No description available.