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The oxaloacetate acetylhydrolase ( OAH, EC 3.7.1.1)-encoding gene Ss-oah1 was cloned and functionally characterized from Sclerotinia sclerotiorum. Ss-oah1 transcript accumulation mirrored oxalic acid ( OA) accumulation with neutral pH induction dependent on the pH-responsive transcriptional regulator Ss- Pac1. Unlike previously characterized ultraviolet ( UV)-induced oxalate-deficient mutants (' A' mutants) which retain the capacity to accumulate OA, gene deletion Δ ss-oah1 mutants did not accumulate OA in culture or during plant infection. This defect in OA accumulation was fully restored on reintroduction of the wild-type ( WT) Ss-oah1 gene. The Δ ss-oah1 mutants were also deficient in compound appressorium and sclerotium development and exhibited a severe radial growth defect on medium buffered at neutral pH. On a variety of plant hosts, the Δss-oah1 mutants established very restricted lesions in which the infectious hyphae gradually lost viability. Cytological comparisons of WT and Δ ss-oah1 infections revealed low and no OA accumulation, respectively, in subcuticular hyphae. Both WT and mutant hyphae exhibited a transient association with viable host epidermal cells at the infection front. In summary, our experimental data establish a critical requirement for OAH activity in S. sclerotiorum OA biogenesis and pathogenesis, but also suggest that factors independent of OA contribute to the establishment of primary lesions. [ABSTRACT FROM AUTHOR]

Objectives: To assess whether the use of a graft and/or membrane post-tooth extraction improves healing of the site dimensionally, radiographically, and/or histologically. Materials and Methods: MEDLINE and EMBASE and the Cochrane Central register of controlled trials (CENTRAL) were searched up until August 2011. Randomized controlled trials that included and compared healing post-tooth extraction between a control (no intervention) and a graft and/or membrane (test) were selected. Results: Titles and abstracts of 2,861 papers were screened. A total of 42 papers were selected for full text reading. Nine papers met the eligibility criteria and were selected for further analysis. Because of the varying graft materials used and the different methods of investigation, as well as the variation in follow-up times, a meta-analysis was not possible. The present review found that clinically, there was a range in loss of width in the control sites of 2.46 mm (SD 0.4 mm) to 4.56 mm (SD 0.33 mm) compared to 1.14 mm (SD 0.87 mm) to 2.5 mm (SD 1.2 mm) in the test sites. The range in loss of height in control sites was 0.9 mm (SD 1.6 mm) to 3.6 mm (SD 1.5 mm) compared to a gain of 1.3 mm (SD 2 mm) to a loss of 0.62 mm (SD 0.51 mm) in test sites. Radiographically a range of change in bone height of between 0.51 mm (No SD) to 1.17 mm (SD 1.23 mm) was noted in control sites compared to a change of between 0.02 mm (SD 1.2 mm) and 1 mm (SD 1.4 mm) in test sites. Conclusion: There is limited data regarding the effectiveness of alveolar ridge preservation therapies when compared to the control. Overall the socket intervention therapies did reduce alveolar ridge dimensional changes post-extraction, but were unable to prevent resorption. Histology did demonstrate a large proportion of residual graft material that may account for some of the difference in alveolar ridge dimensions at follow up. [ABSTRACT FROM AUTHOR]

Aim This study developed the Schiff Index into a Cumulative Hypersensitivity Index ( CHI) to measure dentine hypersensitivity ( DH) severity per subject. It validates this score by investigating if it compares to one comprising a percentage score from all tooth surfaces and as a highest score per subject. Materials and methods Overall, 350 subjects were recruited from hospital and general practice in south-east England. Buccal, occlusal and oral Schiff Index scores were collected and percentages calculated based on scores 1, 1 and above, 2 and above and 3. CHI scores and highest Schiff Index scores were also recorded per subject. Spearman correlation coefficients ( p-values) assessed the relationship between CHI scores, Schiff Index percentages and Schiff Index highest per subject. Results In subjects with a Schiff Index score of 1 or more on at least one tooth surface (indicating DH was present), correlation of the CHI score to the Schiff Index percentage score was 0.982 ( p < 0.001). Correlation of the sextant score to the highest Schiff Index score per subject was 0.963, ( p < 0.001). DH was more likely on tooth surfaces with gingival recession ( p < 0.001) and without bleeding on probing ( p < 0.01). Conclusions This study has validated a novel CHI score to indicate DH severity per subject and may help guide clinical management. [ABSTRACT FROM AUTHOR]

Objective To compare the diagnostic accuracy of conventional periapical radiography and cone beam computed tomography ( CBCT) at detecting peri-implant bone defects. Materials and methods Implants were placed in fresh bovine ribs in osteotomy sites of varying diameter (five with no peri-implant space, five with a 0.35 mm space, five with a 0.675 mm space) and imaged using (i) digital long cone periapical radiographs ( LCPAs), (ii) limited volume CBCT using 3D Accuitomo 80® and (iii) large volume CBCT using i- CAT Next Generation®. Images from each were randomly presented to nine examiners on two occasions. Confidence in diagnosing the presence or absence of a peri-implant radiolucency was recorded on a five-point scale. Receiver Operating Characteristic ( ROC) analysis and Kappa tests were performed. Results Digital LCPAs were better at diagnosing a peri-implant bone defect when the peri-implant space was 0.35 mm ( P < 0.02). As the peri-implant space increased to 0.675 mm, there was no significant difference in diagnostic accuracy between the three imaging methods. Sensitivity of LCPAs (100) and Accuitomo (97.8) was better than i- CAT (64.4) ( P < 0.02). LCPAs and i- CAT had significantly better specificity and positive predictive value than Accuitomo. The negative predictive value of LCPA was significantly better than i- CAT. LCPAs showed better intra-examiner and inter-examiner agreement than CBCT. Conclusion Within the limitations of this study, LCPAs are a reliable and valid method of detecting circumferential peri-implant bone defects and performed significantly better than CBCT. [ABSTRACT FROM AUTHOR]

Background: The effect of smoking on soft tissues after periodontal treatment has been extensively studied. However, little focus has been placed on the impact of smoking on bone regeneration after treatment. The aim of this review is to systematically assess the effect of smoking on bone regeneration after periodontal treatment. Methods: A protocol was established and studies were sourced from five electronic databases. Screening, data abstraction, and quality assessment was conducted by two review authors. Prospective and retrospective clinical studies assessing bone regeneration in smokers and non-smokers after periodontal therapy were selected. In addition, arms of clinical trials comparing different interventions that reported results separately for smokers and non-smokers were also included. Primary outcome measures were based on clinical and/or radiographic indicators of bone regeneration after periodontal therapy. The review and meta-analysis followed many of the recommendations outlined in the preferred reporting items for systematic reviews and meta-analyses statement. Results: Six of 10 studies included in this review concluded that smoking negatively influenced bone regeneration. A metaanalysis of a subgroup of three studies demonstrated that smoking resulted in significantly less bone gain (P = 0.03) as measured by a change in the probing bone level after the treatment of intrabony defects with guided tissue regeneration. The meta-analysis showed a standardized mean difference of-2.05 (95% confidence interval: -2.64 to -1.47) using the random effects model. Conclusions: Smoking has a negative effect on bone regeneration after periodontal treatment. Patients should be advised that their smoking habit may result in poorer bone regeneration after periodontal treatment. J Periodontol 2012;83:143-155. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the use of a single Astra Tech implant to support a two-unit cantilever fixed dental prosthesis. Materials and method: Twenty-nine subjects with an edentulous space (at least equivalent to two bicuspid units) in the premolar/molar segments of the maxilla or mandible with opposing natural teeth or a fixed/removable prosthesis were treated. They were provided with either a 4 or 5.0 mm diameter fixture MT OsseoSpeed. Prostheses were constructed using a cast-to abutment as a one-piece unit with porcelain fused to precious metal to allow direct screw retention. Results: Subjects expressed a high satisfaction with treatment, including appearance and function. The most important complication was abutment screw loosening. It occurred as a single episode in four subjects and in another six subjects the loosening was recurrent. Bone levels were stable and there were no significant differences in radiographic bone height between cantilever and non-cantilever sides of the implant at any time point. Conclusion: Single implants can be successfully used to support two-unit cantilever FDPs in the premolar region. A common factor could not be identified in relation to abutment screw loosening. To cite this article: Palmer RM, Howe LC, Palmer PJ, Wilson R. A prospective clinical trial of single Astra Tech 4.0 or 5.0 diameter implants used to support two-unit cantilever bridges: results after 3 years. Clin. Oral Impl. Res. 23, 2012; 35-40. doi: 10.1111/j.1600-0501.2011.02160.x [ABSTRACT FROM AUTHOR]

Moazzez R, Thompson H, Palmer RM, Wilson RF, Proctor GB, Wade WG. Effect of rinsing with ethanol-containing mouthrinses on the production of salivary acetaldehyde. Eur J Oral Sci 2011; 119: 441-446. © 2011 Eur J Oral Sci It has been suggested that the use of alcohol-containing mouthrinses could lead to the presence of acetaldehyde in saliva. In this cross-over study, salivary acetaldehyde levels and microbial profiles were determined before and after rinsing with ethanol-containing mouthrinses with essential oils (EO) and cetyl pyridinium chloride (CPC) as the active ingredients, and with 21.6% ethanol and water controls. After rinsing with all ethanol-containing rinses, acetaldehyde was detected in saliva after 30 s but declined to low levels after 5 min. The highest peak levels were seen with the ethanol control (median = 82.9 μM at 2 min) and were significantly higher than those seen at the same time after rinsing with the EO rinse (43.1 μM). There was no correlation between microbial counts or plaque scores and acetaldehyde levels, although dividing the subjects on the basis of a peak acetaldehyde salivary concentration of > 90.8 μM after the ethanol rinse revealed that the high responders were highly significantly more likely to harbour salivary yeasts than were the low responders. Rinsing with ethanol-containing mouthrinses causes a rapid, but transient, increase in salivary acetaldehyde levels. [ABSTRACT FROM AUTHOR]

Background: A number of studies have suggested that implant failure and associated bone loss is greater in subjects with a history of periodontitis. Purpose: To evaluate the risk for marginal bone loss around implants and implant failure in subjects with a history of periodontitis compared with periodontally healthy subjects in studies with a minimum 3-year follow-up. Materials and Methods: Data sources: The MEDLINE, EMBASE, and PubMed databases and relevant journals were searched up to July 1, 2008, with restriction to English language. Review Methods: Prospective and retrospective longitudinal observational clinical studies comparing periodontal/peri-implant variables among subjects with periodontitis and subjects who were periodontally healthy were included. Screening of studies, quality assessment, and data extraction were conducted independently and in duplicate. Clarification of missing and unclear information was not sought. Outcome measures were: implant survival/failure, peri-implant parameters, changes in radiographic marginal bone level, probing pocket depth, and gingival index. Results: Seventeen potential studies were identified and six studies were accepted comparing patients with periodontitis and periodontally healthy patients treated with implants. Five studies were eligible for meta-analysis of implant survival and four studies were eligible for meta-analysis of bone loss around implants. The odds ratio for implant survival was significantly in favor of periodontally healthy patients (3.02, 95% confidence intervals 1.12–8.15). A random effects model showed more marginal bone loss in periodontitis subjects compared with periodontally healthy subjects (standard mean difference 0.61, 95% confidence interval 0.14–1.09). Conclusions: Within the limitations of the heterogenous studies available, a moderate level of evidence indicates that periodontitis subjects were at significantly higher risk for implant failure and greater marginal bone loss as compared with periodontally healthy subjects. Prospective observational studies with subject-based designs are recommended. [ABSTRACT FROM AUTHOR]

Objective: To assess the accuracy of measuring the cortical bone thickness adjacent to dental implants using two cone beam computed tomography (CBCT) systems. Material and methods: Ten 4 × 11 mm Astra Tech® implants were placed at varying distances from the cortical bone in two prepared bovine ribs. Both ribs were scanned in a reproducible position using two different CBCT scanners. Ten examiners each carried out four measurements on all 10 implants using the two CBCT systems: vertical distance between the top of the implant and the alveolar crest (IT–AC), and thickness of the cortical bone from the outer surface of the implant threads at 3, 6 and 9 mm from the top of the implant. Ground sections were prepared and bone thickness was measured using a light microscope and a graticule to give a gold standard (GS) measurement. Results: The examiner's measurements were significantly different between CBCT systems for the vertical and thickness dimensions ( P<0.001) while measuring the cortical bone thickness between 0.3 and 3.7 mm. Within that range, i-CAT NG® measurements were consistently underestimated in comparison with the GS. Accuitomo 3D60 FPD® measurements closely approximated the GS, except when cortical bone thickness was <0.8 mm. The mean percentage errors from the GS at 3, 6 and 9 mm measurement levels were 68%, 28% and 18%, respectively, for i-CAT NG® and 23%, 5% and 6%, respectively, for Accuitomo 3D60 FPD®. Conclusions: Within the limitations of this study, it was concluded that i-CAT NG® (voxel size 0.3) may not produce sufficient resolution of the thin cortical bone adjacent to dental implants and, therefore, the measurements may not be accurate; whereas, Accuitomo 3D60 FPD® (voxel size 0.125) may produce better resolution and more accurate measurement of the thin bone. To cite this article: Razavi T, Palmer RM, Davies J, Wilson R, Palmer PJ. Accuracy of measuring the cortical bone thickness adjacent to dental implants using cone beam computed tomography. Clin. Oral Impl. Res. 21, 2010; 718–725. doi: 10.1111/j.1600-0501.2009.01905.x [ABSTRACT FROM AUTHOR]

This study investigated the effect of resin coating and occlusal loading on adhesion and microleakage of all-ceramic crowns. Molars were prepared for an all-ceramic crown and were divided into two groups: non-coated (control) and resin-coated with Clearfil Tri-S Bond. Crowns were fabricated using CEREC 3 and cemented using Clearfil Esthetic Cement. After 24 h of storage in water, the restored teeth in each group were divided into two subgroups: unloaded, or loaded while stored in water. Mechanical loading was achieved with an axial force of 80 N at 2.5 cycles s−1 for 250,000 cycles. After immersion in Rhodamine B, the specimens were sectioned and processed for microleakage evaluation by confocal microscopy, which was followed by further sectioning for microtensile bond testing. Loading had no significant effect on microleakage in either the resin-coated or non-resin-coated groups. Resin coating did not reduce the microleakage at the dentine interface but increased the microleakage at the enamel interface. All the beams fractured during slicing when non-coated and loaded. The bond strengths of non-coated and unloaded, resin-coated and unloaded, and resin-coated and loaded groups were 15.82 ± 4.22, 15.17 ± 5.24, and 12.97 ± 5.82 MPa, respectively. Resin coating with Clearfil Tri-S Bond improved the bonding of resin cement to dentine for loaded specimens. However, it was not effective in reducing the microleakage, regardless of whether it was loaded or unloaded. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to assess oral health-related beliefs and attitudes, health behaviour of smokers in relation to the Transtheoretical Model (TTM) of behaviour change, willingness to have smoking cessation provided together with periodontal treatment. Material and Methods: Postal questionnaire was sent to 500 referred patients. Part 1 looked at attitudes and beliefs about periodontal disease, Part 2 aimed at current smokers focused on the TTM and smoking cessation. Results: Response rate was 56% ( n=277); 67% females, 33% males. Mean age was 44.9 years (SD 12.45); 24.5% current smokers, 30.3% past smokers, 45.5% never smokers. Fewer smokers reported “bleeding gums” ( p=0.027), but more smokers reported “having loose teeth” ( p=0.016). The TTM stages of change indicated that 31% of current smokers were in pre-contemplation of quitting smoking, 46% were in contemplation and 23% were in preparation. Twenty-three percent of the past smokers were in action and 77% in maintenance. Smokers showed differences in the “self-re-evaluation” ( p=0.001) and “self-liberation” ( p=0.015) processes of change depending on their stage of change (pre-contemplation or preparation). Nearly half (49%) of the current smokers who wanted to quit requested smoking cessation to be provided alongside their periodontal treatment. Conclusion: A large proportion of periodontal patient smokers may be considering quitting, and nearly half requested provision of smoking cessation intervention in conjunction with the periodontal treatment. [ABSTRACT FROM AUTHOR]

Aim: Transient bacteraemia and endotoxaemia, and elevated levels of systemic cytokines have been reported following subgingival debridement. This study aimed to investigate the effect of chlorhexidine (CHX) solution on circulating levels of lipopolysaccharide (LPS) and interleukin-6 (IL-6) when used as an irrigant during ultrasonic debridement in patients with periodontitis. Material and Methods: Eighteen patients with moderate to advanced chronic periodontitis were treated in a split-mouth, crossover, single-masked study. Irrigation with 0.02% CHX solution or water was used during treatment of two ipsilateral quadrants on two separate occasions 7 days apart, randomized as to order. Peripheral blood samples were collected for circulating levels of LPS and IL-6 at baseline, 5 and 120 min. after instrumentation commenced. Results: Median concentrations of LPS were elevated from baseline to 5 min. into treatment with both CHX and control irrigant ( p<0.05). Median levels of IL-6 increased with both treatments from baseline to 120 min. ( p<0.001): CHX, 0.81–1.85 pg/ml; control, 0.78–1.78 EU/ml. Conclusions: Ultrasonic instrumentation in patients with moderate to advanced periodontitis increases circulating levels of LPS after 5 min. and IL-6 120 min. after commencement of treatment, and is not affected by using 0.02% CHX as an irrigant instead of water. [ABSTRACT FROM AUTHOR]

Objectives: The aim was to investigate the relationship between bone mineral density (BMD) of the jaws (mandible and maxilla) and other skeletal sites. In addition, the influence of gender, smoking and the number of years without natural teeth were examined. Materials and methods: 18 edentulous patients (9 females, 9 males) with a mean age of 67.1 (sd 12.6) years had DXA scans to assess the BMD of the lumbar spine and hip, together with the ramus, body and symphysis of the mandible and the anterior of the maxilla. Results: BMD values for the ramus were similar to those for the femur but significantly lower than the lumbar spine. The body and anterior mandible had higher values and the anterior maxilla lower values than both the femur and ramus. The ramus BMD showed moderately strong relationships with the standard measures of BMD in the spine and hip, but the BMD of other areas of the jaws showed no relationship with skeletal sites. The BMD for both the hip and the ramus showed an inverse relationship with increasing age. There was no statistically significant relationship between BMD of hip, spine and jaw and either years edentulous or cigarette years. (207) Conclusions: Although the ramus of the mandible may show correlation of BMD with skeletal sites, the areas of the jaws where implants may be placed do not. Therefore BMD of the skeletal sites could not be used to predict BMD of the jaws. The BMD of the jaws as measured by DXA showed no relationship with either years edentulous or cigarette smoking. [ABSTRACT FROM AUTHOR]

Background: Previous work has suggested that tobacco smoking has a local as well as a systemic effect on the severity of periodontal disease. Objective: To test the hypothesis that smokers have more disease in the upper anterior region. Methods: A retrospective stratified random sample of 49 non-smokers and 39 heavy smokers (⩾20 cigarettes/day) was obtained from a total of 3678 referred patients with adult periodontitis. Probing depth data were collected from clinical records and radiographic measurements were carried out on existing dental panoramic tomographs to assess the inter-proximal bone levels. Results: The proportion of sites with “bone loss” 4.5 mm or greater was higher in smokers, the greatest difference being observed in upper anterior sites (smokers: 73.3±25.5%, non-smokers: 48.3±31.2%, p<0.001). A difference was also observed when the number of palatal sites probing 4 mm or greater in the upper anterior region was expressed as a proportion of all such sites in the mouth (smokers: 12.3±6.8%, non-smokers: 9.8±8.8%; p=0.050). Conclusion: The overall pattern of tissue destruction was consistent with a systemic effect of smoking. The suggestion of a marginal local effect of the smoking habit in maxillary anterior palatal sites requires further investigation. [ABSTRACT FROM AUTHOR]

Aim: To review the potential biological mechanisms underlying the effects of tobacco smoking on periodontitis. Main findings: Smoking has major effects on the host response, but there are also a number of studies that show some microbiological differences between smokers and non-smokers. Smoking has a long-term chronic effect on many important aspects of the inflammatory and immune responses. Histological studies have shown alterations in the vasculature of the periodontal tissues in smokers. Smoking induces a significant systemic neutrophilia, but neutrophil transmigration across the periodontal microvasculature is impeded. The suppression of neutrophil cell spreading, chemokinesis, chemotaxis and phagocytosis have been described. Protease release from neutrophils may be an important mechanism in tissue destruction. Tobacco smoke has been found to affect both cell-mediated immunity and humoral immunity. Research on gingival crevicular fluid has demonstrated that there are lower levels of cytokines, enzymes and possibly polymorphonuclear cells in smokers. In vitro studies have shown detrimental effects of nicotine and some other tobacco compounds on fibroblast function, including fibroblast proliferation, adhesion to root surfaces and cytotoxicity. Conclusion: Tobacco smoking has widespread systemic effects, many of which may provide mechanisms for the increased susceptibility to periodontitis and the poorer response to treatment. [ABSTRACT FROM AUTHOR]

Background: The acute-phase response involves molecules including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP). This study aimed to determine whether subgingival scaling resulted in rapid changes in plasma concentrations of these molecules. Methods: Twenty-three non-smoking adults with chronic periodontitis received subgingival scaling for 60 minutes. Venous blood samples were taken at 0, 15. 30, 60, and 120 minutes. TNF-α and IL-6 were assayed from all samples and CRP From the baseline and final samples. Lipopolysaccharide (LPS) was assayed at 0, 15, and 30 minutes using limulus lysate assay (LAL) and EndoCAb Ig assays. Results: LPS assays were suggestive of a transient low-grade bacteremia, but changes in LPS approaching significance (P = 0.061) were seen with LAL only. There was a significant increase in circulating TNF-α (P = 0.0387) and IL-6 (P <0.0001), and the degree of charge in TNF-α was correlated with the severity of periodontal breakdown (P = 0.001). There was also a significant correlation between levels of IL-6 and TNF-α (P <0.001). Conclusions: Chronic periodontitis patients undergoing an episode of subgingival scaling show a significant elevation in circulating TNF-α and IL-6. This may account for anecdotal reports of pyrexia following treatment and may be significant in terms of the relationship between periodontal disease, bacteremia, and cardiovascular disease. [ABSTRACT FROM AUTHOR]

Discusses the age and gender differences in Merriam's turkeys. Incremental tarsometatarsus lengths and probabilities for classifying gender and gender-age; Formulation of a null hypothesis from the differentiation of age and gender based on leg morphology; Rejection of the null hypothesis.