Examining the Case for Dental Hygienists' Teaching Predoctoral Dental Students: A Two-Part Study.

Dental students in North American dental schools are exposed to faculty members with various professional backgrounds. These faculty members may include dentists, dental hygienists, and scientists without clinical dental credentials. The practice of dental hygienists' educating predoctoral dental students has not been well documented. The aims of this two-part study were to investigate the parameters of didactic, preclinical, and clinical instruction of dental students by dental hygienist faculty members in North American dental schools and to explore dental students' perceptions of this form of teaching. In part one, a survey was sent electronically to the clinical or academic affairs deans of all 76 American Dental Education Association (ADEA) member dental schools in 2017. Twenty-nine responded, for a 38.2% response rate. In 76% of the responding schools, dental hygienists were teaching dental students. Most respondents reported that, in their schools, the minimum degree required to teach didactically was a master's, while a bachelor's degree was required for preclinical and clinical courses. There was no significant association between dental hygienists' instructing dental students and having a dental hygiene educational program at the institution. In part two of the study, a questionnaire was completed by 102 graduating dental students (85% response rate) at one U.S. university to evaluate the impact of dental hygienist educators. Among the respondents, 87% reported feeling that dental hygienists were very effective educators. There were no significant differences in responses between traditional and advanced standing international dental students. This study found that dental hygienists were educating dental students in many North American dental schools and were doing so in curricular content beyond periodontics and that their educational contributions at a sample school were valued by the dental students there.

Periodontal Microorganisms and Cardiovascular Risk Markers in Youth With Type 1 Diabetes and Without Diabetes.

BACKGROUND: A subset of periodontal microorganisms has been associated with cardiovascular disease (CVD), which is the leading complication of type 1 diabetes (t1DM). The authors therefore evaluated the association between periodontal microorganism groups and early markers of CVD in youth with t1DM. METHODS: A cross-sectional analysis was conducted among youth aged 12 to 19 years at enrollment; 105 had t1DM for ≥5 years and were seeking care at the Barbara Davis Center, University of Colorado, from 2009 to 2011, and 71 did not have diabetes. Subgingival plaque samples were assessed for counts of 41 periodontal microorganisms using DNA-DNA hybridization. Microorganisms were classified using cluster analysis into four groups named red-orange, orange-green, blue/other, and yellow/other, modified from Socransky's color scheme for periodontal microorganisms. Subsamples (54 with t1DM and 48 without diabetes) also received a periodontal examination at the University of Colorado School of Dental Medicine. RESULTS: Participants were ≈15 years old on average, and 74% were white. Mean periodontal probing depth was 2 mm (SE 0.02), and 17% had bleeding on probing. In multivariable analyses, glycated hemoglobin (HbA1c) was inversely associated with the yellow/other cluster (microorganisms that are not associated with periodontal disease) among youth with t1DM. Blood pressure, triglycerides, low-density lipoprotein, high-density lipoprotein, and total cholesterol were not associated with microorganism clusters in this group. HbA1c was not associated with periodontal microorganism clusters among youth without diabetes. CONCLUSION: Among youth with t1DM who had good oral health, periodontal microorganisms were not associated with CVD risk factors.

Comparison of Frequency and Duration of Periodontal Disease With Progression of Coronary Artery Calcium in Patients With and Without Type 1 Diabetes Mellitus.

People with type 1 diabetes mellitus manifest a greater burden of both periodontal disease and coronary artery disease (CAD); however, little is known about their interrelation. Coronary artery calcium (CAC) measures subclinical atherosclerosis and predicts major adverse coronary events. The relation between periodontal disease and CAC progression in individuals with type 1 diabetes has not been previously described. We determined the prevalence and progression of CAC in relation to self-reported periodontal disease. Multivariate logistic and tobit regression models were used to examine the relation between periodontal disease duration and CAC progression and whether this relation differs by diabetes status after controlling for age, gender, total and high-density lipoprotein cholesterol, hypertension, smoking, body mass index (BMI), duration of diabetes, and baseline CAC. A total of 473 patients with type 1 diabetes and 548 without diabetes were followed for a mean of 6.1 years. At baseline, the prevalence and duration of periodontal disease did not differ between subjects with and without diabetes (14.5% vs 13.4%, p = 0.60; 6 vs 9 years, p = 0.18). Duration of periodontal disease was not significantly associated with baseline CAC prevalence. In patients with type 1 diabetes, periodontal disease duration was significantly related to CAC progression (p = 0.004) but not in subjects without diabetes (p = 0.63). In conclusion, this study suggests that periodontal disease is an independent predictor of long-term progression of CAC in patients with type 1 diabetes.

Validation of a method for quantifying carotid artery calcification from panoramic radiographs.

OBJECTIVE: Carotid artery calcification can be visualized on panoramic radiographs. Incidental observation of these calcifications could identify patients in need of further screening. The purpose of this study was to validate the assessment and quantification of calcification on panoramic radiographs with the stenosis and the calculated resistive index (RI) from Doppler ultrasonography. STUDY DESIGN: Digital panoramic radiographs were used to assess the area of carotid artery calcification using tools available in NIH's ImageJ. Inpatient and outpatient discharge records were reviewed to identify subjects with a completed carotid Doppler ultrasound exam (n = 122). RESULTS: The quantification of carotid artery calcification was found to correlate well with the degree of stenosis (area under the curve [AUC] 0.81 [95% confidence interval [CI] 0.64, 0.98]) and the RI of the common carotid artery (AUC 0.79 [95% CI 0.59, 0.98]). CONCLUSION: This method for quantification of carotid artery calcification could identify patients in need of further evaluation.

Loss of alveolar bone due to periodontal disease exhibits a threshold on the association with coronary heart disease.

BACKGROUND: A number of epidemiologic studies were published that looked at the association between coronary heart disease (CHD) and periodontal disease. However, debate exists about whether this association is a true relationship or simply an example of an uncontrolled confounder. This retrospective cohort study examines the relationship between periodontal disease and CHD. METHODS: Digital panoramic radiographs were used to assess alveolar bone loss (ABL) using a Schei ruler. Participants consisted of Veterans Administration (VA) patients who were eligible for dental benefits and had a digital panoramic radiograph taken at the VA Medical Center, Denver, Colorado. Information on CHD and other important clinical variables were obtained from electronic medical records. RESULTS: The examination of the relationship between ABL and CHD revealed a significant non-linear relationship with a threshold at ≈ 20% bone loss with a doubling of the probability ratios of CHD compared to those at 7.5% bone loss. CONCLUSIONS: To our knowledge, this is the first study to demonstrate a non-linear relationship between ABL and CHD. A significant positive association between ABL and CHD was found at even low levels of bone loss between 10% and 20%.

Oral Health Knowledge and Behaviors among Adolescents with Type 1 Diabetes.

Early onset and more advanced periodontal disease has been reported for children with diabetes. We surveyed oral health knowledge, attitudes, and behaviors among adolescents with diabetes in order to inform potential intervention strategies. Study subjects were youth (ages 12-19 years) with type 1 diabetes (N = 90) participating in a cohort study investigating determinants of periodontal disease at a regional pediatric diabetes specialty clinic. Over 90% of the youth had been instructed on how to brush and floss and had preventive dental care in the past year. However, 44% knew that periodontal disease is associated with diabetes and 32% knew that it can start in childhood with bleeding gums. Despite being at high risk for developing periodontal disease, the mean toothbrushing frequency was once per day and 42% did not floss. Significant opportunity exists for improving periodontal disease knowledge and adoption of preventive oral hygiene behaviors in adolescents with diabetes.

Sodium channel expression and localization at demyelinated sites in painful human dental pulp.

UNLABELLED: The expression of sodium channels (NaCh(s)) change after inflammatory and nerve lesions, and this change has been implicated in the generation of pain states. Here we examine NaCh expression within nerve fibers from normal and painful extracted human teeth with special emphasis on their localization within large accumulations, like those seen at nodes of Ranvier. Pulpal tissue sections from normal wisdom teeth and from teeth with large carious lesions associated with severe and spontaneous pain were double-stained with pan-specific NaCh antibody and caspr (paranodal protein used to visualize nodes of Ranvier) antibody, while additional sections were triple-stained with NaCh, caspr and myelin basic protein (MBP) antibodies. Z-series of images were obtained with the confocal microscope and evaluated with NIH ImageJ software to quantify the density and size of NaCh accumulations, and to characterize NaCh localization at caspr-identified typical and atypical nodal sites. Although the results showed variability in the overall density and size of NaCh accumulations in painful samples, a common finding included the remodeling of NaChs at atypical nodal sites. This remodeling of NaChs included prominent NaCh expression within nerve regions that showed a selective loss of MBP staining in a pattern consistent with a demyelinating process. PERSPECTIVE: This study identifies the remodeling of NaChs at demyelinated sites within the painful human dental pulp and suggests that the contribution of NaChs to spontaneous pulpal pain generation may be dependant not only on total NaCh density but may also be related to NaCh expression at atypical nodal sites.

Sodium channel Nav1.6 accumulates at the site of infraorbital nerve injury.

BACKGROUND: Sodium channel (NaCh) expressions change following nerve and inflammatory lesions and this change may contribute to the activation of pain pathways. In a previous study we found a dramatic increase in the size and density of NaCh accumulations, and a remodeling of NaChs at intact and altered myelinated sites at a location just proximal to a combined partial axotomy and chromic suture lesion of the rat infraorbital nerve (ION) with the use of an antibody that identifies all NaCh isoforms. Here we evaluate the contribution of the major nodal NaCh isoform, Nav1.6, to this remodeling of NaChs following the same lesion. Sections of the ION from normal and ION lesioned subjects were double-stained with antibodies against Nav1.6 and caspr (contactin-associated protein; a paranodal protein to identify nodes of Ranvier) and then z-series of optically sectioned images were captured with a confocal microscope. ImageJ (NIH) software was used to quantify the average size and density of Nav1.6 accumulations, while additional single fiber analyses measured the axial length of the nodal gap, and the immunofluorescence intensity of Nav1.6 in nodes and of caspr in the paranodal region. RESULTS: The findings showed a significant increase in the average size and density of Nav1.6 accumulations in lesioned IONs when compared to normal IONs. The results of the single fiber analyses in caspr-identified typical nodes showed an increased axial length of the nodal gap, an increased immunofluorescence intensity of nodal Nav1.6 and a decreased immunofluorescence intensity of paranodal caspr in lesioned IONs when compared to normal IONs. In the lesioned IONs, Nav1.6 accumulations were also seen in association with altered caspr-relationships, such as heminodes. CONCLUSION: The results of the present study identify Nav1.6 as one isoform involved in the augmentation and remodeling of NaChs at nodal sites following a combined partial axotomy and chromic suture ION lesion. The augmentation of Nav1.6 may result from an alteration in axon-Schwann cell signaling mechanisms as suggested by changes in caspr expression. The changes identified in this study suggest that the participation of Nav1.6 should be considered when examining changes in the excitability of myelinated axons in neuropathic pain models.

Increased sodium channel immunofluorescence at myelinated and demyelinated sites following an inflammatory and partial axotomy lesion of the rat infraorbital nerve.

The localization of sodium channels (NaChs) change following nerve lesions and this change may contribute to the development of increased pain states. Here we examine the change in distribution of NaChs within the rat infraorbital nerve (ION) two weeks after a combined inflammatory/partial axotomy lesion that results in behavior showing increased sensitivity to mechanical stimuli. Sections from experimental and normal control IONs were double-stained for indirect immunofluorescence using an antibody that identifies all NaCh isoforms and caspr-antibody to identify nodes of Ranvier, and a confocal microscope z-series of optically sectioned images were then obtained. ImageJ (NIH) software was used to quantify the area of pixels showing maximum NaCh intensity within both caspr and non-caspr associated accumulations. Analysis showed that the lesioned IONs had many more split nodes, heminodes and caspr-negative "naked" accumulations, a significantly increased area of NaCh staining within typical nodes and "naked" accumulations, as well as an increased density and size of significant accumulations when compared to normal IONs. This study demonstrates a dramatic redistribution and increased immunofluorescence of NaChs especially at myelinated and demyelinated sites in fibers located just proximal to the lesion. The remodeling of NaChs seen in this study may represent an important event associated with the development of increased nerve excitability after lesions.

Localization of the Nav1.8 sodium channel isoform at nodes of Ranvier in normal human radicular tooth pulp.

The activation of voltage-gated sodium channels is necessary for action potential propagation and multiple sodium channel isoforms have been identified that show a differential distribution throughout the nervous system. An evaluation of sodium channel localization in the radicular pulp from normal human extracted third molars established the presence of the Na(v)1.8 isoform at nodes of Ranvier in a subpopulation of the myelinated axons as demonstrated with immunofluorescence confocal microscopy. A caspr antibody was used to identify the paranodal region of nodes of Ranvier and quantitative analysis revealed that 16.5% of the nodes contained significant Na(v)1.8 immunoreactivity. Since the Na(v)1.6 isoform has been described as the predominant sodium channel at essentially all nodes, the finding of Na(v)1.8 in a subpopulation of nodes suggests that multiple isoforms may coexist at some nodes of Ranvier and also suggests that this isoform may be an important nodal sodium channel type in the peripheral sensory nervous system of humans.

Ultrasound measurement of mandibular arterial blood supply: techniques for defining ischemia in the pathogenesis of alveolar ridge atrophy and tooth loss in the elderly?

PURPOSE: To adapt ultrasound methods used to measure blood flow in the extremities to quantify mandible blood flow in order to determine the role of ischemia in the pathogenesis of mandible atrophy and tooth loss in the elderly. PATIENTS AND METHODS: Doppler and duplex ultrasound techniques as used in measurement of arterial pulse in the extremities were adapted for recording the intraoral pulse profile at 7 sites in 57 patients of varying ages. RESULTS: After omitting the large number (26 patients) with signals of indeterminate strength, the mental artery pulse was strong in 11 of 12 (92%) in those younger than 65 versus 9 of 19 (47% in those older than 65 years; P = .02). The equivalent figures for the sublingual artery were 15 of 15 strong for those younger than 65 and 11 of 17 (65%) for those older than 65 years ( P = .02). The varying depth of soft tissue overlying the inferior alveolar artery made its signal difficult to evaluate, but there was no statistically significant age-related difference in the inferior alveolar artery signals. In 4 elderly patients (2 with established carotid artery disease), Doppler and duplex scanning showed reversal of mental artery flow, indicating collateral flow to the mandible. CONCLUSIONS: Ultrasound Doppler techniques used for measuring peripheral arterial flow can be adapted to quantify mandible alveolar ridge perfusion. This provides means to evaluate the role of arterial obstruction in mandible alveolar ridge atrophy and tooth loss in the elderly. The mental artery is the best site for this purpose. Preliminary data suggest an age-related reduction in mental artery flow.

The effects of subgingival calculus on the clinical outcomes of locally-delivered controlled-release doxycycline compared to scaling and root planing.

BACKGROUND/AIM: The effect of subgingival calculus on the clinical outcomes of the local delivery of antimicrobials is unknown. This study examines the clinical outcomes of treatment with locally delivered controlled-release doxycycline (DH) or scaling and root planing (SRP) in subsets of adult periodontitis patients with known baseline levels of subgingival calculus. METHODS: The data examined were obtained from 393 patients who participated in 2 multi-center trials. All patients had baseline subgingival calculus levels assessed and were then treated at baseline and month 4 with either DH or SRP. Clinical attachment levels (CAL), pocket depth (PD) and bleeding on probing (BOP) were assessed at baseline and months 1, 2, 4, 5, 6, 8 and 9. RESULTS: Treatment with either DH or SRP resulted in significant statistical and clinical improvements in CAL, PD and BOP. These clinical outcomes were equivalent regardless of the extent of subgingival calculus present at baseline. CONCLUSIONS: The results indicate that the primary clinical effects of these therapies are the result of a disruption and reduction of the subgingival plaque and not the effect of the removal of subgingival calculus and contaminated cementum.