Training in the use of the water jet and cold atmospheric plasma jet for the decontamination of dental implants.

OBJECTIVES: Clinical trials testing new devices require prior training on dummies to minimize the "learning curve" for patients. Dentists were trained using a novel water jet device for mechanical cleaning of dental implants and with a novel cold plasma device for surface functionalisation during a simulated open flap peri-implantitis therapy. The hypothesis was that there would be a learning curve for both devices. MATERIALS AND METHODS: 11 dentists instrumented 44 implants in a dummy-fixed jaw model. The effect of the water jet treatment was assessed as stain removal and the effect of cold plasma treatment as surface wettability. Both results were analysed using photographs. To improve treatment skills, each dentist treated four implants and checked the results immediately after the treatment as feedback. RESULTS: Water jet treatment significantly improved from the first to the second implant from 62.7% to 75.3% stain removal, with no further improvement up to the fourth implant. The wettability with cold plasma application reached immediately a high level at the first implant and was unchanged to the 4th implant (mean scores 2.7 out of 3). CONCLUSION: A moderate learning curve was found for handling of the water jet but none for handling of the cold plasma. CLINICAL RELEVANCE: Scientific rational for study: Two new devices were developed for peri-implantitis treatment (Dental water jet, cold plasma). Dentists were trained in the use of these devices prior to the trial to minimize learning effects. PRINCIPAL FINDINGS: Experienced dentists learn the handling of the water jet very rapidly and for cold plasma they do not need much training. PRACTICAL IMPLICATIONS: A clinical study is in process. When the planned clinical study will be finished, we will find out, if this dummy head exercise really minimised the learning curve for these devices.

Influence of gender and bruxism on the masseter muscle: A population-based magnetic resonance imaging study.

INTRODUCTION: This study aimed to (1) examine the cross-sectional area (CSA) of the masseter muscle in relation to bruxism and (2) investigate if there are gender-related differences in the masseter muscle in a population-based magnetic resonance imaging (MRI) study. METHODS: The study included 720 subjects aged 30-89 years (391 women and 329 men) from the Study of Health in Pomerania, a cross-sectional population-based study assessing the prevalence and incidence of common population-relevant diseases and their risk factors in Northeastern Germany. The participants underwent both a whole-body MRI and a full oral examination. The CSAs of the masseter muscles on both sides were measured from MRI images. The presence or absence of awake and/or sleep grinding and clenching, unilateral chewing, and other parafunctional activities were obtained from the dental interview. Linear and ordinal logistic regression models were used to examine the associations between the CSAs of the masseter, bruxism, and gender. RESULTS: The frequency of bruxism and reports of muscle or joint pain were significantly higher in women. The analysis revealed that a larger masseter CSA was significantly associated with bruxism only in men. The larger CSA was manifested only in the higher frequency bruxers. CONCLUSIONS: Bruxism had heterogeneous effects on the masseter muscle between genders. Although a higher prevalence of bruxism was reported by women, the larger CSA of the masseter muscle was significantly higher in bruxing men but not in women. This study emphasizes the need for a gender-specific approach when evaluating the clinical implications of bruxism on the masseter muscle.

Impact of dental restorations and removable prostheses on potentially malignant oral mucosal disorders in the general population.

STATEMENT OF PROBLEM: Dental restorations and removable dental prostheses have been considered as risk factors for potentially malignant disorders of the oral mucosa. It remains unclear whether amalgam, composite resins, and prosthesis materials can induce potentially malignant disorders. PURPOSE: The purpose of this clinical study was to determine the relationship between the presence of amalgam and composite resin restorations, crowns and fixed partial dentures, and removable prostheses in potentially malignant disorders. MATERIAL AND METHODS: The data of 6041 participants in the population-based Studies of Health in Pomerania (SHIP) were accessed. Potentially malignant disorders had been clinically diagnosed by calibrated dentists and documented with photographs. Dental treatment was subdivided into restored and replaced teeth. Dental restorations were subclassified as buccal composite resin or amalgam restorations. Prosthetic treatment was subclassified into removable partial or complete prostheses and definitive restorations with crowns and fixed partial dentures. RESULTS: In the maxilla, participants with removable prostheses had a higher incidence of potentially malignant disorders than participants not undergoing treatment with removable prostheses (OR 2.12; 95% CI: 1.08-4.18), but not in the mandible (OR 1.30; 95% CI: 0.67-2.53). The surfaces with composite resin restorations were associated with a slightly higher risk of mucosal lesions than those without the restorations (OR 1.04; 95% CI: 1.01-1.07). No significant association was found between amalgam restorations and mucosal lesions. CONCLUSIONS: Participants with removable prostheses have a higher risk of potentially malignant disorders. Composite resin restorations are associated with a higher risk of mucosal lesions, whereas no significant association was found between amalgam restorations and mucosal lesions.

Prevalence of SARS-CoV-2 IgG antibodies among dental teams in Germany.

OBJECTIVES: During the corona pandemic, dental practices temporarily closed their doors to patients except for emergency treatments. Due to the daily occupational exposure, the risk of SARS-CoV-2 transmission among dentists and their team is presumed to be higher than that in the general population. This study examined this issue among dental teams across Germany. MATERIALS AND METHODS: In total, 2784 participants provided usable questionnaires and dry blood samples. Dry blood samples were used to detect IgG antibodies against SARS-CoV-2. The questionnaires were analyzed to investigate demographic data and working conditions during the pandemic. Multivariable logistic mixed-effects models were applied. RESULTS: We observed 146 participants with positive SARS-CoV-2 IgG antibodies (5.2%) and 30 subjects with a borderline finding (1.1%). Seventy-four out of the 146 participants with SARS-CoV-2 IgG antibodies did not report a positive SARS-CoV-2 PCR test (50.7%), while 27 participants without SARS-CoV-2 IgG antibodies reported a positive SARS-CoV-2 PCR test (1.1%). Combining the laboratory and self-reported information, the number of participants with a SARS-CoV-2 infection was 179 (6.5%). Though after adjustment for region, mixed-effects models indicated associations of use of rubber dams (OR 1.65; 95% CI: 1.01-2.72) and the number of protective measures (OR 1.16; 95% CI: 1.01-1.34) with increased risk for positive SARS-CoV-2 status, none of those variables was significantly associated with a SARS-CoV-2 status in fully adjusted models. CONCLUSIONS: The risk of SARS-CoV-2 transmission was not higher among the dental team compared to the general population. CLINICAL RELEVANCE: Following hygienic regulations and infection control measures ensures the safety of the dental team and their patients.

Do Third Molars Contribute to Systemic Inflammation? Results From a Population-Based Study From Northeast Germany.

PURPOSE: Erupted and impacted third molars have been reported to contribute to systemic inflammation. This study investigated the systemic effect of third molars on serum levels of inflammatory parameters and on inflammatory messenger peptide hormones in a general population sample. MATERIALS AND METHODS: Data of 2,151 participants from the Study of Health in Pomerania were included in this study. Erupted or impacted third molars were assessed with whole-body magnetic resonance imaging at 1.5 T and associated with biomarkers of inflammation, lipid metabolism, glucose metabolism, and peptide hormones by linear regression. Models were adjusted for age, gender, smoking status, education, and type 2 diabetes mellitus. RESULTS: Neither erupted nor impacted third molars were associated with high-sensitivity C-reactive protein, white blood cell count, or fibrinogen as markers for systemic inflammation. Participants with erupted third molars had markedly lower serum levels of leptin (ß coefficient, -2.47; 95% confidence interval [CI], -4.47 to -0.48), angiopoietin-2 (ß coefficient, -135.1; 95% CI, 248.6 to -21.5), and ratio of angiopoietin-2 to tyrosine kinase with immunoglobulin-like loop epidermal growth factor homology domain 2 (ß coefficient, -6.57; 95% CI, -13.06 to -00.7) than participants without third molars. No such associations were observed for impacted third molars. CONCLUSION: The present results did not substantiate a relation between third molars and an increase in systemic inflammatory markers. Therefore, dental practitioners should be careful when considering this as the only indication for removal of third molars, especially in medically compromised patients. The results of this study showed that participants with erupted third molars had lower levels of messenger peptide hormones, such as leptin and angiopoetin-2.

Alexithymia and temporomandibular joint and facial pain in the general population.

BACKGROUND: Associations of alexithymia with temporomandibular pain disorders (TMD), facial pain, head pain and migraine have been described, but the role of the different dimensions of alexithymia in pain development remained incompletely understood. OBJECTIVES: We sought to investigate the associations of alexithymia and its subfactors with signs of TMD and with facial pain, head pain and migraine in the general population. METHODS: A total of 1494 subjects from the general population completed the Toronto Alexithymia Scale-20 (TAS-20) and underwent a clinical functional examination with palpation of the temporomandibular joint and masticatory muscles. Facial pain, migraine and head pain were defined by questionnaire. A set of logistic regression analyses was applied with adjustment for age, sex, education, number of traumatic events, depressive symptoms and anxiety. RESULTS: Alexithymia was associated with TMD joint pain (Odds Ratio 2.63; 95% confidence interval 1.60-4.32 for 61 TAS-20 points vs the median of the TAS-20 score) and with facial pain severity (Odds Ratio 3.22; 95% confidence interval 1.79-5.79). Differential effects of the subfactors were discovered with difficulties in identifying feelings as main predictor for joint, facial, and head pain, and externally oriented thinking (EOT) as U-shaped and strongest predictor for migraine. CONCLUSION: Alexithymia was moderately to strongly associated with signs and symptoms of TMD. These results should encourage dental practioners using the TAS-20 in clinical practice, to screen TMD, facial or head pain patients for alexithymia and could also help treating alexithymic TMD, facial or head pain patients.

Third molars and periodontal damage of second molars in the general population.

AIM: The aim of this study was to clarify the association between impacted or erupted third molars and periodontal pathology, assessed by probing depth (PD) and clinical attachment levels (CAL), in adjacent second molars. MATERIALS AND METHODS: Data from the population-based Study of Health in Pomerania (SHIP) was used. This is the first project with whole-body magnetic resonance imaging (WB-MRI) application in a general population setting with dental issues. Calibrated and licensed dentists measured PD and CAL with a periodontal probe. RESULTS: In the mandible, individuals with erupted third molars had a 1.45-fold higher odds ratio (CI:1.03; 2.05; p = 0.031) and individuals with impacted third molars had a 2.37-fold higher odds ratio (CI:1.45; 3.85; p < 0.001) to have higher PD values in the adjacent distal site of second molar than individuals with missing third molars in the total population. These significant associations were even more pronounced in the population free of periodontitis disease. In participants with periodontitis in the maxilla, there was an association of erupted third molars with an increased PD of adjacent molars. CONCLUSION: In particular, in the mandible, those findings could guide dental practitioners more in the direction to remove the third molars after having evaluated the periodontium of the adjacent teeth.

Prevalence and risk factors of potentially malignant disorders of the mucosa in the general population: Mucosa lesions a general health problem?

AIM: Oral cancer mostly develops from oral mucosa regions with morphological alterations transforming malignant. These visible precancerous mucosa lesions are named potentially malignant disorders (PMD). We aimed to analyze the prevalence of PMD and its risk factors for PMD in a population-based sample in Northern Germany. MATERIAL AND METHODS: Data of 6078 individuals from the population-based Study of Health in Pomerania (SHIP) was used. PMD were photographically documented and periodontal health was assessed in a standardized procedure. RESULTS: PMD were observed in 54 individuals (0.9%). The most prevalent PMD was homogenous leukoplakia (n = 37) followed by Lichen ruber (n = 9). Smoking (Odds Ratio (OR) 2.70; 95% confidence interval (CI): 1.24-5.87), male sex (OR 3.32; 95%-CI: 1.77-6.21), type 2 diabetes mellitus (OR 2.07; 95%-CI: 1.08-3.98) and body mass index (OR 1.09; CI 1.04-1.14) were significantly associated with PMD, with the corresponding area under the curve (AUC) being 0.696 (CI: 0.655; 0.737). CONCLUSION: Our results suggest a clinically relevant prevalence of PMD in the population. We identified male sex, type 2 diabetes mellitus, current smoking, and obesity as risk factors. We recommend photographic documentation and intensified training of medical and dental staff to detect and monitor PMD.

SHIP-MR and Radiology: 12 Years of Whole-Body Magnetic Resonance Imaging in a Single Center.

The Study of Health in Pomerania (SHIP), a population-based study from a rural state in northeastern Germany with a relatively poor life expectancy, supplemented its comprehensive examination program in 2008 with whole-body MR imaging at 1.5 T (SHIP-MR). We reviewed more than 100 publications that used the SHIP-MR data and analyzed which sequences already produced fruitful scientific outputs and which manuscripts have been referenced frequently. Upon reviewing the publications about imaging sequences, those that used T1-weighted structured imaging of the brain and a gradient-echo sequence for R2* mapping obtained the highest scientific output; regarding specific body parts examined, most scientific publications focused on MR sequences involving the brain and the (upper) abdomen. We conclude that population-based MR imaging in cohort studies should define more precise goals when allocating imaging time. In addition, quality control measures might include recording the number and impact of published work, preferably on a bi-annual basis and starting 2 years after initiation of the study. Structured teaching courses may enhance the desired output in areas that appear underrepresented.

Are third molars associated with orofacial pain? Findings from the SHIP study.

OBJECTIVES: To examine the association between third molars and orofacial pain. We hypothesized that impacted third molars are a cause of orofacial pain. METHODS: Magnetic resonance images of 1808 participants from two population-based cohorts from Northeastern Germany were analysed to define the status of third molars according to the Pell and Gregory classification. A self-reported questionnaire and a clinical dental examination were used to detect chronic and acute complaints of orofacial pain, masticatory muscle pain, migraine and other types of headache. Logistic regression models were used to analyse the associations between third molar status and orofacial pain. RESULTS: Individuals with impacted third molars in the maxilla had a higher chance of chronic orofacial pain than those with erupted third molars (odds ratio 2.19; 95% CI 1.19-4.02). No such association was detected for third molars in the lower jaw. Third molars were not associated with masticatory muscle pain, migraine or other types of headache. CONCLUSIONS: Impacted maxillary third molars might be a cause of chronic orofacial pain. Thus, physicians should consider the eruption/impaction status of third molars in their decision-making process when treating patients who complain of orofacial pain.

Association Between Symptoms of Posttraumatic Stress Disorder and Signs of Temporomandibular Disorders in the General Population.

AIMS: To estimate the association between signs of temporomandibular disorders (TMD) and symptoms of posttraumatic stress disorder (PTSD) in a representative sample from the general population of northeastern Germany. METHODS: Signs of TMD were assessed with a clinical functional analysis that included palpation of the temporomandibular joints (TMJs) and masticatory muscles. PTSD was assessed with the PTSD module of the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, ed 4. The change-in-estimate method for binary logistic regression models was used to determine the final model and control for confounders. RESULTS: After the exclusion of subjects without prior traumatic events, the sample for joint pain consisted of 1,673 participants with a median age of 58.9 years (interquartile range 24.8), and the sample for muscle pain consisted of 1,689 participants with a median age of 59.1 years (interquartile range 24.8). Of these samples, 84 participants had pain on palpation of the TMJ, and 42 participants had pain on palpation of the masticatory muscles. Subjects having clinical PTSD (n = 62) had a 2.56-fold increase in joint pain (odds ratio [OR] = 2.56; 95% confidence interval [CI]: 1.14 to 5.71, P = .022) and a 3.86-fold increase (OR = 3.86; 95% CI: 1.51 to 9.85, P = .005) in muscle pain compared to subjects having no clinical PTSD. CONCLUSION: These results should encourage general practitioners and dentists to acknowledge the role of PTSD and traumatic events in the diagnosis and therapy of TMD, especially in a period of international migration and military foreign assignments.

Does craniofacial morphology affect third molars impaction? Results from a population-based study in northeastern Germany.

OBJECTIVES: It is still not clear why impaction of third molars occurs. Craniofacial morphology and facial parameters have been discussed to be strong predictors for third molar impaction. Thus, this study aimed to investigate the effect of craniofacial morphology on erupted or impacted third molars in a German population sample. MATERIALS AND METHODS: Erupted and impacted third molars in 2,484 participants from the Study of Health in Pomerania were assessed by whole-body magnetic resonance imaging. Markers of facial morphology were determined in 619 individuals of those participants in whose 421 participants (16.7%) had at least one impacted third molar. Craniofacial morphology was estimated as linear measurements and was associated in a cross-sectional study design with impacted and erupted third molars by multinomial logistic regression models. Erupted third molars were used as reference outcome category and regression models were adjusted for age and sex. RESULTS: Maximum Cranial Width (Eurion-Eurion distance) was significantly associated with impacted third molars (RR: 1.079; 95% confidence interval 1.028-1.132). This association was even more pronounced in the mandible. Individuals with a lower total anterior facial height (Nasion-Menton distance) and a lower facial index also have an increased risk for impacted third molars in the mandible (RR 0.953; 95% confidence interval 0.913-0.996 and RR: 0.943; 95% confidence interval 0.894-0.995). No significant associations of third molar status with facial width (Zygion-Zygion distance), and sagittal cranial dimension (Nasion-Sella distance; Sella-Basion distance) were observed. CONCLUSION: Individuals with an increased maximal cranial width have a higher risk for impaction of third molars in the mandible and in the maxilla. Individuals with a lower anterior total anterior facial height and lower facial index also have an increased risk for third molars impaction in the mandible. These findings could help orthodontic dentists, oral surgeons and oral and maxillofacial surgeons in decision-making for third molars removal in their treatment. These findings highlight the necessity of an additional analysis of the maximal cranial width by the Eurion- Eurion distance.