Impact of loading protocol of a mandibular single implant-supported complete denture on oral health-related quality of life over a period of 5 years: A randomized controlled trial

OBJECTIVES

The aim of the present study was to assess the long-term course of OHRQoL and the impact of the loading protocol in patients receiving a single mandibular implant supporting a complete denture over a period of five years.

METHODS

In this multicenter RCT, a total of 158 edentulous patients were initially included and were randomly allocated immediately after placement of a mandibular midline implant to either immediate loading (IL) or to conventional loading (CL) with submerged healing. The assessment of OHRQoL was performed with the 49-item Oral Health Impact Profile (OHIP) at baseline and 1, 4, 12, 24, and 60 months after loading. At 5-year follow-up, 100 patients (mean age: 69.2 years; 45.0% female) with completed OHIP were available for analyses. A mixed-effects model with patients as random effect and an unstructured covariance matrix was developed to address repeated outcome measurement.

RESULTS

The OHRQoL improved substantially after loading, indicated by a decrease of mean OHIP summary scores from 51.0 points at baseline, by 14.2 (95%-CI: 9.4 - 19.1; p<0.001) points to 37.2 points at 1-month follow-up, and by continuous improvement to 20.4 OHIP points at final follow-up. Considering constant treatment effects, the loading protocol had no significant effect on OHIP scores (-3.7, 95%-CI: -9.4 - 2.2; p = 0.204). Time effect was statistically significant with -0.21 (95%-CI: -0.28 - -0.15; p<0.001) points per month.

CONCLUSION

Both the immediate and conventional loading of a single mandibular midline implant supporting a complete denture offer long-lasting high levels of OHRQoL, with no significant or clinically relevant long-term differences.

CLINICAL SIGNIFICANCE

The study firstly presents long-term data for OHRQoL by investigating the loading protocol of single mandibular implant-supported complete dentures. Since immediate loading has been associated with a reduced implant survival rate for this concept, information on patient benefits is essential for evidence-based decision making.

Retrospective determination of fallout radionuclides and 236U/238U, 233U/236U and 240Pu/239Pu atom ratios on air filters from Vienna and Salzburg, Austria

137Cs and 241Pu (via 241Am) concentrations were measured γ-spectrometrically on air filters from the early 1960s (mainly from 1964-66) from Vienna, Austria, and an alpine station in Salzburg, Austria. Accelerator mass spectrometry (AMS) was used to determine 240Pu/239Pu, 236U/238U and 233U/236U atom ratios as well as 236U, 239Pu and 240Pu atom concentrations. The maximum 236U/238U atom ratio of these unique undisturbed global fallout samples was (1.19 ± 0.31) × 10-5 in spring 1964. The 233U/236U atom ratios were found within (0.15-0.49) × 10-2 and indicate that the weapons tests of the early 1960s can be excluded as 233U source. The 236U/239Pu atom ratios were calculated in the range of 0.22-0.48.

Actual vs. perceived exertion during active virtual reality game exercise

Background

Virtual exercise has become more common as emerging and converging technologies make active virtual reality games (AVRGs) a viable mode of exercise for health and fitness. Our lab has previously shown that AVRGs can elicit moderate to vigorous exercise intensities that meet recommended health benefit guidelines. Dissociative attentional focuses during AVRG gameplay have the potential to widen the gap between participants' perception of exertion and actual exertion.

Objective

The aim of this study was to determine actual exertion (AEx) vs. perceived exertion (PEx) levels during AVRGs by measuring heart rate (HR) and ratings of perceived exertion (RPE) in two different settings.

Materials and methods

HR and RPE were collected on participants (N = 32; age 22.6 ± 2.6) during 10 min of gameplay in LabS and GymS using the HTC VIVE with the following games played: Fruit Ninja VR (FNVR), Beat Saber (BS), and Holopoint (HP).

Results

Participants exhibited significantly higher levels of AEx compared to reported PEx for all three AVRGs (Intensity): FNVR [AEx = 11.6 ± 1.8 (Light), PEx = 9.0 ± 2.0 (Very Light)], BS [AEx = 11.3 ± 1.7 (Light), PEx = 10.3 ± 2.1 (Very Light)], HP [AEx = 13.1 ± 2.3 (Somewhat Hard), PEx = 12.3 ± 2.4 (Light–Somewhat Hard)]. Additionally, participants playing in the GymS experienced significantly higher levels of AEx [12.4 ± 2.3 (Light–Somewhat Hard)] and PEx [10.8 ± 2.5 (Very Light–Light)] compared to the LabS [AEx = 11.6 ± 1.8 (Light), PEx = 10.3 ± 2.6 (Very Light–Light)].

Conclusion

Perceptions of exertion may be lower than actual exertion during AVRG gameplay, and exertion levels can be influenced by the setting in which AVRGs are played. This may inform VR developers and health clinicians who aim to incorporate exercise/fitness regimens into upcoming ‘virtual worlds' currently being developed at large scales (i.e., the “metaverse”).

POS1089 ASSOCIATION BETWEEN PAIN SEVERITY AND HEALTHCARE UTILIZATION IN AN OSTEOARTHRITIS POPULATION: AN 18-YEAR RETROSPECTIVE COHORT STUDY

Background:

Osteoarthritis (OA) is a common disease that varies in severity among patients. A standardized definition to classify patients into different severity levels is lacking, however, due to the disease’s complex pathogenesis and presentation. Prior studies have shown associations between pain severity and higher healthcare resource utilization (HRU) and costs. We investigated an association between pain severity and higher healthcare resource utilization by examining the use of specific OA-related treatments across pain intensity levels in a large, integrated health system’s OA population over an 18-year period.

Objectives:

Our aim was to compare use of medications and other treatments among OA patients experiencing mild, moderate, or severe pain.

Methods:

This was a retrospective study of electronic health records from 2001 to 2018 at Geisinger, an integrated health system in Pennsylvania. Patients were included with a diagnosis code for OA (ICD-9: 715.*, ICD-10 M15-19) on a problem list or encounter or an OA-specific procedure (hip or knee replacement, arthroscopy or injection). We examined pain scores (0-10 scale, with 10 being worst pain) taken after the first OA diagnosis date and defined pain episodes starting on the pain score’s date and lasting for 90 days. If a new pain score was measured before 90 days elapsed, the episode was extended for an additional 90 days, with this process repeated as necessary. Each episode was categorized as mild (pain score 0-3), moderate (4-6), or severe (7-10) based on initial score, and patients could contribute multiple episodes to the analysis. Descriptive statistics were used to quantify treatment utilization during each patients’ mild, moderate and severe episodes. Percentages of patients who had any use of 10 medication types (tramadol, non-tramadol opioids, nonsteroidal anti-inflammatory drugs (NSAIDs), injectable corticosteroids, acetaminophen, salicylates, duloxetine, homeopathic medications, other topical medications, and other over-the-counter (OTC) medications were compared across pain episode types. Percentages of patients with knee or hip surgeries, spine or joint imaging procedures (x-ray, computed tomography or magnetic resonance) and consults to OA-related care (pain management, orthopedics or physical medicine and rehabilitation) were also compared. All analyses used logistic regression with p-values <0.05 considered significant.

Results:

We identified 290,897 patients with OA, representing 34% of the health system population in 2018; 58% were female with mean age of 49 years and mean BMI of 30.5 kg/m2. A total of 801,144 pain episodes were defined, with 75% of patients having at least one pain score. The two most frequently occurring pain scores were 0 (17%) and 5 (13%), and pain episodes were classified as 43% mild, 32% moderate and 25% severe. Significantly higher percentages of patients used certain medication types (NSAIDs, injectable corticosteroids, non-tramadol opioid, duloxetine) in both moderate and severe pain episodes as compared to mild episodes, but other medication types were less likely to be used as pain severity increased (acetaminophen, salicylates, homeopathic medications, other OTC medications). Knee or hip surgeries, imaging, and consults to OA-related specialists were all consistently significantly more likely to occur in patients during moderate or severe pain episodes versus mild episodes (relative risk ratios of 1.76, 1.25 and 1.35 for moderate vs mild, respectively, and 2.00, 1.44 and 1.46 for severe vs mild, all p-values <0.05).

Conclusion:

While pain is generally recognized to be a subjective measure that could be influenced by other unmeasured factors and can be confounded with treatment effectiveness, it is nevertheless the primary symptom of OA. It is important to understand the relationship between pain intensity and treatment utilization, and our results support an overall association between pain and utilization but provide new details on the extent to which it depends on specific utilization type.

Acknowledgements:

Pfizer and Eli Lilly and Company for sponsoring this study.

Disclosure of Interests:

Jove Graham Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Tonia Novosat Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Haiyan Sun Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Brian Piper Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Joseph Boscarino Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Vanessa Duboski Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Melissa Kern Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Eric Wright Grant/research support from: I am an employee of Geisinger which received financial support from Pfizer and Eli Lilly and Company in connection with the development of this abstract, Rebecca Robinson Shareholder of: Eli Lilly & Co., Employee of: Eli Lilly & Co., Edward Casey Shareholder of: Pfizer, Inc., Paid instructor for: As an employee of Pfizer, Inc. this is part of my role., Employee of: Pfizer, Inc., Craig Beck Shareholder of: Pfizer, Inc., Employee of: Pfizer, Inc., Jerry Hall Shareholder of: Eli Lilly & Co., Employee of: Eli Lilly & Co., Patricia Schepman Shareholder of: Pfizer, Inc., Employee of: Pfizer, Inc.

A Handheld Metabolic Device (Lumen) to Measure Fuel Utilization in Healthy Young Adults: Device Validation Study

Background

Metabolic carts measure the carbon dioxide (CO₂) produced and oxygen consumed by an individual when breathing to assess metabolic fuel usage (carbohydrates versus fats). However, these systems are expensive, time-consuming, and only available in health care laboratory settings. A small handheld device capable of determining metabolic fuel usage via CO₂ from exhaled air has been developed.

Objective

The aim of this study is to evaluate the validity of a novel handheld device (Lumen) for measuring metabolic fuel utilization in healthy young adults.

Methods

Metabolic fuel usage was assessed in healthy participants (n=33; mean age 23.1 years, SD 3.9 years) via respiratory exchange ratio (RER) values obtained from a metabolic cart as well as % CO₂ from the Lumen device. Measurements were performed at rest in two conditions: fasting, and after consuming 150 grams of glucose, in order to determine changes in metabolic fuel usage. Reduced major axis regression and simple linear regression were performed to test for agreement between RER and Lumen % CO₂.

Results

Both RER and Lumen % CO₂ significantly increased after glucose intake (P<.001 for both) compared with fasting conditions, by 0.089 and 0.28, respectively. Regression analyses revealed an agreement between the two measurements (F_1,63=18.54; P<.001).

Conclusions

This study shows the validity of Lumen for detecting changes in metabolic fuel utilization in a comparable manner with a laboratory standard metabolic cart, providing the ability for real-time metabolic information for users under any circumstances.

Improved betulinic acid biosynthesis using synthetic yeast chromosome recombination and semi-automated rapid LC-MS screening

Synthetic biology, genome engineering and directed evolution offer innumerable tools to expedite engineering of strains for optimising biosynthetic pathways. One of the most radical is SCRaMbLE, a system of inducible in vivo deletion and rearrangement of synthetic yeast chromosomes, diversifying the genotype of millions of Saccharomyces cerevisiae cells in hours. SCRaMbLE can yield strains with improved biosynthetic phenotypes but is limited by screening capabilities. To address this bottleneck, we combine automated sample preparation, an ultra-fast 84-second LC-MS method, and barcoded nanopore sequencing to rapidly isolate and characterise the best performing strains. Here, we use SCRaMbLE to optimise yeast strains engineered to produce the triterpenoid betulinic acid. Our semi-automated workflow screens 1,000 colonies, identifying and sequencing 12 strains with between 2- to 7-fold improvement in betulinic acid titre. The broad applicability of this workflow to rapidly isolate improved strains from a variant library makes this a valuable tool for biotechnology.

[Palliative care of patients receiving opioid substitution therapy]

Patients with opioid use disorder survive longer and reach higher ages due to harm reduction and maintenance programs. Therefor and because of concomitant comorbidities there is an increased incidence of life-limiting diseases. Thus, increasing numbers of patients with opioid use disorder or in maintenance programs will require palliative care. However, both inpatient and outpatient service providers are uncertain about providing palliative care for these patients. Home-care teams and inpatient hospices have been known to refuse admission for patients with opioid use disorder. Providing medical care to patients receiving substitution therapy can be challenging because maintenance programs require strict compliance with their rules and regulations; however, an individualized approach with knowledge of basic legal requirements enables good palliative care. In this manner, it is possible to ensure healthcare for these aging patients.

[Psychological stressors, resources and well-being of surgeons in Germany : A cross-sectional study]

BACKGROUND

Psychological stress at work is associated with detrimental and health-impairing consequences for employees.

OBJECTIVE

In this study major stress factors and the resource job control at the workplace of surgeons and facets of mental health were examined and compared to benchmark results of a large reference sample.

METHOD

Data were collected by a representative online survey among surgeons throughout Germany who were contacted via the Professional Association of German Surgeons. In total 643 surgeons from different organizations and different disciplines completed the questionnaire that was developed using well-validated instruments.

RESULTS

Time pressure was the most meaningful stress factor for surgeons. Moreover, the results for medical assistants showed adverse stress combinations of high goal uncertainty and low job control as well as high emotional exhaustion and low job satisfaction. In addition, the results indicated that surgeons in single and group practices as well as in outpatient healthcare centers have less stressors and more job resources.

CONCLUSION

The survey results suggest high levels of burnout risk for German surgeons, especially among medical assistants and medical specialists from large hospitals. In order to maintain a high quality in the surgical disciplines, a concerted effort by all players in the healthcare system is necessary.

Ultra-broadband EPR spectroscopy in field and frequency domains

Electron paramagnetic resonance (EPR) is a powerful technique to investigate the electronic and magnetic properties of a wide range of materials.

Characterization of pharyngeal peristaltic pressure variability during volitional swallowing in healthy individuals

BACKGROUND

Recent technological advances incorporated in high resolution manometry have justifiably heightened interest in manometric evaluation of the pharynx. Despite this interest, from both physiologic and clinical perspective there remain a number of unanswered questions regarding the magnitude of variability of pharyngeal pressure phenomena. Therefore, the aim of the present study was to characterize in healthy individuals the inter-subject and recording-site specific variability of pharyngeal peristaltic pressure phenomena.

METHODS

We studied 32 healthy subjects (age: 21-83 years,20 under 35 years) during dry,5 and 10 mL water swallows ×3. Pharyngeal peristaltic pressures were recorded using a high resolution (HR) manometric system and a catheter assembly with 36 circumferential sensors spaced at 1 cm intervals positioned trans-nasally to traverse the pharynx, UES and proximal esophagus.

KEY RESULTS

Both site-specific pressure data and the Pharyngeal contractile integral (PhCI) showed wide dispersion ranging between values under 50 mm Hg to over 300 mm Hg and 100-600 mm Hg/cm/s,respectively. There was also wide range of dispersion of data for both the standard deviations and the coefficient of variation for all sites (P=.001). The coefficient of variation for PhCI ranged between 0.02 and 0.25 representing data dispersion of 2-25 percent of the mean among subjects (P=.001). Position, age and volume of swallowed fluid did not influence the magnitude of variability.

CONCLUSIONS

Deglutitive Pharyngeal peristalsis generates pressures with significant degree of site-related and inter-subject variability. This variability is not influenced by age, position and volume of swallowed fluid.

Survival and Complications of Single Dental Implants in the Edentulous Mandible Following Immediate or Delayed Loading: A Randomized Controlled Clinical Trial

It was the aim of this 24-mo randomized controlled clinical trial to investigate whether the survival of a single median implant placed in the edentulous mandible to retain a complete denture is not compromised by immediate loading. Secondary outcomes were differences in prosthetic complications between the loading principles. Each of the 158 patients who received an implant was randomly assigned to the immediate loading group (n = 81) or the delayed loading group (n = 77). Recall visits were performed 1 mo after implant placement (for only the delayed loading group) and 1, 4, 12, and 24 mo after implant loading. Nine implants failed in the immediate loading group, all within the first 3 mo of implant loading, and 1 implant failed in the delayed loading group prior to loading. Noninferiority of implant survival of the immediate loading group, as compared with the delayed loading group, could not be shown (P = 0.81). Consistent with this result, a secondary analysis with Fisher exact test revealed that the observed difference in implant survival between the treatment groups was indeed statistically significant (P = 0.019). The most frequent prosthetic complications and maintenance interventions in the mandible were retention adjustments, denture fractures, pressure sores, and matrix exchanges. There was only 1 statistically significant difference between the groups regarding the parameter “fracture of the denture base in the ball attachment area” (P = 0.007). The results indicate that immediate loading of a single implant in the edentulous mandible reveals inferior survival than that of delayed loading and therefore should be considered only in exceptional cases (German Clinical Trials Register: DRKS00003730).

Influence of Contamination on Zirconia Ceramic Bonding

The removal of contaminants prior to the bonding of ceramics is critical for the clinical success of a long-term durable resin bond. This study tested the null hypotheses that there are no contaminants on the zirconia ceramic surface left after try-in simulation, and there are no influences of contamination and cleaning methods on zirconia ceramic bonding durability with 10-methacryloyloxy-decyl dihydrogenphosphate-containing composite resins. After saliva immersion and the use of a silicone disclosing agent, airborne-particle-abraded ceramic specimens were cleaned with acetone, 36% phosphoric acid, additional airborne-particle abrasion, or only water spray. Chemical analyses of specimen surfaces were performed by x-ray photoelectron spectroscopy. The influences of contamination and cleaning methods on ceramic bond durability were examined by tensile testing after 3 or 150 days’ water storage with 37,500 thermal cycles. Contamination, existing after try-in simulation as confirmed by chemical analysis, significantly reduced zirconia ceramic-resin bonds. Airborne-particle abrasion may be the most effective cleaning method.

The effect of two doses of dried plum on bone density and bone biomarkers in osteopenic postmenopausal women: a randomized, controlled trial

Daily consumption of 50 g of dried plum (equivalent to 5-6 dried plums) for 6 months may be as effective as 100 g of dried plum in preventing bone loss in older, osteopenic postmenopausal women. To some extent, these results may be attributed to the inhibition of bone resorption with the concurrent maintenance of bone formation.

INTRODUCTION

The objective of our current study was to examine the possible dose-dependent effects of dried plum in preventing bone loss in older osteopenic postmenopausal women.

METHODS

Forty-eight osteopenic women (65-79 years old) were randomly assigned into one of three treatment groups for 6 months: (1) 50 g of dried plum; (2) 100 g of dried plum; and (3) control. Total body, hip, and lumbar bone mineral density (BMD) were evaluated at baseline and 6 months using dual-energy X-ray absorptiometry. Blood biomarkers including bone-specific alkaline phosphatase (BAP), tartrate-resistant acid phosphatase (TRAP-5b), high-sensitivity C-reactive protein (hs-CRP), insulin-like growth factor-1 (IGF-1), and sclerostin were measured at baseline, 3 months, and 6 months. Osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B ligand (RANKL), calcium, phosphorous, and vitamin D were measured at baseline and 6 months.

RESULTS

Both doses of dried plum were able to prevent the loss of total body BMD compared with that of the control group (P < 0.05). TRAP-5b, a marker of bone resorption, decreased at 3 months and this was sustained at 6 months in both 50 and 100 g dried plum groups (P < 0.01 and P < 0.04, respectively). Although there were no significant changes in BAP for either of the dried plum groups, the BAP/TRAP-5b ratio was significantly (P < 0.05) greater at 6 months in both dried plum groups whereas there were no changes in the control group.

CONCLUSIONS

These results confirm the ability of dried plum to prevent the loss of total body BMD in older osteopenic postmenopausal women and suggest that a lower dose of dried plum (i.e., 50 g) may be as effective as 100 g of dried plum in preventing bone loss in older, osteopenic postmenopausal women. This may be due, in part, to the ability of dried plums to inhibit bone resorption. This clinical trial was registered at ClinicalTrials.gov: NCT02325895 .

The influence of hydration state on thermoregulation during a 161-km ultramarathon

It is advised that individuals should avoid losing >2% of their body mass during exercise in order to prevent hyperthermia. This study sought to assess whether a loss of >2% body mass leads to elevations in core temperature during an ultramarathon. Thirty runners agreed to take part in the study. Body mass and core temperature were measured at the start, at three locations during the race and the finish. Core temperature was not correlated with percent body mass change (p = 0.19) or finish time (p = 0.11). Percent body mass change was directly associated with finish time (r = 0.58, p < 0.01), such that the fastest runners lost the most mass (~3.5-4.0%). It appears that a loss of >3% body mass does not contribute to rises in core temperature. An emphasis on fluid replacement for body mass losses of this magnitude during prolonged exercise is not justified as a preventative measure for heat-related illnesses.

The effect of brain injury on the inflammatory response following severe trauma

INTRODUCTION

The inflammatory response is an important part of the pathophysiology of severe injury and, in particular, of severe traumatic brain injury (TBI). This study evaluates the inflammatory course following major trauma and focuses on the effect of severe TBI on inflammatory markers.

MATERIAL AND METHODS

This was a retrospective analysis of prospectively collected data in 123 severely injured (ISS ≥16) trauma patients. The study cohort was divided into patients with isolated TBI (Head AIS ≥3, all other AIS <3), polytraumatized patients with severe TBI (Head AIS ≥3; AIS of other body area ≥3; Polytrauma+TBI) and polytraumatized patients without TBI (Head AIS <3; Polytrauma). Levels of inflammatory markers (Interleukin-6 [IL-6], C-reactive Protein [CRP], leukocytes) measured upon arrival and through hospital days 1-3 were compared between the groups.

RESULTS

On admission and through hospital day 3, IL-6 levels were significantly different between the 3 groups (admission: isolated TBI vs. Polytrauma+TBI vs. Polytrauma; 94±16 vs. 149±20 vs. 245±50pg/mL; p<0.05). Interleukin-6 levels peaked on hospital day 1 and declined thereafter. C-reactive protein and leukocyte counts were not significantly different between the cohorts on arrival and peaked on hospital day 2 and 1, respectively. In patients with severe TBI, admission IL-6 levels significantly predicted the development of septic complications (ROC analysis, AUC: 0.88, p=0.001, 95% CI: 0.79-0.97) and multiple organ dysfunction (ROC analysis, AUC: 0.83, p=0.001, 95% CI: 0.69-0.96).

CONCLUSION

Severe TBI reduced the inflammatory response following trauma. Significant correlations between admission IL-6 values and the development of MOF, sepsis and the neurological outcome were found in patients with TBI.

Mechanical resistance of the periorbita and the orbital floor complex--are isolated orbital floor fractures only a soft tissue problem?

The primary aims of orbital floor reconstruction are to prevent enophthalmos and herniation of the orbital contents in order to achieve correct globe position. Theoretically, the mechanical load of the orbital floor is approximately 0.0005N/mm(2) (30g orbital content onto 600mm(2) of orbital floor area). Therefore, low mechanical stress from orbital floor reconstruction materials is expected. The periorbita and orbital floor complex (bony orbital floor with periorbita) of 12 human cadavers were investigated for their mechanical resistance to distortion and compared to different absorbable pliable reconstruction materials after modification with pores (Bio-Gide, Creos, and PDS). The human periorbita resistance (approximately 1.4N/mm(2)) was comparable to that of the absorbable membranes (Creos, Bio-Gide), and the resistance of PDS (approximately 2.3N/mm(2)) was comparable to that of the orbital floor complex. The periorbita has a higher stability than the bony orbital floor. Therefore, in isolated orbital floor fractures with a traumatized bony orbital floor and periorbita, reconstruction of the soft tissue as a periorbita equivalent with a resorbable membrane appears to be adequate to prevent enophthalmos and herniation of the orbital contents.

Mechanical properties of collagen membranes modified with pores--are they still sufficient for orbital floor reconstruction?

Adequate mechanical strength is essential for materials used to reconstruct the orbital floor, and collagen membranes have recently been suggested for the repair of isolated fractures of the orbital floor. However, their mechanical properties after modification with pores for increased drainage of blood into the sinus have not been sufficiently investigated. We have tested the mechanical resistance of polydioxanone foils (PDS) to distortion and compared it with that of 3 resorbable collagen membranes (Smartbrane(®), Bio-Gide(®), and Creos(®)) in mint condition and when artificially aged (3 weeks, 6 weeks, and 8 weeks) after modification with pores (diameter 2mm) in a standard configuration (n=12 in each group). PDS and Creos(®) had comparable initial values for mechanical resistance of about 2.3N/mm(2), and Bio-Gide(®) and Smartbrane(®) had about 20% and 80% lower initial mechanical resistance, respectively. All materials tested had lower values after artificial ageing. After eight weeks of ageing, PDS lost about 99% of its initial mechanical resistance, Creos(®) about 66%, Bio-Gide(®) about 30%, and Smartbrane(®) about 95%. After 3 weeks the mechanical resistance in all groups was significantly less than the initial values (p=0.05), but there was no difference between samples aged artificially for 6 compared with 8 weeks. The mechanical resistance of the tested materials was not influenced by the presence of pores in a standard configuration and was in the appropriate range for moderate fractures of the orbital floor. We recommend further clinical investigations of collagen membranes modified with pores.

Autophagy in adipose tissue of patients with obesity and type 2 diabetes

BACKGROUND

Pathophysiology of obesity is closely associated with enhanced autophagy in adipose tissue (AT). Autophagic process can promote survival or activate cell death. Therefore, we examine the occurrence of autophagy in AT of type 2 diabetes (T2D) patients in comparison to obese and lean individuals without diabetes.

METHODOLOGY/PRINCIPAL FINDINGS

Numerous autophagosomes accumulated within adipocytes were visualized by electron transmission microscopy and by immunofluorescence staining for autophagy marker LC3 in obese and T2D patients. Increased autophagy was demonstrated by higher LC3-II/LC3-I ratio, up-regulated expression of LC3 and Atg5 mRNA, along with decreased p62 and mTOR protein levels. Increased autophagy occurred together with AT inflammation.

CONCLUSIONS

Our data suggest fat depot-related differences in autophagy regulation. In subcutaneous AT, increased autophagy is accompanied by increased markers of apoptosis in patients with obesity independently of T2D. In contrast, in visceral AT only in T2D patients increased autophagy was related to higher markers of apoptosis.

Detection of the genial spinal canal in atrophic mandibles with a CBCT: a cadaver study

OBJECTIVES

The use of a single midline implant to retain a complete mandibular denture when more implants cannot be used is an incipient treatment modality. However, in the mandibular symphysis, the genial spinal canal (GSC) is an anatomical structure with neurovascular content that can be harmed during dental implant surgery. The purpose of the present study was to use CBCT of edentulous atrophic cadaver mandibles and evaluate how often the simulated placement of a single midline implant would contact the GSC if present.

METHODS

CBCT scans of 47 edentulous cadaver mandibles were performed. A digital simulation of the placement of a single midline implant (3.8 × 11.0 mm) was performed, and the implant-GSC contact was evaluated.

RESULTS

A GSC was detected in the CBCT scan of all atrophic mandibles. In 42 cases (89.4%), the single midline implant contacted the GSC. On average, the five cases without GSC contact had a higher alveolar ridge (4.1 mm) and a lower GSC (0.79 mm) than did the cases with GSC contact.

CONCLUSIONS

CBCT scans can adequately detect the GSC during pre-surgical diagnostics. There is a high risk of implant-GSC contact during surgery of the anterior mandible. However, the clinical relevance of such a contact is not known yet, because none of the clinical studies evaluating a single midline implant has reported any implant-GSC contact-related complications.