Cost and complications associated with implant-supported overdentures with a resilient-attachment system: A retrospective study.

STATEMENT OF PROBLEM: Implant-supported overdentures with a splinted or nonsplinted attachment system have been a successful treatment option for edentulous mandibles with excessive hard tissue resorption. Currently, the 2 most common treatment approaches for an implant overdenture uses either a bar attachment system (splinted) or resilient (LOCATOR)-attachment system (nonsplinted). The LOCATOR-attachment system is often chosen for the lower initial cost. However, whether the ongoing maintenance costs of the LOCATOR-attachment system increase the overall cost of this system is unclear. PURPOSE: The purpose of this retrospective study was to investigate the frequency of maintenance procedures, complications, and costs associated with the LOCATOR-supported overdenture treatment. MATERIAL AND METHODS: The retrospective data of 75 patients who had received implant-supported overdentures with LOCATOR-attachments at the University of Colorado School of Dental Medicine in the previous 10 years were collected and screened to evaluate the number of maintenance visits, type of complications, and cost (actual fees for the service) of the maintenance visits. The data were analyzed, and the mean values calculated. RESULTS: The average number of maintenance visits was 7.7 in the mean observation time of 5.2 years. Replacement of the attachment was the most frequent complication (63%). The average maintenance cost charged to the patient for maintenance was 56.2% ($795) of the initial cost over the average 5.2 years of follow-up. The average total maintenance cost (actual fees for the service) was 95.4% ($1349) of the initial cost over the average of 5.2 years of follow-up. The average maintenance cost adjusted or lost over the 5.2 years follow-up was 39.2%. CONCLUSIONS: The 5-year costs for the maintenance of mandibular overdentures with a LOCATOR-attachment system were equal to or higher than the initial cost of the treatment. The number of maintenance visits and the cost were higher for patients who were older than 75 years.

Comparative Accuracy of Facial Models Fabricated Using Traditional and 3D Imaging Techniques.

PURPOSE: The purpose of this investigation was to compare the accuracy of facial models fabricated using facial moulage impression methods to the three-dimensional printed (3DP) fabrication methods using soft tissue images obtained from cone beam computed tomography (CBCT) and 3D stereophotogrammetry (3D-SPG) scans. MATERIALS AND METHODS: A reference phantom model was fabricated using a 3D-SPG image of a human control form with ten fiducial markers placed on common anthropometric landmarks. This image was converted into the investigation control phantom model (CPM) using 3DP methods. The CPM was attached to a camera tripod for ease of image capture. Three CBCT and three 3D-SPG images of the CPM were captured. The DICOM and STL files from the three 3dMD and three CBCT were imported to the 3DP, and six testing models were made. Reversible hydrocolloid and dental stone were used to make three facial moulages of the CPM, and the impressions/casts were poured in type IV gypsum dental stone. A coordinate measuring machine (CMM) was used to measure the distances between each of the ten fiducial markers. Each measurement was made using one point as a static reference to the other nine points. The same measuring procedures were accomplished on all specimens. All measurements were compared between specimens and the control. The data were analyzed using ANOVA and Tukey pairwise comparison of the raters, methods, and fiducial markers. RESULTS: The ANOVA multiple comparisons showed significant difference among the three methods (p < 0.05). Further, the interaction of methods versus fiducial markers also showed significant difference (p < 0.05). The CBCT and facial moulage method showed the greatest accuracy. CONCLUSIONS: 3DP models fabricated using 3D-SPG showed statistical difference in comparison to the models fabricated using the traditional method of facial moulage and 3DP models fabricated from CBCT imaging. 3DP models fabricated using 3D-SPG were less accurate than the CPM and models fabricated using facial moulage and CBCT imaging techniques.

The use of a laser-level paralleling device for the fabrication of a unilateral auricular prosthesis.

This article describes the use of a laser-level paralleling device for the fabrication of a unilateral auricular prosthesis. Traditional methods require use of calipers to obtain orientation of contralateral auricular anatomy, which in turn can be difficult to replicate on the patient. The purpose of this clinical report is to describe a simple means to record unilateral auricular anatomy.

An investigation of heat transfer to the implant-bone interface when drilling through a zirconia crown attached to a titanium or zirconia abutment.

STATEMENT OF PROBLEM: Thermal injury to the implant-bone interface may lead to bone necrosis and loss of osseointegration. This is a concern during manipulation of the implant throughout the restorative phase of treatment. The risk of heat transfer to the implant-bone interface during abutment preparation or prosthesis removal should be considered. PURPOSE: The purpose of the study was to examine the amount of heat transferred to the implant-bone interface when a zirconia crown is drilled to access the screw channel or section a crown with a high-speed dental handpiece. MATERIAL AND METHODS: Of the 64 ceramic-veneered zirconia crowns fabricated, 32 had a coping thickness of 0.5 mm and 32 had a coping thickness of 1.0 mm. The crowns were cemented on either titanium stock abutments or zirconia stock abutments. Each group was further subdivided to evaluate heat transfer when the screw channel was accessed or the crown was sectioned with a high-speed handpiece with or without irrigation. Temperature change was recorded for each specimen at the cervical and apical aspect of the implant with thermocouples and a logging thermometer. ANOVA was used to assess the statistical significance in temperature change between the test combinations, and nonparametric Mann-Whitney U tests were used to evaluate the findings. RESULTS: The use of irrigation during both crown removal processes yielded an average temperature increase of 3.59 ±0.35°C. Crown removal in the absence of irrigation yielded an average temperature increase of 18.76 ±3.09°C. When all parameter combinations in the presence of irrigation were evaluated, the maximum temperature change was below the threshold of thermal injury to bone. The maximum temperature change was above the threshold for thermal injury at the coronal aspect of the implant and below the threshold at the apical aspect in the absence of irrigation. CONCLUSIONS: Within the limitations of this investigation, the use of irrigation with a high-speed dental handpiece to remove a ceramic-veneered zirconia crown results in a temperature increase at the implant-bone interface insufficient to cause irreversible damage. Conversely, a lack of irrigation may yield a temperature increase capable of producing irreversible damage at the coronal aspect of the implant.

Product labeling accuracy and contamination analysis of commercially available cannabidiol product samples.

Background and objective: Commercially available cannabidiol (CBD) products are increasingly being used for medicinal purposes, including for the treatment of various neurological conditions, but there are growing concerns around adherence to quality control measures that protect consumers. This study was conducted to assess the purity and label accuracy of commercially available CBD products. Methods: Commercially available CBD products were chosen from the open stream of commerce in the United States based on formulations as a tincture, gummy, vape, or topical product. Cannabinoid concentrations were analyzed to verify label accuracy including "full spectrum," "broad spectrum," and "CBD isolate" claims on the product label. Analysis for the presence of contaminants included evaluation for heavy metals, pesticides, and residual solvents. Labeled and actual total amounts of CBD and levels of impurities such as heavy metals, residual solvents, and pesticides were measured. Results: A total of 202 CBD products (100 tinctures, 48 gummies, 34 vape products, and 20 topicals) were chosen to represent a broad sample in the United States. Of the products tested (full spectrum, n = 84; broad spectrum, n = 28; CBD isolate, n = 37), 26% did not meet the definition for product type claimed on the packaging. The majority of products (74%) deviated from their label claim of CBD potency by at least 10%. Heavy metals were detected 52 times across 44 of the 202 products tested, with lead being the most prevalent heavy metal. Residual solvents were detected 446 times across 181 of 202 products, with the highest concentrations reported for hexane, m/p-xylene, methanol, and o-xylene. Of 232 pesticides tested, 26 were found 55 times across 30 products. A total of 3% of heavy metals, 1% of residual solvents, and 1% of pesticides violated >1 regulatory threshold. Discussion: This study demonstrated that the majority of commercially available CBD products tested within the current study are inaccurately labeled. Heavy metals, residual solvents, and pesticides were found in several products, some of which violated regulatory thresholds. Thus, uniform compliance with CBD quality control measures is lacking and raises consumer protection concerns. Improved regulatory oversight of this industry is recommended.

Reliable and repeatable centric relation adjustment of the maxillary occlusal device.

This technique article describes a quantifiable, repeatable, and reliable method for occlusal device adjustment in centric relation using a leaf gauge. In addition, specific suggestions for occlusal device design are provided to enhance patient comfort with the prosthesis in place.

One-way valved speech bulb obturator using a tracheoesophageal prosthesis.

This article describes the fabrication procedures to create a one-way valved speech bulb obturator.

The Ultrasound-guided Anteromedial Joint Line Approach: A Targeted Corticosteroid Injection Technique for Patients With Medial Knee Pain.

BACKGROUND: Medial knee pain is a common complaint in the adult population. When conservative measures fail, intraarticular knee corticosteroid injections are often offered through the superolateral approach into the suprapatellar recess to provide short-term relief. However, some patients fail to respond and require alternative approaches. The anteromedial joint line (AMJL) approach, which targets the medial compartment, may be more effective when pain-generating pathologies such as synovitis are located in the medial compartment. To date, there have been no dedicated studies evaluating ultrasound-guided (USg) corticosteroid injections through the AMJL approach to reduce medial knee pain. OBJECTIVES: The current study aims to assess the clinical characteristics, ultrasound findings, and clinical outcomes for patients with medial knee pain who received USg corticosteroid injections via the AMJL approach. STUDY DESIGN: Retrospective study. SETTING: This study took place at one academic musculoskeletal ultrasound clinic at an urban tertiary care center. METHODS: Sixty-five patients (76 knees; 11 patients with bilateral injections) with medial knee pain who had received USg-AMJL corticosteroid injections from January 2016 through  March 2020 were reviewed for inclusion. Baseline demographic information and clinical characteristics from one year prior to 6 months following USg-AMJL injection were analyzed for each patient. Responders were defined as those who reported pain relief, decreased usage of analgesic medications, or increased physical activity. Nonresponders  were defined as those not meeting any of the responder endpoints. RESULTS: Within one year prior to receiving a USg-AMJL injection, 51.3% (39/76 knees) had attempted superolateral knee injections without relief. Immediately following a USg-AMJL injection, 98.7% (75/76) experienced symptomatic relief. Follow-up visits took place on average at 11 weeks postinjection with 92.3% (60/65 patients) responding positively. In comparison to the responder group, the nonresponder group had a significantly older mean age (P = 0.009), lower mean body mass index (P = 0.007), and higher burden of morbidities as measured by the Charlson Comorbidity Index (P = 0.044). One patient reported a steroid flare within one week of injection. The most common diagnoses contributing to medial knee pain for these patients were osteoarthritis, medial meniscal injury, crystal arthropathy, and medial collateral ligament injury, which were supported by point-of-care ultrasound findings. LIMITATIONS: This study was limited by its sample size and retrospective observational design. CONCLUSIONS: USg AMJL injection is a safe and effective procedure for targeting medial knee pain, particularly in the settings of obesity and prior failed superolateral and suprapatellar knee injections. Further investigation is required to assess long-term clinical outcomes of this injection approach.

Clinical and cost-effectiveness of bracing in symptomatic knee osteoarthritis management: protocol for a multicentre, primary care, randomised, parallel-group, superiority trial.

BACKGROUND: Brace effectiveness for knee osteoarthritis (OA) remains unclear and international guidelines offer conflicting recommendations. Our trial will determine the clinical and cost-effectiveness of adding knee bracing (matched to patients' clinical and radiographic presentation and with adherence support) to a package of advice, written information and exercise instruction delivered by physiotherapists. METHODS AND ANALYSIS: A multicentre, pragmatic, two-parallel group, single-blind, superiority, randomised controlled trial with internal pilot and nested qualitative study. 434 eligible participants with symptomatic knee OA identified from general practice, physiotherapy referrals and self-referral will be randomised 1:1 to advice, written information and exercise instruction and knee brace versus advice, written information and exercise instruction alone. The primary analysis will be intention-to-treat comparing treatment arms on the primary outcome (Knee Osteoarthritis Outcomes Score (KOOS)-5) (composite knee score) at the primary endpoint (6 months) adjusted for prespecified covariates. Secondary analysis of KOOS subscales (pain, other symptoms, activities of daily living, function in sport and recreation, knee-related quality of life), self-reported pain, instability (buckling), treatment response, physical activity, social participation, self-efficacy and treatment acceptability will occur at 3, 6, and 12 months postrandomisation. Analysis of covariance and logistic regression will model continuous and dichotomous outcomes, respectively. Treatment effect estimates will be presented as mean differences or ORs with 95% CIs. Economic evaluation will estimate cost-effectiveness. Semistructured interviews to explore acceptability and experiences of trial interventions will be conducted with participants and physiotherapists delivering interventions. ETHICS AND DISSEMINATION: North West Preston Research Ethics Committee, the Health Research Authority and Health and Care Research in Wales approved the study (REC Reference: 19/NW/0183; IRAS Reference: 247370). This protocol has been coproduced with stakeholders including patients and public. Findings will be disseminated to patients and a range of stakeholders. TRIAL REGISTRATION NUMBER: ISRCTN28555470.

Laser-welded hollow pontic full-gold fixed dental prosthesis.

This article describes a technique for the fabrication of a laser-welded hollow pontic full-gold fixed dental prosthesis. Reference to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government. The opinions of the authors expressed herein do not necessarily state or reflect those of the U.S. Government, and shall not be used for advertising or product endorsement purposes.

Epidemiology, Mechanical Power, and 3-Year Outcomes in Acute Respiratory Distress Syndrome Patients Using Standardized Screening. An Observational Cohort Study.

Rationale: Limited data on the epidemiology of acute respiratory distress syndrome (ARDS) using a standardized screening program exist.Objectives: To describe the population-based incidence of hypoxemic respiratory failure and ARDS using a prospective standardized screening protocol; and to describe the mechanical ventilation practice and the mechanical power and examine their association with 28-day and 3-year survival outcomes.Methods: A prospective standardized screening program for ARDS, as a quality improvement initiative, was initiated at four adult intensive care units over a 27-month period. An ancillary analysis of this observational cohort was performed. Patients requiring mechanical ventilation for ≥24 hours underwent prospective and consecutive screening using standardized ventilator settings. Patient physiological data and outcomes were collected prospectively through an electronic clinical-information system and retrospectively analyzed to apply Berlin criteria.Results: Screened were 7,944 patients, among which 986 (12.4%) had hypoxemic respiratory failure (arterial oxygen tension to inspired fraction of oxygen ratio ≤300), and 731 (9.2%) met criteria for ARDS. Age-adjusted incidence of hypoxemic respiratory failure and ARDS were 37.7 and 27.6 cases per 100,000 person-years, respectively. Patients sustaining the diagnosis of ARDS had a hospital mortality of 26.5% for mild, 31.8% for moderate, and 60.0% for severe ARDS and a 3-year mortality of 43.5% for mild, 46.9% for moderate, and 71.1% for severe ARDS. Mechanical power >22 J/min was associated with increased 28-day hospital and 3-year mortality. Determinants of mechanical power associated with lower 28-day hospital and 3-year survival included plateau pressure >30 cm H2O and driving pressure >15 cm H2O, but not tidal volumes >8 ml/kg of predicted body weight.Conclusions: Using standardized screening, a large proportion of patients with hypoxemic respiratory failure met criteria for ARDS. Increasing ARDS severity was associated with increased 28-day hospital and 3-year mortality. Increased mechanical power was associated with increased mortality. Potentially modifiable determinants of mechanical power associated with lower survival included plateau pressure and driving pressure.

Phytochemical and genetic analyses of ancient cannabis from Central Asia.

The Yanghai Tombs near Turpan, Xinjiang-Uighur Autonomous Region, China have recently been excavated to reveal the 2700-year-old grave of a Caucasoid shaman whose accoutrements included a large cache of cannabis, superbly preserved by climatic and burial conditions. A multidisciplinary international team demonstrated through botanical examination, phytochemical investigation, and genetic deoxyribonucleic acid analysis by polymerase chain reaction that this material contained tetrahydrocannabinol, the psychoactive component of cannabis, its oxidative degradation product, cannabinol, other metabolites, and its synthetic enzyme, tetrahydrocannabinolic acid synthase, as well as a novel genetic variant with two single nucleotide polymorphisms. The cannabis was presumably employed by this culture as a medicinal or psychoactive agent, or an aid to divination. To our knowledge, these investigations provide the oldest documentation of cannabis as a pharmacologically active agent, and contribute to the medical and archaeological record of this pre-Silk Road culture.

Odor and gas release from anaerobic treatment lagoons for swine manure.

Odor and gas release from anaerobic lagoons for treating swine waste affect air quality in neighboring communities but rates of release are not well documented. A buoyant convective flux chamber (BCFC) was used to determine the effect of lagoon loading rate on measured odor and gas releases from two primary lagoons at a simulated wind speed of 1.0 m s(-1). Concentrations of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) in 50-L air samples were measured. A panel of human subjects, whose sensitivity was verified with a certified reference odorant, evaluated odor concentration, intensity, and hedonic tone. Geometric mean odor concentrations of BCFC inlet and outlet samples and of downwind berm samples were 168 +/- 44 (mean +/- 95% confidence interval), 262 +/- 60, and 114 +/- 38 OU(E) m(-3) (OU(E), European odor unit, equivalent to 123 microg n-butanol), respectively. The overall geometric mean odor release was 2.3 +/- 1.5 OU(E) s(-1) m(-2) (1.5 +/- 0.9 OU s(-1) m(-2)). The live mass specific geometric mean odor release was 13.5 OU(E) s(-1) AU(-1) (animal unit = 500 kg live body mass). Overall mean NH3, H2S, CO2 and SO2 releases were 101 +/- 24, 5.7 +/- 2.0, 852 +/- 307, and 0.5 +/- 0.4 microg s(-1) m(-2), respectively. Nitric oxide was not detected. Odor concentrations were directly proportional to H2S and CO2 concentrations and odor intensity, and inversely proportional to hedonic tone and SO2 concentration (P < 0.05). Releases of NH3, H2S, and CO2 were directly proportional (P < 0.05) to volatile solids loading rate (VSLR).

Novel magnet-retained prosthetic system for facial reconstruction.

Traumatic facial defects negatively impact speech, mastication, deglutition, dental hygiene, and psychosocial well-being. Reconstruction must address restoration of function and aesthetics to provide quality of life. This report describes soft-tissue reconstruction using a novel magnet-retained facial prosthesis without osseointegrated abutments, performed in a patient after traumatic loss of the entire left lower part of the face, including lips, commissure, and mentum. This reconstructive technique successfully addressed the cosmetic defect while also restoring function with respect to speech and oral nutrition. For this reason, magnet-retained facial prosthesis should be added to free tissue transfer and regional flaps as a reasonable option in the reconstructive algorithm for complex soft-tissue defects of the lower face.

Effect of swine manure dilution on ammonia, hydrogen sulfide, carbon dioxide, and sulfur dioxide releases.

Animal manure is a significant source of environmental pollution and manure dilution in barn cleaning and slurry storage is a common practice in animal agriculture. The effect of swine manure dilution on releases of four pollutant gases was studied in a 30-day experiment using eight manure reactors divided into two groups. One group was treated with swine manure of 6.71% dry matter and another with manure diluted with water to 3.73% dry matter. Ammonia release from the diluted manure was 3.32 mg min(-1)m(-2) and was 71.0% of the 4.67 mg min(-1)m(-2) from the undiluted manure (P<0.01). Because the ammonia release reduction ratio was lower than the manure dilution ratio, dilution could increase the total ammonia emissions from swine manure, especially in lagoons with large liquid surface areas. Carbon dioxide release of 87.3 mg min(-1)m(-2) from the diluted manure was 56.4% of the 154.8 mg min(-1)m(-2) from the undiluted manure (P<0.01). Manure dry matter was an important factor for carbon dioxide release from manure. No differences were observed between the treatments (P>0.05) for both hydrogen sulfide and sulfur dioxide releases. Therefore, dilution could also significantly increase the total releases of hydrogen sulfide and sulfur dioxide to the environment because dilution adds to the total manure volume and usually also increases the total gas release surface area.

Fabrication of a functionally generated, implant-retained fixed partial denture.

Partially edentulous patients are frequently restored with implant-supported restorations between and opposing natural teeth. Differences in horizontal and vertical mobility of teeth and dental implants necessitate occlusal contact modification to create prostheses that harmonize with the opposing dentition. This article describes a functionally generated path technique to achieve optimal articulation between an implant-retained fixed partial denture and the patient's dentition.