The precision of drill calibration for dynamic navigation.

OBJECTIVES: To quantify the reproducibility of the drill calibration process in dynamic navigation guided placement of dental implants and to identify the human factors that could affect the precision of this process in order to improve the overall implant placement accuracy. METHODS: A set of six drills and four implants were calibrated by three operators following the standard calibration process of NaviDent® (ClaroNav Inc.). The reproducibility of the position of each tip of a drill or implant was calculated in relation to the pre-planned implants' entry and apex positions. Intra- and inter-operator reliabilities were reported. The effects of the drill length and shape on the reproducibility of the calibration process were also investigated. The outcome measures for reproducibility were expressed in terms of variability range, average and maximum deviations from the mean distance. RESULTS: A satisfactory inter-rater reproducibility was noted. The precision of the calibration of the tip position in terms of variability range was between 0.3 and 3.7 mm. We noted a tendency towards a higher precision of the calibration process with longer drills. More calibration errors were observed when calibrating long zygomatic implants with non-locking adapters than with pointed drills. Flexible long-pointed drills had low calibration precision that was comparable to the non-flexible short-pointed drills. CONCLUSION: The clinicians should be aware of the calibration error associated with the dynamic navigation placement of dental and zygomatic implants. This should be taken in consideration especially for long implants, short drills, and long drills that have some degree of flexibility. CLINICAL SIGNIFICANCE: Dynamic navigation procedures are associated with an inherent drill calibration error. The manual stability during the calibration process is crucial in minimising this error. In addition, the clinician must never ignore the prescribed accuracy checking procedures after each calibration process.

The Accuracy of Intraoral Registration for Dynamic Surgical Navigation in the Edentulous Maxilla.

PURPOSE: Despite the high clinical accuracy of dynamic navigation, inherent sources of error exist. The purpose of this study was to improve the accuracy of dynamic navigated surgical procedures in the edentulous maxilla by identifying the optimal configuration of intra-oral points that results in the lowest possible registration error for direct clinical implementation. MATERIALS AND METHODS: Six different 4-area configurations were tested by 3 operators against positive and negative controls (8-areas and 3-areas, respectively) using a skull model. The two dynamic navigation systems (X-Guide® and NaviDent®) and the two registration methods (bone surface tracing and fiducial markers) produced four registration groups. The accuracy of the registration was checked at the frontal process of the zygoma. Intra- and inter- operator reliability for each registration group were reported. Multiple comparisons were conducted to find the best configuration with the minimum registration error. RESULTS: Ranking revealed one configuration in the tracing groups (Conf.3) and two configurations in the fiducial groups (Conf.3 and Conf.5) that had the best accuracy. When the inferior surfaces of the zygomatic buttress were excluded, fiducial registration produced better accuracy with both systems (p 0.006 and <0.0001). However, tracing 1 cm areas at these surfaces bilaterally resulted in similar registration accuracy as placing fiducial markers there (p 0.430 and 0.237). NaviDent® performed generally better (p 0.049, 0.001 and 0.002) albeit having a wider margin of uncertainty in the obtained values. Changing the distribution of the 4 tracing areas or fiducial markers had a less pronounced effect with X-Guide® than with the NaviDent® system. CONCLUSION: For edentulous maxillary surgeries, 4 fiducial markers placed according to configuration 3 or 5 result in the lowest registration error. Where implants are being placed bilaterally, an additional 2 sites may reduce the error further. For bilateral zygomatic implant placement, it is optimal to place 2 fiducials on the inferior surfaces of the maxillary tuberosities, other 2 on their buccal surfaces, and 2 on the anterior labial surface of the alveolar bone. Utilising the inferior zygomatic buttress is recommended over the inferior maxillary tuberosities in other types of maxillary surgeries.

Radiographic bone loss in a Scottish non-smoking type 1 diabetes mellitus population: A bitewing radiographic study.

BACKGROUND: The dental complications of uncontrolled diabetes include reduced salivary flow rate, candidiasis and periodontal manifestations. A recent meta-analysis concluded that diabetes patients have a significantly higher severity, but not extent, of destructive periodontal disease than non-diabetics. The authors reported that most type-1 diabetes studies using dental radiographic data have not controlled for confounding factors such as smoking. The aim of this cross-sectional study was to compare radiographic alveolar bone loss between type 1 diabetes (T1DM) and non-diabetes (NDM) participants in a Scottish non-smoking population. METHODS: Digital bitewing radiographs for 174 Scottish adults never or ex-smoker (>5 years) participants (108 T1DM, 66 NDS), recruited from outpatient clinics throughout Greater Glasgow and Clyde, were included in the analysis. A single blinded, trained, and calibrated examiner recorded the radiographic bone loss seen on bitewing radiographs using the digital screen caliper (Screen Calliper ICONICO version 4.0 (Copyright (C) 2001-6 Iconico), New York). The bone loss was measured as the distance between the cemento-enamel junction (CEJ) and the deepest radiographic alveolar bone margin interproximally of each tooth. RESULTS: T1DM participants had more radiographic alveolar bone loss throughout the all teeth measured (median:1.27 mm versus 1.06 mm, P < 0.001) and more than a two-fold increase in the risk of having sites with ≥2 mm periodontal destruction (OR = 2.297, 95%CI 1.058 to 4.986, P = 0.036) compared with non-diabetes subjects. CONCLUSIONS: Patients suffering from type 1 diabetes are at higher risk of periodontitis even when controlling for multiple possible confounding factors and this difference can be detected on routine dental radiographs at an early stage. These data confirm radiographically the previously reported association between T1DM and periodontal bone loss.

Emerging Impact of Malnutrition on Surgical Patients: Literature Review and Potential Implications for Cystectomy in Bladder Cancer.

PURPOSE: Malnutrition is emerging as a significant factor in patient outcomes. A contemporary review of malnutrition has not been performed for the urologist. We review the available literature and current standards of care for malnutrition screening, assessment and intervention, focusing on patients with bladder cancer treated with cystectomy. MATERIALS AND METHODS: Our multidisciplinary team searched PubMed® for available literature on malnutrition, focusing on definition and significance, importance to urologists, screening, assessment, diagnosis, immunological and economic impacts, and interventions. RESULTS: The prevalence of malnutrition in hospitalized patients is estimated to range from 15% to 60%, reaching upward of 71% in those with cancer. Malnutrition has been shown to increase inflammatory markers, further intensifying catabolism and weight loss. Bladder cancer is catabolic and patients undergoing cystectomy have increased resting energy expenditure postoperatively. Data are emerging on the impact of malnutrition in the cystectomy population. Recent studies have identified poor nutritional status based on low albumin or sarcopenia (loss of muscle) as having an adverse impact on length of hospitalization, complications and survival. The current standard of care malnutrition assessment tool, the 2012 consensus statement of the Academy of Nutrition and Dietetics and the American Society for Parenteral and Enteral Nutrition, has not been evaluated in the urological literature. Perioperative immunonutrition in patients undergoing colorectal surgery has been associated with significant decreases in postoperative complications, and recent pilot work has identified the potential for immunonutrition to positively impact the cystectomy population. CONCLUSIONS: Malnutrition has a significant impact on surgical patients, including those with bladder cancer. There are emerging data in the urological literature regarding how best to identify and improve the nutritional status of patients undergoing cystectomy. Additional research is needed to identify malnutrition in these patients and interventions to improve surgical outcomes.

Dentures are a Reservoir for Respiratory Pathogens.

PURPOSE: Recent studies have established a relationship between dental plaque and pulmonary infection, particularly in elderly individuals. Given that approximately one in five adults in the UK currently wears a denture, there remains a gap in our understanding of the direct implications of denture plaque on systemic health. The aim of this study was to undertake a comprehensive evaluation of putative respiratory pathogens residing upon dentures using a targeted quantitative molecular approach. MATERIALS AND METHODS: One hundred and thirty patients' dentures were sonicated to remove denture plaque biofilm from the surface. DNA was extracted from the samples and was assessed for the presence of respiratory pathogens by quantitative polymerase chain reaction (qPCR). Ct values were then used to approximate the number of corresponding colony forming equivalents (CFEs) based on standard curves. RESULTS: Of the dentures, 64.6% were colonized by known respiratory pathogens. Six species were identified: Streptococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, Haemophilus influenzae B, Streptococcus pyogenes, and Moraxella catarrhalis. P. aeruginosa was the most abundant species followed by S. pneumoniae and S. aureus in terms of average CFE and overall proportion of denture plaque. Of the participants, 37% suffered from denture stomatitis; however, there were no significant differences in the prevalence of respiratory pathogens on dentures between healthy and inflamed mouths. CONCLUSIONS: Our findings indicate that dentures can act as a reservoir for potential respiratory pathogens in the oral cavity, thus increasing the theoretical risk of developing aspiration pneumonia. Implementation of routine denture hygiene practices could help to reduce the risk of respiratory infection among the elderly population.

Commercial mouthwashes are ineffective against oral MRSA biofilms.

OBJECTIVE: The aim of this study was to evaluate and compare the activity of oral mouthwashes against biofilm forms of MRSA isolated from the oral cavity and the bloodstream. STUDY DESIGN: The time-kill kinetics efficacy of 7 over-the-counter mouthwashes were tested against 28 clinical MRSA biofilm isolates for 0.5, 1 and 2 min. RESULTS: Treatments of MRSA biofilms formed by oral and bloodstream isolates were not significantly different, with mouthwashes displaying a rapid and modest anti-biofilm effect. None of the biofilm isolates were completely eradicated by the compounds tested, with a maximal killing of only approximately 70% shown by Corsodyl and Peroxyl. Maximum activity of all compounds tested was observed after 0.5 min. Fluorigard showed the poorest overall activity (57% reduction). CONCLUSIONS: MRSA colonize the oral cavity, and are more prevalent in institutionalized persons and the elderly. Over-the-counter mouthwashes are ineffective at killing MRSA biofilms, which has infection control implications.

Hydrolytic enzyme production is associated with Candida albicans biofilm formation from patients with type 1 diabetes.

Oral candidosis is common in patients with diabetes mellitus, as yeasts, particularly Candida albicans, have the propensity to colonise, form biofilms and release hydrolytic enzymes which cause inflammation. This study aimed to investigate these characteristics in isolates from three groups of patients with type 1 diabetes: individuals with better controlled diabetes (BCD; >or=6 <8%), individuals with poorly controlled diabetes (PCD; >or=8%) and non-diabetics (ND; HbA(1c) <5.9%). The biomass (Bm), phospholipase (P(z)), haemolysin (H(z)) and proteinase (Pr(z)) were assessed using a microtitre biofilm assay and agar-based hydrolytic enzyme assays. Biofilm formation was significantly increased in the PCD group compared to ND and BCD groups (P < 0.05). No significant differences in P(z) levels were observed between groups, whereas both H(z) and Pr(z) were significantly greater in the diabetes groups than in the healthy control group (P < 0.05). Statistically significant correlations were found to exist between the HbA(1c) levels of the patients and the Bm (R = 0.384; P = 0.033), haemolysin activity (R = -0.455; P = 0.010) and proteinase activity (R = -0.531; P = 0.002). There was no apparent correlation between the Bm and P(z) activity (R = -0.305; P = 0.053) or H(z) activity (R = -0.100; P = 0.296). However, a negative correlation was found between Bm and Pr(z) values (R = -0.343; P = 0.030). These data suggest that biofilm formation is likely to play a role in the pathogenicity of oral candidosis, and in patients with diabetes, this may be due to the ability of C. albicans to adapt to the altered physiological environment. The production of hydrolytic enzymes is independently associated with this growth modality.