Parental experiences in navigating health services for paediatric residual obstructive sleep apnoea: An exploratory qualitative descriptive study.

OBJECTIVES: To explore parents' experiences and perceptions regarding engagement in health services for managing residual paediatric obstructive sleep apnoea (OSA) across levels of care. METHODS: Qualitative description guided study design. Data were collected through semi-structured interviews with parents of children diagnosed with residual OSA at a university-based sleep clinic. The relevant literature informed the interview guide and was piloted before data collection. Inductive, manifest content analysis was used to describe parents' perceptions and experiences using data-driven categories and sub-categories. Several strategies were employed to ensure rigour in this study. RESULTS: Eight interviews were conducted. Parents' views were organized into five categories: awareness of the sleep issue, interaction with non-sleep specialists, interaction with sleep specialists, interaction with dental professionals, and further actions and support. Parents reported several engagement issues due to their interactions with different care providers. These issues included having to personally identify and raise the sleep problem, feeling that care providers did not take this problem seriously, waiting for an extended period to be referred for sleep services, and receiving conflicting or insufficient treatment recommendations. Overall, parents perceived that their actions and the services received across levels of care were not effective enough to address paediatric OSA. CONCLUSION: Based on this exploratory qualitative descriptive research, along with developing evidence-based clinical guidelines for paediatric OSA screening and management tailored to different levels of care, strategies intended to improve the engagement of patients and care providers in addressing paediatric OSA should be developed and empirically tested.

In vitro biomechanics of divot use, and their placement, in orthodontic aligner therapy.

INTRODUCTION: To evaluate biomechanics of an aligner utilizing divots and the effect of their vertical placement on the right maxillary central incisor. METHODS: An in vitro Orthodontic SIMulator (OSIM) was used to test forces and moments generated by aligners incorporating divots. The OSIM arch was scanned to generate a. STL version that was modified to create four models by placing divots on different positions of the right central maxillary incisor: GI - divots on gingival-third of lingual surface and incisal-third of labial surface; GM - divots on gingival-third of lingual surface and middle-third of labial surface; MI - divots on middle-third of lingual surface and incisal-third of labial surface; MM - divots on middle-third of lingual surface and middle-third of labial surface. Aligners (n = 30/model) were fabricated using a 0.75 mm thick polyethylene terephthalate material and Biostar® machine following the manufacturer's recommendations. A one-way MANOVA followed by one-way ANOVA (α = 0.05) was utilized to test effect of models on buccolingual force (Fy) and mesiodistal moment (Mx) at 0.20 mm of lingual displacement of the right maxillary central incisor. RESULTS: Mean Mx for GI (-5.68 ± 7.38 Nmm), GM (3.75 ± 5.54 Nmm), MI (-4.27 ± 1.48 Nmm) and MM (1.96 ± 0.99 Nmm) models showed statistical differences between GI and GM, GI and MM, GM and MI and MI and MM. GI exerted the largest Fy (1.87 ± 0.75 N) followed by GM (1.10 ± 0.47 N), MI (0.70 ± 0.23 N) and MM (0.28 ± 0.08 N) with significant differences between GI and GM, GI and MI, GI and MM and GM and MM models. CONCLUSIONS: Vertical divot placement on a right central incisor had a significant effect on aligner biomechanics. Buccolingual forces exerted by models GI, GM and MI were within the range suggested by literature for bodily tooth movement without major root tipping for GM and MI models.

An evaluation of root resorption associated with the use of photobiomodulation during orthodontic treatment with clear aligners: a retrospective cohort pilot study.

OBJECTIVES: To evaluate the change in tooth root volume using cone-beam computed tomography (CBCT) in a group of patients treated concurrently with clear aligners and an adjunctive photobiomodulation (PBM) device. MATERIALS AND METHODS: This retrospective cohort pilot study included the records of 32 consecutively treated clear aligner patients (23 female, 9 male) from the private practice of one orthodontist. The PBM group (n = 16) used the device once per day for 5 minutes per arch and was compared with a matched control group (n = 16). A semiautomated segmentation technique was used to obtain tooth volume of anterior teeth from CBCT imaging prior to (T0) and during or immediately following (T1) orthodontic treatment with clear aligners. The change in root volume between time points was assessed. RESULTS: There was no statistically significant difference between the pre- and posttreatment root volumes of maxillary and mandibular anterior teeth, regardless of which intervention group the patient belonged to (P > .05). There was also no difference in the mean percentage change in root volume between clear aligner patients in this study who were treated with the PBM device compared with a matched control group (P > .05). CONCLUSIONS: Clear aligner patients in this study who changed their aligners every 3 to 5 days and used adjunctive photobiomodulation therapy did not experience clinically relevant orthodontically induced external root resorption. Due to the small sample size and measurement error in the root segmentation process, the results should be interpreted with caution.

Characterization of craniofacial-based clinical phenotypes in children with suspected obstructive sleep apnea.

STUDY OBJECTIVES: We conducted this study to identify phenotypes of obstructive sleep apnea (OSA) in children based on lifestyle, sleep habits, age, obesity, sex, soft tissue facial features, and specific craniofacial abnormalities. METHODS: Seventy-three children with symptoms of pediatric OSA who underwent overnight observed polysomnography participated in this study. Soft tissue facial features were assessed using a 3-dimensional stereophotogrammetric system. Craniofacial abnormalities were evaluated based on the most common facial features associated with orthodontic treatment needs. Data regarding lifestyle, sleep habits, age, obesity, and sex were also collected. To identify phenotypes of OSA, a sequential analysis was then performed on categories of variables using fuzzy clustering with medoids. RESULTS: Craniofacial abnormalities and soft tissue facial features defined clusters. Three clusters were identified. Cluster 1 comprised a group of younger children (5.9 ± 3.8 years) without obesity, without craniofacial abnormalities, and with smaller soft tissue facial features dimensions. Cluster 2 comprised a group of older children (9.6 ± 3.9 years) without obesity and with larger mandibular dimensions and mildly arched palates (71.4%). Cluster 3 comprised a group of older children (9.2 ± 3.9 years) with obesity and a history of health issues (68.4%), excessive lower facial height (63.2%), and midface deficiency (73.7%). No differences were observed across clusters regarding sleep features. A moderate severity of obstructive and mixed respiratory events was observed in all 3 clusters. CONCLUSIONS: The study results did not identify distinct phenotypes of pediatric OSA based on soft tissue facial features or craniofacial abnormalities alone. Age and body mass index likely modify the effect of soft tissue facial features and craniofacial abnormalities as risk factors for OSA in children. CITATION: Fernandes Fagundes NC, Loliencar P, MacLean JE, Flores-Mir C, Heo G. Characterization of craniofacial-based clinical phenotypes in children with suspected obstructive sleep apnea. J Clin Sleep Med. 2023;19(11):1857-1865.

Investigating the role of aligner material and tooth position on orthodontic aligner biomechanics.

The primary objective of this work was to investigate the effect of material selection and tooth position on orthodontic aligner biomechanics. Additionally, material property changes with thermoforming were studied to elucidate its role in material performance in-vitro. An orthodontic simulator (OSIM) was used to evaluate forces and moments at 0.20 mm of lingual displacement for central incisor, canine and second premolar using Polyethylene terephthalate (PET), Polyurethane (PU) and Glycol-modified polyethylene terephthalate (PET-G) materials. The OSIM was scanned to generate a model used to fabricate aligners using manufacturer-specified thermoforming procedures. Repeated measures of MANOVA was used to analyze the effect of teeth and material on forces/moments. The role of thermoforming was evaluated by flexural modulus estimated by 3-point bend tests. Pre-thermoformed and post-thermoformed samples were prepared using as-received sheets and those thermoformed over a simplified arch using rectangular geometry, respectively. Groups were compared using Two-way ANOVA. The PET, PU, and PET-G materials exerted maximum buccal force and corresponding moments on the canine. PU exerted more buccal force than PET-G on the canine and second premolar, and more than PET on the second premolar. The impact of thermoforming varied according to the specific polymer: PET-G remained stable, there was a slight change for PET, and a significant increase was noted for PU from pre-thermoformed to post-thermoforming. The results of this study elucidate the influence of material and arch position on the exerted forces and moments. Further, the mechanical properties of thermoplastic materials should be evaluated after thermoforming to characterize their properties for clinical application.

Estimation for the bivariate quantile varying coefficient model with application to diffusion tensor imaging data analysis.

Despite interest in the joint modeling of multiple functional responses such as diffusion properties in neuroimaging, robust statistical methods appropriate for this task are lacking. To address this need, we propose a varying coefficient quantile regression model able to handle bivariate functional responses. Our work supports innovative insights into biomedical data by modeling the joint distribution of functional variables over their domains and across clinical covariates. We propose an estimation procedure based on the alternating direction method of multipliers and propagation separation algorithms to estimate varying coefficients using a B-spline basis and an $L_2$ smoothness penalty that encourages interpretability. A simulation study and an application to a real-world neurodevelopmental data set demonstrates the performance of our model and the insights provided by modeling functional fractional anisotropy and mean diffusivity jointly and their association with gestational age and sex.

Orthodontic interventions as a management option for children with residual obstructive sleep apnea: a cohort study protocol.

INTRODUCTION: Obstructive sleep apnoea (OSA) is a sleep-breathing disorder that seems likely to have long-term negative social and health consequences in children and adolescents. There are no established standard management approaches when the first line of therapy, the tonsillectomy and adenoidectomy (T&A), is not indicated or fails to address paediatric OSA (residual paediatric OSA). This protocol describes a prospective cohort study that aims to assess the effectiveness of orthodontic interventions for managing residual paediatric OSA in patients with concomitant craniofacial issues. METHODS AND ANALYSIS: Children aged 6-16 years who with an OSA diagnosis and did not benefit from previous T&A or qualified for T&A will be recruited. Orthodontic intervention(s), when adequately indicated (maxillary expansion, mandibular advancement or maxillary complex advancement with skeletal anchored headgear), and a control (orthodontic intervention declined) cohorts will be involved. A sample size of 70 participants (n=35 per cohort) is planned. Effectiveness data will be assessed through nocturnal polysomnography, a craniofacial index, sleep questionnaires and medical records. Additionally, the association of residual OSA and two comorbidities, obesity and asthma, will be investigated through assessing blood, urine and saliva metabolites. The changes on body mass index will also be investigated as a secondary outcome. Other additional outcomes, including association between residual paediatric OSA and periodic limbs movement, restless leg syndrome, insomnia, and the use of abiometric shirt to sleep monitoring purposes will also be considered. All participants will be followed up for 12 months after treatment allocation. The effectiveness of the intervention will be analysed by the assessment of sleep parameters, medical history (from medical chart reviews), questionnaire responses, craniofacial characteristics and metabolomic markers using an algorithm to be developed. ETHICS AND DISSEMINATION: This study was approved by the Health Research Ethics Board-Health Panel, University of Alberta, Edmonton, Canada (Pro00084763). The findings will be shared with scientific and patient content-specific social network communities to maximise their impact on clinical practice and future research in the study topic. TRIAL REGISTRATION NUMBER: NCT03821831; Pre-results.

Inflammatory bowel disease and periodontitis: A retrospective chart analysis.

OBJECTIVES: This study examined the variation in prevalence of periodontitis among different sexes, age groups, smoking status, and oral hygiene adherence in patients affected by either Crohn's disease (CD) or ulcerative colitis (UC). MATERIALS & METHODS: This study was a retrospective chart analysis that collected data from the School of Dentistry's Oral Health Clinic at the University of Alberta, Edmonton, Canada. Patients' electronic health records between the years of 2013 and 2019 were analyzed. Multiple keywords such as IBD, CD, UC, and periodontal disease with various spelling combinations were used for searching and gathering pertinent data, which was then further assessed. After applying the inclusion and exclusion criteria, a total of 80 patient charts were included. These patient charts were thoroughly screened to gather information such as age, sex, smoking status, and a variety of periodontal parameters. Collected data were analyzed using SPSS software by using Pearson's χ2 , Pearson's correlation, and Mann-Whitney U-test. RESULTS: IBD had an impact on the severity of periodontitis in patients between the ages of 50 and 64 years with higher odds ratio (OR). Biological sex or history of smoking in IBD patients did not have higher odds of developing periodontitis. Plaque score derived from this retrospective study was used to estimate the patient's oral hygiene status and showed no impact. Also, prevalence of periodontitis did not differ between UC and CD. We anticipated some of these findings because of the retrospective nature of the study. CONCLUSIONS: Within the limitation of the retrospective study, IBD patients in the 50-64 age group years showed a higher odds ratio for a greater prevalence of periodontitis. Thus, a closer periodontal recall and evaluation in these patients is recommended for early diagnosis and preventive care. It is advised that periodontists work closely with gastroenterologists to maintain periodontal health in IBD-affected individuals.

Craniofacial features in children with obstructive sleep apnea: a systematic review and meta-analysis.

STUDY OBJECTIVES: This review aimed to evaluate the association between craniofacial features in children and adolescents with pediatric obstructive sleep apnea (OSA). METHODS: Seven databases were searched to fulfill our research objectives. Clinical studies that included participants younger than 18 years with fully diagnosed OSA or without OSA and that evaluated skeletal, soft craniofacial features, or dental arch morphology were considered for this review. The risk of bias and certainty of evidence were assessed. A meta-analysis was performed when low methodological and clinical heterogeneity were detected. This review followed the protocols recommended by the Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA-2020) guidelines. RESULTS: Nine studies were identified at the end of the selection process, from which 5 did not report differences. Four studies reported differences between craniofacial features when OSA was compared to an asymptomatic control group. Mandibular retrognathia, reduced anteroposterior linear dimensions of the bony nasopharynx (decreased pharyngeal diameters at the levels of the adenoids), longer facial profile, and a narrower intercanine width were described among children with OSA. A meta-analysis was performed considering the studies with a similar methodological approach, and no differences were observed in all the considered cephalometric angles (SNA, SNB, ANB, NSBa, U1-L1, U1-SN). All the included studies were considered at low risk of bias even though some limitations were noted. CONCLUSIONS: Due to the very low to moderate level of certainty, neither an association nor a lack thereof between craniofacial morphology and pediatric OSA can be supported by these data. CITATION: Fagundes NCF, Gianoni-Capenakas S, Heo G, Flores-Mir C. Craniofacial features in children with obstructive sleep apnea: a systematic review and meta-analysis. J Clin Sleep Med. 2022;18(7):1865-1875.

Use of facial stereophotogrammetry as a screening tool for pediatric obstructive sleep apnea by dental specialists.

STUDY OBJECTIVES: To evaluate facial 3-dimensional (3D) stereophotogrammetry's effectiveness as a screening tool for pediatric obstructive sleep apnea (OSA) when used by dental specialists. METHODS: One hundred forty-four participants aged 2-17 years, including children fully diagnosed with pediatric OSA through nocturnal polysomnography or at high-risk or low-risk of pediatric OSA, participated in this study. 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire were obtained from all participants. Ten dental specialists with interest in pediatric sleep breathing disorders classified OSA severity twice, once based only on 3D stereophotogrammetry and then based on 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire. Intrarater and interrater reliability and diagnostic accuracy of pediatric OSA classification were calculated. A cluster analysis was performed to identify potential homogeneous pediatric OSA groups based on their craniofacial features classified through the Craniofacial Index . RESULTS: Intrarater and interrater agreement suggested a poor reproducibility when only 3D facial stereophotogrammetry was used and when all tools were assessed simultaneously. Sensitivity and specificity varied among clinicians, indicating a low screening ability for both 3D facial stereophotogrammetry, ranging from 0.36-0.90 and 0.10-0.70 and all tools ranging from 0.53-1.0 and 0.01-0.49, respectively. A high arched palate and reversed or increased overjet contributed to explaining how participating dental clinicians classified pediatric OSA. CONCLUSIONS: 3D stereophotogrammetry-based facial analysis does not seem predictive for pediatric OSA screening, alone or combined with the Pediatric Sleep Questionnaire and Craniofacial Index when used by dental specialists interested in sleep-disordered breathing. Some craniofacial traits, more specifically significant sagittal overjet discrepancies and an arched palate, seem to influence participating dental specialists' classification. CITATION: Fernandes Fagundes NC, Carlyle T, Dalci O, et al. Use of facial stereophotogrammetry as a screening tool for pediatric obstructive sleep apnea by dental specialists. J Clin Sleep Med. 2022;18(1):57-66.

Tooth and root size as determined from 0.25- and 0.30-mm voxel size cone-beam CT imaging when contrasted to micro-CT scans (0.06 mm): An ex vivo study.

OBJECTIVE: To quantify tooth volume differences from extracted teeth when using three different three-dimensional (3D) computed tomography (CT)-based imaging modalities. DESIGN: Ex vivo study. SETTING: Laboratory and clinics of the University of Alberta. METHODS: Cone-beam CT (CBCT) of 12 extracted teeth were scanned using 0.25- and 0.30-mm voxel size from CBCT and a 0.06-mm voxel size from micro-CT (reference standard). 3D reconstructions for each tooth from each imaging modality were made through the software ITK-SNAP®. The mean volume differences between each pair of scanning modalities were calculated and then compared and analysed through a repeated measures ANOVA. RESULTS: The average overestimations of the teeth volume were 15.2% for the high-resolution CBCT and 28.1% for the low-resolution CBCT compared to micro-CT measurements. The differences in absolute volume were 81.6 mm3 and 152.8 mm3, respectively. All differences were statistically significant (P < 0.05). CONCLUSIONS: Orthodontists and researchers who assess root resorption through CBCT imaging should be aware that the depicted volumes may likely be overestimating tooth volume and camouflaging real root volumetric treatment changes.

An in vitro evaluation of orthodontic aligner biomechanics around the maxillary arch.

INTRODUCTION: The objective of this study was to evaluate the forces and moments exerted by orthodontic aligners on 3 different displaced maxillary teeth and their adjacent supporting teeth. METHODS: An in vitro orthodontic simulator was used to measure the forces and moments of a 0.75-mm thick glycol-modified polyethylene terephthalate material for 3 maxillary teeth: central incisor, canine, and second premolar. Forces and moments were recorded for tested teeth displaced lingually one by one for 0.20 mm. Repeated measures of multivariate analysis of variance was used to assess the outcome. RESULTS: The mean buccolingual force applied on a displaced canine (2.25 ± 0.38 N) was significantly (P <0.001) more than the central incisor (1.49 ± 0.18 N) and second premolar (1.50 ± 0.16 N). The mean moment (that tends to tip the teeth buccally) exerted on a canine (-20.11 ± 5.27 Nmm) was significantly more (P <0.001) than the central incisor (-8.42 ± 1.67 Nmm) and second premolar (-11.45 ± 1.29 Nmm). The forces and moments acting on teeth adjacent to the displaced tooth were clinically significant and acted in opposing directions to those on the displaced tooth. CONCLUSIONS: The results of this study highlighted that for the same amount of displacement on a given tooth, the forces and moments imposed by the orthodontic aligner depend on location around the arch. These findings highlight the need to further study aligner mechanics around the dental arch and optimize aligner design to impose desired mechanical loads to avoid detrimental effects during orthodontic tooth movement.

Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions.

STUDY OBJECTIVES: To analyze differences in mandibular cortical width (MCW) among children diagnosed with obstructive sleep apnea (OSA) or at high- or low-risk for OSA. METHODS: A total of 161 children were assessed: 60 children with polysomnographically diagnosed OSA, 56 children presenting symptoms suggestive of high-risk for OSA, and 45 children at low risk for OSA. Children at high- and low-risk for OSA were evaluated through the Pediatric Sleep Questionnaire. MCW was calculated using ImageJ software from panoramic radiograph images available from all participants. Differences between MCW measurements in the 3 groups were evaluated using analysis of covariance and Bonferroni post-hoc tests, with age as a covariate. The association between MCW and specific cephalometric variables was assessed through regression analysis. RESULTS: The participants' mean age was 9.6 ± 3.1 years (59% male and 41% female). The mean body mass index z-score was 0.62 ± 1.3. The polysomnographically diagnosed OSA group presented smaller MCW than the group at low-risk for OSA (mean difference = -0.385 mm, P = .001), but no difference with the group at high-risk for OSA (polysomnographically diagnosed OSA vs high-risk OSA: P = .085). In addition, the MCW in the group at high-risk for the OSA was significantly smaller than the group at low-risk for the OSA (mean difference = -0.301 mm, P = .014). The cephalometric variables (Sella-Nasion-A point angle (SNA) and Frankfort - Mandibular Plane angle (FMA)) explained only 8% of the variance in MCW. CONCLUSIONS: Reductions in MCW appear to be present among children with OSA or those at high-risk for OSA, suggesting potential interactions between mandibular bone development and/or homeostasis and pediatric OSA. CITATION: Fernandes Fagundes NC, d'Apuzzo F, Perillo L, et al. Potential impact of pediatric obstructive sleep apnea on mandibular cortical width dimensions. J Clin Sleep Med. 2021;17(8):1627-1634.

Comparison of Skeletal and Dental Changes Obtained from a Tooth-Borne Maxillary Expansion Appliance Compared to the Damon System Assessed through a Digital Volumetric Imaging: A Randomized Clinical Trial.

The purpose of this study was to evaluate and compare dental and skeletal changes associated with the Damon and Rapid Maxillary Expander (RME) expansion using Cone-Beam Computed Tomography (CBCT). Eighty-two patients, from The University of Alberta Orthodontic Clinic, were randomly allocated to either Group A or B. Patients in Group A received orthodontic treatment using the Damon brackets. Patients in Group B received treatment using the Hyrax (a type of RME) appliance. CBCT images were taken two times (baseline and after expansion). The AVIZO software was used to locate 18 landmarks (dental and skeletal) on sagittal, axial, and coronal slices of CBCT images. Comparison between two groups showed that transverse movement of maxillary first molars and premolars was much greater in the Hyrax group. The lateral movements of posterior teeth were associated with buccal tipping of crowns. No clinically significant difference in the vertical or anteroposterior direction between the two groups was noted. Alveolar bone next to root apex of maxillary first premolar and molar teeth showed clinically significant lateral movement in the Hyrax group only. The comparison between two groups showed significantly greater transverse expansion of the first molar and first premolars with buccal tipping in the RME group.

Dental and skeletal changes associated with the Damon system philosophical approach.

OBJECTIVE: To compare the skeletal and dentoalveolar changes produced by the Damon system's treatment philosophy to traditional orthodontic treatment techniques. MATERIALS AND METHODS: An electronic search in four major databases was completed: Cochrane, PubMed, EMBASE, and Google Beta Scholar on October 5th, 2018. Randomized controlled trials, prospective and retrospective controlled clinical trials were included in this systematic review. The quality assessment of individual studies was done using two different tools: The Cochrane Risk of Bias Assessment Tool (RTCs) and The Methodological Index for Non-Randomized Studies (MINORS) (non-RCTs). RESULTS: Seven studies were included for this qualitative analysis. Six studies compared the Damon system to various types of conventional (non self-ligating bracket) system as a comparison group. One study used a quad helix as a comparison for a few months before a full bonding appointment with conventional brackets. The majority of studies found an increase in maxillary inter-canine, inter-premolar, and intermolar distance after the treatment in both the Damon and comparison groups. Yet, all studies concluded that there is no significant difference in the final transverse dimension between the two groups. One study also found that the transverse expansion was achieved mainly by tipping movement of posterior dentition, and a decrease in the posterior buccal bone area was evident in both groups after treatment. CONCLUSION: There is not enough evidence to support the claim that the Damon system allows additional arch expansion with better tipping control than with traditional techniques.

Outcomes of implant-based oral rehabilitation in head and neck oncology patients-a retrospective evaluation of a large, single regional service cohort.

BACKGROUND: The study reports on implant survival outcomes in head and neck cancer patients who received implant-based oral rehabilitation in a regional service centre. METHODS: A retrospective analysis of implant survival outcomes in patients treated in a regional service from 2012 to 2017 was performed. The primary outcome measure was implant survival. The secondary outcome measure was to assess the effect of covariates associated with implant failure including bone type, radiotherapy, chemotherapy, gender and surgical implant complications. Kaplan-Meier survival curves were applied to compare differences in the survival rates of groups of variables. Cox proportional hazards models were applied to identify covariates associated with implant failure. p value was set at 0.05. RESULTS: The sample was composed of 167 head and neck cancer patients who had 779 dental implants placed. Implant survival estimates were calculated: 3 years, 95.7% [95%CI 94.3-97.2%] and 5 years, 95.5% [95%CI 93.9-97.0%], with a median follow-up of 38 months. Gender (p = 0.09), radiotherapy (p = 0.16) and chemotherapy (p = 0.17) did not significantly influence implant survival, whereas implant failure was higher in transported (reconstructed) bone sites in comparison with native bone (p < 0.01). CONCLUSION: The result of this study suggests that overall implant survival as part of the routine oral rehabilitation is high in this patient cohort; however, implant failure was found to be statistically higher for implant placed into transported bone in comparison to native bone.

Comparison of the contact angle of water on set elastomeric impression materials.

PURPOSE: The hydrophilicity of some elastomeric impression materials has not been fully established. The purpose of this study was to measure and compare the advancing contact angle of water on the surface of several set elastomeric impression materials. MATERIALS AND METHODS: We tested various consistencies of vinyl polysiloxane (VPS; Imprint 4) and vinyl polyether silicone (VPES; EXA'lence) with a polyether (PE; Impregum Soft) control. Impression discs (25.07 mm) were made using a metal die and ring. Deionized ultra-filtered water was placed on each disc and contact-angle measurements were made at 0, 15, 30, 45 and 60 s using a video contact angle drop shape analysis machine. The data were analyzed using repeated ANOVA and a post-hoc test with Bonferroni correction. RESULTS: VPS contact angles reached a mean of 10.1° ± 0.2° at 60 s vs. 40.7° ± 0.1° for VPES. Overall, VPS contact angles were smaller than those for VPES at all measured times. However, heavy and super quick heavy VPS had much higher contact angles at 0 s compared with other VPS consistencies. There was a significant difference in contact angles between VPS and VPES (mean difference 33.9°, p < 0.05) and between VPS and PE (mean difference 32.8°, p < 0.05) but not between VPES and PE (P = 0.196). VPS heavy and super quick heavy were significantly different from other VPS materials (p < 0.05), but not from each other (p = 1.00). CONCLUSIONS: Set VPS is more hydrophilic than VPES. Contact-angle values of VPS indicated super hydrophilicity. VPES was hydrophilic, with measurements similar to the PE control. Thus, VPS impression materials may be excellent in terms of spreading and copying wet surfaces.

Associations between patients' understanding of periodontal disease, treatment compliance, and disease status.

OBJECTIVE: The aim of the present study was to investigate the associations between patients' understanding of periodontal disease, their individual compliance to homecare, self-reported periodontal disease, and how they have been educated regarding their oral health. METHOD AND MATERIALS: A cross-sectional study was performed by distributing questionnaires to patients at the University of Alberta Dental Clinic. A survey consisting of 45 questions was constructed in order to quantify patients' understanding of periodontal disease (section 1), where they received their information, how often they have been instructed by dental practitioners, their homecare habits (section 2), and their self-reported periodontal status (section 3). RESULTS: In total, 286 surveys were analyzed from participants (92 males; 191 females; 3 other), with an age range of 15-87 years (mean 42.6 ± 15.1). Correctly answered questions ranged from 39.5% to 95.8%, the highest related to smoking and lowest regarding gingival pockets. Only 42.0% and 42.7% understood the purpose of periodontal probing and the difference between gingivitis and periodontitis respectively. Of the participants, 13.3% and 54.2% had never been shown how to clean their teeth or counselled regarding dietary habits from dental professionals respectively, and only 24.8% had been shown more than four times how to clean their teeth. A moderate association was found between sections 1 (knowledge) and 2 (habits/instruction), between sections 1 and 3 (self-reported health), and between sections 2 and 3. CONCLUSION: Moderate association between knowledge, homecare habits, instruction from dental professionals, and self-reported periodontal health was found. Patient understanding is lacking in certain areas and there seems to be a lack of patient education from dental professionals. As dental professionals improve patient instruction, there may be an improvement in patient compliance to homecare and periodontal health.

The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials.

PURPOSE: Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. MATERIALS AND METHODS: 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. RESULTS: The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups (P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. CONCLUSION: The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks.