Age related impairments in ingestion from a large population based-sample.

OBJECTIVES: Epidemiological data regarding the evolution of problems related to mastication and swallowing with age are lacking. This study aims to (i) describe changes in oral function with age, using data from a large French population, (ii) validate online, self-report uses of an ICF questionnaire in older persons, and (iii) assess whether impairment is related to avoidance of certain foods, xerostomia, body mass index (BMI) and oral health related quality of life (OHRQoL). METHODS: Volunteers aged ≥18 years with internet access completed a series of questionnaires on sociodemographic, anthropometric and oral health characteristics (oral function, Xerostomia Index (XI), OHRQoL, reasons for avoidance of certain food). Oral function was assessed using items derived from the International Classification of Functioning (ICF). Five ICF items related to ingestion function and six items related to activities and participation were used. A validation study was undertaken to identify those with poor chewing ability and low salivary flow amongst older participants reporting impairment. FINDINGS: 39 597 individuals were included. The prevalence of individuals with impairment for ICF items related to ingestion function and oral activity (eating, drinking and speaking), and the percentage of participants with poor OHRQoL increased significantly with age (p < 0.001). Each ICF item was significantly associated with OHRQoL (p < 0.001), XI (p < 0.001), BMI (p < 0.001) and avoidance of certain food due to chewing or swallowing difficulties. CONCLUSION: Overall, 21.5% and 13.5% of the study population had chewing and/or biting impairments respectively, which might affect food selection and consumption. These findings raise individual and population-based issues. Further studies are needed to assess whether impairment in oral function might increase frailty in older individuals, and also to compare data with those from other countries.

Evaluation and comparison of the accuracy of three intraoral scanners for replicating a complete denture.

STATEMENT OF PROBLEM: Technological advances in digital acquisition tools have increased the scope of intraoral scanners (IOSs), including scanning a removable complete denture (RCD) to replicate it. However, studies assessing the accuracy of IOSs for replicating a maxillary or mandibular RCD are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the accuracy (trueness and precision) of 3 IOSs while replicating a maxillary and mandibular RCD. MATERIAL AND METHODS: One maxillary and 1 mandibular RCD were scanned with a desktop scanner (D2000) to obtain the reference model. Two operators scanned each RCD 5 times with 3 different IOSs (TRIOS 4, Primescan, and IS3800), following a predefined acquisition protocol. The 60 study models obtained were compared with the reference model using the Geomagic software program. For each comparison, the mean and standard deviation of discrepancy were calculated. Distances were measured on both the reference and the study model, and differences were calculated to assess whether sagittal or transverse deformations were present. The tolerance percentage of the volume of the digital model compared with the volume of the reference model was determined (difference tolerance was set at 0.1 mm). A univariate analysis of variance followed by a post hoc analysis using the Student-Newman-Keuls (α=.05) test was performed to determine the truest and the most precise IOS. RESULTS: The TRIOS 4 and Primescan IOSs had comparable trueness, with mean dimensional variations of 47 ±27 µm and 57 ±8 µm respectively compared with the reference model. The IS3800 had a lower trueness (98 ±35 µm). Primescan was significantly more precise with a mean standard deviation of 64 ±15 µm (P<.05). The TRIOS 4 (141 ±48 µm) and IS3800 (129 ±24 µm) had comparable precision. Primescan showed the least sagittal and transverse deformation. CONCLUSIONS: This study determined that an RCD can be replicated using an IOS, although all IOSs did not have equal accuracy. An in vivo study needs to assess whether this procedure is clinically acceptable.

Metal-Free Catalytic Hydrogenolysis of Chlorosilanes into Hydrosilanes with "Inverse" Frustrated Lewis Pairs.

The challenging metal-free catalytic hydrogenolysis of silyl chlorides to hydrosilanes is unlocked by using an inverse frustrated Lewis pair (FLP), combining a mild Lewis acid (Cy2 BCl) and a strong phosphazene base (BTPP) in mild conditions (10 bar of H2 , r. t.). In the presence of a stoichiometric amount of the base, the hydrosilanes R3 SiH (R=Me, Et, Ph) are generated in moderate to high yields (up to 95 %) from their chlorinated counterparts. A selective formation of the valuable difunctional monohydride Me2 SiHCl is also obtained from Me2 SiCl2 . A mechanism is proposed based on stoichiometric experiments and DFT calculations; it highlights the critical role of borohydride species generated by the heterolytic splitting of H2 .

Implant-supported prostheses in patients with special needs: A systematic literature review of protocols and outcomes.

STATEMENT OF PROBLEM: Implant-supported prostheses for individuals with special needs have been considered high-risk because of the prevalence of poor oral hygiene and parafunction in this population; however, systematic evidence on protocols and outcomes is scarce. PURPOSE: The purpose of this systematic review was to summarize implant procedures and outcomes for the special needs population. MATERIAL AND METHODS: A systematic literature review was conducted using PubMed, Embase, and Scopus databases in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodological framework. Data collected included patient information, location and number of implants, surgical and prosthetic procedures, behavior support techniques, postoperative follow-up, complications, and criteria for outcome assessment. Survival rates were pooled for quantitative analysis, and a separate analysis pooling data from groups of special needs patients that present similar risks was undertaken. RESULTS: The qualitative analysis included 79 studies involving 759 patients and 2269 implants. The quantitative analysis included 65 studies concerning 666 patients with special needs and 1886 implants. The overall weighted implant survival rate was 95.4%, with a mean follow-up duration of 40.7 ±29.5 months. CONCLUSIONS: In individuals with special needs considered suitable for implant-supported prostheses by their clinician, implant survival rates were similar to those reported in the general population. (J Prosthet Dent xxxx;xxx:xxx-xxx).

Metal-Free Catalytic Hydrogenolysis of Silyl Triflates and Halides into Hydrosilanes.

The metal-free catalytic hydrogenolysis of silyl triflates and halides (I, Br) to hydrosilanes is unlocked by using arylborane Lewis acids as catalysts. In the presence of a nitrogen base, the catalyst acts as a Frustrated Lewis Pair (FLP) able to split H2 and generate a boron hydride intermediate capable of reducing (pseudo)halosilanes. This metal-free organocatalytic system is competitive with metal-based catalysts and enables the formation of a variety of hydrosilanes at room temperature in high yields (>85 %) under a low pressure of H2 (≤10 bar).

A Copper(I)-Catalyzed Sulfonylative Hiyama Cross-Coupling.

An air-tolerant Cu-catalyzed sulfonylative Hiyama cross-coupling reaction enabling the formation of diaryl sulfones is described. Starting from aryl silanes, DABSO and aryliodides, the reaction tolerates a large variety of polar functional groups (amines, ketones, esters, aldehydes). Control experiments coupled with DFT calculations shed light on the mechanism, characterized by the formation of a Cu(I)-sulfinate intermediate via fast insertion of a SO2 molecule.

Evaluation of the design-driven prediction of removable partial denture retention.

STATEMENT OF PROBLEM: Removable partial dentures (RPDs) are a cost-effective treatment designed to replace missing teeth for partially edentulous patients. However, RPDs often have insufficient retention, which results in treatment failure and patient dissatisfaction. PURPOSE: The purpose of this clinical study was to investigate the factors related to RPD retention that affect patient satisfaction, to clinically validate a newly published model for predicting RPD retention based on the number and position of missing teeth and clasps, and to identify the predictions of patient satisfaction to improve the guidelines for RPD design. MATERIAL AND METHODS: Seventy-five patients treated with 107 RPDs delivered at the McGill University Dental Clinic (Montreal, Canada) and Estaing University Hospital (Clermont-Ferrand, France) participated in this study. Data on the RPD design were collected from the clinical records, and the retention of each RPD was tested with the mathematical model designed for predicting RPD retention. Data on patient satisfaction with their RPDs were collected by using a standardized questionnaire (McGill Denture Satisfaction Instrument). Statistical analysis of factors related to RPD retention and patient satisfaction was performed by using the chi-square test and Mann-Whitney test, while the developed model for predicting RPD retention was evaluated by using sensitivity and specificity analysis. RESULTS: The average satisfaction score for all RPDs was 8.2 ±1.7 out of 10. Patients were more satisfied with RPDs in the maxillary arch, tooth-supported, or retained by ≥3 clasps than with RPDs in the mandibular arch, with distal extension bases, or retained by <3 clasps. The materials used for RPD fabrication (metal-based or acrylic resin-based), the number of missing teeth, and the presence of indirect retention were not associated with patient satisfaction. Participants were significantly more satisfied with RPD designs predicted by the developed mathematical model to have enough retention than with RPD designs predicted to have insufficient retention. The mathematical model for predicting the RPD retention showed a clinical specificity of 83% in predicting patient satisfaction. CONCLUSIONS: RPD retention predicted from the number and position of clasps and missing teeth might help to determine patient satisfaction. In addition, patient satisfaction with RPDs was influenced by the arch type, the presence of a distal extension base, and the number of clasps.

Démographie des chirurgiens-dentistes en région Centre-Val de Loire : opportunités et perspectives.

The Center Val de Loire region is particularly affected by the shortage of health professionals. The demographics of dentists are not immune to this situation and the retirement of a practitioner has become a real public health issue. For this purpose, bridges were created between the faculties of odontology of Nantes, Clermont-Ferrand and the Faculty of Medicine of Tours, to welcome short cycle students in Center Val de Loire region, to create a link with the liberal practitioners and to allow the students to confront the health issues of this territory.

The "Plan" phase of a Deming cycle: Measurement of quality and outcome of root canal treatments in a university hospital.

INTRODUCTION: In many countries, dental students are taught in private or university hospitals where they treat patients under the supervision of teachers. Assessing the quality of root canal treatments (RCT) would provide information about the quality of care patients receive when treated by students. METHODS: This study describes the six-step "Plan" phase of a Plan-Do-Check-Act (PDCA) cycle that identifies and analyses clinical practices in endodontics in a university dental hospital service. RESULTS: Step 3 reported that the proportion of RCTs of adequate quality reached 57.1% and this proportion was significantly decreased when specific indicators for treatment difficulties were present. The proportion of successful RCTs after 1 year was 65.6%, and its variation was influenced by the preoperative periapical status rather than the quality of RCTs. The consensual meeting in Step 6 proposed to introduce three new procedures for the further Do, Check and Act phases of the PDCA cycle. CONCLUSION: This study encourages systematic evaluation of RCTs and provides the first step of the methodology that can be reproduced in private and hospital practices where students are asked to treat patients.

[Dentistry demographics of Center Val de Loire region: Opportunities and prospects]. / Démographie des chirurgiens-dentistes en région Centre-Val de Loire : opportunités et perspectives.

The Center Val de Loire region is particularly affected by the shortage of health professionals. The demographics of dentists are not immune to this situation and the retirement of a practitioner has become a real public health issue. For this purpose, bridges were created between the faculties of odontology of Nantes, Clermont-Ferrand and the Faculty of Medicine of Tours, to welcome short cycle students in Center Val de Loire region, to create a link with the liberal practitioners and to allow the students to confront the health issues of this territory.

Carbonylation of C-N Bonds in Tertiary Amines Catalyzed by Low-Valent Iron Catalysts.

The first iron catalysts able to promote the formal insertion of CO into the C-N bond of amines are reported. Using low-valent iron complexes, including K2 [Fe(CO)4 ], amides are formed from aromatic and aliphatic amines, in the presence of an iodoalkane promoter. Inorganic Lewis acids, such as AlCl3 and Nd(OTf)3 , have a positive influence on the catalytic activity of the iron salts, enabling the carbonylation at a low pressure of CO (6 to 8 bars).

Ring-opening of Epoxides Mediated by Frustrated Lewis Pairs.

Treatment of the preorganized frustrated Lewis pairs (FLPs) tBu2 PCH2 BPh2 (1) and o-Ph2 P(C6 H4 )BCat (Cat=catechol) (4) with 2-methyloxirane, 2-phenyloxirane and 2-(trifluoromethyl)oxirane resulted in epoxide ring-opening to yield the six- and seven-membered heterocycles 2 a-c and 5 a-c, respectively. These zwitterionic products were characterized spectroscopically, and compounds 2 a, 2 b, 5 a and 5 c were structurally characterized by single-crystal X-ray structure analyses. Based on computational and kinetic studies, the mechanism of these reactions was found to proceed via activation of the epoxide by the Lewis acidic borane moiety followed by nucleophilic attack of the phosphine of a second FLP molecule. The resulting chain-like intermediates afford the final cyclic products by ring-closure and concurrent release of the second equivalent of FLP that behaves as catalyst in this reaction.

A new digital denture procedure: a first practitioners appraisal.

BACKGROUND: Historically, the complete removable denture is the last prosthetic procedure to switch to digital techniques whose advantages are mainly observed in the laboratory stages; however, it is not possible to measure the depressibility of the oral mucosa using optical cameras, thus conventional impression techniques are still necessary. This article describes the clinical and laboratory procedure and practitioners appraisal of the first fifteen digitally designed complete removable dental prostheses. METHODS: Several systems are now available including the Wieland® Digital Denture® which offers a complete procedure. This system is composed of a five axis-milling machine combined with a laboratory scanner and a design software application. Fifteen rehabilitations were carried out using the Wieland® system. RESULTS: The practitioner's role is simplified by intraoral recording with a central point and a reduced number of sessions. The prosthesis laboratory requires considerable investment in learning and equipment, making it possible to obtain ideal mounting assemblies in accordance with the occluso-prosthetic concept of bilateral balanced occlusion. The absence of polymerization and therefore of base deformation risks reduce the equilibration step. Finally, the creation of templates as an alternative to the assembly of teeth on wax makes it possible to functionally validate (masticatory and phonatory) the future dentures. However, this procedure still presented some limitations in terms of scanning and software scope of applications. CONCLUSION: Digital denture design software is relatively efficient and helps to standardize clinical results. However, to this date, improvements of the software are still required for a routine use.

A Significant but Constrained Geometry Pt→Al Interaction: Fixation of CO2 and CS2, Activation of H2 and PhCONH2.

Reaction of the geminal PAl ligand [Mes2PC(═CHPh)AltBu2] (1) with [Pt(PPh3)2(ethylene)] affords the T-shape Pt complex [(1)Pt(PPh3)] (2). X-ray diffraction analysis and DFT calculations reveal the presence of a significant Pt→Al interaction in 2, despite the strain associated with the four-membered cyclic structure. The Pt···Al distance is short [2.561(1) Å], the Al center is in a pyramidal environment [Σ(C-Al-C) = 346.6°], and the PCAl framework is strongly bent (98.3°). Release of the ring strain and formation of X→Al interactions (X = O, S, H) impart rich reactivity. Complex 2 reacts with CO2 to give the T-shape adduct 3 stabilized by an O→Al interaction, which is a rare example of a CO2 adduct of a group 10 metal and actually the first with η(1)-CO2 coordination. Reaction of 2 with CS2 affords the crystalline complex 4, in which the PPtP framework is bent, the CS2 molecule is η(2)-coordinated to Pt, and one S atom interacts with Al. The Pt complex 2 also smoothly reacts with H2 and benzamide PhCONH2 via oxidative addition of H-H and H-N bonds, respectively. The ensuing complexes 5 and 7 are stabilized by Pt-H→Al and Pt-NH-C(Ph) = O→Al bridging interactions, resulting in 5- and 7-membered metallacycles, respectively. DFT calculations have been performed in parallel with the experimental work. In particular, the mechanism of reaction of 2 with H2 has been thoroughly analyzed, and the role of the Lewis acid moiety has been delineated. These results generalize the concept of constrained geometry TM→LA interactions and demonstrate the ability of Al-based ambiphilic ligands to participate in TM/LA cooperative reactivity. They extend the scope of small molecule substrates prone to such cooperative activation and contribute to improve our knowledge of the underlying factors.

Assessment of the oral health knowledge of healthcare providers in geriatric nursing homes: additional training needs required.

OBJECTIVES: This study was aimed at assessing the knowledge of oral health and training needs of health workers in geriatric nursing homes. BACKGROUND: Providing daily oral care to dependent elderly people is the best way to prevent oral disorders. Because there are no dental hygienists in France, health workers play an important role in providing oral care in nursing homes and should have correct and adequate knowledge. MATERIALS AND METHODS: Health workers from 8 geriatric nursing homes in Puy de Dôme (France) completed a 58-item questionnaire. Oral health knowledge regarding dental decay, periodontal diseases, oral hygiene and denture care was assessed. Univariate and bivariate analyses were performed. RESULTS: A total of 99 health workers took part in the study. The total mean score was significantly different if health workers had received training in oral disorders (49.3 ± 11.7 vs. 43.9 ± 10; p < 0.05) or in the maintenance of oral health (50.5 ± 10.5 vs. 42.9 ± 10; p < 0.01). The mean scores obtained in the 'dental decay' subsection and in the 'oral and denture hygiene' subsection were the lowest. CONCLUSION: Geriatric nursing home staff need training in understanding the impact of oral health on general health. Theoretical knowledge of oral diseases has to be improved in order for health workers to understand oral hygiene procedures and to help them identify early oral disorders.

Dative Au→Al interactions: crystallographic characterization and computational analysis.

Hitherto unknown Au→Al interactions have been evidenced upon coordination of the geminal phosphorus-aluminum Lewis pair Mes2 PC(=CHPh)AltBu2 (Mes=2,4,6-trimethylphenyl). Four different gold(I) complexes featuring alkyl (Me), aryl (Ph, C6F5), and alkynyl (C≡CPh) co-ligands have been prepared. X-ray diffraction analyses show that P→Au→Al bridging coordination induces noticeable bending of the ligand (the PCAl bond angle shrinks by 13°). This new type of transition metal→Lewis acid interaction has been analyzed by DFT calculations.

"(Diphosphine)Nickel"-catalyzed negishi cross-coupling: an experimental and theoretical study.

The use of a strongly donating "(bis-dialkylphosphine)Ni" fragment promotes the catalytic coupling of a large range of ArCl and ArZnCl derivatives under mild conditions. Stoichiometric mechanistic investigations and DFT calculations prove that a Ni(0) /Ni(II) cycle is operative in this system.

A follow-up study of pulpotomies and root canal treatments performed under general anaesthesia.

OBJECTIVES: A previous study considered whether the proportions of clinically satisfactory root canal treatments (RCT) done under general anaesthesia (GA) or under local anaesthesia were equivalent, but the proportion of treatment with long-term satisfactory endodontic outcomes remains unknown. Moreover, no evaluation of pulpotomies performed under GA has been reported. MATERIALS AND METHODS: From 614 endodontic treatments (ETs) performed on permanent teeth under GA, 225 [193 RCT and 32 pulpotomies (P)] were examined after follow-up periods of 1-6 months (71 cases), 6-24 months (77 cases) and over 2 years (77 cases). Changes in the periapical index between the treatment date (T0) and the control time (T1) allowed the treatment to be classified as "success," "uncertain outcome" or "failure." Explicative variables for success of ET were the duration of follow-up and tooth-related criteria expected to affect the outcomes of endodontic treatment. RESULTS: Overall, 87 % of ETs were scored as "success," while 9 % were uncertain and 4 % were failures. There was no difference in the distribution of success in relation with the type of tooth, the pulpal status, the level of endodontic difficulty, the periapical status or the technical quality of RCT. The proportion of endodontic cases with high level of difficulties was higher in the P group than in the RCT group. CONCLUSION: Longer follow-ups and higher numbers of cases are needed to analyse the factors affecting success and failure in endodontic treatments performed under GA. CLINICAL RELEVANCE: The relatively high rates of success of pulpotomies and RCT support undertaking endodontic treatment under GA.

Ceramo-Metal Crown or Cad-Cam Rehabilitation: Patient and Practitioner Appraisal.

Crowns produced using CAD-CAM technology must be evaluated so they can be integrated in the dentist's therapeutic arsenal. To this end, an evaluation tool for the fixed element units was developed and tested in a randomized cross-over pilot study. At a hospital centre, 10 single crowns from the same dental preparation and produced using CEREC technology were compared to Ceramo-Metal Crowns produced using a conventional procedure. Practitioners generally evaluated CEREC crowns more positively, corroborating the subjects' preference for these crowns. The CEREC technology used in a hospital setting meets the requirements of both patients and practitioners.