Search

We used finite element analysis to study the mechanical stress distribution of a new intramedullary implant used for proximal interphalangeal joint (PIPJ) arthrodesis (PIPJA) to surgically correct the claw-hammer toe deformity that affects 20% of the population. After geometric reconstruction of the foot skeleton from claw toe images of a 36-year-old male patient, two implants were positioned, in the virtual model, one neutral implant (NI) and another one 10° angled (10°AI) within the PIPJ of the second through fourth HT during the toe-off phase of gait and results were compared to those derived for the non-surgical foot (NSF). A PIPJA was performed on the second toe using a NI reduced tensile stress at the proximal phalanx (PP) (45.83 MPa) compared to the NSF (59.44 MPa; p < 0.001). When using the 10°AI, the tensile stress was much higher at PP and middle phalanges (MP) of the same toe, measuring 147.58 and 160.58 MPa, respectively, versus 59.44 and 74.95 MPa at corresponding joints in the NSF (all p < 0.001). Similar results were found for compressive stresses. The NI reduced compressive stress at the second PP (-65.12 MPa) compared to the NSF (-113.23 MPa) and the 10°AI (-142 MPa) (all p < 0.001). The von Mises stresses within the implant were also significantly lower when using NI versus 10°AI (p < 0.001). Therefore, we do not recommend performing a PIPJA using the 10°AI due to the increase in stress concentration primarily at the second PP and MP, which could promote implant breakage., (© 2024 The Author(s). International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

The present study evaluated the mechanical behavior of five designs of Morse taper (MT) connections with and without the application of loads. For this, the detorque of the fixing screw and the traction force required to disconnect the abutment from the implant were assessed. A total of 100 sets of implants/abutments (IAs) with MT-type connections were used, comprising five groups ( n = 20/group): (1) Group Imp 11.5: IA sets with a cone angulation of 11.5°; (2) Group SIN 11.5: with a cone angulation of 11.5°; (3) Group SIN 16: with a cone angulation of 16°; (4) Group Neo 16: with a cone angulation of 16°; and (5) Group Str 15: with a cone angulation of 15°. All sets received the torque recommended by the manufacturer. After applying the torque, the counter torque of the fixing screws was measured in ten IA sets of each group without the application of cyclic loads (frequencies ≤ 2 Hz, 360,000 cycles, and force at 150 Ncm). The other ten sets of each group were subjected to cyclic loads, after which the detorque was measured. Afterwards, the force for disconnection between the implant and the abutment was measured by traction on all the samples. The untwisting of the abutment fixation screws showed a decrease in relation to the initial torque applied in all groups. In the unloaded samples, it was found to be -25.7% in Group 1, -30.4% in Group 2, -36.8% in Group 3, -29.6% in Group 4, and -25.7% in Group 5. After the applied loads, it was found to be -44% in Group 1, -43.5% in Group 2, -48.5% in Group 3, -47.2% in Group 4, and -49.8% in Group 5. The values for the IA sets were zero for SIN 16 (Group 3) and Neo16 (Group 4), both without and with loads. In the other three groups, without loads, the disconnection value was 56.3 ± 2.21 N (Group 1), 30.7 ± 2.00 N (Group 2), and 26.0 ± 2.52 N (Group 5). After applying loads, the values were 63.5 ± 3.06 N for Group 1, 34.2 ± 2.45 N in Group 2, and 23.1 ± 1.29 N in Group 5. It was concluded that in terms of the mechanical behavior of the five designs of MT IA sets, with and without the application of loads, the Imp 11.5, SIN 11.5, and Srt 15 groups showed better results compared to the SIN 16 and Neo 16 groups, showing that lower values of cone angulation increase the friction between the parts (IA), thus avoiding the need to maintain the torque of the fixing screw to maintain the union of the sets.

Background: The goal of this in vitro study was to compare three different surfaces: two types of implant surfaces commercially available ([a] smooth/machined and [b] acid-treated surface) versus (c) anodized surface. Discs were manufactured with commercially pure titanium (CP) grade IV, which were subsequently analyzed by scanning microscopy and fibroblastic and osteoblastic cell cultures., Methods: Ninety-nine discs (5 × 2 mm) were manufactured in titanium grade IV and received different surface treatments: (i) Mach group: machined; (ii) AA group: double acid etch; and (iii) AN group: anodizing treatment. Three discs from each group were analyzed by Scanning Electron Microscopy (SEM) to obtain surface topography images and qualitatively analyzed by EDS. Balb/c 3T3 fibroblasts and pre-osteoblastic cells (MC3T3-E1 lineage) were used to investigate each group's biological response (n = 10/cellular type). The data were compared statistically using the ANOVA one-way test, considered as a statistically significant difference p < 0.05., Results: The AA group had numerous micropores with diameters between 5 and 10 μm, while nanopores between 1 and 5 nm were measured in the AN group. The EDX spectrum showed a high titanium concentration in all the analyzed samples. The contact angle and wetting tension were higher in the AA, whereas similar results were observed for the other groups. A lower result was observed for base width in the AA, which was higher in the other two groups. The AN showed the best values in the fibroblast cells, followed by Mach and AA; whereas, in the culture of the MC3T3 cells, the result was precisely the opposite (AA > Mach > AN). There was similar behavior for cell adhesion for the test groups (Mach and AN), with greater adhesion of Balb/c 3T3 fibroblasts compared to MC3T3 cells; in the AA group, there was greater adherence for MC3T3 cells compared to Balb/c 3T3 fibroblasts., Conclusions: The findings suggest that different surface characteristics can produce different biological responses, possibly cell-line dependent. These findings have important implications for the design of implantable medical devices, where the surface characteristics can significantly impact its biocompatibility., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interestsSergio Alexandre Gehrke reports was provided by Ministry of Science Technology and Innovations. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Objectives: Micromotion between a dental implant and abutment can adversely affect clinical performance and compromise successful osseointegration by creating a bacterial harbor, enabling screw loosening, and imparting disruptive lateral forces on the cortical bone. Thus, the aim of the present study was to measure the abutment stability evolution using resonance frequency analysis (RFA) in vivo at four different times (baseline, 3, 4, and 12 months), and compare these data obtained with the RFA measured after mechanical cycling (in vitro) corresponding to the proposed times in numbers of cycles., Methods: To evaluate the abutment stability, RFA was performed in 70 sets of implant/abutment (IA) with a total of 54 patients (31 women, 23 men). These IA sets were divided into three groups, according to the abutment angulation: straight abutment (Abt1 group), 17-degree angled abutment (Abt2 group), and 30-degree angled abutment (Abt3 group). Abutment stability was measured immediately at implant placement and the abutment installation (T1), 3 (T2), 4 (T3), and 12 months (T4) later. For the in vitro analysis, ten sets of each group were submitted to mechanical cycling: T1 = 0 cycles, T2 = 90,000 cycles, T3 = 120,000 cycles, and T4 = 360,000 cycles. All data collected were statistically evaluated using the GraphPad Prism 5.01 software, with the level of significance was α = 0.05., Results: In vivo, the overall data of implant stability quotient (ISQ) values obtained for all groups in each evaluation time were 61.5 ± 3.94 (95% CI: [60-63]) at T1, 62.8 ± 3.73 (95% CI, [61-64]) at T2, 63.4 ± 3.08 (95% CI: [61-64]) at T3, and 65.5 ± 4.33 (95% CI: [63-68]) at T4. Whereas in vitro, the ISQ were 61.5 ± 2.66 (95% CI: [59-63]) at T1, 63.2 ± 3.02 (95% CI, [61-65]) at T2, 63.9 ± 2.55 (95% CI: [62-66]) at T3, and 66.5 ± 2.97 (95% CI: [64-68]) at T4. In both evaluations (in vivo and in vitro), the data showed a significant difference (ANOVA test with p < 0.0001)., Conclusions: The RFA to measure the abutment stability used in this study showed that there was a progressive increase in stability among the predetermined times for the measurements, in both analysis (in vivo and in vitro). Furthermore, the values at each time point were similar, with no statistical difference between them., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

To investigate the reliability of panoramic dental images to detect calcified carotid atheroma, electronic databases (PubMed, IEEE/Xplore and Embase) were searched. Outcomes included cerebrovascular disease events, cardiovascular disease events, patient previous diseases, and combined endpoints. Risk of bias was evaluated using the Newcastle-Ottawa Scale. Hence, 15 studies were selected from 507 potential manuscripts. Five studies had a low risk of bias, while the remaining nine studies were found to have a moderate risk. Heterogeneous results were obtained but showed that patients with risk factors, such as obesity, diabetes mellitus, hypertension, and smoking, and with calcified carotid atheroma on panoramic images, have a higher prevalence than healthy patients. The evidence in the literature was found to be equivocal. However, the findings of this systematic review exhibit that panoramic radiographs can be used for dental diagnosis and treatment planning, as well as to detect calcified carotid artery atheroma.

Statement of Problem: The use of reduced platform sets (implants and abutments) can help to control crestal bone loss around implants, which is essential for optimizing esthetics and biomechanical behavior. However, the information available on the fracture resistance of implants with a reduced platform is sparse., Purpose: The purpose of this in vitro study was to analyze the maximum fracture strength value of implants with different platform designs during quasistatic fatigue, followed by a simulation of different bone levels of cervical insertion., Material and Methods: One hundred and twenty sets of dental implants and abutments with different diameters and platform designs were tested. All implants had an internal hexagon connection and conical macrogeometry. Four groups (n=30) were studied: Ø4.0-mm implants with a regular matched platform (rMatch group), Ø4.0-mm implants with a regular switched platform (PSwitch group), Ø5.0-mm implants with a wide matched platform (wMatch group), and Ø5.0-mm implants with a wide switched platform (wSwitch group). Three conditions simulating different levels of bone position around the cervical portion of the implants were proposed: insertion at the implant shoulder level=0 mm (L0), level=3 mm of insertion loss (L3), and level=5 mm of insertion loss (L5). All sets of all groups and proposed insertion level were subjected to a fracture strength test at 30 degrees in relation to the axis of the sets in a universal testing machine., Results: Regardless of the insertion levels tested, the switched platform implants (rSwitch and wSwitch groups) showed similar mean fracture strength values (P>.05), while the implants of matched platforms (rMatch and wMatch groups) showed different fracture strength values for all insertion levels tested (P<.001)., Conclusions: The fracture strength values of the switched platform implants were lower at all insertion levels tested. However, for all insertion levels tested, the implants with a switched platform presented less deformation, whereas, in the matched platform implants, there was significant deformation of the implant structure., (Copyright © 2020 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

(1) Background: contact between indigenous and European populations has often resulted in changes in oral health attributed to the introduction of sucrose. Most studies are per tooth over considerable periods and with few ethnological references. (2) Aim: dental epidemiology of 96 autochthonous frozen bodies from Yakutia between the early 17th century and the late 19th century; comparisons with historical texts and ethnographic data. (3) Material and methods: we use descriptive statistics and discriminant factorial analyses to identify dominant variables in the dataset and compare periods and subjects, considering all variables. (4) Results: the peculiarities of the population are the rarity of cavities and the relative frequency of dental pathologies leading to death. Assimilation into the Russian Orthodox culture has led to decreased tooth wear and an increase in tooth loss. Dental health evolves only two centuries after the contact. (5) Conclusions: the confrontation with historical data suggests that changes are not related to the growing importance of sucrose but to a combined action: the substitution of dendrophagy by cereal flour; the decrease in immunity linked to the development of chronic infectious diseases; tobacco addiction and the mandibular torus: a risk factor promoting apical cysts.

The aim of this study was to assess the long-term clinical behavior of straight implants in comparison with intentionally tilted dental implants (ITDI) supporting fixed restorations in partial or total edentulous arches, analyzing implant survival and success rates, complications, and marginal bone loss (MBL) after >5 years of function. An electronic search was conducted in five electronic databases (MEDLINE/Pubmed, Embase, Web of Science, Scopus, and Cochrane Central Register of Controlled Trials) supplemented by a manual search. The electronic and manual search identified 1853 articles, of which 8 articles were selected for analysis. Out of a total of 3987 dental implants, 2036 were axial dental implants and 1951 tilted. Similar results were found in implant survival or overall implant success rates. Moreover, no statistically significant differences were found in MBL ( p = 0.369; MD 0.116 mm (-0.137; 0.369) 95% CI) The prosthodontic/biological complications reported in the articles were very diverse and irregularly distributed. This systematic review suggests that there is no difference between tilted compared with straight dental implants in the medium-long term (>5 years). However, further research is needed to generate long-term data and confirm the present review's findings.

Background: Halitosis of oral origin is very common in the general population. Due to their antimicrobial properties, chlorhexidine-based products are widely used in the management of this condition, but these are associated with reversible side effects. In this study we evaluated the efficacy of Lacer Hali TM mouthrinse and toothpaste in subjects with intraoral halitosis after several applications under normal conditions of use., Methods: In this randomized clinical trial with mouth rinse and toothpaste, single-center, double-blinded, parallel participants were assigned to an experimental group (Lacer Hali TM, , n = 20), a positive control group (Halita TM , n = 20), and a placebo group ( n = 20). The active duration of the study was 18 days. The clinical follow-up evaluations were performed at five time points (T0, T1, T2, T3, and T4). The intensity of halitosis was evaluated by organoleptic measurement and the portable gas chromatograph OralChroma TM . The data were analyzed using generalized mixed linear models., Results: Sixty patients completed the study. Lacer Hali TM , in comparison with Halita TM , did not show statistically significant differences at any time during the study except for the levels of hydrogen sulfide and total volatile sulfur compounds at 15 days, where Halita TM was better. Compared to the placebo treatment, Lacer Hali TM , was significantly more efficient, in terms of both the organoleptic evaluations at 8 days and the levels of hydrogen sulfide., Conclusions: Lacer Hali TM is an alternative to chlorhexidine-based toothpaste and mouthwashes in the management of halitosis.

This systematic review and meta-analysis set out to assess the clinical behavior of mandibular implant-supported fixed complete dental prostheses (ISFCDP) on three dental implants by analyzing implant and prosthetic survival rates, marginal bone loss, biological/technical complications, and patient-reported outcomes. The review was conducted according to PRISMA guidelines. Electronic searches were conducted in the Medline (PubMed), Web of Science, and Cochrane databases, complimented by a manual search in specialist journals for relevant articles published up to February 2021. The Newcastle-Ottawa Quality Assessment Scale tool was used to assess the quality of evidence in the studies reviewed. The study included 13 articles with 728 patients treated with 2184 implants. A mean implant survival rate of 95.9% (95% CI: 94.6-97.3%) and a prosthetic survival rate of 97.0% (95% CI: 95.7-98.3%) were obtained over 1-6-year follow-up periods. Mandibular implant-supported fixed complete dental prostheses on three dental implants would appear to be a viable option for restoring the edentulous mandible in comparison with mandibular ISFCDP on more than three implants. Further comparative studies are needed, with adequate protocols, as well as sufficient sample sizes and follow-up periods to confirm these findings.

The objective of our in vivo study was to compare the effects of the osteotomy on the thermal alterations, the bone healing and count of polymorphonuclear cells, comparing the drill design (cylindrical or conical) using continuous or intermittent movement. Twelve rabbits were used, which were made four osteotomies (n = 2 per tibia) to simulate the surgical drilling sequence for the installation of a dental implant at 8 mm of length and regular diameter. Four groups were proposed: group G1, cylindrical drill with continuous movement; group G2, cylindrical drill with intermittent movement; group G3, conical drill with continuous movement; and, group G4, conical drill with intermittent movement. Thermal mean variation was 6.91 ± 1.4 °C in group 1, 4.30 ± 1.3 °C in group 2, 2.78 ± 0.6 °C in group 3, and 2.77 ± 0.7 °C in group 4. Whereas the mean area of new bone formation was 1.00 ± 0.3 mm 2 in group 1, 1.48 ± 0.3 mm 2 in group 2, 2.20 ± 0.4 mm 2 in group 3, and 2.43 ± 0.4 mm 2 in group 4. The mean count of polymorphonuclear cells, in the group 1 was 62.4 ± 5.9 cells, group 2 was 50.7 ± 4.2 cells, group 3 was 44.4 ± 3.7 cells, and group 4 was 42.4 ± 3.7 cells. The conical drill sequence produced a significantly smaller increase in temperature during both techniques (continuous and intermittent), more effective new bone formation and a smaller number of polymorphonuclear cells. During the osteotomy for the installation of implants, the professional must take to consider the drill design to perform a less traumatic surgical technique, which can improve and facilitate the healing of peri-implant tissues.

Dental caries is the most prevalent dental disease worldwide, and neural networks and artificial intelligence are increasingly being used in the field of dentistry. This systematic review aims to identify the state of the art of neural networks in caries detection and diagnosis. A search was conducted in PubMed, Institute of Electrical and Electronics Engineers (IEEE) Xplore, and ScienceDirect. Data extraction was performed independently by two reviewers. The quality of the selected studies was assessed using the Cochrane Handbook tool. Thirteen studies were included. Most of the included studies employed periapical, near-infrared light transillumination, and bitewing radiography. The image databases ranged from 87 to 3000 images, with a mean of 669 images. Seven of the included studies labeled the dental caries in each image by experienced dentists. Not all of the studies detailed how caries was defined, and not all detailed the type of carious lesion detected. Each study included in this review used a different neural network and different outcome metrics. All this variability complicates the conclusions that can be made about the reliability or not of a neural network to detect and diagnose caries. A comparison between neural network and dentist results is also necessary.

Bone plays an important role in dental implant treatment success. The goal of this literature review is to analyze the influence of bone definition and finite element parameters on stress in dental implants and bone in numerical studies. A search was conducted of Pubmed, Science Direct and LILACS, and two independent reviewers performed the data extraction. The quality of the selected studies was assessed using the Cochrane Handbook tool for clinical trials. Seventeen studies were included. Titanium was the most commonly-used material in dental implants. The magnitude of the applied loads varied from 15 to 300 N with a mean of 182 N. Complete osseointegration was the most common boundary condition. Evidence from this review suggests that bone is commonly defined as an isotropic material, despite being an anisotropic tissue, and that it is analyzed as a ductile material, instead of as a fragile material. In addition, and in view of the data analyzed in this review, it can be concluded that there is no standardization for conducting finite element studies in the field of dentistry. Convergence criteria are only detailed in two of the studies included in this review, although they are a key factor in obtaining accurate results in numerical studies. It is therefore necessary to implement a methodology that indicates which parameters a numerical simulation must include, as well as how the results should be analyzed.

The objective of this study was to analyze three-dimensionally the morphological characteristics of the pterygomaxillary region related to pterygoid implants. Volume, height, width and bone density were studied in relation to age, sex and dental status. This retrospective observational study analyzed the CBCT of 52 hemi-maxillas three-dimensionally (females n = 28, males n = 24; dentate = 31, edentulous = 21). Patients were exposed between September 2009 and October 2014, and data collection was performed between November 2015 and May 2016. Bone density, volume, height and width were analyzed in various locations of the maxilla and pterygoid process, and the variables age, gender and dental status patients were compared. The results show that the mean width of the pterygomaxillary joint was 7.5 mm (SD 1.00 mm), mean height was 12.51 mm (SD 1,82 mm) and mean volume was 321.7 mm 3 (SD 142.02 mm 3 ). Statistically significant differences between dentate and edentulous patients were found, showing a higher osseous density in dentate patients in the pterygoid process (758.2, SD 106.8, 95% CI 729.2 to 787.3 GSD - Gray Scale Density - compared to 689.9, SD 107.3, 95% CI 660.8 to 719.1 GSD; P = 0.022). In the maxilla, density was statistically significant lower in female subjects (571.0, SD 74.1, 95% CI 594.9 to 645.4 GSD) than in male subjects (620.2, SD 93.8, 95% CI 594.4 to 645.4 GSD, P = 0.047). In conclusion, due to the significant variation in the morphological characteristics of the pterygomaxillary region among subjects, personalized pre-surgical radiological assessment should always be performed. Gender, age and dental status are critical factors as they significantly affect bone density in this region.

The aim of this study was to estimate the age of subjects from their dental age by showing the different stages of tooth development using the Nolla method in a Spanish population sample considering the gender, age group, and the development of the two dental arches. The sample consisted of 604 orthopantomographs corresponding to Spanish children (male: 302 and female: 302) aged from 4 to 14 years old. The resulting chronological and dental ages were compared using Student's t-test. We obtained a good index of agreement between the evaluators and good internal consistency in the evaluation of the ages of the teeth. In general, the dental age estimates were lower than the chronological ages, obtaining an underestimation with the application of the Nolla method. In the male group, the average dental age of the maxillary teeth was 8.36 years and that of the mandibular teeth was 8.40 years, compared to the chronological age of 8.84 years in both cases. In the female group, the average dental age of the maxillary teeth was 7.76 years and that of the mandibular teeth was 7.88 years, compared to the chronological age of 8.70 years in both cases. On applying the Nolla method to our sample, a significant overestimation was observed only in children aged between 4 and 6.9 years. The Nolla method can be used as a complementary tool for estimating age in children of Spanish origin. The application of this method is more favourable in the case of individuals evaluated under the law applied to minors. In general, with this method, age is underestimated, but the calculations involved are reliable, and greater precision has been observed in male than in female. The data from this study can be used as a reference to determine the dental maturity of Spanish children and to estimate their ages., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: The goal of this study was to analyze the stress distribution on two types of extra-short dental implants with 5 mm of length: An internal hexagon (IH) and morse taper connection (MT)., Methods: The three-dimensional model was composed of trabecular and cortical bone, a crown, an extra-short dental implant and their components. An axial load of 150 N was applied and another inclined 30° with the same magnitude., Results: Stress concentrations on the IH implant are observed in the region of the first threads for the screw. However, in the MT implant the highest stress occurs at the edges of the upper implant platform., Conclusions: In view of the results obtained in this study the two types of prosthetic fittings present a good stress distribution. The Morse taper connections presented better behavior than the internal in both loading configurations., Competing Interests: The authors declare no conflict of interest.

Objectives: The aim of this study was to perform an in vivo histological comparative evaluation of bone formation around titanium (machined and treated surface) and zirconia implants. For the present study were used 50 commercially pure titanium implants grade IV, being that 25 implants with a machined surface (TiM group), 25 implants with a treated surface (TiT group) and, 25 implants were manufactured in pure zirconia (Zr group). The implants ( n = 20 per group) were installed in the tibia of 10 rabbits. The implants distribution was randomized ( n = 3 implants per tibia). Five implants of each group were analyzed by scanning electron microscopy and an optical laser profilometer for surface roughness characterization. Six weeks after the implantation, 10 implants for each group were removed in counter-torque for analysis of maximum torque value. The remaining samples were processed, included in historesin and cut to obtain non-decalcified slides for histomorphological analyses and histomorphometric measurement of the percentage of bone-implant contact (BIC%). Comparisons were made between the groups using a 5% level of significance ( p < 0.05) to assess statistical differences. The results of removal torque values (mean ± standard deviation) showed for the TiM group 15.9 ± 4.18 N cm, for TiT group 27.9 ± 5.15 N cm and for Zr group 11.5 ± 2.92 N cm, with significant statistical difference between the groups ( p < 0.0001). However, the BIC% presented similar values for all groups (35.4 ± 4.54 for TiM group, 37.8 ± 4.84 for TiT group and 34.0 ± 6.82 for Zr group), with no statistical differences ( p = 0.2171). Within the limitations of the present study, the findings suggest that the quality of the new bone tissue formed around the titanium implants present a superior density (maturation) in comparison to the zirconia implants.

To evaluate the bending and torsional properties of four nickel-titanium endodontic files, we simulated and compared WaveOne® primary size 25 with 0.07 taper, WaveOne Gold® primary size 25 with 0.07 taper, Reciproc® primary size 25 with 0.08 taper, and Reciproc Blue® primary size 25 with 0.08 taper. Three-dimensional models were created using computer-aided design software and numerically analyzed in ANSYS® Workbench. Boundary conditions for the numerical analyses were based on the ISO 3630-1 specifications. The highest stress levels were recorded for WaveOne® and Reciproc®. Numerical results of the bending test showed that WaveOne Gold® is 86% more flexible than WaveOne® with a deflection of 3 mm. Reciproc Blue® was 42.31% more flexible than Reciproc® file with a deflection of 3 mm. The WaveOne® instrument withstood the highest stress under the torsion test, followed by Reciproc®, then Reciproc Blue® files. The stress under torsion in the WaveOne® and WaveOne Gold® files is reduced in a 51%. Regarding Reciproc® and Reciproc Blue® files, the stress under torsional moments remains very similar. Our results exposed a considerable difference in terms of stress tolerance between WaveOne® and WaveOne Gold®. However, Reciproc® files demonstrated a similar stress distribution. The results obtained through finite element analysis suggest that thermal treatment of files might improve their flexibility, increasing resistance during the preparation of highly curved canals. Also, the values obtained regarding the improvement of flexibility were in accordance with the manufacturer claims., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The aim of this study was to fully characterize the mechanical behavior of an external hexagonal implant connection (ø3.5 mm, 10-mm length) with an in vitro study, a three-dimensional finite element analysis, and a probabilistic fatigue study. Ten implant-abutment assemblies were randomly divided into two groups, five were subjected to a fracture test to obtain the maximum fracture load, and the remaining were exposed to a fatigue test with 360,000 cycles of 150 ± 10 N. After mechanical cycling, all samples were attached to the torque-testing machine and the removal torque was measured in Newton centimeters. A finite element analysis (FEA) was then executed in ANSYS® to verify all results obtained in the mechanical tests. Finally, due to the randomness of the fatigue phenomenon, a probabilistic fatigue model was computed to obtain the probability of failure associated with each cycle load. FEA demonstrated that the fracture corresponded with a maximum stress of 2454 MPa obtained in the in vitro fracture test. Mean life was verified by the three methods. Results obtained by the FEA, the in vitro test, and the probabilistic approaches were in accordance. Under these conditions, no mechanical etiology failure is expected to occur up to 100,000 cycles. Graphical abstract ᅟ.

Objective: The aim of this study was to evaluate the effect of topical applications of melatonin and apigenin (4',5,7-trihydroxyflavone) on new bone formation in post-extraction sockets after 30, 60 and 90 days., Materials and Methods: Six American fox hounds were used in the study, extracting mandibular premolars (P2, P3 and P4) and first molar (M1). Melatonin or apigenin impregnated in collagen sponges were applied at P3, P4 and M1 sites in both hemimandibles; P2 sites were used as control sites. Bone biopsies were taken at 30, 60 and 90 days and stained with hematoxylin-eosin., Results: At 30 days, a higher percentage of immature bone was observed in the control group (58.11 ± 1.76%) than in the apigenin (34.11 ± 1.02%) and melatonin groups (24.9 ± 0.14%) with significant differences between the three groups (P < 0.05). At 60 days, results were significantly better at melatonin sites (10.34 ± 1.09%) than apigenin (19.22 ± 0.35%) and control sites (36.7 ± 1.11%) (P < 0.05). At 90 days, immature bone percentages were similar for all groups. New bone formation was higher in melatonin group (79.56 ± 1.9%) than apigenin (68.89 ± 1.5%) and control group (58.87 ± 0.12%)., Conclusions: Topical applications of either melatonin or apigenin have a potential to accelerate bone tissue in early healing stages; melatonin was seen to have stimulated bone maturation to a greater extent at the 60 days of follow-up., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Purpose: The goal of this study was to foresee the fatigue life of two implant connections, evaluate the failure probability with several bone levels, and compare the in vitro test results with finite element results., Materials and Methods: Mechanical tests were done with 60 implants (Ø3.50 mm), and abutments were used. These implants were divided into two groups with 30 implants each: internal hexagon and Morse taper. Three bone levels and 10 implants for each level were analyzed. The first level was considered at the platform level, the second at 3 mm, and the last level at 5 mm above the platform resin. A quasi-static loading at 30 degrees was applied to the axis of the implant in a universal machine. Six models were created and assembled to reproduce the conditions used in the laboratory testing. All models had restricted all displacement at the bone (bottom and lateral). Loads employed in the numerical test were obtained experimentally. Loads and material properties were supposed to be random. Then, failure probability was calculated by the probabilistic methodology., Results: The internal hexagon group obtained the following mean fracture strengths: 2,092 N at the first level, 1,041 N at the second level, and 898 N at the third level. The mean fracture strengths for the Morse taper group were as follows: 1,687 N at the first level, 1,644 N at the second level, and 1,159 N at the third level. Results obtained by the finite element analysis are in accordance with the in vitro mechanical test results. The Morse taper group obtained a better behavior at bone levels 2 and 3 than the internal hexagon group. An important dependency between failure probability and bone level was found in the internal hexagon group. However, a similar behavior in levels 2 and 3 was obtained for the Morse taper group., Conclusion: In view of the mechanical results, the Morse taper group has a better behavior in bone levels 2 and 3 than the internal hexagon group. This is also in accordance with the probabilistic fatigue outcomes.

Porous ceramics doped with silicon and pure β-TCP were analyzed in terms of internal microstructure, cell behavior, and the percentage of newly formed bone. Additionally the materials were tested to determine which of the two had better properties to load and release vancomycin hydrochloride. Internal pore distribution and porosity were determined through high pressure mercury porosimetry and the specific surface area was measured by the Brunauer Emmet-Teller method. The proliferation and viability of the human osteoblast-like cell line MG-63 was studied to validate both materials. The materials were tested on eight New Zealand rabbits which created defects, 10 mm in diameter, in the calvaria bone. After 8 and 12 weeks a histological and histomorphometric analysis was performed. Si-β-TCP showed a higher porosity and specific surface area. The cytocompatibility test revealed acceptable results in terms of proliferation and viability whereas the percentage of new bone was higher in Si-β-TCP with a two-time study being statistically significant with 12 weeks of healing (p < 0.05).The vancomycin loaded within the ceramic scaffolds were burst released and the material had the ability to inhibit bacterial growth. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2307-2315, 2018., (© 2017 Wiley Periodicals, Inc.)

Objectives: The present study aims to compare the drilling protocol effect on osseointegration event in three commercially available titanium dental implants with different drill protocol using a rabbit tibia model., Materials and Methods: Three different drilling sequences were compared as follows: drilling sequence using a single unique drill of 4.2 mm conical implant (Group 1), drilling sequence using 3 consecutive cylindrical drills for a 4.1 mm cylindrical implant (Group 2), and drilling sequence using 3 consecutive conical drills for a 4.3 mm conical implant (Group 3). For each group, 18 drilling procedures and implant placements were performed, totalizing 54 commercially available titanium dental implants. The samples were removed 6 weeks after implantation. Resonance frequency analyses (RFA) were performed immediately after the implantation, and at 6 weeks removal torque test (RTt) and histological analysis were performed., Results: The RFA measured showed statistical difference between the groups in time 1 and no significant statistical differences in time 2 ( p > 0.05). In the RTt no significant difference was found between the 3 groups tested. Histomorphometric analysis showed no significant difference between groups in the bone-to-implant contact% ( p > 0.05)., Conclusion: In the present preclinical study, osteotomy using a single bur did not show differences regarding the proposed and evaluated tests parameters for assessing the peri-implant behavior.

Purpose: This study aimed to evaluate the misfit of three different implant-abutment connections before and after cycling load., Materials and Methods: One hundred twenty dental implants and correspondent prefabricated titanium abutments were used. Three different implant-abutment connections were evaluated: Morse taper (MT group), external hexagon (EH group), and internal hexagon (IH group). Forty implants and 40 abutments were used per group. The parameters for the mechanical evaluation were set as: 360,000 cycles, load of 150 N, and frequency of 4 Hz. Samples were sectioned in their longitudinal and transversal axes, and the misfit of the implant-abutment connection was evaluated by scanning electron microscopy analysis. One-way analyses of variance, Tukey post hoc analyses (α = .05), and t test (P < .05) were used to determine differences between groups., Results: At the longitudinal direction, all the groups showed the presence of microgaps before cycling load; after cycling load, microgaps were reduced in all groups (P > .05). Transversally, only the MT group showed full fitting after cycling load compared with the other groups (EH and IH) (P < .0001)., Conclusion: The application of cycling load produces an accommodation of the implant-abutment connection in internal, external, and Morse taper connections. In the longitudinal direction, the accommodation decreases and/or eliminates the gap observed initially (before load). In the horizontal direction, Morse cone implant-abutment connections experience a complete accommodation with the elimination of the gap.

Introduction: Calcifying odontogenic cysts (COC) represent 0.3-0.8% of all odontogenic cysts. We describe the finding and the treatment of a COC in a 67-year-old female., Observation: An asymptomatic well-limited radioluscent mandibular lesion was fortuitously discovered on the panoramic X-ray in the periapical region of teeth No. 33 and 34. Treatment consisted in enucleation and curettage. Histologic examination was in favour of a COC. At 6 years follow-up, X-ray control showed new bone formation and the patient was free of symptoms. Pulp vitality was maintained in all teeth in the operated area., Discussion: Total enucleation is the preferred treatment of COC. Absence of recurrence is attested by X-ray controls and pulp vitality tests., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Objectives: The aim of this study is to evaluate the effect of the surface modification and cervical implant design on the bone remodeling in implants installed at the crestal and subcrestal bone level., Methods: Ten American Fox Hound of approximately 1 year of age, each weighing approximately 14 to 15 kg, were used for this study. Two different dental implant macrodesign were used: cylindric-conical with 3.5 mm of diameter and 9 in length (implant A) and conical with 2.9 mm of diameter and 9 mm in length (implant B). Two surfaces were used: sandblasting and acid etching (surface 1) and sandblasting and acid etching, then maintained in an isotonic solution of 0.9% sodium chloride (surface 2). Four groups were performed (n = 20 implants): Group A1 (implant A with the surface 1), Group A2 (implant A with surface 2), Group B1 (implant B with surface 1), and Group B2 (implant B with surface 2). The mandibular premolars and molars (P1, P2, P3, M1) were removed and, after 2 months of healing, implants were inserted at the crestal and 2 mm subcrestal position related to the buccal bone level. Analysis was performed at 4 and 8 weeks. Histomorphometry with longitudinal measurements and bone implant contact, bone remodeling and implant stability quotient analysis were realized., Results: The surface 2 showed to get more close contact between implant and new bone formed after implant placement and more stability surrounding platform both at 4 and 8 weeks. Surface 2 groups and subrestally placed showed to have better results in terms of linear measurements, with less bone loss and soft tissue distance to the IS. The data showed significant differences among the groups (P < 0.001)., Conclusions: Surface modification (surface 2) has shown to be an effective alternative to conventional surface with better results in situations placed subcrestally and combined with implant design.

Purpose: The aim of this study was to investigate the prevalence and length of the anterior loop (AL), the distance from this landmark to the alveolar crest and its relation with the shape of the foramen and emergency pattern in the Spanish population on helical computed tomography scan (helical CT scan) through tridimensional reconstructions., Methods: Helical CT scan images of 41 patients aged 65 or older were analyzed. A total of 82 human hemi-mandibles were examined in this study. A tridimensional reconstruction of each mandible and Inferior Alveolar Nerve canal was created in AMIRA ® software (AMIRA, Mercury Computer Systems, Berlin, Germany). Prevalence, length and distance between the AL, mental foramen and alveolar ridge were measured. This retrospective observational study was performed according to the STROBE guidelines., Results: Prevalence of the AL was 53.7 % (n = 44) and the mean length was 1.3 ± 0.64 mm. The mean distance from the highest point of the loop to the alveolar ridge was 13.4 ± 2.8 mm. The mean diameter of the mental foramen was 3.5 ± 0.65 mm and the proportion of the oval-shaped was 62.2 % (n = 51) and round-shaped was 37.8 % (n = 31). The study found that patients with type 1 pattern emergency pattern had a higher prevalence of the AL (p = 0.03)., Conclusions: Prevalence, location and length of the anterior loop can be overlooked if only two-dimensional pre-surgical studies are performed. Therefore, three-dimensional imaging and modeling of anatomic structures should be used for the pre-operative examination of the interforaminal area. Given the wide variability of the emergency pattern of the mental nerve and the prevalence and location of the anterior loop, it should be studied in every patient individually.

Calcium phosphate materials (CPM) are widely used in dentistry and maxillofacial surgery. The presence of microbial biofilms and external infections is responsible for the failure of many procedures of dental implants and bone grafts. In an attempt to reduce the percentage of these infectious processes antibiotics have been associated with CPM improving certain conditions. For instance, antibiotics administered orally or intravenously have less effect and the blood flow in relation to this is poor near implants and grafts. Tissue engineering (TE) has employed CPM as a local drug delivery vehicle to be more effective and efficient in bone infections. This review is presented to describe current antibiotics used and the physical and chemical properties of scaffolds., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

The aim of this study was to predict the fatigue life of two different connections of a dental implant as in load transfer to bone. Two three-dimensional models were created and assembled. All models were subjected to a natural masticatory force of 118 N in the angle of 75° to the occlusal plane. All degrees of freedom in the inferior border of the cortical bone were restrained, and the mesial and distal borders of the end of the bone section were constrained. Fatigue material data and loads were assumed as random variables. Maximum principal stresses on bone were evaluated. Then, the probability of failure was obtained by the probabilistic approach. The maximum principal stress distribution predicted in the cortical and trabecular bone is 32 MPa for external connection and 39 MPa for internal connection. A mean life of 103 and 210 million cycles were obtained for external and internal connection, respectively. Probability cumulative function was also evaluated for both connection types. This stochastic model employs a cumulative damage model and probabilistic finite element method. This methodology allows the possibility of measured uncertainties and has a good precision on the results.

To measure fatigue in dental implants and in its components, it is necessary to use a probabilistic analysis since the randomness in the output depends on a number of parameters (such as fatigue properties of titanium and applied loads, unknown beforehand as they depend on mastication habits). The purpose is to apply a probabilistic approximation in order to predict fatigue life, taking into account the randomness of variables. More accuracy on the results has been obtained by taking into account different load blocks with different amplitudes, as happens with bite forces during the day and allowing us to know how effects have different type of bruxism on the piece analysed.

The objectives of this study were to evaluate the survival after 5 years of implants placed using inferior alveolar nerve (IAN) lateralization in cases of mandibular atrophy and to determine the incidence of complications. Twenty-seven patients received 74 implants by means of the IAN lateralization technique. Implant survival after 5 years of loading was 98.6%. Eighteen months after surgery, the recovery of sensitivity was complete in 26 cases. Implant placement with IAN lateralization was seen to be a satisfactory and predictable technique. IAN lateralization requires a high level of technical skill, and strict criteria should be applied when prescribing this treatment., (Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Low-level laser therapy (LLLT) has proved to have biostimulating effects on tissues over which they are applied, therefore accelerating the healing process. Most studies in implantology were focused on a reduction of the duration of osseointegration. There exist few articles analyzing the potential effects of these therapies on the osseointegration of titanium dental implants. The aim of this study was to assess the effect of LLLT on the interaction between the bone and the titanium dental implant and the methodological quality of the studies. We conducted an electronic search in PubMed, ISI Web, and Cochrane Library. From 37 references obtained, only 14 articles met the inclusion criteria. The analysis of the studies shows that most of the experiments were performed in animals, which have a high risk of bias from the methodological point of view. Only two studies were conducted in human bone under different conditions. Several protocols for the use of low-power laser and different types of laser for all studies analyzed were used. Although animal studies have shown a positive effect on osseointegration of titanium implants, it can be concluded that it is necessary to improve and define a unique protocol to offer a more conclusive result by meta-analysis.

Purpose: The aim of this report is to present photogrammetry as a reliable step in the fabrication of a full-arch immediate rehabilitation., Materials and Methods: A 59-year-old man attended the department seeking dental rehabilitation for the sequelae of severe oral health neglect. The mandibular teeth suffered from advanced periodontal disease and the patient wore a maxillary complete denture. An irreversible hydrocolloid impression of the mandibular arch was made, poured in stone, and digitally scanned to create the first stereolithography (STL) file. All teeth with the exception of two retained as landmarks were extracted, and seven implants were placed under local anesthesia and their positions recorded using photogrammetry. Maxillary and mandibular dental arch alginate impressions were made, poured in laboratory stone, and scanned. A provisional restoration was placed 7 hours after surgery using the STL files to determine the best-fit line., Results: Radiographic and clinical follow-up after 1 year showed a favorable evolution of the implants. No screw loosening or other mechanical or biologic complications were observed., Conclusion: The case history using the described system suggests certain advantages over conventional techniques. More research is needed to assess the possible benefits associated with photogrammetry when making implant-supported restorations.

The aim of this retrospective radiological study was to evaluate the variability of the mandibular anatomy in the presence and absence of teeth and to consider how it could influence implant planning. 187 mandibular CT DentaScans were selected from our department archive according to the inclusion criteria. The axial height, vertical height, angulation of the bone crest, and the bone available for ideal implant placement were measured. The analysis of the data shows that the mandible contour presents a constant degree of angulation. The variation of angulation in the absence of teeth was statistically significant only in the region between the canine and the first premolar and in that between the second premolar and the first molar. The difference between the crest height and the available distance to place the implant was greater in the region of the second molar while in the other regions the implant planning was made complex by postextraction resorption. Alveolar bone resorption after tooth loss can be considered as a risk factor for lingual cortical perforation during the insertion of an implant. To avoid potential intra/postoperative complications, 3D radiographic examination is recommended in order to study the mandibular anatomy and identify the risk areas.

It is well known that dental implants have a high success rate but even so, there are a lot of factors that can cause dental implants failure. Fatigue is very sensitive to many variables involved in this phenomenon. This paper takes a close look at fatigue analysis and explains a new method to study fatigue from a probabilistic point of view, based on a cumulative damage model and probabilistic finite elements, with the goal of obtaining the expected life and the probability of failure. Two different dental implants were analysed. The model simulated a load of 178 N applied with an angle of 0°, 15°, and 20° and a force of 489 N with the same angles. Von Mises stress distribution was evaluated and once the methodology proposed here was used, the statistic of the fatigue life and the probability cumulative function were obtained. This function allows us to relate each cycle life with its probability of failure. Cylindrical implant has a worst behaviour under the same loading force compared to the conical implant analysed here. Methodology employed in the present study provides very accuracy results because all possible uncertainties have been taken in mind from the beginning.

The aim of this study was to evaluate the effectiveness of techniques for soft tissue augmentation in the placement of immediate implants with and without provisionalization and to assess the quality of the reports in the literature. Randomized clinical trials, prospective clinical trials, and case series were included in this review. Clinical questions were formulated and organised according to the PICOS strategy. An electronic search was performed in PubMed, Cochrane Central Register of Controlled Trials, Scopus, and ISI Web up until June 2016. Interexaminer agreement on eligibility (k = 0.842; p = 0.103) and quality (k = 0.933; p < 0.001) was high. Methodological approaches were assessed using criteria based on design related forms designed by the Dutch Cochrane Collaboration. Finally, 14 papers were identified. In two studies, the implant survival was 90%; for the rest of the studies it was 100%. All studies reported favourable aesthetic, biological, and radiographic outcomes. Surgical and biomechanical complications of this technique were not relevant. This technique effectively compensates for the expected loss of volume of the oral soft tissues and maintains high success rates with good aesthetic results over time.

Self-reporting is the most widely used pain measurement tool, although it may not be useful in patients with loss or deficit in communication skills. The aim of this paper was to undertake a systematic review of the literature of pain assessment through the Facial Action Coding System (FACS). The initial search found 4,335 references and, within the restriction «FACS», these were reduced to 40 (after exclusion of duplicates). Finally, only 26 articles meeting the inclusion criteria were included. Methodological quality was assessed using the GRADE system. Most patients were adults and elderly health conditions, or cognitive deficits and/or chronic pain. Our conclusion is that FACS is a reliable and objective tool in the detection and quantification of pain in all patients., (Copyright © 2014 Elsevier España, S.L.U. All rights reserved.)

β-tricalcium phosphate (β-TCP) is an osteoconductive and biodegradable material used in bone regeneration procedures, while iron has been suggested as a tool to improve the biological performance of calcium phosphate-based materials. However, the mechanisms of interaction between these materials and human cells are not fully understood. In order to clarify this relationship, we have studied the iron role in β-TCP ceramics. Iron-containing β-TCPs were prepared by replacing CaCO3 with C6H5FeO7 at different molar ratios. X-ray diffraction analysis indicated the occurrence of β-TCP as the sole phase in the pure β-TCP and iron-containing ceramics. The incorporation of iron ions in the β-TCP lattice decreased the specific surface area as the pore size was shifted toward meso- and/or macropores. Furthermore, the human osteoblastlike cell line MG-63 was cultured onto the ceramics to determine cell proliferation and viability, and it was observed that the iron-β-TCP ceramics have better cytocompatibility than pure β-TCP. Finally, in vivo assays were performed using rabbit calvaria as a bone model. The scaffolds were implanted for 8 and 12 weeks in the defects created in the skullcap with pure β-TCP as the control. The in vivo behavior, in terms of new bone formed, degradation, and residual graft material were investigated using sequential histological evaluations and histomorphometric analysis. The in vivo implantation of the ceramics showed enhanced bone tissue formation and scaffold degradation for iron-β-TCPs. Thus, iron appears to be a useful tool to enhance the osteoconductive properties of calcium phosphate ceramics.

Background: The purpose of this study was to delineate the relationship of the terminal extensor hallucis longus tendon insertion to the proximal limit of the nail matrix of the great toe., Material and Methods: Fifty fresh-frozen human cadaver great toes with no evidence of trauma (average age, 62.5 years; 29 males and 21 females) were used for this study. Under 25X magnification, the proximal limit of the nail matrix and the terminal bony insertion of the extensor hallucis longus tendons were identified. The distance from the terminal tendon insertion to the nail matrix was ascertained using precision calipers, an optical microscope, and autocad(®) software for windows. Twenty-five great toes were placed in a neutral formalin solution and further analysed by histological longitudinal-sections. The specimens were stained with haematoxylin and eosin and examined microscopically to determine the presence of the extensor hallucis longus tendon along the dorsal aspect of the distal phalanx of each great toe., Results: The main result we found in great toes was that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx in all, 100%, specimens. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of the distal phalanx as is the case for fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone., Conclusions: We have found that the extensor tendon is between the matrix and the phalanx and extends dorsally to the distal aspect of the distal phalanx. The nail matrix of the great toe is not attached to the periosteum of the dorsal aspect of the base of distal phalanx as is the case in fingers, because the extensor hallucis tendon is plantar or directly underneath the nail matrix and the tendon is dorsal to the bone. Our anatomic study demonstrates that the proximal limit of the matrix and nail bed of the human great toe are dorsal and overlapping the terminal extensor hallucis longus tendon until its distal bony insertion in all specimens., (© 2015 European Academy of Dermatology and Venereology.)

Background: Knowing that patients desire reduced duration of local anesthesia, the authors performed a meta-analysis to evaluate the efficacy of phentolamine mesylate (PM) in reducing anesthesia duration and the occurrence of adverse effects., Types of Studies Reviewed: The authors searched studies in 4 electronic databases up to December 18, 2014. For each study, the methodological quality was assessed according to the Cochrane Collaboration's tool for assessing risk of bias. Randomized controlled trials (RCTs) that used PM met the inclusion criteria., Results: Six RCTs met the inclusion criteria and were used to carry out a meta-analysis of the effectiveness of PM and a qualitative analysis of its adverse effects. The use of PM was more effective in reversing the anesthetic effect on the lower lip and tongue than was applying a placebo. Adverse effects reported in the studies were not statistically significant, the most frequent being headache, pain during injection, and postprocedure pain., Conclusions and Practical Implications: Based on limited evidence, PM is effective in reducing the persistence of anesthesia duration on the lower lip and tongue, with infrequent adverse effects of little clinical significance., (Copyright © 2015 American Dental Association. Published by Elsevier Inc. All rights reserved.)

This study was conducted to develop novel ceramic bone substitute that resembles the autologous bone behavior when used as graft material. Solid-state reaction at 1100°C was performed to synthesize β-tricalcium phosphate (β-TCP) and biphasic calcium phosphate (BCP). The ceramics were further analyzed to characterize phase composition, microstructural properties, cytocompatability and then challenged to regenerate critical bone defects in the parietal bone of rabbits. X-ray diffraction analysis confirmed the production of β-TCP and indicated the synthesis of novel BCP composed of β-TCP and silicocarnotite (calcium phosphate silicate mineral). The cytocompatibility test with human osteoblast cell line revealed enhanced cell proliferation on the BCP ceramic. The novel BCP induced the filling of about 73% of the bone defect with a newly formed bone tissue and an almost complete degradation after 12 weeks of healing. This novel ceramic resembles the autologous bone properties of complete degradation and efficient enhancement of bone formation, making it promising as bone graft material., (© 2014 Wiley Periodicals, Inc.)

Objective: To show how random variables concern fatigue behaviour by a probabilistic finite element method., Methods: Uncertainties on material properties due to the existence of defects that cause material elastic constant are not the same in the whole dental implant the dimensions of the structural element and load history have a decisive influence on the fatigue process and therefore on the life of a dental implant. In order to measure these uncertainties, we used a method based on Markoff chains, Bogdanoff and Kozin cumulative damage model, and probabilistic finite elements method., Results: The results have been obtained by conventional and probabilistic methods. Mathematical models obtained the same result regarding fatigue life; however, the probabilistic model obtained a greater mean life but with more information because of the cumulative probability function., Conclusions: The present paper introduces an improved procedure to study fatigue behaviour in order to know statistics of the fatigue life (mean and variance) and its probability of failure (fatigue life versus probability of failure).

Objectives: This study aims to evaluate the in situ antibacterial activity of a mouthwash containing essential oils (M-EO) on undisturbed de novo plaque-like biofilm (PL-biofilm) up to 7 h after its application., Patients and Methods: An appliance was designed to hold six glass disks on the buccal sides of the lower teeth, allowing PL-biofilm growth. Fifteen healthy volunteers wore the appliance for 48 h and then performed a M-EO. Disks were removed after 30 s and at 1, 3, 5, and 7 h later. After a washout period, the same procedure was repeated with a M-WATER and a M-0.2 % chlorhexidine. After PL-biofilm vital staining, samples were analyzed using a confocal laser scanning microscope., Results: At 30 s after M-EO, the levels of bacterial vitality were 1.18 %, significantly lower than that of the basal sample (p < 0.001). After 7 h, the antibacterial effect of essential oils was still patent with a 47.86 % difference in bacterial vitality compared to the basal sample (p < 0.001)., Conclusion: A single M-EO presents high antibacterial immediate activity and penetration capacity in situ and a substantivity which lasts for at least 7 h after its application over de novo biofilm. These results were better than those observed with 0.2 % chlorhexidine under the same conditions., Clinical Relevance: A single M-EO is an effective measure against the de novo biofilm, presenting a good alternative to clorhexidine such as a preoperative rinse, in periodontal procedures or post-treatment applications.

During the course of human evolution, the retraction of the face underneath the braincase, and closer to the cervical column, has reduced the horizontal dimension of the vocal tract. By contrast, the relative size of the tongue has not been reduced, implying a rearrangement of the space at the back of the vocal tract to allow breathing and swallowing. This may have left a morphological signature such as a chin (mental prominence) that can potentially be interpreted in Homo. Long considered an autopomorphic trait of Homo sapiens, various extinct hominins show different forms of mental prominence. These features may be the evolutionary by-product of equivalent developmental constraints correlated with an enlarged tongue. In order to investigate developmental mechanisms related to this hypothesis, we compare modern 34 human infants against 8 chimpanzee fetuses, whom development of the mandibular symphysis passes through similar stages. The study sets out to test that the shared ontogenetic shape changes of the symphysis observed in both species are driven by the same factor--space restriction at the back of the vocal tract and the associated arrangement of the tongue and hyoid bone. We apply geometric morphometric methods to extensive three-dimensional anatomical landmarks and semilandmarks configuration, capturing the geometry of the cervico-craniofacial complex including the hyoid bone, tongue muscle and the mandible. We demonstrate that in both species, the forward displacement of the mental region derives from the arrangement of the tongue and hyoid bone, in order to cope with the relative horizontal narrowing of the oral cavity. Because humans and chimpanzees share this pattern of developmental integration, the different forms of mental prominence seen in some extinct hominids likely originate from equivalent ontogenetic constraints. Variations in this process could account for similar morphologies.

The ontogenetic development of the mental region still poses a number of unresolved questions in human growth, development and phylogeny. In our study we examine the hypotheses of DuBrul & Sicher (1954) (The Adaptive Chin. Springfield, IL: Charles) and Enlow (1990) (Facial Growth, 3rd edn. Philadelphia, PA: Saunders) to explain the presence of a prominent mental region in anatomically modern humans. In particular, we test whether the prominence of the mental region and the positioning of the teeth are both correlated with the developmental relocation of the tongue and the suprahyoid muscles inserting at the lingual side of the symphysis. Furthermore, we test whether the development of the mental region is associated with the development of the back of the vocal tract. Using geometric morphometric methods, we measured the 3D mandibular and tooth surfaces in a cross-sectional sample of 36 CT-scanned living humans, incorporating the positions of the tongue and the geniohyoid and digastric muscle insertions. The specimens' ages range from birth to the complete emergence of the deciduous dentition. We used multivariate regression and two-block partial least squares (PLS) analysis to study the covariation among the mental region, the muscle insertions, and the teeth both across and within age stages. In order to confirm our results from the 3D cross-sectional sample, and to relate them to facial growth and the position of the cervical column and the hyoid bone, we used 46 lateral radiographs of eight children from the longitudinal Denver Growth Study. The 3D analysis demonstrates that the lingual side of the lower border of the symphysis develops downwards and forwards. These shape changes are significantly correlated with the relocation of muscle insertion sites and also with the vertical reorientation of the anterior teeth prior to emergence. The 2D analysis confirms the idea that as the mental region prominence develops, the space of the laryngopharynx becomes restricted due to upper mid-face retraction and the acquisition of upright body posture. In agreement with the hypotheses of DuBrul & Sicher (1954) and Enlow (1990), our results suggest that the presence of a prominent mental region responds to the space restriction at the back of the vocal tract, and to the packaging of the tongue and suprahyoid muscles in order to preserve the functionality of the laryngopharynx during respiration, feeding and speech., (© 2012 The Authors Journal of Anatomy © 2012 Anatomical Society.)