Summary Objectives: The clinical management of bisphosphonate-related osteonecrosis of the jaw (BRONJ) remains controversial. Since universally accepted guidelines have not been released yet, ...clinicians usually chose the type of treatment according to position papers based on expert opinion, or on empirical experience. The aim of this systematic review is to identify different therapeutical approaches for BRONJ that have been described in literature and to describe their effectiveness. Materials and Methods: A Medline via Pubmed and Scopus database literature search was conducted and all publications fulfilling the inclusion and exclusion criteria were included in eligibility assessment. The full texts of 146 retrieved articles were then screened and 40 studies were included in the quality assessment process. Results: After quality assessment, 22 full text articles were selected for the final review. 14 articles out of 22 were screened for stage-related outcomes. The overall outcome results and results for every disease stage were the highest when patients were treated with extensive surgery or extensive laser assisted surgery.
This study aims to identify the presence, timing, and magnitude of a prepubertal mandibular growth spurt in a Class I and Class II population.
From the Burlington and Iowa Growth study of the AAOF ...Craniofacial Growth Legacy Collection, 83 Class I subjects (37 females and 46 males) and 32 Class II subjects (18 males and 14 females) were identified, as having at least seven consecutive annual lateral cephalograms taken from 5 to 11 years of age. Only subjects with a normodivergent facial pattern were considered. A customized cephalometric analysis was performed, and total mandibular length, defined as the distance between Condylion (Co) and Gnathion (Gn), was calculated.
Overall, a significant early peak of mandibular growth was present in all the subjects analysed both in Class I (4.69 mm for males and 4.18 mm for females; P < .05) and in Class II (5.85 mm for males and 4.05 mm for females; P < .05). No differences between males and females were found for the timing of this peak (7 years for Class I and Class II females and 7 years for Class I and 6.5 years for Class II males). In males, a significantly larger peak was observed in Class II than Class I subjects (P = .007).
The main limitations of this study were the impossibility of using a suitable growth indicator to identify the timing of the early mandibular growth peak and the limited Class II records retrievable.
This investigation suggests that a prepubertal mandibular growth peak is consistently present in both Class I and Class II males and females of clinically significant magnitude. Despite that, chronological age confirms to be unsuitable to identify this peak.
Resin coating in implants rehabilitation cannot always be aesthetic, durable and comfortable for the patient mainly due to the limited dimensions of the final structure. Intraoral welding technique ...and computer-aided designed prosthetic shells may be a solution. This in vitro study evaluates the capacity of load and the weakest point of implant-supported provisional prosthesis using welded titanium framework. Twelve samples were produced to simulate an implant supported fixed prosthetic bridge. Two implants (Ankylos; Dentsply Sirona Implants; Germany) were inserted inside blocks of nanoceramic material produced with a stereolithographic 3D printer. A polymethylmethacrylate (PMMA) resin shell was performed with CAD/CAM and relined on welded framework. Six samples were produced with the same procedure reducing resin thickness. The samples were subjected to fatigue test (6,500,000 cycles) using ElectroForce 3310 fatigue machine (
); subsequently a mechanical compression test using a universal Shimadzu AGS-X 10 machine (
). The samples were analyzed with a photographic and radiographic documentation at
,
and
. The samples survived mechanical fatigue test without evidence of failure. The radiographic and photographic evaluation revealed the fracture of resin coating after the mechanical compression test. The samples with minimal resin thickness fractured first. Adequate assessment of the resin thickness is mandatory to improve the longevity of these rehabilitations. CAD-CAM digital prosthetic design allows us to optimize the thicknesses and the prosthetic shapes, allowing us to obtain good degrees of resistance even in the presence of reduced prosthetic spaces.
Few studies used thermal quantitative sensory testing to assess the effects of repeated capsaicin gel administration in the oral cavity. This study aimed to investigate thermal sensory and pain ...thresholds before and after repeated capsaicin gel administration.
Ten healthy females (22 ± 2 years) applied a capsaicin gel on the gingival mucosa twice daily for 14 days, and heat pain threshold, warm detection threshold, cold pain threshold, and cold detection threshold were assessed on the oral mucosa. Measurements were performed before and after the 14 days and were compared to a control sample (n = 10, all females, 23 ± 3 years).
Capsaicin increased heat pain threshold in the anterior maxilla by 2.9°C (95% CI: 1.6-4.2) (p < 0.001) and in the anterior mandible by 2.2°C (95% CI: 1.0-3.4) (p = 0.001), similar to warm detection threshold that increased by Δ1.1°C (95% CI: 0.3-1.9) (p = 0.009). No significant changes were found in the controls.
These findings encourage the use of thermal quantitative sensory testing in the oral cavity to assess thermal sensation, which might be useful for assessing the effects of therapies aimed at reducing pain.
Highlights • Processes responsible for the degradation of resin-bonded interfaces are described. • Durability of the resin–dentin bond strength may be improved by inhibiting intrinsic collagenolytic ...activity. • Cross-linking agents may increase the durability of resin–dentin bonds by increasing the mechanical properties of the collagen matrix.
This study aimed at investigating the effect of a methacrylate-modified chitosan on the durability of adhesive interfaces to improve the clinical performance of dental restorations. Chitosan was ...modified with methacrylic acid (Chit-MA70) on 16% of the amino groups. Viscosity, rheology, and 1H NMR spectroscopy were performed to characterize the modified polysaccharide. Chit-MA70 was blended into a primer of an “etch-and-rinse” experimental adhesive system and tested on human teeth. The presence of methacrylate moieties and of residual positive charges on the polysaccharide chain allowed Chit-MA70 to covalently bind to the restorative material and electrostatically interact with demineralized dentin. The Chit-MA70 containing an adhesive system showed values of the immediate bond strength (26.0 ± 8.7 MPa) comparable to the control adhesive system (25.5 ± 8.7 MPa). However, it was shown that upon performing thermo-mechanical cycling treatment of the dental restoration on human teeth, the adhesive with the methacrylate-modified chitosan, in variance with the control adhesive, did not show any decrease in the bond strength (28.4 ± 8.8 MPa). The modified chitosan is proposed as a component of the “etch-and-rinse” adhesive system to efficiently improve the durability of dental restorations.
The aim of the present study was to characterize nanohybrid and nanofilled composites in terms of degree of conversion (DC), rate of cure (RC), microhardness (Vickers hardness number; VHN), depth of ...cure, and contraction stress (CS). Ceram.X® universal- A3, duo enamel E2, and duo dentin D3 composites were compared to Tetric EvoCeram® and FiltekTMSupreme XTE composites of equivalent dentin and enamel shades under a 40 s photopolymerization protocol. DC was measured by infrared spectroscopy, calculating RC from the kinetic curve. Top and bottom VHN were determined using a Vickers indenter, and bottom/top surface ratio (Vickers hardness ratio; VHR) calculated. CS vs. time was assessed by a universal testing machine and normalized for the specimen bonding area. All materials showed DC < 60%, Ceram.X® composites reaching higher values than the other composites of corresponding shades. RC at 5 s of photopolymerization was always higher than that at 10 s. All the Ceram.X® composites and the lighter-shaded Tetric EvoCeram® and FiltekTMSupreme XTE composites reached the RC plateau after 25 s, the remaining materials showed a slower kinetic trend. Tetric EvoCeram® and FiltekTMSupreme XTE composites displayed the softest and the hardest surfaces, respectively. Differently from darker-shaded materials, the universal and the three enamel-shaded composites resulted optimally cured (VHR > 80%). The tested composites differed in CS both during and after light cure, Tetric EvoCeram® and FiltekTMSupreme XTE composites displaying the highest and the lowest CS, respectively. Only the Ceram.X® universal-A3 reached a CS plateau value. The tested composites exhibited material-dependent chemo-mechanical properties. Increasing the curing time and/or reducing the composite layer thickness for dentin-shaded composites appears advisable.
Stresses produced during the fabrication of copings and by chewing activity can induce a tetragonal-to-monoclinic (t⁻m) transformation of zirconia. As a consequence, in the m-phase, the material is ...not able to hinder possible cracks by the favorable mechanism known as "transformation toughening". This study aimed at evaluating if different marginal preparations of zirconia copings can cause a premature phase transformation immediately after manufacturing milling and after chewing simulation.
Ninety copings using three commercial zirconia ceramics (Nobel Procera Zirconia, Nobel Biocare Management AG; Lava Classic, 3M ESPE; Lava Plus, 3M ESPE) were prepared with deep-chamfer, slight-chamfer, or feather-edge finish lines (n = 10). Specimens were tested in a chewing simulator (CS-4.4, SD Mechatronik) under cyclic occlusal loads simulating one year of clinical service. Raman spectra were acquired and analyzed for each specimen along the finish lines and at the top of each coping before and after chewing simulation, respectively.
Raman analysis did not show any t⁻m transformation both before and after chewing simulation, as the typical monoclinic bands at 181 cm
and 192 cm
were not detected in any of the tested specimens.
After a one-year simulation of chewing activity, irrespective of preparation geometry, zirconia copings did not show any sign of t⁻m transformation, either in the load application areas or at the margins. Consequently, manufacturing milling even in thin thickness did not cause any structural modification of zirconia ceramics "as received by manufacturers" both before and after chewing simulation.
Background and Objective
Periodontitis in one of the most prevalent dental diseases. Despite numerous studies have investigated its aetiopathogenetic factors, few works have focused on its genetic ...predisposition and most of them took into account only candidate genes. Therefore, we conducted a Genome Wide Association Study in an Italian isolated population aimed at uncovering genetic variants that predispose to this disorder.
Methods
Diagnosis of chronic periodontitis was made following the criteria of the American Academy of Periodontology. Patients with chronic periodontitis were grouped into different categories: slight, severe, localized and generalized. A control group composed by people without signs of periodontitis or gingivitis was defined. DNA was genotyped using 370k Illumina chips. Linear mixed model regression was used to test the association between each single nucleotide polymorphism (SNP) (independent variable) and the periodontitis status (dependent variable), controlling for confounders sex, age and smoking. The genomic kinship matrix was also used as random effect.
Results
Four SNPs on the gene EFCAB4B resulted significantly associated to localized periodontitis (P < 5 × 10−8), with the best hit on the rs242016 SNP (P = 1.5 × 10−8).
Conclusion
We have identified a novel significant association between the EFCAB4B gene and localized periodontitis. These results open a new perspective in the understanding of genetic factors contributing to this common disorder.
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