Evaluation of surface treatments of monolithic zirconia in different sintering stages

Purpose

This study evaluated the effect of surface treatment of zirconia in pre-sintered and post-sintered stages on its surface roughness, phase transformation, and biaxial flexural strength (BFS).

Molybdenocene–DNA interaction studies using electrochemical analysis

The binding interactions of molybdenocene dichloride (Cp₂MoCl₂) and [Cp₂Mo(L)_n]Cl₂ (n = 1, L = 6-mercaptopurine, 6-mercaptopurineribose, 2-amine-6-mercaptopurine and 2-amine-6-mercaptopurineribose and n = 2, L = d-penicillamine) complexes with calf-thymus DNA have been investigated by cyclic voltammetry. Cp₂MoCl₂ belongs to a group of metallocene antitumor agents and [Cp₂Mo(L)_n]Cl₂ complexes are structural modifications of molybdenocene dichloride that have also been shown to possess antitumor properties. From the mechanistic point, there is interest in discovering whether molybdenocene dichloride binds DNA or not. To investigate this issue in more detail, we carried out molybdenocene–DNA titrations monitored by cyclic voltammetry. The changes in oxidation potentials (E_pa) allowed us to determine the degree of Mo–DNA interaction. (Cp₂MoCl₂) and [Cp₂Mo(L)_n]Cl₂ (n = 1, L = 2-amine-6-mercaptopurine and 2-amine-6-mercaptopurineribose and n = 2, L = d-penicillamine) complexes showed weak DNA bindings (3.2–10.1%) while the complexes containing the ligands 6-mercaptopurine and 6-mercaptopurineribose showed negligible interactions. ICP-AES was used to corroborate the CV results.     

Features of fracture of prosthetic tooth-endocrown constructions by means of acoustic emission analysis

Objective

The study aims at comparing the fracture resistance of different restorative materials used in dental endocrown restorations and respective endocrown restorations under a quasi-static compressive load using acoustic emission (AE) method.

Three-dimensional assessment of proximal contact enamel using optical coherence tomography

Objective

The purpose of this study was to detect and investigate the association of enamel microcracks with demineralization at proximal contact areas of premolars, using 3D swept-source optical coherence tomography (SS-OCT).

Thirty years of submental intubation: a review

Submental intubation has been used as an alternative to conventional intubation in the field of oral and maxillofacial surgery since its introduction by Francisco Hernández Altemir in 1986. A review of submental intubation was performed using data from all case reports, case-series, and prospective and retrospective studies published between 1986 and 2016. The indications, variations in incision length, incision sites, types of endotracheal tube used, methods of exteriorization, and complications were recorded and analyzed. A total of 70 articles reporting 1021 patients were included. The main indication was maxillofacial trauma (86.9%, n = 887), followed by orthognathic surgery (5.8%, n = 59), skull base surgery (2.8%, n = 29), and rhinoplasty and rhytidectomy (1.5%, n = 15). The complication rate was relatively low: 91.0% of patients (n = 929) were complication-free. The most common complication was infection, occurring in 3.5% (n = 36) of the total number of patients, followed by scarring (1.2%, n = 12) and formation of an orocutaneous or salivary fistula (1.1%, n = 11). In summary, submental intubation is a good alternative airway with minimal complications.     

Immediate dental implant placement with a horizontal gap more than two millimetres: a randomized clinical trial

The purpose of this study was to evaluate the horizontal dimensional changes in buccal alveolar bone immediately after dental implant placement in the upper premolar area with horizontal gaps >2 mm. A total of 48 patients were enrolled in this randomized clinical trial and were randomly assigned to one of three groups. Group I (flap with graft; n = 16) patients received an immediate implant with bone graft, membrane, and primary flap closure. Group II (flap without graft; n = 16) patients received an immediate implant with primary flap closure only. Group III (flapless without graft; n = 16) patients received an immediate implant without graft, membrane, or primary closure. Cone beam computed tomography (CBCT) scans were obtained preoperatively, immediately after implant placement, and at 6 months postoperative to evaluate horizontal dimensional changes in the buccal alveolar bone. Pain intensity was measured using a numerical rating scale. CBCT examinations revealed that bone had filled the horizontal gap in all three groups. Group II showed the greatest horizontal dimensional changes in the buccal alveolar bone, followed by group I. The least amount of change was recorded for group III. Furthermore, significantly less postoperative pain was recorded in group III when compared to the other groups. Short-term results suggest that the ‘flapless without graft’ technique shows similar results to the ‘flap with graft technique’ for immediate implant placement in the maxillary premolar extraction site with a horizontal gap >2 mm, when the bone plate is intact.     

Fracture resistance and failure modes of polymer infiltrated ceramic endocrown restorations with variations in margin design and occlusal thickness

Purpose

The purpose of this in vitro study was to assess the effect of varying the margin designs and the occlusal thicknesses on the fracture resistance and mode of failures of endodontically treated teeth restored with polymer infiltrated ceramic endocrown restorations.

Tuberculosis: the great imitator in the head and neck - our experience of 24 cases in 22 years

This retrospective study covered over two decades, during which an individual head and neck surgeon treated 24 patients with cervicofacial lymphadenitis that was related to both Mycobacterium tuberculosis complex (n = 17, made up of M tuberculosis (n = 16) and M bovis (n = 1)), and non-tuberculous mycobacteria. The seven cases of non-tuberculous mycobacteria were caused by M avium complex (n = 3), M malmoense (n = 3), and M kansaii (n = 1). By using a tailored management approach, at times selective combined surgical and antimycobacterial treatment, he achieved a success rate of 23/24 cases, with only one recurrence and no major complications. The results suggest that patients with tuberculosis confined to the head and neck rarely develop constitutional symptoms, so the absence of such symptoms may not exclude tuberculosis. There was also a good correlation between predictive variables (immune state, inflammatory markers on admission, causative mycobacterium, and the antimycobacterial regimen used) and time spent under follow-up at the head and neck outpatient clinic.     

Effect of aging and testing method on bond strength of CAD/CAM fiber-reinforced composite to dentin

Objectives

To evaluate and compare the outcomes of shear (S) and microtensile (μT) bond strength tests of CAD/CAM fiber-reinforced composite (FRC) to dentin. Aging with either fatigue or thermocycling were conducted for comparison with baseline microtensile group.

Oral medicine psychiatric liaison clinic: study of 1202 patients attending over an 18-year period

Patients with orofacial pain and discomfort often suffer from psychiatric disorders. However, few studies involving a large sample have examined the diagnostic results of patients with orofacial pain or discomfort in relation to psychiatric disorders. The purpose of this study was to summarize and clarify the characteristics and demographic data of 1202 patients attending the psychiatric liaison clinic at Aichi Gakuin University Hospital. Psychiatric diagnosis was performed by psychiatrists for all patients, based on the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Among the 1202 patients, 992 (82.5%) were female. The average age of the patients was 57.2 ± 15.0 years. The predominant broad categories of orofacial pain and discomfort seen were burning mouth syndrome (n = 484, 40.3%), persistent idiopathic facial pain (n = 258, 21.5%), and oral dysesthesia (n = 215, 17.9%). The predominant broad categories of psychiatric diagnoses seen were somatic symptoms and related disorders (n = 934, 77.7%) and depressive disorders (n = 76, 6.3%). Among the 934 patients with somatic symptoms and related disorders, 678 had a somatic symptom disorder with predominant pain. The results confirmed that most patients with orofacial pain and discomfort were middle-aged and elderly women suffering from a somatic symptom disorder with predominant pain.     

Reconstruction of intraoral defects after resection of cancer with two types of submental artery perforator flaps

The submental island flap is a common choice for reconstruction of intraoral defects. To obtain a thinner, more pliable flap and get a better oncological result, the submental artery perforator flap has been proposed, and to assess its feasibility for closure of defects after resection of cancers of the oral cavity we studied 20 patients, each of whom was treated in this way. All the flaps were classified into those with septocutaneous perforators (n = 16) and those with musculocutaneous perforators (n = 4), and the main veins that drained the flaps were two submental veins (n = 17). There were two patterns of venous drainage: in pattern 1 (n = 9) the external jugular vein provided the primary venous drainage, and in pattern 2, the submental veins drained mainly into the facial vein, the common facial vein, and the internal jugular (n = 10). In one patient the submental veins bypassed the facial vein to drain into the internal jugular. Eighteen of the 20 patients had no postoperative complications. The remaining two developed mild venous congestion of the flaps, which was resolved with conservative management and no skin loss. No local or regional recurrence was detected after a mean (range) follow-up of 21 (4-35) months. This is a simple, reliable flap that can be used for the reconstruction of intraoral defects after resections for cancer, but its oncological outcome still requires proof in long-term, large-scale, clinical trials.     

Optimization of the etch-and-rinse technique: New perspectives to improve resin–dentin bonding and hybrid layer integrity by reducing residual water using dimethyl sulfoxide pretreatments

Objective

To determine whether bonding effectiveness and hybrid layer integrity on acid-etched dehydrated dentin would be comparable to the conventional wet-bonding technique through new dentin biomodification approaches using dimethyl sulfoxide (DMSO).

Impact of resveratrol on bone repair in rats exposed to cigarette smoke inhalation: histomorphometric and bone-related gene expression analysis

This study investigated the effect of resveratrol on bone healing and its influence on the gene expression of bone-related markers in rats exposed to cigarette smoke. Two calvarial defects were created in each of 60 rats, which were assigned equally (n = 20) to three groups: (1) resveratrol (10 mg/kg) + smoke exposure (SMK + RESV); (2) placebo + smoke exposure (SMK + PLA); or (3) placebo + no smoke exposure (NS + PLA). Substances were administered daily for 30 days following surgery. Smoke inhalation was started 7 days before surgery and continued for 30 days after surgery. One defect was processed for histomorphometric analysis and the other was used for mRNA quantification of bone-related gene expression by qPCR. The remaining defect was smaller in the SMK + RESV (2.27 ± 0.61 mm, P = 0.0003) and NS + PLA (2.17 ± 0.74 mm, P = 0.0005) groups than in the SMK + PLA group (3.12 ± 0.47 mm). Higher levels of Runx2 were observed in the NS + PLA group than in the smoke exposure groups (vs. SMK + PLA, P = 0002; vs. SMK + RESV, P = 0.052); levels of Lrp-5 were also higher in the no smoke exposure group (vs. SMK + RESV, P = 0.009; vs. SMK + PLA, P = 0.003). Resveratrol therapy decreased RANKL/OPG expression when compared to placebo (SMK + RESV vs. SMK + PLA, P = 0.017). Dkk1 levels were decreased in the SMK + RESV group when compared to the SMK + PLA (P = 0.006) and NS + PLA groups (P = 0.005). In conclusion, resveratrol optimizes the repair of critical-sized bone defects, up-regulating the gene expression of important bone remodelling markers in rats exposed to cigarette smoke inhalation.     

The effect of hydrofluoric acid concentration on the fatigue failure load of adhesively cemented feldspathic ceramic discs

Objective

This study investigated the influence of hydrofluoric acid (HF) etching at different concentrations on the fatigue failure load of adhesively cemented feldspathic ceramic discs (Vita Mark II). Besides, their effect on the micromorphology of ceramic surface was investigated.

Flexural resistance of heat-pressed and CAD-CAM lithium disilicate with different translucencies

Objective

To compare flexural strength of CAD-CAM and heat-pressed lithium disilicate.

Voltammetric determination of stability constants of iron(III)–glycine complexes in water solution

Determination of the stability constants of dissolved iron(III)–glycine system in water solution (I = 0.6 mol L^?1 in NaClO₄ at 25 ± 1 °C) using differential pulse cathodic voltammetry (DPCV) was performed on a static mercury drop electrode (SMDE). Iron(III) concentration of 2.5 × 10^?5 mol L^?1 and the pH range from 9.05 to 6.36 ensured the formation of enough concentration of iron(III)–glycine higher coordination complexes (1:2 and 1:3) to be measured by the applied method. The concentrations of total glycine varied from 0.1 to 0.5 mol L^?1. Cyclic voltammetry (CV) measurements were used to investigate reversibility of the iron(III)–glycine complexes which showed one-electron reversible character. The stability constants of iron(III) [Fe(Gly)₂]⁺ and Fe(Gly)₃ complexes, which had not been reported in the literature so far, were found to be log β₂ = 16.83 ± 0.47 and log β₃ = 18.64 ± 0.70, respectively. The model that best fitted the data gave two iron(II)–glycine stability constants for [FeGly]⁺ log K₁ = 3.69 ± 0.19 and for Fe(Gly)₂ log β₂ = 5.08 ± 0.60. According to the constants found, chemical distribution of iron(III) in glycine water solution, as a function of pH, was calculated and proposed.     

Warthin’s tumour in oral and maxillofacial regions: an 18-year retrospective study of 1084 cases in an eastern-Chinese population

There is little information in the English-language literature regarding Warthin’s tumour (WT) in the eastern-Chinese population. A large retrospective study (1084 primary tumours over a period of 18 years) was carried out to investigate the clinicopathological features (patients’ gender, age and tumour location) of these tumours in this population. A total of 994 (91.7%) patients were male and 90 (8.3%) were female, with a male/female ratio of 11:1. The mean age was 56.48 years (range 20–89 years), with a peak incidence in the fifth to seventh decade (82.1%). The favorite primary site of the tumour was the parotid gland (n = 1055), followed by intra-/peri-parotid lymph nodes (n = 13), upper neck (n = 10), submandibular gland (n = 4) and upper lip (n = 1). Multifocal WTs arose in 9.5% (103 patients) of cases whereas bilateral multifocal WTs were found in 0.65% (seven patients). In 24 (2.2%) patients, WT were found to coexist with other different types of neoplasm synchronously. The most common subtype of metaplasia was the squamous metaplasia (166/250, 66.4%). The usual treatment measure is (bilateral) superficial parotidectomy and the patients should be followed long term, in view of possible metachronous WT, even after prolonged time intervals.     

Risk factors and clinical outcomes of sinus membrane perforation during lateral window sinus lifting: analysis of 120 patients

The aim of this study was to identify the risk factors associated with sinus membrane perforation and the effect of sinus membrane perforation and other risk factors on graft success and postoperative sinusitis. Sinus membrane perforation, graft failure, and postoperative sinusitis were tested for an association with age, sex, operator experience, side of the operation, residual bone height, presence of septa, presence of a mucous retention cyst, and smoking (χ² test). Logistic regression analysis was used to model the odds ratio (OR) with corresponding risk factors. One hundred and twenty patients were included in this study. A total of 22 (18.3%) perforations occurred. A residual bone height of 3–6 mm (OR 6.808, P = 0.002) and presence of septa (OR 4.023, P = 0.025) were identified as significant risk factors. Twenty-eight (23.3%) sinus grafts were classified as failed. Membrane perforation (OR 16.819, P < 0.005) and residual bone height of 3–6 mm (OR 5.363, P = 0.01) were identified as significant risk factors for graft failure. None of the risk factors investigated in this study was significantly associated with postoperative sinusitis. These results suggest that the presence of septa and a residual bone height of 3–6 mm are associated with an increased risk of sinus membrane perforation, and that sinus membrane perforation has a negative effect on graft success.     

Titanium dioxide and modified titanium dioxide by silver nanoparticles as an anti biofilm filler content for composite resins

Objective

The aim of this study was to evaluate the antibacterial activity of a composite resin modified by TiO₂ and TiO₂/Ag nanoparticles and their influence over different properties.

Effects of three drying methods of post space dentin bonding used in a direct resin composite core build-up method

Purpose

The purpose of this study was to evaluate drying methods for post space dentin bonding in a direct resin composite core build-up method.