Analysis of mandible trabecular structure using digital periapical radiographs to assess low bone quality in postmenopausal women

PurposeTo analyze the quality of mandibular trabecular structure in postmenopausal women using periapical radiographs. Postmenopausal women are subjected to low bone quality; hence, early detection methods are needed. In addition to bone mineral density (BMD), trabecular architecture must be assessed to determine bone quality. The mandible represents bone quality and allows the assessment of trabecular structure from periapical radiographs.Material and MethodsLumbar (BMDL) and femoral BMD (BMDF) examinations were performed using dual-energy X-ray absorptiometry (DXA) in 31 postmenopausal women and divided into normal, osteopenia, and osteoporotic groups. Periapical radiographs were taken at both posterior sites of the mandible. The region of interest was taken 2 mm from the apical root of the first molar. Trabecular parameters consisting of trabecular thickness (Tb.Th) and bone percentage (BA/TA) were measured using BoneJ.ResultsBoth trabecular parameters were significantly correlated with BMDF [BA/TA ​​(r = 0.3796; p < 0.05) and Tb.Th (r = 0.508; p < 0.05)]. BA/TA and Tb.Th were significantly different between the osteoporosis and normal groups (p < 0.05) contrast to osteopenia and normal groups (p > 0.05).ConclusionChanges in mandibular trabeculae structure in postmenopausal women can be assessed using periapical radiographs.     

Volumetric analysis of the periodontal microstructure under antiresorptive therapy: an experimental study in rabbits

Objectives

The objective of this study was to volumetrically assess changes in the periodontal microstructure under antiresorptive therapy.

Materials and methods

Microtomographic scans from a total of 9 Dutch Belted rabbits having been randomly allocated to either the intravenous administration of amino-bisphosphonate (zoledronic acid) (Za) (n?=?5) or a negative control group (nZa) (n?=?4) were obtained at 10 months following a repeated drug administration. A quantification of the periodontal space thickness (P.Th) of both maxillary and mandibular most posterior premolars, as well as of the 2nd molars was performed. Bone micromorphometry was assessed by means of bone volume per total volume (BV/TV), the bone mineral density (BMD), trabecular thickness (Tb.Th), trabecular number (Tb.N), bone surface (BS), and the specific bone surface (BS/BV).

Results

Za was associated with significantly higher P.Th (P?=?0.010), which was most pronounced in the upper jaw. Bone micromorphometry revealed no significant differences among the two groups, i.e., Za and nZa, for all the investigated parameters.

Conclusions

Volumetric analysis revealed that antiresorptive therapy was associated with periodontal space widening, whereas major effects on the bone micro-morphology could not be observed.

Clinical relevance

A deep understanding of specific periodontal and alveolar bone alterations in patients under antiresorptive therapy might help to prevent the onset of medication-related osteonecrosis of the jaw.

     

A three-dimensional study of hemimandibular hyperplasia,hemimandibular elongation,solitary condylar hyperplasia,simple mandibular asymmetry and condylar osteoma or osteochondroma

PurposeTo investigate the morphological features of hemimandibular hyperplasia (HH) in comparison to other condylar hyperplasia-associated asymmetries, including hemimandibular elongation (HE), solitary condylar hyperplasia (SCH), simple mandibular asymmetry (SMA) and condylar osteoma or osteochondroma (COS).Materials and methodsA total of 31 HH, 9 HE, 6 SCH, 10 SMA and 10 COS patients were included in this study. Clinical documentation, panoramic radiography and computed tomography data were retrospectively reviewed. The three-dimensional measurements were performed on multi-planar reformation images and volume rendering images. The accuracy of the subjective radiological signs was evaluated using sensitivity, specificity and receiver operating curve analysis. Discriminant analysis was performed to generate predictive formulas using quantitative data.ResultsThe condyles in HH were regularly or irregularly enlarged, with significantly enlarged anterior-posterior length [16.2/5.29 (mean/SD, mm) P < 0.001] and volume [5.3/2.9(mean/SD, cm³) P < 0.001] compared to the normal values. The condyles in HE and SMA were normally shaped, and the quantitative measurements were within the normal range. The ramus heights in the HH patients [55.7/5.4(mean/SD, mm)] were enlarged in comparison to the contralateral side (P < 0.001) and normal values (P < 0.001). The ramus heights in the HE [52.4/7.1 (mean/SD, mm), P < 0.001] and SMA [50.3/5.0(mean/SD, mm), P = 0.002] patients were enlarged in the contralateral side comparison but were within the normal range. The mandibular body heights in HH were enlarged in the premolar [16.6/1.3 (mean/SD, mm), P < 0.001] and molar [24.8/1.4 (mean/SD, mm), P < 0.001] regions. The inferior convexity of the lower mandibular border and inferiorly displaced mandibular canal produced high specificity, sensitivity and area under the curve for the diagnosis of HH. Discriminant analysis could predict the diagnoses with a cross-validation accuracy rate of 85.7%.ConclusionsHH is a distinct clinical entity characterized by enlargement of the condyle, ramus and mandibular body. The inferior convexity of the lower mandibular border and inferiorly displaced mandibular canal is accurate and specific for the diagnosis of HH. The condyles in HE are not hyperplastic. The term “condylar hyperplasia” alone cannot be used to refer to HH or HE.     

Reliable critical sized defect rodent model for cleft palate research

BackgroundSuitable animal models are necessary to test the efficacy of new bone grafting therapies in cleft palate surgery. Rodent models of cleft palate are available but have limitations. This study compared and modified mid-palate cleft (MPC) and alveolar cleft (AC) models to determine the most reliable and reproducible model for bone grafting studies.MethodsPublished MPC model (9 × 5 × 3 mm³) lacked sufficient information for tested rats. Our initial studies utilizing AC model (7 × 4 × 3 mm³) in 8 and 16 weeks old Sprague Dawley (SD) rats revealed injury to adjacent structures. After comparing anteroposterior and transverse maxillary dimensions in 16 weeks old SD and Wistar rats, virtual planning was performed to modify MPC and AC defects dimensions, taking the adjacent structures into consideration. Modified MPC (7 × 2.5 × 1 mm³) and AC (5 × 2.5 × 1 mm³) defects were employed in 16 weeks old Wistar rats and healing was monitored by micro-computed tomography and histology.ResultsMaxillary dimensions in SD and Wistar rats were not significantly different. Preoperative virtual planning enhanced postoperative surgical outcomes. Bone healing occurred at defect margin leaving central bone void confirming the critical size nature of the modified MPC and AC defects.ConclusionsPresented modifications for MPC and AC models created clinically relevant and reproducible defects.     

Mechanical and electrochemical characterization of 3D printed orthodontic metallic appliances after in vivo ageing

ObjectivesThree-dimensional (3D) printing technology is a promising technique for fabricating custom orthodontic metallic appliances. Aim of this study was to assess the effect of intraoral aging on the mechanical / electrochemical properties of 3D-printed orthodontic metallic appliances.MethodsTwelve molar orthodontic distalization appliances 3D-printed from cobalt chromium (Co-Cr) alloy were retrieved after intraoral use and twenty blocks fabricated under similar conditions were used as control. The samples’ microstructural / elemental composition assessment was assessed with SEM/EDS, while their mechanical properties (modulus of elasticity [E_IT], Martens hardness [HM] and the elastic index [η_IT]) were measured by instrumented indentation testing. Finally, the samples’ electrochemical features were assessed with a potentiostat-connected cell arrangement in terms of open circuit potential (OCP), corrosion potential (E_z), current density (I₃₀₀) and breaking potential (E_pit). Results were analyzed by t-test / Mann-Whitney test (α = 0.05).ResultsThe used Co-Cr alloy was found to have a highly homogenous structure with no significant differences between retrieved and new specimens in HM (4037.7 ± 215.6 vs 4090.9 ± 259.8 N/mm²), E_IT (120.0 ± 13.2 vs 123.8 ± 12.9 GPa), or n_IT (28.4 ± 2.6 vs 28.6 ± 2.9 %) (P > 0.05 in all instances). Metallic surfaces retained the same oxidation tendency and oxide dissolution rate in passive region in both groups (P > 0.05 for OCP, E_z, and I₃₀₀). However, intraorally-aged specimens had a significantly lower breakdown potential due to degraded protection efficacy of surface oxide (P = 0.003 for E_pit).SignificanceThe tested 3D-printed Co-Cr orthodontic appliances present clinically-acceptable mechanical properties that remained unaffected by intraoral ageing, which however degraded the protection of surface oxide against pitting corrosion.     

Assessment of aging characteristics of female condylar trabecular structure by cone-beam computed tomography

Objectives

This study was performed to analyze the aging-related changes of the female condylar bone mineral density (BMD) and trabecular structure by cone-beam computed tomography (CBCT), and determine whether the condylar structure shows obvious changes after menopause.

Methods

The CBCT images of 160 female patients who met the inclusion criteria for the study were collected and divided into four groups by age (20–29 years, 30–39 years, premenopausal, and postmenopausal groups). Computer processing software CT-Analyser (Version 1.15.2.2+; SkyScan, Antwerp, Belgium) was used to measure the condylar BMD and related indexes, namely the bone volume/tissue volume ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular structure model index (SMI), and bone surface area/volume ratio (BS/BV). SPSS 12.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the radiographic findings and statistical differences.

Results

No significant differences were found between the bilateral condyles in each group (P?>?0.05). BV/TV, Tb.N, and Tb.Th of the condyle decreased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01). Tb.Sp, SMI, and BS/BV of the condyle increased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01).

Conclusions

With increasing age, the female condylar bone volume decreases, the Tb.N and Tb.Th decrease, the gap between the trabecular bone increases, and plate-like trabecular bone gradually transforms into a rod-like form. These changes are much more obvious in postmenopausal women.

     

Efficacy of tissue engineered bone grafts containing mesenchymal stromal cells for cleft alveolar osteoplasty in a rat model

The development of sufficient tissue engineered bone grafts for alveolar cleft osteoplasty could reduce the necessity of autogenous bone grafts and its donor site morbidity. The aim of the study was to evaluate tissue engineered bone grafts in an artificially created bone defect.Bone grafts were created in vitro colonizing a synthetic hydroxyapatite–tricalciumphosphate scaffold (BONITmatrix^®) with either undifferentiated mesenchymal stromal cells (group 1) or osteogenic differentiated mesenchymal stromal cells (group 2). Cells were multiplied from bone marrow of donor rats. Unmodified scaffolds (group 3) and the tissue engineered bone grafts were inserted into artificial maxillary defects of 54 Lewis rats. In 18 animals the defects remained unfilled (control). After one, three and six weeks the rats were sacrificed. The defect was evaluated radiologically and histologically with regard to the remaining defect volume and diameter. Statistical analysis followed.The bone grafts led to a specific bone formation at the defect margin. No complete reunion of any defect was observed within the healing time. After six weeks, the remaining defect volume was 6.86 ± 3.21 mm³ (control), 4.08 ± 1.36 mm³ (group 1), 5.00 ± 0.84 mm³ (group 2) 5.50 ± 1.05 mm³ (group 3). The remaining defect diameter measured 2.63 ± 0.52 mm (control), 2.39 ± 0.23 mm (group 1), 2.53 ± 0.22 mm (group 2) and 2.70 ± 0.66 mm (group 3). In all experimental groups the defect volume and diameter decreased over time, which was significant for group 1 (p = 0.014), group 2 (p = 0.025) and group 3 (p = 0.048). The defect volume and width was significantly reduced for bone grafts containing undifferentiated cells compared to control (p = 0.035) or scaffolds only (p = 0.05).ConclusionTissue engineered bone grafts induce a pronounced bone formation in artificial bone defects compared to unfilled controls or scaffolds only.     

Computer-Controlled CO2 Laser Ablation System for Cone-beam Computed Tomography and Digital Image Guided Endodontic Access: A Pilot Study

IntroductionIdeal endodontic access provides unobstructed entry to the pulp chamber and visualization of the canal orifices while preserving the maximum amount of tooth structure. The aim of this study was to implement the use of lasers to accurately and predictably access teeth to follow the principles of minimally invasive endodontics.MethodsTraditional, conservative, ultraconservative, bridge, truss, and orifice-directed accesses were performed. A computer-controlled 9.3-μm CO₂ laser ablation system was assembled and coupled with custom software capable of combining cone-beam computed tomographic (CBCT) volumetric data with spatially calibrated digital images of teeth to provide an augmented reality environment for designing and preparing endodontic accesses. Twenty (N = 20) sound posterior teeth with fully developed root canal systems were imaged with CBCT scans and accessed via laser ablation in vitro.ResultsAll 20 (20/20) teeth were successfully accessed without iatrogenic errors. Volumetric renderings from post-access CBCT scans were used to verify the access and determine accuracy qualitatively. The volumetric measurements of hard tissue removed were as follows: traditional = 39.41 mm³, conservative = 9.76 mm³, ultraconservative = 7.1 mm³, bridge = 11.53 mm³, truss = 19.21 mm³, and orifice directed = 16.86 mm³.ConclusionsDigital image guidance based on feature recognition and registration with CBCT data is a viable method to address the challenge of dynamic navigation for accessing the pulp chamber. Modern lasers with high pulse repetition rates integrated with computer-controlled scanning systems are suitable for the efficient cutting of dental hard tissues.     

Biochemical and X-ray micro-computed tomographic analyses of critical size bone defects grafted with autogenous bone and mercerized bacterial cellulose membranes salified with alendronate

ObjectivesThis study aimed to evaluate the repair of critical-sized bone defects grafted with autogenous bone and mercerized bacterial cellulose membranes (BCm) salified with alendronate (ALN).MethodsForty-eight male Wistar rats underwent surgery to create a 5 mm-diameter bone defect in the calvarium. The removed bone was particularized, regrafted into the defect, and covered by a BCm according to the group: control group (CG), simply mercerized BCm; group 1 (G1), negatively charged BCm (BCm-CM^-) salified with ALN; and group 2 (G2), positively charged BCm (BCm-DEAE⁺) salified with ALN. Serum samples were collected preoperatively and before euthanasia to analyze osteoprotegerin (OPG), parathyroid hormone (PTH), sclerostin (SOST), and fibroblast growth factor 23 (FGF23) levels. The animals were euthanized after 15 or 60 d. Calvaria were analyzed using quantitative microtomography (μCT).ResultsThere was an increased level of PTH in the CG compared to the G2 group, at day 60 (p = 0.019). When analyzing the same group over time, G1 presented an increased FGF23 level on days 15 and 60 (p < 0.05). CG presented an increase in PTH (p = 0.037) at day 60. The μCT analysis detected increased trabecular separation on day 15 in G2 compared to G1 (p = 0.040).ConclusionsSalification of ionized BCm with ALN had no direct effect on bone repair; however, BCm-CM^- increased the levels of FGF23 over time. BCm-DEAE⁺ decreased PTH levels compared to mercerized BCm. BCm-CM-salified with ALN-induced superior bone quality, with respect to trabecular separation, compared to BCm-DEAE⁺.     

Microcomputed tomography analysis of particular autogenous bone graft in sinus augmentation at 5 months: differences on bone mineral density and 3D trabecular structure

Objectives

This study investigated the effects of gender on the three-dimensional (3D) bone mineral density (BMD) and micromorphology of the trabeculae of matured autogenous bone grafts after sinus floor augmentation, and compared them to those of adjacent native bone.

Materials and methods

Ten bone biopsy samples were removed from the implant placement areas of patients who had received second-stage sinus floor augmentation, and analyzed by microcomputed tomography. BMD phantoms with two calcium hydroxyapatite densities (0.25 and 0.75 g/cm³) were used to determine the BMD of the grafted and native bone samples. The 3D structural parameters of the trabeculae, including percentage of bone volume (bone volume/tissue volume, BV/TV), trabecular thickness (Tb.Th), trabecular number, trabecular separation, trabecular pattern factor (Tb.Pf), and structure model index, were analyzed between males and females and between grafted bone and native bone.

Results

No significant gender-specific differences in BMD and 3D trabecular structure of either native or grafted bone were found (P?>?0.05). Compared to the adjacent native bone, the autogenous grafted bone exhibited lower BV/TV and Tb.Th as well as a higher Tb.Pf (P?<?0.05). Additionally, there was a weak positive correlation between the Tb.Th values of grafted and native bone (R ²?=?0.58).

Conclusions

In the maxillary sinus, autogenous grafted bone exhibited lower BV/TV, Tb.Th, and trabecular connectivity than the adjacent native bone. No significant gender-specific differences were found for either the BMD or 3D trabecular structure of grafted bone.

Clinical relevance

After bone remodeling, autogenous grafted bone revealed different 3D trabecular structure as compared to native bone.     

Does non-surgical periodontal treatment influence on rheumatoid arthritis? A systematic review and meta-analysis

ObjectiveThe objective of this systematic review was to evaluate the efficacy of non-surgical periodontal therapy on rheumatoid arthritis activity.Material and methodsArticles published until April 2019 were electronically searched and screened using PubMed / MEDLINE, Scopus, and Cochrane databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). This study was recorded in the international PROSPERO database (CRD42019132205). The PICO question (population, intervention, comparison, results) was: in adult patients with rheumatoid arthritis and periodontitis (P), does non-surgical periodontal treatment (I), as compared to no treatment (C), provides better outcomes in rheumatoid arthritis activity (O).ResultsAfter searching the databases, seven articles were selected for qualitative and five for quantitative analysis. The total number of participants included was 292, with an average age of 50.5 years. All patients had rheumatoid arthritis and periodontal disease. Non-surgical periodontal treatment significantly reduced Disease Activity Score 28 (P = 0.004; I² = 92%) and erythrocyte sedimentation rate (P = 0.01; I² = 78%), but with no significant effect on C-reactive protein (P = 0.34; I² = 92%).ConclusionsIt can be concluded that non-surgical periodontal treatment can benefit patients with rheumatoid arthritis.     

The effect of a hydroxyapatite impregnated PCL membrane in rat subcritical calvarial bone defects

ObjectiveThe present study evaluated the effect of polymeric-nanofibers membranes impregnated with microparticulate hydroxyapatite (HA) in the subcritical calvarial bone defects (SCBD) healing.DesignPCL membranes with and without HA were obtained by electrospinning. SCBD were perforated (3.3 mm) in left and right sides of 36 rat calvarias. The right-side SBCD of 18 animals was filled with HA mixed with blood clot and blood clot at the contralateral side. The remaining animals received PCL + HA membrane at the right-side SCBD and PCL membrane at the contralateral side. Animals were killed after 30, 60 and 90 days after surgery. Bone defect volume (in mm³) was measured by tomography (CBCT). Qualitative histological analysis and SBCD area (in mm²) were measured. Quantitative data were submitted to Kruskal-Wallis/Dunn tests.ResultsReduction of SBCD volume was observed in all treatments but PCL. Association with HA significantly improved bone healing induced by PCL and blood clot. PCL + HA induced the lowest SBCD volume at 60 and 90 days. Complete bone healing was not observed even at 90 days in SCBD treated with blood clot. In every period, more bone formation was observed for SCBD treated with membranes.ConclusionsWe concluded that both PCL membrane and HA were able to improve bone healing.     

Microcomputed tomographic analysis of bone microarchitecture after sinus augmentation with hyaluronic matrix: a case–control study

Background

The aim of this study was to analyze trabecular microarchitecture of augmented sinuses with hyaluronic matrix and xenograft by microcomputed tomography, and to investigate whether hyaluronic matrix has an effect on the newly formed bone quality.

Materials and methods

Thirteen patients undergoing maxillary sinus augmentation were included in this split-mouth study. Right and left sinus sites were randomly assigned to test and control group. In test group, the sinus was grafted with hyaluronic matrix and xenograft; in control group, only with xenograft. Four months after augmentation, bone samples were harvested during implant placement and analyzed for the following trabecular microarchitecture parameters using microcomputed tomography: bone volume (BV), total volume (TV), bone volume fraction (BV/TV), bone surface (BS), specific bone surface (BS/BV), bone surface density (BS/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular pattern factor (Tb.Pf), and fractal dimension (FD).

Results

There was statistically significant difference only for BS/TV parameter between two groups. BS/TV was higher in hyaluronic matrix group compared with control group.

Conclusions

Addition of hyaluronic matrix to xenograft may enhance bone quality in terms of bone surface density. However, more research investigating the microstructural variation of augmented sinuses is needed with a greater sample.

     

Root Surface Changes in Endodontically Treated Teeth following Orthodontic Movement

IntroductionOrthodontically induced external root resorption has been labeled an unavoidable consequence of orthodontic tooth movement (OTM). The objective of this study was to investigate the change in surface area (mm²) and volume (mm³) of endodontically treated teeth (ETT) compared with contralateral teeth with a vital pulp (VPT) after OTM.MethodsSeventy-six teeth were included in this retrospective analysis: ETT (n = 38) and VPT (n = 38). All teeth were evaluated using cone-beam computed tomographic imaging at 2 time periods: before OTM (T1) and after OTM (T2). Study teeth were segmented to include all areas contained within the lamina dura and then were converted into a mesh model for data calculation. The surface area (mm²) and volume (mm³) of each tooth were calculated at T1 and T2 based on the number of cubic voxels present within the mesh model. Statistical analysis was performed using a linear mixed-effects model.ResultsThe average change in surface area after OTM in ETT was 13.01 mm² and 19.95 mm² in VPT (P < .05). The average percent change in surface area after OTM in ETT was 2.09% and 3.38% in VPT (P < .05). The average change in volume after OTM in ETT was 22.48 mm³ and 32.44 mm³ in VPT (P < .05). The average percent change in volume after OTM in ETT was 2.62% and 4.10% in VPT (P < .05).ConclusionsThe results from this study suggest that ETT are less susceptible to root resorption after OTM than their vital counterparts.     

Osteodistraction of mandibles with a small bone defect at the planned osteotomy site: A histological pilot study in dogs

AimTo develop a treatment plan for cases in which a bone defect is located on the osteotomy line of mandibular osteodistraction (DO).Subjects and methodsBilateral DO was performed in 17 Mongrel dogs. Prior to surgery, the 34 hemi-mandibles were randomly allocated to three groups: C (n = 10; a standard DO was performed), D − G (n = 12; a bone defect was created on the DO osteotomy line), and D + G (n = 12; the bone defect on the osteotomy line was grafted). After one week of latency, 8 days of distraction, and 4 weeks of consolidation the animals were sacrificed, and the newly formed bone were examined.ResultsIn group C, two zones of immature trabecular bone originating from host bone margins were separated by a central fibrous zone. In group D + G uniform new bone formation of the entire distraction gap was observed. In group D − G the distraction gap was mainly filled with fibrous tissue. The values for the newly formed bone volume and trabecular thickness were not significantly different between groups D + G and C, but were higher than values in group D − G (p < 0.05).ConclusionWhen a mandibular defect is located at the site of distraction osteotomy, DO can be performed simultaneous with bone grafting of the defect.     

Which antibiotic regimen prevents implant failure or infection after dental implant surgery? A systematic review and meta-analysis

ObjectiveTo assess which antibiotic regimen prevents dental implant failures or postoperative infections following dental implant placement.Materials and methodsSystematic review and meta-analysis. Data sources: Pubmed, Cochrane, Science Direct, and EMBASE via OVID were searched up to August 2017. Only randomized controlled clinical trials (RCT) using antibiotics were included. Outcome measures were set on dental implant failures or postoperative infection incidence after dental implant surgery. Three reviewers independently undertook risk of bias assessment and data extraction. Stratified meta-analyses of binary data using fixed-effects models were performed using Stata 14.0. The risk ratio (RR) and 95% confidence interval (CI) were estimated.ResultsNine articles were included corresponding to 15 RCTs. All RCTs tested only oral amoxicillin. Implant-failure analysis: overall RR = 0.53 (P = .005, 95% CI: 0.34–0.82) and overall NNT = 55 (95% CI, 33–167). Single-dose oral amoxicillin preoperatively (SDOAP) is beneficial (RR = 0.50, CI: 0.29–0.86. P = .012), when compared to postoperative oral amoxicillin (POA): RR = 0.60, CI: 0.28–1.30. P = .197. Postoperative-infection analysis: overall RR = 0.76 (P = 0.250, 95% CI: 0.47–1.22). Neither SDOAP (RR = 0.82, CI = 0.46–1.45, P = .488) nor POA (RR = 0.64, CI = 0.27–1.51, P = .309) are beneficial. I² = 0.0%, chi-squared tests P ≈ 1.ConclusionOnly SDOAP is effective and efficacious at preventing implant failures, but it was not significant for postoperative infections following dental implant surgeries.     

Xerostomia and hyposalivation among a 65‐yr‐old population living in Oslo,Norway

This study aimed to describe the prevalence and associated factors for xerostomia and hyposalivation in a young‐elderly population. A random sample of 460 65‐yr‐old people living in Oslo, Norway, answered a questionnaire and underwent a clinical examination (237 men and 223 women; response rate 58%). Ten percent of respondents reported xerostomia. The median Summated Xerostomia Index was 6 (interquartile range [IQR]: 5–7) and the median Clinical Oral Dryness Score was 2 (IQR: 1–3). The median unstimulated whole saliva (UWS) secretion rate was 0.34 (IQR: 0.20–0.53) mL min^–1 and the median stimulated whole saliva (SWS) secretion rate was 1.74 (IQR: 1.24–2.38) mL min^–1. In 8% of the study participants the UWS secretion rate was ≤0.1 mL min^–1 and in 4% the SWS secretion rate was ≤0.7 mL min^–1. Three percent of the study participants had both xerostomia and hyposalivation with respect to UWS. Xerostomia was significantly associated with medication use, having rheumatic disease, and having received radiation therapy to the head/neck region. Hyposalivation with respect to UWS and SWS was significantly associated with medication use and type II diabetes. Even though xerostomia and hyposalivation were not prevalent conditions in this population, clinicians should be especially aware of the salivary conditions in patients taking four or more medications, patients diagnosed with type II diabetes, and those who have undergone radiation therapy to the head/neck region.     

Wear resistance of crowns made from different CAM/CAD materials

ObjectivesThe aim of this laboratory study was to evaluate the wear resistance of crowns made from current computer-aided design and computer-aided manufacture (CAD/CAM) materials. In addition, the abrasion of the steatite antagonist against these materials was compared.MethodsIdentically shaped crowns of lithium disilicate, zirconia-reinforced lithium disilicate and a polymer-infiltrated ceramic network (PICN) were fabricated with an occlusal thickness of 1.5 mm and a lateral wall thickness of 1.2 mm (n = 8). The crowns were cemented with a dual-polymerizing luting resin on composite resin dies. Using spherical steatite antagonists, all specimens were loaded with 49 N for 1,200,000 cycles in a mastication simulator with additional thermocycling. After 120,000, 240,000, 480,000, 960,000, and 1,200,000 cycles, precision impressions were made and investigated with a laser scanning microscope. The vertical and volume substance loss was measured. Additionally, the substance loss of the antagonists was evaluated after 1,200,000 loading cycles.ResultsNo significant difference (p > 0.05) was found in the median volume loss of the test materials after 1,200,000 cycles (lithium disilicate: 0.405 mm³, PICN: 0.362 mm³, zirconia-reinforced lithium disilicate: 0.340 mm³). The vertical substance loss of PICN (157 μm) was significantly lower (p ≤ 0.05) than that of lithium disilicate (201 μm) and zirconia reinforced lithium disilicate (191 μm). However, the substance loss of steatite against zirconia-reinforced lithium disilicate (0.191 mm³) was significantly lower (p ≤ 0.05) than against lithium disilicate (0.296 mm³) and PICN (0.531 mm³).SignificanceAll three CAD/CAM materials showed wear resistance that seems appropriate for clinical application. Also, the abrasion of the antagonist looks promising.     

Efficacy of articaine vs lignocaine in maxillary and mandibular infiltration and block anesthesia in the dental treatments of adults: A systematic review and meta‐analysis

The aim of the present systematic review and meta‐analysis was to address the following Population, Intervention, Comparison, and Outcome question: Is the efficacy of articaine better than lignocaine in adults requiring dental treatment? Four percent articaine was compared with 2% lignocaine for maxillary and mandibular infiltrations and block anesthesia, and with the principal outcome measures of anesthetic success. Using RevMan software, the weighted anesthesia success rates and 95% confidence intervals (CIs) were estimated and compared using a random‐effects model. For combined studies, articaine was more likely to achieve successful anesthesia than lignocaine (N = 18, odds ratio [OR]: 1.92, 95% CI: 1.45‐2.56, P < 0.00001, I² = 32%). Maxillary and mandibular infiltration studies showed obvious superiority of articaine to lignocaine (N = 8, OR: 2.50, 95% CI: 1.51‐4.15, P = 0.0004, I² = 41%). Maxillary infiltration subgroup analysis showed no significant difference between articaine and lignocaine (N = 5, OR: 1.69, 95% CI: 0.88‐3.23, P = 0.11, I² = 19%). For combined mandibular anesthesia studies, articaine was superior to lignocaine (N = 14, OR: 1.99, 95% CI: 1.45‐2.72, P < 0.0001, I² = 32%), with further subgroup analysis showing significant differences in both mandibular block anesthesia (N = 11, OR: 1.55, 95% CI: 1.19‐2.03, P = 0.001), I² = 0%) and mandibular infiltration (N = 3, OR: 3.87, 95% CI: 2.62‐5.72, P < 0.00001, I² = 0%), indicating that articaine is more effective than lignocaine in providing anesthetic success in routine dental procedures.     

Coulometric titration of water content and uptake in CAD/CAM chairside composites

ObjectivesThis study aimed to evaluate the water content and uptake of CAD/CAM chairside composites over 60 days using coulometric Karl Fischer (KF) titration.MethodsRectangular plates (10 ×10×1 mm³ of thickness) were cut from the blocks of composites Cerasmart 270 (CS), Katana Avencia (KA), Grandio Blocs (GB), and Lava Ultimate (LU). Specimens were stored in distilled water for up to 60 days at 37 °C, and non-stored specimens were used as a control (n = 5). Specimens were isothermally heated at 200 °C, and the water content was evaporated and transferred to the titration cell throughout a nitrogen gas flow. The KF coulometer determined the percentage of water in each specimen. Data were analyzed by 2-way ANOVA and Tukey`s test (α = 0.05).ResultsThe water content of non-stored specimens ranged from 0.29 to 1.66 wt% (6.9–32.9 μg/mm³) for GB and LU, respectively. The water content increased underwater storage (0.82–2.96 wt% after 60 days). The extend of water sorption (11.9–26.1 μg/mm³) among the materials was directly related to their base water content. No additional water content increase was observed after 7 (LU and KA) or 21 (GB and CS) days. Measuring the water content in wt% or μg/mm³ affected the ranking of materials when KA and CS were analyzed.SignificanceComposites with higher base water content also presented higher water sorption. KF titrationshowed to be a reliable method to measure the water sorption of composites, including their base water content.