D3 Bone Research Articles

Activation of the calcium sensing receptor attenuates TRPV6-dependent intestinal calcium absorption.

Plasma calcium (Ca2+) is maintained by amending the release of parathyroid hormone and through direct effects of the Ca2+ sensing receptor (CaSR) in the renal tubule. Combined, these mechanisms alter intestinal Ca2+ absorption by modulating 1,25-dihydroxy vitamin D3 production, bone resorption, and renal Ca2+ excretion. The CaSR is a therapeutic target in the treatment of secondary hyperparathyroidism and hypocalcemia a common complication of calcimimetic therapy. The CaSR is also expressed in intestinal epithelium, however, a direct role in regulating local intestinal Ca2+ absorption is unknown. Chronic CaSR activation decreased expression of genes involved in Ca2+ absorption. In Ussing chambers, increasing extracellular Ca2+ or basolateral application of the calcimimetic cinacalcet decreased net Ca2+ absorption across intestinal preparations acutely. Conversely, Ca2+ absorption increased with decreasing extracellular Ca2+ concentration. These responses were absent in mice expressing a non-functional TRPV6, TRPV6D541A. Cinacalcet also attenuated Ca2+ fluxes through TRPV6 in Xenopus oocytes when co-expressed with the CaSR. Moreover, the phospholipase C inhibitor, U73122, prevented cinacalcet-mediated inhibition of Ca2+ flux. These results reveal a regulatory pathway whereby activation of the CaSR in the basolateral membrane of the intestine directly attenuates local Ca2+ absorption via TRPV6 to prevent hypercalcemia and help explain how calcimimetics induce hypocalcemia.

The Effect Of Tapered And Cylindrical Implants On Stress Distribution In Different Bone Qualities: A Finite Element Analysis.

To examine the stress values of different bone densities and to compare the tapered and the cylindrical implant designs. Finite element analysis was used to apply a force of 100 N vertically and at an angle of 30 degrees to implants with a cylindrical or tapered design in D1and D4 bones in eight separate models. The von Mises and principal stress values obtained from the models were compared, and the optimal stress values were determined and compared with the physiologic stress limit of the bone. Von Mises stress was found to be lower in D1 bone densities, in vertical loading, and in implants with a tapered design. In the case of both implant designs, the von Mises and principal stress values were lower for D1 bone densities. The tapered implant was found to have higher principal stress than the cylindrical implant in both bone densities, while von Mises stress was higher in the cylindrical implant than in the tapered implant. Vertical loading was found to induce less stress than loading at a 30-degree angle. D4 bone density and loading at a 30-degree angle increases von Mises and principal stress more than selection of different implant designs.

Biomechanical Evaluation of Zygomatic Implant Use in Patients With Different Buccal Maxillary Defect Levels.

The purpose of this study was to examine the biomechanics of zygomatic implants that were planned on an atrophic maxilla with five different buccal defect types and two different bone types. Three-dimensional models of zygomatic implants, human skulls, and maxillary prostheses were modeled with SolidWorks software. Ten finite element models of skulls with five different buccal defect types and two different bone types were constructed to mimic various clinical scenarios. Two bilateral zygomatic implants and two anterior dental implants were inserted into all models. The data were processed by ANSYS Workbench software. 150-N vertical occlusal and 300-N masseteric loads were simulated on a modeled prosthesis. The stresses on and deformations of the bones and implants were then observed and compared. Maximum Von Mises stress was found in skulls modeled with a type 4 defect and D3 bone type. Minimal stress values were found in the skull model with a type 1 buccal bone defect and D2 bone type. Displacement values were correlated with stress values. Cortical bone anchorage and bone type of zygomatic implants positively affect their biomechanics. Alveolar crest support has an effective role in the biomechanics of zygomatic implants.

Three-Dimensional Finite Element Analysis of the Effect of Endosteal Implants with Different Macro Designs on Stress Distribution in Different Bone Qualities.

The aim of this study was to analyze stress distribution on four different implant designs and four different qualities of cortical bone surrounding the implant crest modules using three-dimensional finite element analysis. Four different implant designs of the same diameter and length (3.75 ± 11.5 mm) were used. Rhinoceros 4.0 3D modeling software was used for preparing the four types of bone quality (D1, D2, D3, and D4). Mandibular second premolar crowns were constructed as prosthetic superstructures of the implants, and a total force of 300 N was vertically applied to the crowns. Stress distribution on dental implants and cortical bone of D1, D2, D3, and D4 bone quality was evaluated. Among all of the implants, the maximum von Mises stress value on cortical bone surrounding the neck region of the implants was found in D4 bone quality, while the minimum stress was detected in D1 bone quality. The stress distribution on the threads of dental implants exhibited the most homogeneous distribution in D1 bone quality, while higher von Mises stress values were observed in the apical blade segment of the implants in D3 and D4 bone quality. It was found that the maximum stress of cortical bone surrounding the implant crest module decreased as the bone density increased. The microthreads on the implant crest module might cause an increase in stress to cortical bone surrounding the neck region of implants.

Insertion Torque of Variable-Thread Tapered Implants in the Posterior Maxilla: A Clinical Study.

Primary stability is a key factor for successful implant osseointegration, especially in poor bone quality and early/immediate loading. In the immediate loading protocol, insertion torque values (ITVs) have been suggested to be the most valid prognostic factor for osseointegration of maxillary implants. The objectives of this study were to: (1) evaluate ITVs achieved by a variable-thread tapered implant in the posterior maxilla; and (2) assess the impact of bone quality, implant dimensions, bicortical anchorage, and implant location on ITVs. Twenty-six adult, systemically healthy patients received 173 variable-thread tapered implants in maxillary premolar and molar healed edentulous sites with a minimum subsinus height of 8 mm. Implant sites were prepared using the bone-quality adjusted drilling sequence according to manufacturer's recommendations. Bone quality was recorded subjectively during drilling based on Misch criteria (D1-D4), and ITVs were measured with a manual torque wrench. Univariate and multivariate analyses were performed at the 0.05 significance level. First and second molar sites accounted for 46.8% of all implants. D4 bone was encountered in 61.3% of the sites. Most of the implants were 4.3 mm in diameter (59.5%), and lengths of 11.5 and 13 mm were most commonly used (75.2%). Approximately half of the implants were associated with apical cortical anchorage (51.4%). The overall mean ITV was 44.5 ± 23.0 Ncm, with 65.5 ± 15.6 Ncm, 55.5 ± 19.6 Ncm, and 36.6 ± 21.7 Ncm for D2, D3, and D4 bone, respectively. Bone quality and implant location significantly affected ITVs, while implant dimensions and apical cortical anchorage did not. ITVs of variable-thread implants were significantly influenced by variations in bone quality and implant position in the posterior maxilla. Despite the influence of bone quality on primary stability, the mean ITVs attained with variable-thread tapered implants in poor bone quality were within the recommended range for immediate loading.

Evaluation of Peri-implant Bone Stress on D1 Bone Using a Computerized Torque-Measuring Implant Motor: A Study on Photoelastic Resin Blocks.

Recently, a torque-measuring micromotor that calculates the integral (I) of torque-depth curve at implant insertion was developed. This device was used to investigate the correlation between (I) and mechanical stress in photoelastic resin blocks with the density of D1 bone. Using the micromotor, 40 implants (3.75 × 12 mm) were placed in 40 D1 blocks that had been prepared in four different ways. Four groups of 10 blocks each were prepared according to tunnel length (12 or 14 mm) and debris removal (yes or no). After insertion, peri-implant mechanical stress and its correlation with (I) were assessed by photoelastic and linear regression analysis, respectively. Analysis of variance (ANOVA) and Kruskal-Wallis tests investigated differences in mechanical stress patterns and dynamic parameters among the groups. (I) significantly correlated with mechanical stress in D1 resin under all conditions, except for 12-mm implant sites still containing debris. The correlation was significant concerning the whole dataset (r = 0.979) and separately for the coronal (r = 0.940), middle (r = 0.964), and apical (r = 0.948) portions of the implants. Peak torque did not correlate significantly with peri-implant mechanical stress. Longer implant sites and debris removal were significantly associated with lower peri-implant mechanical stress. (I) provides a reliable measure of mechanical stress in D1 bone during implant placement. Preparation of longer osteotomies and routine removal of all debris might reduce peri-implant bone stress significantly.

Influence of short implants geometry on primary stability.

BackgroundA correct design is needed in short implants to improve primary stability (PS) in low quality bone. This study aimed to compare PS of double thread and single thread short implants.Material and MethodsThirty implants with single thread design (PHI/SHORT-I) and 30 implants with double thread design (PHIA/SHORT-I) (Radhex®, Inmet-Garnick S.A., Guadalajara, Spain) were placed in 30 randomly selected bovine ribs. PS was assessed in implant stability quotients (ISQ) and periotest values (PV) with Osstell™ and Periotest® devices, respectively. Computed tomographies of the ribs were taken and bone quality was evaluated in Hounsfield Units (HU) using Ez3D Plus software (Vatech Co., Korea). Only implants placed in low quality bone according to Misch and Kircos classification were selected (D3 bone: 350-850 HU; and D4 bone: 150-350 HU). Ten implants were not included in the study for being placed in D1 and D2 bone. Finally, 50 implants were selected: 17 and 9 PHI/SHORT-I in D3 and D4 bone respectively, and 15 and 9 PHIA/SHORT-I in D3 and D4 bone respectively.ResultsThe one-way ANOVA showed statistically significant differences in ISQ (61.35 ± 4.77 in PHI/SHORT-I and 66.43 ± 4.49 in PHIA/SHORT-I, P<0.005) and PV (-2.76 ± 0.8 and -4.11 ± 1.24 respectively, P<0.005) between two implant designs in D3 bone, and statistically significant differences in ISQ (53.44 ± 3.34 in PHI/SHORT-I and 60.56 ± 1.53 in PHIA/SHORT-I, P<0.0001) and PV (1.13 ± 0.95 and -2.5 ± 0.61 respectively, P<0.0001) between two groups in D4 bone.ConclusionDouble thread design short implants resulted to have higher PS in comparison with single thread design short implants in D3 and D4 bone. Key words:ISQ, osstell, periotest, primary stability, resonance frequency analysis, short implants.

Error analysis of 3D printing surgical guide according to tooth position

The purpose of this study is to evaluate the accuracy of digital surgical guide according to implant position. Dentiform with D2 bone density, which has a #15, 16, 17, 24, 25, 26, 34, 35, 36, 45, 46, 47 edentulous space, is fabricated. Model scanning and cone beam computed tomography (CBCT) data was taken and overlapped using In2Guide software, and the implants were planned. The digital surgical guide was fabricated using 3D printing and the implants were installed using the surgical stent. CBCT were retaken after the implants were installed, and the “before” surgery and “after” surgery CBCTs were overlapped. Then, the degree differences and length differences at implant shoulder and tip area were statistically analysed. The mesial implant of the tooth-supported type showed 1.06±0.53°, 0.29±0.19 mm, 0.39±0.24 mm, the middle implant showed 1.36±0.67°, 0.40±0.15 mm, 0.42±0.23 mm and the distal implant showed 1.39±0.69°, 0.59±0.29 mm, 0.67±0.41 mm respectively. The mesial implant of the tissue-supported type showed 1.76±0.83°, 0.57±0.29 mm, 0.88±0.31 mm, the middle implant showed 2.15±0.65°, 0.69±0.25 mm, 1.08±0.28 mm. and the distal implant showed 2.83±1.17°, 1.09±0.50 mm, 1.34±0.45 mm. The greater the proximity of the implant to the mesial side, the smaller the error.

Is bone density or implant design more important in implant stress formation in patients with bruxism?

ABSTRACTThe aim of this study was to compare the stresses on cylindrical and conical dental implants under heavy bruxing forces, in D1 and D4 bone densities, using three-dimensional finite element analysis (FEA). Eight different stress models were created according to implant design (cylindrical or conical), bone density (D1 or D4) and load (1000 N, vertical or oblique). The von Mises stresses for each model were compared using FEA. The obtained results showed that D1 bone density and vertical force were associated with the least stress on the implant. Bone density was more important than implant design in stress formation. The results from the two implant types were very similar. The von Mises stress values were greater in the neck region of the implant. We suggest that the implant region should be considered firstly for less stress on the implant.

A New Highly Hydrophilic Electrochemical Implant Titanium Surface: A Histological and Biomechanical In Vivo Study.

The aim was to compare the osseointegration degree and secondary implant stability between implants with different surface treatments. A novel electrochemical treatment was applied to modify the sandblasted and acid-etched surface (SLA) to obtain the new hydrophilic Feeling (FEL) surface presenting a highly soluble and homogenous film made of calcium and phosphorus nanocrystals. Twenty 3.8 × 10-mm dynamix implants (Cortex) were inserted in sheep iliac crests. Sheep were killed after 2 months. Bone-to-implant contact percentage (%BIC) and biomechanical parameters, such as implant stability quotient (ISQ) and value of actual micromotion (VAM), were evaluated for each implants. No implant failures were observed. Implants of test group showed %BIC value 30% higher in respect with control group (P = 0.001). No statistical differences were detected between the 2 groups in VAM and ISQ values. Both surface treatments were highly osteoconductive because they were able to significantly increase the bone density onto implant surface in respect with that in which they were inserted (D4 bone density). The hydrophilic FEL surface demonstrated an increase of about 216% in BIC in respect with host bone density and an additional 30% more in respect with SLA surface. Faster osseointegration process is desirable in case of early implant loading protocol.

Biomechanical evaluation of implant-supported prosthesis with various tilting implant angles and bone types in atrophic maxilla: A finite element study

Background and ObjectiveThe purpose of this study is to evaluate and compare bone stress that occurs as a result of using vertical implants with simultaneous sinus augmentation with bone stress generated from oblique implants without sinus augmentation in atrophic maxilla. MethodsSix, three-dimensional (3D) finite element (FE) models of atrophic maxilla were generated with SolidWorks software. The maxilla models were varied for two different bone types. Models 2a, 2b and 2c represent maxilla models with D2 bone type. Models 3a, 3b and 3c represent maxilla models with D3 bone type. Five implants were embedded in each model with different configurations for vertical implant insertion with sinus augmentation: Model 2a/Model 3a, 30° tilted insertion; Model 2b/Model 3b and 45° tilted insertion; Model 2c/Model 3c. A 150 N load was applied obliquely on the hybrid prosthesis. The maximum von Mises stress values were comparatively evaluated using color scales. ResultsThe von Mises stress values predicted by the FE models were higher for all D3 bone models in both cortical and cancellous bone. For the vertical implant models, lower stress values were found in cortical bone. Tilting of the distal implants by 30° increased the stress in the cortical layer compared to vertical implant models. Tilting of the distal implant by 45° decreased the stress in the cortical bone compared to the 30° models, but higher stress values were detected in the 45° models compared to the vertical implant models. ConclusionsAugmentation should be the first treatment option in atrophic maxilla in terms of biomechanics. Tilted posterior implants can create higher stress values than vertical posterior implants. During tilting implant planning, the use of a 45° tilted implant results in better biomechanical performance in peri-implant bone than 30° tilted implant due to the decrease in cantilever length.

A case of intrathyroidal parathyroid adenoma presented with severe 25(OH)D3 deficiency, bone pain and high PTH

A case of intrathyroidal parathyroid adenoma presented with severe 25(OH)D3 deficiency, bone pain and high PTH

Developing Stability of Posterior Mandibular Implants Placed With Osteotome Expansion Technique Compared With Conventional Drilling Techniques.

Clinical decisions regarding the stability and osseointegration of mandibular implants positioned using the bone expansion techniques are conflicting and limited. The objective was to evaluate the stability of implants placed using 2 surgical techniques, selected according to the initial width of the mandibular posterior edentulous ridge, with D3 bone density, during a 12-week period. Fifty-eight implants in 33 patients were evaluated. Thirty-two implants in 24 patients were positioned using the osteotome expansion technique, and 26 fixtures in 17 patients were installed using the conventional drilling technique. The implant stability quotient values were recorded at weeks 0, 1, 2, 3, 4, 6, 8, 10, and 12 postsurgery and evaluated using analysis of variance, independent, and paired t tests. Calibrated according to the stability reading of a 3.3-mm diameter implant, the osteotome expansion group was associated with a lower bone density than the conventional group (64.96 ± 6.25 vs 68.98 ± 5.06, P = .011). The osteotome expansion group achieved a comparable primary stability (ISQb-0, P = .124) and greater increases in secondary stability (ISQb-12, P = .07) than did the conventional technique. A D3 quality ridge with mild horizontal deficiency is expandable by using the osteotome expansion technique. Although the 2 groups presented similar implant stability quotient readings during the study period, the osteotome expansion technique showed significant improvement in secondary stability. The healing patterns for these techniques are therefore inconsistent.

In vitro comparison of primary stability of two implant designs in D3 bone

In vitro comparison of primary stability of two implant designs in D3 bone

Submerged Plateau Implants: A Practical Solution for Mandibular Posterior Region

ABSTRACT Introduction Placement of endosseous plateau implants represents a valid treatment in the setting of limited alveolar bone height. This study's objectives were to evaluate the effect of submerging and platform switching on crestal bone loss and redistribution of occlusal forces, the advantage of plateau design in providing more surface area for osseointegration, and the outcome of autogenous bone grafting from the implant osteotomy site as an alternate to exogenous bone graft. Materials and methods A prospective study of 10 patients with mandibular posterior edentulism was selected. Preoperative alveolar bone height (mean 11.87 mm) and width (8.22 mm) were measured on cone beam computed tomography. Two-staged implants were placed with 2.0 mm of submergence, which remained below the alveolar crest. The distribution of site according to bone quality and implant dimension was D2. Patients were followed up after 7 days for pain, infection, soft tissue dehiscence, and paresthesia followed by an average period of 1 year and evaluated for bone gain over implant shoulder, crestal bone loss, and peri-implant radiolucency. Results One-year postloading survival rates for submerged plateau implants was 100.0% in D2 bone, with no peri-implant radiolucency and statistically insignificant (~0–0.8 mm) crestal bone loss. Conclusion Submerged plateau implants have excellent survival rates and crestal bone level maintenance. The results of this study support the hypothesis that plateau implants can be successfully used in mandibular areas with limited bone height. How to cite this article Shukla DH, Anchlia SM, Patel NP, Nagavadiya V, Panwar RK, Domadiya HL. Submerged Plateau Implants: A Practical Solution for Mandibular Posterior Region. Int J Oral Implantol Clin Res 2017;8(1):5-11.

Increased bone quantity around an ailing implant in esthetic zone using progressive bone loading: A case report

Introduction: Progressive loading protocol is a high-demanding procedure suggested to increase the quality of bone when the implant is inserted in D3 or D4-typed bone. The purpose of this study was to present a case report regarding simultaneously progressive and immediately loading implants in the anterior position of the maxilla. Case report: One patient whose implants in the anterior maxilla (in site of teeth #7, #9, #11) had questionable to poor prognosis who was treated immediate and delayed progressive loading protocol and was followed up for 2 years. Discussion: Although the number of studies in this field is limited, it can be concluded that the progressive loading protocol can predictably enhance the treatment success in immediate-loaded implants with poor prognosis and when inserted in low quality bone such as the present case.

Three-dimensional microstructure of human alveolar trabecular bone: a micro-computed tomography study.

PurposeThe microstructural characteristics of trabecular bone were identified using micro-computed tomography (micro-CT), in order to develop a potential strategy for implant surface improvement to facilitate osseointegration.MethodsAlveolar bone specimens from the cadavers of 30 humans were scanned by high-resolution micro-CT and reconstructed. Volumes of interest chosen within the jaw were classified according to Hounsfield units into 4 bone quality categories. Several structural parameters were measured and statistically analyzed.ResultsAlveolar bone specimens with D1 bone quality had significantly higher values for all structural parameters than the other bone quality categories, except for trabecular thickness (Tb.Th). The percentage of bone volume, trabecular separation (Tb.Sp), and trabecular number (Tb.N) varied significantly among bone quality categories. Tb.Sp varied markedly across the bone quality categories (D1: 0.59±0.22 mm, D4: 1.20±0.48 mm), whereas Tb.Th had similar values (D1: 0.30±0.08 mm, D4: 0.22±0.05 mm).ConclusionsBone quality depended on Tb.Sp and number—that is, endosteal space architecture—rather than bone surface and Tb.Th. Regardless of bone quality, Tb.Th showed little variation. These factors should be taken into account when developing individualized implant surface topographies.

Impact of radiotherapy on implant-based prosthetic rehabilitation in patients with head and neck cancer: A prospective observational study on implant survival and quality of life-Preliminary results.

To study implant-based prosthetic rehabilitation of head and neck cancer patients with focus on implant survival and quality of life. The prospective observational study presents preliminary results of 29 edentulous head neck cancer patients (20 patients after radiotherapy) with 165 OsseoSpeed implants. Implant success after 1-year follow-up was evaluated by means of the Albrektsson criteria. Quality of life was analysed with the EORTC QLQ-C30, QLQ-H&N35, and OHIP 14 questionnaires. The overall implant survival rate after 1 year was 95.2% (157/165). Implant success measured by the Albrektsson criteria showed a lower success rate of 86.7% (143/165), mainly because of peri-implant marginal bone loss with a mean of 0.8mm after 1 year. Xerostomia (p=0.008), implant insertion within the radiation target volume (p=0.09), implantation in transplanted bone (p=0.05), and smoking (p=0.041) were the main reasons for implant failure, followed by D4 bone quality, maxillary implant site, and insufficient primary stability. Speaking, swallowing, eating, as well as social integration and individual self-confidence had considerably improved 1 year after denture placement compared to before treatment. Implant-based prosthetic rehabilitation of head and neck cancer patients is possible at a calculable risk and significantly improves patients' quality of life.

Vitamin D3 supplementation, bone health and quality of life in adults with diabetes and chronic kidney disease: Results of an open label randomized clinical trial

Adults with diabetes (DM) and chronic kidney disease (CKD) are at risk for vitamin D (vitD) insufficiency, suboptimal bone health and reduced quality of life (QoL) due to limited sunlight exposure, poor vitD intake and CKD. This open-labeled, randomized clinical trial, compared the impact of daily (2000IU/D) verses monthly (40,000IU/month) vitD3 supplementation over six months on markers of vitD status, bone health and QoL in adults with DM and CKD (stages: 1-4). Participants (18-80 years) were randomized to daily (n=60) or monthly (n=60) vitD3 for six months. Primary outcomes included: vitD status (25-hydroxyvitD [25(OH)D], 1, 25-dihydroxyvitD [1,25(OH)2D], bone health (bone mineral density [BMD] and serum concentrations of bone-specific alkaline phosphatase [BSAP], osteocalcin [OC], N-telopeptide-type 1-collagen [NTx]) and Fibroblast Growth Factor-23 (FGF-23). Secondary outcomes included QoL (Short Form-36 questionnaire). Adherence by dose allocation over six months was 95.0±5.7% (daily) and 94.1±4.1% (monthly), respectively (p=0.44); resulting in an overall median [95% CI] increase in serum 25(OH)D of 19 (12-26)nmol/L (p<0.001). Serum 25(OH)D increased at three (p<0.001) and six months (p<0.001) in the daily and monthly groups, respectively. No significant differences over six months between groups were observed in serum concentrations of 1,25(OH)2D, FGF-23, OC and NTx, BMD and QoL measures (p>0.05). Serum 25(OH)D≥75nmol/L was associated with significant reductions in BSAP (p=0.01) and improved physical functioning vs those with concentrations<75nmol/L (62.5±26.8 vs 52.7±26.3; p=0.03) in the monthly and daily groups, respectively. Daily (2000IU/D) and monthly (40,000IU/month) vitD3 supplementation for six months in adults with DM and CKD was safe, and resulted in equivalent adherence and improvements in overall vitD status, but only modest changes in markers of bone health and QoL.

Use of digital panoramic radiology in presurgical implant treatment planning to accurately assess bone density

Statement of problemNo cost-effective method of ascertaining bone density from 2-dimensional radiographic images is currently available for dental implants before surgery. PurposeThe purpose of this in vivo study was to use digital panoramic radiology and dental computed tomography (CT) to evaluate the bone density of specific points in the jaw near the tooth-bearing areas. The objective was to determine whether digital panoramic radiology can be used in assessing bone density as an alternative to a more expensive and complex dental CT. Material and methodsThis study involved determining bone densities at predetermined anatomic landmarks near tooth-bearing areas of the jaws of 20 participants, using digital panoramic radiology in gray-level scale with a lead step wedge. Subsequently, the bone densities of the same points were determined in Hounsfield units (Hu) with dental CT. The data collected after interpretation of the panoramic radiograph and CT were tabulated and analyzed statistically. ResultsBone density measured using CT correlated with the first 3 steps of (A, B, and C) the digital scale of gray. Further analysis conducted using the Mann-Whitney U test showed a significant association between step A to detect D4 bone, step B to detect D3 bone, and step C to detect D2 type bone. ConclusionsThe digital scale of gray obtained from a lead step wedge can be effectively used with digital orthopanoramic radiology to assess bone density before the placement of implants, but with certain restrictions.