Objectives
To compare the survival and complication rates of posterior screw‐retained monolithic lithium disilicate (LS2)/veneered zirconia (ZrO2) single implant crowns (SICs), as well as analyze the ...occlusal changes observed during a 3‐year follow‐up period.
Materials and Methods
Thirty‐three patients were included and randomly divided into two groups. The test group consisted of 17 patients who received monolithic‐LS2–SIC, while the control group consisted of 16 patients who received veneered‐ZrO2‐SIC. Implant/prosthesis survival rates, technical complications, peri‐implant soft tissue conditions, and quantitative occlusal changes of SIC (obtained by the intra‐oral scanner and analyzed in reverse software Geomagic Control 2015) were assessed at 1‐ and 3‐year follow‐ups. Bone loss and Functional Implant Prosthodontic Score (FIPS) were evaluated at a 3‐year follow‐up.
Results
After a 3‐year follow‐up period, one patient dropped out of the follow‐up. No implant loss was observed. One crown was fractured, resulting in prosthesis survival rates of 93.75% for the monolithic group and 100% for the veneered group. A technical complication rate of 25% (4/16) was observed in the veneered group (p = .333). No significant differences in the marginal bone loss were observed at the 3‐year follow‐up (0.00 (−0.22, 0.17) mm versus 0.00 (−0.12, 0.12) mm, p = .956). The total FIPS scores for the test group were 9.0 (9.0, 9.0), while the control group received scores of 9.0 (8.0, 10.0) (p = .953). The changes in mean occlusal clearance were 0.022 ± 0.083 mm for the test and 0.034 ± 0.077 mm for the control group (at 3 years, p = .497). The changes in occlusal contact area were 1.075 ± 2.575 mm2 for the test and 1.676 ± 2.551 mm2 for the control group (at 3 years, p = .873).
Conclusion
After a 3‐year follow‐up, screw‐retained monolithic LS2 and veneered ZrO2 SIC demonstrated similar survival rates. The occlusal performance of implant prostheses needs to be closely examined during follow‐up, and appropriate occlusal adjustments need to be considered.
We aimed to retrospectively evaluate the long-term clinical outcomes of lateral sinus floor elevation (LSFE) in patients with sinus floor defects.
Between 2008 and 2020, patients with sinus floor ...defects were recruited after confirmation on preoperative cone-beam computed tomography (CBCT). The split-thickness flap technique with a palatal crestal incision was used to manage tissue adhesion in the bone defects area. A resorbable collagen membrane was used to close the sinus floor defects from the crestal side before bone substitute placement. Of 58 implants, 47 (81.0%) were placed after an 8-month healing period, whereas 11 were placed simultaneously. Patients were followed up by radiography and clinical examination for 1-9 years. Finally, the cumulative survival rate (CSR) of implants, surgical complications, and marginal bone loss (MBL) were recorded and analyzed.
In total, LSFE was performed in 36 sinuses (35 patients) with sinus floor defects, of which surgery was completed in 35 sinuses (97.2%) in the first attempt. Schneiderian membrane perforations (SMP) occurred in 10/36 (27.8%) sinuses; nine were repaired carefully, whereas one surgery was suspended due to complicated SMP, and successful re-entry LSFE was performed 4 months later. After a follow-up period of 1-9 years, the CSR was 96.5% at the 1-year, 3-year, 5-year, and 7-year follow-ups and 64.3% at the 8-year follow-up.
Within the limitations of this study, sinus floor defects seem not to compromise LSFE therapy after appropriate management and long-term clinical outcomes are predictable.
Objectives
To compare the three‐dimensional changes in quantity and morphology following clinical adjustment of a posterior single implant crown between chairside digital workflow (test) and hybrid ...digital workflow (control).
Materials and Methods
A total of 33 participants were included for single‐tooth replacement with screw‐retained crowns in posterior sites of either the maxillary or mandible. A total of 17 participants were carried to a chairside digital workflow, receiving monolithic lithium disilicate (LS2)‐crowns (test), while the remaining 16 participants were fitted with CAD/CAM‐fabricated zirconia superstructures and hand‐layered ceramic veneering crowns (control). As each crown underwent intraoral scanning (3Shape TRIOS Color, 3Shape), 3D digital models were rendered. These scans were taken both before and after try‐in. Clinical adjustment dimensional changes were measured by superimposing the optical scans of models within a reverse software (Geomagic Control 2014). Adjustment counts and amounts (from vertical dimension) between two workflows were assessed and compared. Time consumption was recorded for efficiency analysis.
Results
All patients were successfully treated in both groups. The median maximum vertical adjustment (taking both occlusal and interproximal surfaces into consideration) was 237 μm ± 112 in the test group and 485 μm ± 195 in the control group (p < .0001), respectively. The median adjustment count was 2.00 ± 1.09 in test group and 3.00 ± 1.05 in control group (p = .001), respectively. The total active working time/ total time for two workflows was 92.3/113.7 min for the test group and 146.3/676.3 min for the control group, respectively.
Conclusion
The test group showed fewer adjustments and apparent precision on the occlusal surface compared with the control group with only a fifth of the consumption of a hybrid workflow.
Objectives
To assess the accuracy of intraoral digital impressions for gingival contour captured in the esthetic zone in vivo.
Material and methods
Five participants with full upper dentition were ...recruited. For each participant, three scans were taken using two intraoral scanning (IOS) systems (3Shape TRIOS Color, TRC; CEREC Omnicam, OC) respectively; three conventional impressions (CIs) were taken using vinyl polysiloxane materials. The CIs of all participants were casted and then digitized with a model scanner (IScan D103i, Imetric). Precision was evaluated by superimposing three repeated STL datasets per participant within each group and calculating the (90th
-
10th)percentile/2 values. The CIs were the reference for evaluating the level of system error of the two IOS systems from the true value. Digital models from CI and each IOS group were superimposed and (mean positive deviation-mean negative deviation)/2mean negative deviation, mean positive deviation were calculated to assess trueness level of the two IOS systems.
Results
For the soft tissue acquisition, precision results of each group were 45.10 ± 12.54 μm in TRC, 66.04 ± 13.46 μm in OC, and 63.66 ± 17.19 in CI (TRC vs OC,
p
< 0.001; TRC vs CI,
p
= 0.001; OC vs CI,
p
= 0.66). Trueness results were 80.12 ± 8.69− 112.10 ± 9.88, 48.13 ± 13.79 μm in TRC and 82.70 ± 8.85− 121.41 ± 15.40, 43.98 ± 11.86 μm (
p
> 0.05).
Conclusions
In dentate situations, the two tested IOS systems achieved a clinically satisfying accuracy for capturing gingival contour in anterior maxilla, with a comparable or superior precision to the CI. TRC achieved a similar trueness and a higher precision level compared with OC.
Clinical relevance
Intraoral digital impressions could be a recommended method for recording 3-dimensional gingival contour in the esthetic zone.
Background
Although small perforation of the maxillary sinus schneiderian membrane is a well‐documented complication during lateral sinus floor elevation (LSFE), complete perforations larger than 10 ...mm often result in discontinuation of surgery. Reports on reentry LSFE and its long‐term outcomes are sparse.
Purpose
To evaluate the long‐term outcomes of reentry LSFE following complete membrane perforation to elucidate the technical details of the reentry procedure.
Materials and methods
We assessed the medical records of all patients receiving LSFE from 2008 to 2017 in the Department of Oral Implantology, Peking University Hospital of Stomatology. Twenty‐two patients receiving reentry LSFE after complete membrane perforation were enrolled. Data were recorded using cone beam computer tomography: including the residual bone height, membrane thickness of the sinus prior to surgery (MT1), and before reentry (MT2), and height of the bone graft during the reentry procedure (HBG). Cumulative survival rate of implants (CSR), marginal bone loss (MBL), and subsequent complications were also recorded.
Results
From 2008 to 2017, 2023 consecutive patients (2262 sinuses) who underwent LSFE were screened. Complete membrane perforation occurred in 28 patients and resulted in discontinuation of surgery (1.2%). Twenty two patients were enrolled and received reentry LSFE within 3‐6 months. Two patients undergoing the reentry procedure were suspended due to excessive membrane perforation, while the other 20 finished reentry sinus bone graft. In the reentry procedure, the HBG was 9.73 ± 2.67 mm with 34 implant placements. The MT1 and MT2 were 1.03 ± 0.43 and 1.91 ± 1.45 mm, respectively, showing a statistically significant difference (P < .05). After a follow‐up of 2‐10 years, CSR was 97.1%, and MBL was 0.64 ± 0.50 mm.
Conclusions
The long‐term outcome of reentry LSFE is predictable and reentry LSFE offers a reliable alternative following complete membrane perforation. However, the procedure is relatively sensitive and should be performed by experienced surgeons.
Background
Soft tissue dynamics in the esthetic zone are gaining increasing attention in recent years. Emerging intraoral scanning technology allows easier capture of soft tissue contours.
Purpose
To ...quantitatively assess the time‐dependent contour alterations of labial soft tissue following single immediate implants and immediate provisionalization (IIPP) in maxillary incisors via intraoral scanning.
Materials and Methods
This was a prospective cohort study. Thirty eligible consecutive patients were included and received immediate replacement of a failure maxillary single incisor. A screw‐retained immediate restoration was delivered for each patient. Subsequently, the anterior maxillary region was scanned by an intraoral scanning system at four time points: preoperation (baseline, BL), 3 months (3 m), 6 months (6 m), and 12 months (12 m). The Standard Tessellation Language files were exported to a dedicated software and superimposed for visual analysis. At 3, 6, and 12 months, the mid‐facial mucosa level (ML) was assessed, and the precise three‐dimensional (3D) configuration of the altered volume was calculated and reconstructed for visual analysis. Furthermore, quantitative analysis of the reconstructed morphology was performed using the following parameters: mean change in thickness (△d), mesio‐distal width (w), coronal‐apical height (h), and horizontal and vertical position of the thickest point represented by coordinates (x, z).
Result
Twenty‐seven of thirty enrolled patients were finally available for analysis at the 1‐year follow‐up. In general, the frontal view of the reconstructed volume exhibited a crescent shape. The mid‐facial ML change at 3, 6, and 12 months was −0.05 ± 0.36 mm, −0.03 ± 0.32 mm, and −0.24 ± 0.37 mm, respectively (P = .012). The mean change in thickness at 3 months (△d3m), 6 months (△d6m), and 12 months (△d12m) was 0.50 ± 0.19 mm, 0.59 ± 0.21 mm, and 0.62 ± 0.22 mm, respectively (P <.001). At 12 months, nine patients had a △d less than 0.5 mm. The mean △d3 m/△d12 m and △d6 m/△d12 m was 0.81 ± 0.17 and 0.96 ± 0.13. The w, h, x, and z results showed no significant differences during the 1‐year observation (P = .126, P = .324, P = .635, P = .263). At 12 months, w, h, x, and z were 11.57 ± 1.77 mm, 6.46 ± 2.01 mm, 0.03 ± 1.43 mm, and 2.16 ± 0.65 mm, respectively.
Conclusion
During the 1‐year observation following single IIPP treatment in maxillary incisors, the labial soft tissue contour showed a continuous alteration resulting in a mean change in thickness of 0.62 mm that occurred mainly in the first 3 months and tended to be relatively stable after 6 months, while the crescent‐like shape, width, height, and thickest point position of the alteration volume remained stable after 3 months. No advanced mid‐facial recession was observed.
Postoperative cone-beam computed tomography (CBCT) examination is considered a reliable method for clinicians to assess the positions of implants. Nevertheless, CBCT has drawbacks involving radiation ...exposure and high costs. Moreover, the image quality can be affected by artifacts. Recently, some literature has mentioned a digital registration method (DRM) as an alternative to CBCT for evaluating implant positions. The aim of this clinical study was to verify the accuracy of the DRM compared to CBCT scans in postoperative implant positioning.
A total of 36 patients who received anterior maxillary implants were included in this clinical study, involving a total of 48 implants. The study included 24 patients in the single implant group and 12 patients in the dual implant group. The postoperative three-dimensional (3D) positions of implants were obtained using both CBCT and DRM. The DRM included three main steps. Firstly, the postoperative 3D data of the dentition and intraoral scan body (ISB) was obtained through the intraoral scan (IOS). Secondly, a virtual model named registration unit which comprised an implant replica and a matching ISB was created with the help of a lab scanner and reverse engineering software. Thirdly, by superimposing the registration unit and IOS data, the postoperative position of the implant was determined. The accuracy of DRM was evaluated by calculating the Root Mean Square (RMS) values after superimposing the implant positions obtained from DRM with those from postoperative CBCT. The accuracy of DRM was compared between the single implant group and the dual implant group using independent sample t-tests. The superimposition deviations of CBCT and IOS were also evaluated.
The overall mean RMS was 0.29 ± 0.05 mm. The mean RMS was 0.30 ± 0.03 mm in the single implant group and 0.29 ± 0.06 mm in the dual implant group, with no significant difference (p = 0.27). The overall registration accuracy of the IOS and CBCT data ranged from 0.14 ± 0.05 mm to 0.21 ± 0.08 mm.
In comparison with the 3D implant positions obtained by CBCT, the implant positions located by the DRM showed clinically acceptable deviation ranges. This method can be used in single and dual implant treatments to assess the implant positions.
Abstract
Background
Computer-aided design and computer-aided manufacturing (CAD-CAM) materials for prosthetic is gaining popularity in dentistry. However, limited information exists regarding the ...impact of thickness and roughening treatment on the optical properties of contemporary CAD-CAM restorative materials. This study aimed to quantitatively evaluate the translucency and opalescence of six dental CAD-CAM materials in response to different thicknesses and roughening treatments.
Methods
Six dental CAD-CAM materials, lithium disilicate glass–ceramic (IPS e.max CAD, LS), polymer-infiltrated ceramic (VITA Enamic, VE), resin-nano ceramic glass–ceramic (LAVA Ultimate, LU), polymethyl methacrylate (Telio CAD, TE), and two zirconia reinforced lithium silicate (VITA Suprinity, VS, and Celtra Duo, CD), in shade A2 were prepared as 12 × 12mm
2
specimens of four thicknesses (0.5mm, 1.0mm, 1.5mm, and 2.0mm) (
N
= 240,
n
= 10). After three different treatments (polished, roughened by SiC P800-grit, and SiC P300-grit), the translucency parameter (TP
00
) and opalescence parameter (OP) were measured with a spectrophotometer (VITA Easyshade V). The surface roughness was analyzed with a shape measurement laser microscope. The data were analyzed using a MANOVA, post hoc Tukey–Kramer test, the
t
test, and regression analysis (α = .05).
Results
The TP
00
and OP were significantly influenced by material type, thickness and roughening treatment (
P
< .05). TP
00
showed a continues decline with increasing thicknesses, while the variations of OP were material-dependent. TP
00
ranged from 37.80 (LS in 0.5mm) to 5.66 (VS in 2.0mm), and OP ranged from 5.66 (LU in 0.5mm) to 9.55 (VS in 0.5mm). The variations in TP
00
of all materials between adjacent thicknesses ranged from 2.10 to 15.29, exceeding the acceptable translucency threshold except for LU. Quadratic and logarithmic regression curves exhibited the best fit for TP
00
among the materials. Compared to polished specimens, rougher specimens exhibited lower TP00 and higher OP in all materials except for LS (
P
< 0.05). Roughening with P300-grit decreased TP
00
and OP by an average of 2.59 and 0.43 for 0.5mm specimens, and 1.26 and 0.25 for 2.0mm specimens, respectively.
Conclusions
Variations in translucency caused by thickness and roughening treatment were perceptible and may be clinically unacceptable. Careful consideration should be given to the selection of CAD-CAM materials based on their distinct optical properties.
Bone defects and fractures heal slowly compared with injuries to other tissues, creating a heavy burden for patients, their families, and society. Alongside conventional treatment methods for ...fractures and bone defects, adjuvant therapies play an important but underappreciated role. In a previous study, we found that systemic administration of flufenamic acid promoted osteogenesis in vivo, but its side effects limited the application of our findings. In the present study, we assess the effects of external butyl flufenamate ointment on the healing of cranial defects in mice. We found that application of butyl flufenamate ointment on the surface of the skin accelerated the healing of cranial defects in mice by promoting BMP2 secretion from mouse-skin mesenchymal stem-cells. These findings indicate that butyl flufenamate ointment has potential therapeutic value for treating superficial fractures or bone defects while avoiding the toxicity and side effects of systemic medication, representing a safe and convenient adjuvant therapy to promote healing of superficial bone defects and fractures.
Computer-aided design and computer-aided manufacturing (CAD-CAM) monolithic restorative materials have become a popular option because of advantages such as convenience and efficiency. However, ...studies that quantitatively analyzed their color accuracy and bias are lacking.
The purpose of this in vitro study was to evaluate the color accuracy and bias of 4 CAD-CAM monolithic restorative materials with different thicknesses by using the CIELab color space.
Four types of dental CAD-CAM monolithic restorative materials in shade A2, lithium disilicate glass-ceramic (IPS e.max CAD), infiltrated ceramic (VITA Enamic), resin-nano ceramic (LAVA Ultimate), and polymethyl methacrylate (Telio CAD), were prepared as 12×12-mm specimens of 10 different thicknesses (from 0.5 to 5.0 mm) (N=200, n=5). After polishing with SiC P1500-grit, CIELab color coordinate parameters of the specimens were measured with a spectrophotometer (VITA Easyshade V). The color accuracy and bias were described by ΔE00, ΔL∗, Δa∗, and Δb∗ in the CIELab color space, and the data were analyzed by using a 2-way ANOVA, post hoc Tukey-Kramer test, and the t test (α=.05).
The ΔE00, ΔL∗, Δa∗, and Δb∗ were significantly influenced by material type and thickness (P<.001). Specimens at a thickness of 0.5 mm represented the maximum ΔE00. The minimum ΔE00 was observed at a thickness of 2.0 mm for LAVA Ultimate, 1.5 mm for VITA Enamic and Telio CAD, and 4.0 mm for IPS e.max CAD. The ΔE00 of all specimens significantly exceeded the 50:50% acceptability threshold (1.8 unit) (P<.001). LU exhibited higher ΔE00, Δa∗, and Δb∗ than the other 3 materials in all thickness expect for 0.5 mm. For color bias, the ΔE00 was more influenced by Δb∗ and ΔL∗ than Δa∗.
The color accuracy and bias were significantly affected by material type and thickness. The color inaccuracy of the tested materials was statistically significant and clinically perceptible. Improved clinical outcomes may be expected from the 1.5-mm- to 2.0-mm-thick restorations.
