Effect of Customized and Prefabricated Healing Abutments on Peri-Implant Soft Tissue and Bone in Immediate Implant Sites: A Randomized Controlled Trial.

This study aimed to evaluate the effect of customized healing abutments compared to prefabricated healing abutments in immediate implant sites. Twelve patients requiring single immediate implant placement were divided into two groups: a prefabricated group received prefabricated titanium healing abutments, and a customized group received a polyetheretherketone (PEEK) customized healing abutments fabricated based on the individuals' digital impressions. Outcomes, including peri-implant horizontal and vertical soft tissue alteration, bone level change, volume change, pain score, and pink esthetic score (PES) change, were evaluated at the 1-, 4-, and 6-month follow-ups compared to pre-extraction teeth. At the 1- and 4-month follow-ups, the customized group had a significantly lower buccal volume variation (BVv). At the 6-month follow-up, neither group showed any significant difference in the marginal bone change; however, the customized group had a significantly lower PES change and a lower pain score. In the anterior and premolar regions, the customized group showed the preservation of peri-implant buccal horizontal soft tissue and buccal volume, while in the molar regions, the preservation of papilla height and midfacial height was observed. The morphology of the customized healing abutment demonstrated a better trend in preservation of peri-implant soft tissue, esthetic outcomes, and lower patient discomfort in immediate implant sites.

Biomaterials and Clinical Application of Dental Implants in Relation to Bone Density-A Narrative Review.

Titanium has been the material of choice for dental implant fixtures due to its exceptional qualities, such as its excellent balance of rigidity and stiffness. Since zirconia is a soft-tissue-friendly material and caters to esthetic demands, it is an alternative to titanium for use in implants. Nevertheless, bone density plays a vital role in determining the material and design of implants. Compromised bone density leads to both early and late implant failures due to a lack of implant stability. Therefore, this narrative review aims to investigate the influence of implant material/design and surgical technique on bone density from both biomechanical and biological standpoints. Relevant articles were included for analysis. Dental implant materials can be fabricated from titanium, zirconia, and PEEK. In terms of mechanical and biological aspects, titanium is still the gold standard for dental implant materials. Additionally, the macro- and microgeometry of dental implants play a role in determining and planning the appropriate treatment because it can enhance the mechanical stress transmitted to the bone tissue. Under low-density conditions, a conical titanium implant design, longer length, large diameter, reverse buttress with self-tapping, small thread pitch, and deep thread depth are recommended. Implant material, implant design, surgical techniques, and bone density are pivotal factors affecting the success rates of dental implant placement in low-density bone. Further study is required to find the optimal implant material for a clinical setting's bone state.

Effect of customized abutment taper configuration on bone remodeling and peri-implant tissue around implant-supported single crown: A 3D nonlinear finite element study.

PURPOSE: The optimal configuration of a customized implant abutment plays a crucial role in promoting bone remodeling and maintaining the peri-implant gingival contour. However, the biomechanical effects of abutment configuration on bone remodeling and peri-implant tissue remain unclear. This study aimed to evaluate the influence of abutment taper configurations on bone remodeling and peri-implant tissue. MATERIALS AND METHODS: Five models with different abutment taper configurations (10°, 20°, 30°, 40°, and 50°) were analyzed using finite element analysis (FEA) to evaluate the biomechanical responses in peri-implant bone and the hydrostatic pressure in peri-implant tissue. RESULTS: The results demonstrated that the rate of increase in bone density was similar in all models. On the other hand, the hydrostatic pressure in peri-implant gingiva revealed significantly different results. Model 10° showed the highest maximum and volume-averaged hydrostatic pressures (69.31 and 4.5 mmHg), whereas Model 30° demonstrated the lowest values (57.83 and 3.88 mmHg) with the lowest excessive pressure area. The area of excessive hydrostatic pressure decreased in all models as the degree of abutment taper increased from 10° to 30°. In contrast, Models 40° and 50° exhibited greater hydrostatic pressure concentration at the cervical region. CONCLUSION: In conclusion, the abutment taper configuration had a slight effect on bone remodeling but exerted a significant effect on the peri-implant gingiva above the implant platform via hydrostatic pressure. Significant decreases in greatest and average hydrostatic pressures were observed in the peri-implant tissues of Model 30°. However, the results indicate that implant abutment tapering wider than 40° could result in a larger area of excessive hydrostatic pressure in peri-implant tissue, which could induce gingival recession.

Effect of gingival height of a titanium base on the biomechanical behavior of 2-piece custom implant abutments: A 3-dimensional nonlinear finite element study.

STATEMENT OF PROBLEM: Titanium base (TiBase) abutments to restore an implant-supported single crown are available in different gingival heights, but information on the biomechanical effects of the gingival heights is lacking. PURPOSE: The purpose of this nonlinear finite element analysis study was to evaluate the effects of TiBase gingival heights on the biomechanical behavior of custom zirconia (CustomZir) abutments and TiBase, including von Mises stress and maximum and minimum principal stress. MATERIAL AND METHODS: TiBases with different gingival heights (0.5 mm, 1 mm, 1.5 mm, and 2 mm) with internal hexagon Morse taper connections were simulated in 3-dimensional models. The simulations (ANSYS Workbench 2020; ANSYS Inc) included the OsseoSpeed EV implant (Ø5.4 mm) (AstraTech; Dentsply Sirona), restoration, and surrounding bone in the mandibular first molar region. An occlusal force of 200 N was applied with a 2-mm horizontal offset toward the buccal side and a 30-degree inclination from the vertical axis. RESULTS: High-stress concentration was observed in the uppermost internal connection area on the buccal side and the antirotational part of the titanium abutment on the lingual side in all models. CustomZir abutments with a shorter gingival height exhibited larger concentrated areas of volume average stress von Mises stress and higher magnitude of maximum and minimum principal stress compared with a taller gingival height. CONCLUSIONS: A TiBase abutment with a taller gingival height reduced the fracture risk of a CustomZir abutment without increasing any mechanical risk.

Effect of implant placement depth on bone remodeling on implant-supported single zirconia abutment crown: A 3D finite element study.

PURPOSE: This study aimed to evaluate the influence of subcrestal implant placement depth on bone remodeling using time-dependent finite element analysis (FEA) with a bone-remodeling algorithm over 12 months. METHODS: Seven models of different subcrestal implant placement depths (0, 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm) were analyzed using FEA to evaluate the biomechanical responses in the bone and implant, including von Mises equivalent stress, strain energy density (SED), and overloading elements. SED was used as a mechanical stimulus to simulate cortical and cancellous bone remodeling over the first 12 months after final prosthesis delivery. RESULTS: The highest increase in cortical bone density was observed at Depth 1.5, whereas the lowest increase was observed at Depth 3.0. In contrast, the highest increase in bone density was observed at Depth 3.0 in the cancellous bone, whereas the lowest increase was observed at Depth 0. The highest peak von Mises stress in the cortical bone occurred at Depth 2.5 (107.24 MPa), while that in the cancellous bone was at Depth 2.5 (34.55 MPa). Notably, the maximum von Mises stress values in the cancellous bone exceeded the natural limit of the bony material, as indicated by the overloading elements observed at the depths of 2.0, 2.5, and 3.0 mm. CONCLUSIONS: Greater bone density apposition is observed with deeper implant placement. An implant depth of more than 1.5 mm exhibited a higher maximum von Mises stress and greater overloading elements.

Biomaterials and Clinical Applications of Customized Healing Abutment-A Narrative Review.

Customized healing abutments have been introduced in clinical practice along with implant surgery to preserve or create natural-appearing hard and soft tissue around the implant. This provides the benefits of reducing the overall treatment time by eliminating the second stage and reducing the elapsed time of the fabrication of the final prostheses. This article aims to review the types and properties of materials used for the fabrication of customized healing abutments and their clinical applications. Articles published in English on customized healing abutments were searched in Google Scholar, PubMed/MEDLINE, ScienceDirect, and the Scopus databases up to August 2022. The relevant articles were selected and included in this literature review. Customized healing abutments can be fabricated from materials available for dental implants, including PEEK, PMMA, zirconia, resin composite, and titanium. All the materials can be used following both immediate and delayed implant placement. Each material provides different mechanical and biological properties that influence the peri-implant tissues. In conclusion, the studies have demonstrated promising outcomes for all the materials. However, further investigation comparing the effects of each material on peri-implant soft and hard tissues is required.

The Accuracy and Reliability of Tooth Shade Selection Using Different Instrumental Techniques: An In Vitro Study.

This study aimed to investigate and compare the reliability and accuracy of tooth shade selection in the model using 30 milled crowns via five methods: (1) digital single-lens reflex (DSLR) camera with twin flash (TF) and polarized filter (DSLR + TF), (2) DSLR camera with a ring flash (RF) and polarized filter (DSLR + RF), (3) smartphone camera with light corrector and polarized filter (SMART), (4) intraoral scanner (IOS), and (5) spectrophotometer (SPEC). These methods were compared with the control group or manufacturer's shade. The CIE Lab values (L, a, and b values) were obtained from five of the methods to indicate the color of the tooth. Adobe Photoshop was used to generate CIE Lab values from the digital photographs. The reliability was calculated from the intraclass correlation based on two repetitions. The accuracy was calculated from; (a) ΔE calculated by the formula comparing each method to the control group, (b) study and control groups were analyzed by using the Kruskal-Wallis test, and (c) the relationship between study and control groups were calculated using Spearman's correlation. The reliability of the intraclass correlation of L, a, and b values obtained from the five methods showed satisfactory correlations ranging from 0.732-0.996, 0.887-0.994, and 0.884-0.999, respectively. The ΔE from all groups had statistically significant differences when compared to the border of clinical acceptance (ΔE = 6.8). The ΔE from DSLR + TF, DSLR + RF, SMART, and SPEC were higher than clinical acceptance (ΔE > 6.8), whereas the ΔE from IOS was 5.96 and all of the L, a, and b values were not statistically significantly different from the manufacturer's shade (p < 0.01). The ΔE of the DSLR + RF group showed the least accuracy (ΔE = 19.98), whereas the ∆E of DSLR + TF, SMART, and SPEC showed similar accuracy ∆E (ΔE = 10.90, 10.57, and 11.57, respectively). The DSLR camera combined with a ring flash system and polarized filter provided the least accuracy. The intraoral scanner provided the highest accuracy. However, tooth shade selection deserves the combination of various techniques and a professional learning curve to establish the most accurate outcome.