Digital Evaluation of Vertical Ridge Augmentation with the Modified Shell Technique Using a Xenogeneic Bone Lamina: A Case Series.

Vertical ridge augmentation is a demanding and technique-sensitive surgical procedure. In the present case series, cone beam CT (CBCT) scans from the clinical routine of patients treated using a novel approach for vertical bone augmentation were assessed. All patients showed a single-tooth class 5 defect and were treated using a modification of the original shell technique. Cortical bone plates were replaced with a lamina composed of a partially demineralized porcine xenograft. CBCT scans of six consecutive patients were treated with the lamina and particulate bone from the mandibular ramus prior to a single tooth implant in the anterior maxilla were included. Pre- and postsurgical CBCT data sets were superimposed and analyzed digitally using surface matching and Boolean subtraction. The volume of the grafted area was calculated with and without the xenograft. The vertical gain of the ridge height measured in this case series varied from 7 to 11.3 mm. The mean vertical gain was 8.97 mm. The mean volume including the xenograft was 382.59 mm3 (SD 73.39) and 250.84 mm3 (SD 53.67) without the lamina. The modified shell technique used in this case series for the vertical augmentation of single-tooth class 5 defects provided sufficient bone for single implant restorations.

Orthodontic pretreatment with aligners for optimizing the result prior to fixed restorations in the esthetic zone.

OBJECTIVE: To show the benefit of a minor orthodontic pretreatment prior to fixed restorations in the esthetic zone in challenging situations. OVERVIEW: Esthetic rehabilitations in complex situations need careful treatment planning and comprehensive interdisciplinary approach. Minor orthodontic pretreatments may transfer complex situations into straight forward situations. Typical indications are space opening in order to provide space for a restoration with anatomic proportion or corrections of the tooth axis. CONCLUSION: This article presents three clinical cases that show how decision making can be facilitated by a functional and esthetic wax-up/mock-up workflow and how orthodontic pretreatment can contribute to a more functional, less invasive, and more esthetic outcome of restorative treatments in the esthetic zone. CLINICAL SIGNIFICANCE: Some complex cases in restorative dentistry can be transformed to straight forward cases with the help of minor orthodontic tooth movements.

Monolithic hybrid abutment crowns (screw-retained) versus monolithic hybrid abutments with adhesively cemented monolithic crowns.

OBJECTIVES: The objective of this study is to compare monolithic hybrid abutment crowns (screw-retained) versus monolithic hybrid abutments with adhesively cemented monolithic single-tooth crowns. MATERIALS AND METHODS: Twenty subjects in need of an implant-borne restoration were randomly assigned to receive either a cement-retained (CRR) or a screw-retained (SRR) implant-supported monolithic lithium disilicate (LS2 ) reconstruction. Each patient received a titanium implant with in internal conic connection. After osseointegration and second-stage surgery, healing abutments were placed for about 10 days. The type of restoration (CRR vs. SRR) was randomly assigned, and the restorations were manufactured of monolithic LS2 . Both types of restorations, CRR and SRR, were based on a titanium component (Ti-base) that was bonded to the abutment (CRR) or the crown (SRR). The follow-up period for all restoration was 36 months. Clinical outcome was evaluated according to Functional Implant Prosthetic Score (FIPS). Quality of live (OHIP) and patient's satisfaction were assessed using patient-reported outcome measures (PROMs). Primary endpoint was loss of restoration for any reason. Kaplan-Meier curves were constructed and log-rank testing was performed (p < .05). RESULTS: One restoration of group CRR failed after 6 months due to loss of adhesion between Ti-base and individual abutment. No further biological or technical failures occurred. Kaplan-Meier analysis showed no significant difference between both treatment options (p = .317). There was no statistically significant difference between both types of restoration, neither for FIPS, OHIP, treatment time nor patient satisfaction (p > .05). CONCLUSION: Monolithic hybrid abutment crowns (screw-retained) and monolithic hybrid abutment with adhesively cemented monolithic crowns using lithium disilicate showed no statistically significant difference for implant-based reconstructions in this pilot RCT setting.

Immediate Implant Placement in Conjunction with Acellular Dermal Matrix or Connective Tissue Graft: A Randomized Controlled Clinical Volumetric Study.

Connective tissue grafts have become a standard for compensating horizontal volume loss in immediate implant placement. The use of new biomaterials like acellular matrices may avoid the need to harvest autogenous grafts, yielding less postoperative morbidity. This randomized comparative study evaluated the clinical outcomes following extraction and immediate implant placement in conjunction with anorganic bovine bone mineral (ABBM) and the use of a porcine acellular dermal matrix (ADM) vs an autogenous connective tissue graft (CTG) in the anterior maxilla. Twenty patients (11 men, 9 women) with a mean age of 48.9 years (range: 21 to 72 years) were included in the study and randomly assigned to either the test (ADM) or control (CTG) group. They underwent tooth extraction and immediate implant placement together with ABBM for socket grafting and either ADM or CTG for soft tissue augmentation. Twelve months after implant placement, the cases were evaluated clinically and volumetrically. All implants achieved osseointegration and were restored. The average horizontal change of the ridge dimension at 1 year postsurgery was -0.55 ± 0.32 mm for the ADM group and -0.60 ± 0.49 mm for the CTG group. Patients of the ADM group reported significantly less postoperative pain. Using xenografts for hard and soft tissue augmentation in conjunction with immediate implant placement showed no difference in the volume change in comparison to an autogenous soft tissue graft, and showed significantly less postoperative morbidity.

Clinical performance of zirconia implant abutments luted to a titanium base - a retrospective cross-sectional study.

AIM: To evaluate the survival of implant-retained restorations fabricated on CAD/CAM-derived zirconia abutments luted to a titanium base. MATERIALS AND METHODS: 153 patients who received a total of 310 dental implants (Camlog Promote plus or Xive S) and all-ceramic restorations on yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) abutments luted to a titanium base during the last 10 years were included. Patients were examined for technical complications during routine visits. Crestal bone level changes were randomly analyzed based on periapical radiographs of 75 implants. RESULTS: Among the included 153 patients, 17 ceramic chippings (5.5%), 6 abutment loosenings (1.9%), and 2 abutment fractures (0.6%) were identified. The mean follow-up time was 4.7 years (standard deviation [SD]: 1.94), with a follow-up period of up to 10 years (maximum). Kaplan-Meier estimation resulted in a survival rate without complications of 91.6% for the restoration and 97.4% for the abutment. There was no statistically significant difference between the two implant systems, either between implant location or regarding the complication rate of the type of restoration. For the 75 implants included in the radiographic analysis, the mean bone level change was 0.384 mm (SD: 0.242, 95% CI: 0.315 to 0.452) for the Camlog implant system and 0.585 mm (SD: 0.366, 95% CI: 0.434 to 0.736) for the Xive system (P = 0.007). CONCLUSION: The results of the present retrospective study demonstrate acceptable clinical outcomes for zirconia abutments luted to a titanium base in combination with all-ceramic restorations. The assessed abutment design does not appear to have a negative impact on peri-implant hard tissue.

Peri-implant soft-tissue esthetic outcome after immediate implant placement in conjunction with xenogeneic acellular dermal matrix or connective tissue graft: A randomized controlled clinical study.

OBJECTIVES: This randomized comparative study evaluated the clinical esthetic outcome of the peri-implant mucosa following extraction and immediate implant placement in conjunction with anorganic bovine bone mineral (ABBM) and the use of a porcine acellular dermal matrix (pADM) versus an autogenous connective tissue graft (CTG) in the anterior maxilla. MATERIALS AND METHODS: Twenty patients (11 men, 9 women) with a mean age of 48,9 years (range 21-72) were included in the study and randomly assigned to either the test (pADM) or control group (CTG). They underwent extraction and immediate implant placement together with ABBM for socket grafting and either pADM or CTG for soft tissue augmentation. Twelve months after implant placement color measurements of the peri-implant mucosa and a reference tooth were performed using a spectophotometer and the color difference (ΔE) was calculated. The overall esthetic appearance of the peri-implant soft tissue was evaluated using the Pink Esthetic Score (PES). Statistical analysis was performed using Student's T-Test, the alpha was set to 0.05. RESULTS: All implants received osseointegration and were restored. The mean color difference of the peri-implant mucosa 1 year after surgery amounted ΔE 4.06 ± 1.6 for the test group (pADM) and ΔE 3.58 ± 1.36 mm for the control group (CTG), showing no statistically significant difference (p = 0.47). The mean PES of the pADM group was 11.4 ± 1.4 and for the CTG group 10.7 ± 1.5, showing no statistically significant difference (p = 0.29). CONCLUSION: Twelve months after surgery, a porcine acellular dermal matrix for soft tissue augmentation in conjunction with immediate implant placement showed no difference in the overall esthetic appearance regarding color match and Pink Esthetic Score in comparison to autogenous soft tissue graft. CLINICAL SIGNIFICANCE: Connective tissue grafts have become a standard in order to enhance the soft tissue quality and esthetic appearance in immediate implant placement. The use of new biomaterials like porcine acellular dermal matrices may avoid the need to harvest autogenous grafts resulting in simplified treatment and less postoperative morbidity.

Impact of timing of dental implant placement and loading: Summary and consensus statements of group 1-The 6th EAO Consensus Conference 2021.

OBJECTIVES: This publication reports on the EAO workshop group 1 summaries, discussions and consensus statements based on four systematic reviews evaluating the impact of timing of dental implant placement and loading. MATERIALS AND METHODS: The first of the systematic reviews was on the influence of the timing of implant placement and loading in the biological outcomes of implant-supported fixed partial dentures. The second systematic review evaluated the influence of the timing of implant placement and loading on the aesthetic outcomes in single-tooth implants. The third systematic review was on the long-term outcomes of maxillary single-tooth implants in relation to timing protocols of implant placement and loading and the fourth on patient's perception of timing concepts in implant dentistry. The group evaluated these systematic reviews, provided comments and additions as required and agreed on the relevant consensus statements as well as on clinical and research recommendations. RESULTS: Different timings of implant placement/loading presented with high implant survival rates. The systematic reviews evaluated from this working group provided a number of conclusions based on the available/current literature. However, the specific topic of timing is an area that further research is required in order to provide detailed guidelines for the different protocols to be employed.

Biocompatibility of Lithium Disilicate and Zirconium Oxide Ceramics with Different Surface Topographies for Dental Implant Abutments.

Gingivafibroblasts were cultured on lithium disilicate, on zirconia dioxide, and on titanium with two different surface roughnesses (0.2 µm and 0.07 µm); Proliferation (MTT), Living/Dead staining, cytotoxicity (LDH), proliferation (FGF2), and inflammation (TNFα) were analyzed after 1 day and 21 days. Furthermore, alteration in cell morphology (SEM) was analyzed. The statistical analysis was performed by a Kruskal-Wallis test. The level of significance was set at p < 0.05. There were no distinct differences in cellular behavior between the tested roughness. There were slight differences between tested materials. Cells grown on zirconia dioxide showed higher cytotoxic effects. Cells grown on lithium disilicate showed less expression of TNFα compared to those grown on zirconia dioxide or titanium. These effects persisted only during the first time span. The results indicate that the two tested high-strength ceramics and surface properties are biologically suitable for transmucosal implant components. The findings may help clinicians to choose the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.

How Thick Is the Oral Mucosa around Implants after Augmentation with Different Materials: A Systematic Review of the Effectiveness of Substitute Matrices in Comparison to Connective Tissue Grafts.

This systematic review aimed to assess the effectiveness of xenogeneic collagen matrices (XCMs) and acellular dermal matrices (ADMs) in comparison to connective tissue grafts (CTGs) for the augmentation of oral mucosa around dental implants. MEDLINE and the Web of Science were searched for clinical studies that compared substitute materials for the augmentation of oral mucosa to the subepithelial connective tissue graft around dental implants during or after implantation. The review was conducted according to the recommendations of the PRISMA statement. From an initial search result set of 1050 references, seven articles were included in the review. The study designs were heterogeneous, so no meta-analysis could be performed. Both the CTG and either type of substitute material resulted in increased mucosal thickness. Four studies showed no significant difference, while three demonstrated a significant difference, favoring the CTGs over alternative materials. Soft tissue augmentation around dental implants is a safe procedure and leads to thicker mucosal tissue. The subepithelial connective tissue graft can still be regarded as the gold standard, but substitute materials may be an acceptable alternative in some situations, such as for pain-sensitive patients, among inexperienced surgeons, and for sites with an already thick biotype.

Soft tissue augmentation applying a collagenated porcine dermal matrix during second stage surgery: A prospective multicenter case series.

BACKGROUND: The achievement and preservation of an adequate amount of soft tissue around implants is a critical factor for the prognosis of the treatment. PURPOSE: To evaluate the effectiveness of a porcine dermal matrix applied during second stage implant surgery for horizontal soft tissue augmentation and preservation of dimensional stability. MATERIALS AND METHODS: Twenty patients (mean age 50.2 ± 11.9 [SD] years) candidate to implant therapy and requiring soft tissue augmentation were recruited in four centers. Augmentation was performed in 24 cases. A porcine dermal matrix was placed into a buccal split-thickness pouch during uncovering surgery. Silicone impressions were taken before surgery (T0), 2 weeks later at suture removal (T2), 6 months (T3), and 24 months (T4) post augmentation. Dimensional changes of soft tissue were evaluated using superimposition of digitalized study casts. RESULTS: Nineteen patients (23 implants) could be evaluated at 6 months and 13 patients (17 implants) at 24 months. After 6-month follow-up, there was a significant dimensional gain respect to baseline, averaging 0.83 ± 0.64 mm (P < .01). This did not change significantly at 24 months (0.77 ± 0.65 mm, P = .19). The gain was >0.5 mm in 65.2% and 64.7% of the cases, respectively. Soft tissue shrinkage averaged 34.2% ± 77.0% from T2 to T3 (P < .01) and did not change thereafter (P = .39). Shrinkage was more consistent in the posterior mandible than in the maxilla, but not significantly (P = .23 at 6-month and .36 at 24-month). No adverse events occurred. CONCLUSION: Within the limitations of this prospective case series, the use of a porcine dermal matrix may provide consistent soft tissue augmentation that maintains up to 24-month follow-up, although graft shrinkage may occur in the first 6 months, depending on the location of surgery.

The Biological Effect of Particulate Titanium Contaminants of Dental Implants on Human Osteoblasts and Gingival Fibroblasts.

PURPOSE: To evaluate the effects of different titanium particle concentrations on viability of human calvarial osteoblasts and human gingival fibroblasts. MATERIALS AND METHODS: Primary human calvarial osteoblasts (HCO, 3H Biomedical) and human gingival fibroblasts (HGF-1, ATCC) were cultivated and allowed to adhere for 24 hours. Titanium powder concentrations (0.01 to 1.0 mg/mL) were added, and samples were analyzed at three time points (24 hours, 7 days, 21 days). Cell viability was analyzed using living cell count, proliferation (MTT) assay, and a live/dead staining. Cytotoxic effects were evaluated using lactated dehydrogenase assay. Qualitative analysis of cell viability was performed. In addition, scanning electron microscopy (SEM) analysis was performed. Release of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-±) was estimated with Human IL-6 / Human TNF-± ELISA. RESULTS: Titanium concentrations of 0.1 mg/mL and 1.0 mg/mL showed medium- and long-term effects on cell growth and proliferation rates. Cytotoxic effects by release of lactate dehydrogenase were observable during the first 24 hours. Human gingival fibroblast cells showed a release factor between 2.6 to 3.4. Titanium powder seemed to be more cytotoxic to human gingival fibroblast cells than to human calvarial osteoblast cells. For human calvarial osteoblasts, only the highest concentration showed cytotoxic effects with a release factor of 2.7. Human calvarial osteoblasts secreted IL-6 only during the first 24 hours and only in the highest titanium concentration, whereas human gingival fibroblasts secreted IL-6 during the entire period. The lowest titanium concentration showed stronger secretion of IL-6 compared to control. Incorporation of smaller and single titanium particles by cells was identified under SEM analysis. CONCLUSION: Cell viability is negatively correlated with titanium concentration. Further, titanium debris might lead to an inflammatory biologic response of dental peri-implant tissue. Also, cells interact with the debris, eg, with incorporation of particles.

The Biological Effect of Particulate Titanium Contaminants of Dental Implants on Human Osteoblasts and Gingival Fibroblasts.

PURPOSE: To evaluate the effects of different titanium particle concentrations on viability of human calvarial osteoblasts and human gingival fibroblasts. MATERIALS AND METHODS: Primary human calvarial osteoblasts (HCO, 3H Biomedical) and human gingival fibroblasts (HGF-1, ATCC) were cultivated and allowed to adhere for 24 hours. Titanium powder concentrations (0.01 to 1.0 mg/mL) were added, and samples were analyzed at three time points (24 hours, 7 days, 21 days). Cell viability was analyzed using living cell count, proliferation (MTT) assay, and a live/dead staining. Cytotoxic effects were evaluated using lactated dehydrogenase assay. Qualitative analysis of cell viability was performed. In addition, scanning electron microscopy (SEM) analysis was performed. Release of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-±) was estimated with Human IL-6 / Human TNF-± ELISA. RESULTS: Titanium concentrations of 0.1 mg/mL and 1.0 mg/mL showed medium- and long-term effects on cell growth and proliferation rates. Cytotoxic effects by release of lactate dehydrogenase were observable during the first 24 hours. Human gingival fibroblast cells showed a release factor between 2.6 to 3.4. Titanium powder seemed to be more cytotoxic to human gingival fibroblast cells than to human calvarial osteoblast cells. For human calvarial osteoblasts, only the highest concentration showed cytotoxic effects with a release factor of 2.7. Human calvarial osteoblasts secreted IL-6 only during the first 24 hours and only in the highest titanium concentration, whereas human gingival fibroblasts secreted IL-6 during the entire period. The lowest titanium concentration showed stronger secretion of IL-6 compared to control. Incorporation of smaller and single titanium particles by cells was identified under SEM analysis. CONCLUSION: Cell viability is negatively correlated with titanium concentration. Further, titanium debris might lead to an inflammatory biologic response of dental peri-implant tissue. Also, cells interact with the debris, eg, with incorporation of particles.

Possibilities and limitations of computer-assisted implant planning and guided surgery in the anterior region.

Three-dimensional (3D) implant positioning is an important prognostic factor for anterior dental implants. Modern 3D imaging and implant treatment planning systems are available today for precise dental implant planning and placement. The transfer of implant position information to industrially manufactured templates for guided implant surgery has been possible for years now. What is new is the possibility of combining the datasets with the surface scan data of a diagnostic wax-up and setup for prosthetic-driven implant planning. Digital setups can also be used. This article describes and discusses the available options for digital implant planning and guided surgery.

Dimensional Evaluation of Different Ridge Preservation Techniques: A Randomized Clinical Study.

The objective of this study was to quantitatively determine ridge contour changes after different alveolar ridge preservation techniques. An initial total of 40 patients provided a final total of 35 single-gap extraction sites. After tooth removal, the socket was subjected to one of four treatment modalities: placement of a deproteinized bovine bone mineral (DBBM; Endobon) covered with a soft tissue punch from the palate (Tx1); placement of DBBM without soft tissue punch (Tx2); placement of an adsorbable collagen membrane (Osseoguard) covering the DBBM (Tx3); and no additional treatment (control). Silicone impressions were obtained before and 6 months after tooth extraction for quantitative-volumetric evaluation on stone cast models. Bone quality and need for further bone augmentation were also noted. Tx1 and Tx3 resulted in significantly less bucco-oral tissue loss when compared to Tx2 and the control group. Premolar teeth and teeth extracted for traumatic reasons revealed significantly less tissue loss. Using barrier membranes or soft tissue punches in addition to placement of DBBM seems to be advantageous to limit bucco-oral tissue atrophy. The clinical benefit, however, is still questionable.

Navigation in implantology.

The primary objective of implant insertion is optimal prosthetic implant positioning while simultaneously protecting sensitive anatomical structures. In this context, navigated implants show significantly better results than freehand-inserted implants. Computer-assisted navigation, in combination with three-dimensional (3D) imaging by cone beam computed tomography (CBCT), is an ideal way to achieve higher predictability for successful implant therapy. Basically, one can distinguish between static navigation using templates, and direct dynamic navigation using optical transmission systems. Both options demonstrate comparably good results as far as the precision of implant positioning is concerned. Today, the gold standard is digital manufacturing of the template. Direct navigation is the more attractive option, provided acquisition costs can be reduced by simplifying the system. This article presents patient cases that demonstrate different variants of navigated implantology.

Histological and radiological evaluation of sintered and non-sintered deproteinized bovine bone substitute materials in sinus augmentation procedures. A prospective, randomized-controlled, clinical multicenter study.

OBJECTIVES: The objective of this study is to histologically and radiologically compare a sintered and a non-sintered bovine bone substitute material in sinus augmentation procedures. MATERIALS AND METHODS: Thirty-three patients were included in the clinically controlled randomized multicentre study resulting in a total of 44 treated sinuses. After lateral approach, sinuses were filled with either a sintered (SBM, Alpha Bio's Graft®) or a non-sintered (NSBM, Bio Oss®) deproteinized bovine bone substitute material. The augmentation sites were radiologically assessed before and immediately after the augmentation procedure as well as prior to implant placement. Bone trephine biopsies for histological analysis were harvested 6 months after augmentation whilst preparing the osteotomies for implant placement. RESULTS: Healing was uneventful in all patients. After 6 months, radiological evaluation of 43 sinuses revealed a residual augmentation height of 94.65 % (±2.74) for SBM and 95.76 % (±2.15) for NSBM. One patient left the study for personal reasons. Histological analysis revealed a percentage of new bone of 29.71 % (±13.67) for SBM and 30.57 % (±16.07) for NSBM. Residual bone substitute material averaged at 40.68 % (±16.32) for SBM compared to 43.43 % (±19.07) for NSBM. All differences between the groups were not statistically significant (p > 0.05, Student's t test). CONCLUSION: Both xenogeneic bone substitute materials showed comparable results regarding new bone formation and radiological height changes in external sinus grafting procedures. CLINICAL RELEVANCE: Both bone substitute materials allow for a predictable new bone formation following sinus augmentation procedures.

Complex fixed implant-supported restoration in a site compromised by periodontitis: a case report.

Periodontal disease presents a big challenge for clinicians placing dental implants. Besides the implant treatment, additional surgical procedures such as grafting or sinus floor elevation are often necessary to achieve a satisfactory result. Patient compliance is also important for achieving long-term treatment success. In the case presented here, digital planning and computer-aided surgery facilitated placement of the implants and fabrication of the prosthetic superstructures. The patient then wore INTERNAT IONAL metal-based provisional fixed partial dentures (FPDs) for about a year, while her compliance and oral hygiene were evaluated. During this period, the occlusal relations remained stable and the good condition of the hard and soft tissue was maintained. In the maxilla, the final restoration incorporated custom zirconia abutments and a zirconia framework fabricated using CAD/CAM technology. Titanium abutments and a cast non-precious metal framework were fabricated for the mandible.

Comparison of design and torque measurements of various manual wrenches.

PURPOSE: Accurate torque application and determination of the applied torque during surgical and prosthetic treatment is important to reduce complications. A study was performed to determine and compare the accuracy of manual wrenches, which are available in different designs with a large range of preset torques. MATERIALS AND METHODS: Thirteen different wrench systems with a variety of preset torques ranging from 10 to 75 Ncm were evaluated. Three different designs were available, with a spring-in-coil or toggle design as an active mechanism or a beam as a passive mechanism, to select the preset torque. To provide a clinically relevant analysis, a total of 1,170 torque measurements in the range of 10 to 45 Ncm were made in vitro using an electronic torque measurement device. RESULTS: The absolute deviations in Ncm and percent deviations across all wrenches were small, with a mean of -0.24 ± 2.15 Ncm and -0.84% ± 11.72% as a shortfall relative to the preset value. The greatest overage was 8.2 Ncm (82.5%), and the greatest shortfall was 8.47 Ncm (46%). However, extreme values were rare, with 95th-percentile values of -1.5% (lower value) and -0.16% (upper value). A comparison with respect to wrench design revealed significantly higher deviations for coil and toggle-style wrenches than for beam wrenches. CONCLUSION: Beam wrenches were associated with a lower risk of rare extreme values thanks to their passive mechanism of achieving the selected preset torque, which minimizes the risk of harming screw connections.