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To show the benefit of a minor orthodontic pretreatment prior to fixed restorations in the esthetic zone in challenging situations.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.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.Some complex cases in restorative dentistry can be transformed to straight forward cases with the help of minor orthodontic tooth movements.

To evaluate the survival of implant-retained restorations fabricated on CAD/CAM-derived zirconia abutments luted to a titanium base.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.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).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.

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.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.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).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.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.

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 &lt, 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.

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.

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.

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.

Limited information is available on how to treat the surface of computer-aided design/computer-aided manufacturing (CAD/CAM)-derived implant abutments made of yttria tetragonal zirconia polycrystal (Y-TZP).The purpose of this study was to assess and compare 4 different standardized polishing protocols of dental zirconia with a standard handpiece and abrasives and to identify a standardized protocol to obtain a surface roughness of Ra=0.2 μm on dental Y-TZP.Forty specimens of Y-TZP were produced and finished with 4 different polishing protocols with standard dental abrasives. Protocol Co used a coarse rubber abrasive, protocol Me used the rubber abrasive of protocol Co plus a medium rubber abrasive, protocol Fi used the polishing sequences of protocol Me plus a fine rubber abrasive, and protocol UF used protocol Me plus ultrafine high-gloss polishing. Ten machined titanium disks served as control (C). Roughness measurement and scanning electron microscopy was performed for each specimen and tested for differences with ANOVA with Bonferroni correction and the Student t test (α=.05).In the zirconia groups, Co (Ra 0.29 ±0.38 μm) showed significantly higher Ra values than Me (Ra 0.22 ±0.38 μm; P=.003), Fi (Ra 0.17 ±0.37 μm; P.001), and UF (Ra 0.07 ±0.06 μm; P.001). UF showed the significantly lowest Ra values of all zirconia groups (Co and Me: P.001, Fi: P=.002). Differences between Me and Fi were not significant (P=.116). Comparison of the 4 zirconia surfaces to the control group (C; Ra=0.17 ±0.03) revealed significant differences for Co (P.001) and UF (P=.006) but not Me (P=1.000) and Fi (P=.055). In comparison with the literature-based optimal roughness of Ra=0.2 μm, significant differences were found for Co, Fi, and UF (P.05), but not for Me (P=.117). However, the machined titanium surface (C) also showed significantly smoother Ra values than 0.2 μm (P.05, Student t test).A roughness of Ra=0.2 μm on zirconia can be achieved by following protocol Me, whereas a roughness comparable to machined titanium is present after protocol Fi.

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.

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.

Objective The purpose of this split-mouth study was to compare macro- and microstructure implant surfaces at the marginal bone level over five years of functional loading. Materials and methods From January to February 2006, 133 implants (70 rough-surfaced microthreaded implants and 63 machined-neck implants) were inserted in the mandible of 34 patients with Kennedy Class I residual dentitions and followed until December 2011. Marginal bone level was radiographically determined at six time points: implant placement (baseline), after the healing period, after six months, and at two years, three years, and five years follow-up. Results Median follow-up time was 5.2 years (range: 5.1–5.4). The machined-neck group had a mean crestal bone loss of 0.5 mm (0.0–2.3) after the healing period, 1.1 mm (0.0–3.0) at two years follow-up, and 1.4 mm (0.0–2.9) at five years follow-up. The rough-surfaced microthreaded implant group had a mean bone loss of 0.1 mm (−0.4 to 2.0) after the healing period, 0.5 mm (0.0–2.1) at two years follow-up, and 0.7 mm (0.0–2.3) at five years follow-up. The two implant types showed significant differences in marginal bone levels. Conclusions Rough-surfaced microthreaded design caused significantly less loss of crestal bone levels under long-term functional loading in the mandible when compared to machined-neck implants.

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.

OBJECTIVES The aim was to study the impact of the defect size of endodontically treated incisors compared to dental implants as abutments on the survival of zirconia two-unit anterior cantilever-fixed partial dentures (2U-FPDs) during 10-year simulation. MATERIALS AND METHODS Human maxillary central incisors were endodontically treated and divided into three groups (n = 24): I, access cavities rebuilt with composite core; II, teeth decoronated and restored with composite; and III as II supported by fiber posts. In group IV, implants with individual zirconia abutments were used. Specimens were restored with zirconia 2U-FPDs and exposed to two sequences of thermal cycling and mechanical loading. Statistics: Kaplan-Meier; log-rank tests. RESULTS During TCML in group I two tooth fractures and two debondings with chipping were found. Solely chippings occurred in groups II (2×), IV (2×), and III (1×). No significant different survival was found for the different abutments (p = 0.085) or FPDs (p = 0.526). Load capability differed significantly between groups I (176 N) and III (670 N), and III and IV (324 N) (p

Introduction This ex vivo pilot study tested the influence of defect extension and quartz-fiber post placement (QFP) on the ex vivo survival rate and fracture resistance of root-treated upper central incisors served as abutments for zirconia 2-unit cantilever fixed partial dentures (2U-FPDs) exposed to 10 years of simulated clinical function. Methods Human maxillary central incisors were endodontically treated and divided into the following 5 groups (n = 8): (1) access cavity filled with core build-up composite, (2) biproximal class III cavities filled as in group 1, (3) specimens restored as in group 2 with QFP placed, (4) specimens decoronated and core buildup as in group 1, and (5) specimens restored as in group 4 but with QFP as in group 3. On all specimens, 2U-FPDs were placed with dual-curing resin cement. In order to simulate 10 years of clinical function, specimens were exposed to thermal cycling and mechanical loading with subsequent loading to failure. Kaplan-Meier curves were constructed, and log-rank tests were performed. Fracture force and patterns were compared by means of Kruskal-Wallis, Mann-Whitney U (post hoc), and Fisher exact tests, respectively (P = .05). Results For specimens only with an access cavity, it was observed that 25% had catastrophic tooth fractures and the lowest load-to-fracture values. In all other groups, chipping combined with or without debonding occurred. Groups did not differ significantly regarding the survival rate (P = .603) and fracture patterns (P = .633), but they did for fracture load including technical failures (P = .017). Conclusions After 10 years of simulated clinical function, both defect extension and placement of QFP had no significant influence on survival of root-treated upper central incisors as abutments restored with zirconia-based 2U-FPDs.

Objectives The purpose of this study was to investigate the optical appearance of the soft tissue labial to dental implants restored with fluorescent ceramic-veneered zircona abutments. It was hypothesized that the tested abutment design leads to an increased brightness in the marginal peri-implant tissue, which does not differ from that of natural teeth. Moreover, a reduction of the color difference that has been reported from other abutment materials was expected. Materials and methods A total of 12 patients with single titanium implants in the maxillary anterior region were recruited. All implants (N = 12) were restored with zirconia abutments veneered with fluorescent ceramic and full-ceramic crowns. Color measurements of the peri-implant mucosa at the test sites were made of the facial aspect of the teeth using a Spectroshade-spectrophotometer. The gingiva of a contralateral or adjacent natural tooth served as a control. Color data (CIE-L*a*b* color coordinates) were obtained in five incremental areas of 1 × 2 mm in both test and control sites. ∆E-values were calculated from the ΔL*, Δa* and Δb* values for each patient. Results Data acquisition from the test site demonstrated lower mean values of L*, a* and b* than the control site. Statistical significance between the test site and control site was reached in the L* values only in the second of the five incremental areas (P

Implant-supported prosthodontics requires precise impressions to achieve a passive fit. Since the early 1990s, in vitro studies comparing different implant impression techniques were performed, capturing the data mostly mechanically. The purpose of this study was to evaluate the accuracy of three different impression techniques digitally. Dental implants were inserted bilaterally in ten polymer lower-arch models at the positions of the first molars and canines. From each original model, three different impressions (A, transfer; B, pick-up; and C, splinted pick-up) were taken. Scan-bodies were mounted on the implants of the polymer and on the lab analogues of the stone models and digitized. The scan-body in position 36 (FDI) of the digitized original and master casts were each superimposed, and the deviations of the remaining three scan-bodies were measured three-dimensionally. The systematic error of digitizing the models was 13 μm for the polymer and 5 μm for the stone model. The mean discrepancies of the original model to the stone casts were 124 μm (±34) μm for the transfer technique, 116 (±46) μm for the pick-up technique, and 80 (±25) μm for the splinted pick-up technique. There were statistically significant discrepancies between the evaluated impression techniques (p ≤ 0.025; ANOVA test). The splinted pick-up impression showed the least deviation between original and stone model; transfer and pick-up techniques showed similar results. For better accuracy of implant-supported prosthodontics, the splinted pick-up technique should be used for impressions of four implants evenly spread in edentulous jaws.

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. 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. 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). Both xenogeneic bone substitute materials showed comparable results regarding new bone formation and radiological height changes in external sinus grafting procedures. Both bone substitute materials allow for a predictable new bone formation following sinus augmentation procedures.

Introduction: To determine the esthetic outcome of implant-based reconstructions after autologous and allogeneic bone grafting. Methods: From 2003 to 2009, 67 patients underwent alveolar ridge augmentation and were enrolled in the study, 41 meet the inclusion criteria and 31 agreed to take part in the study. Patients were 18-69 years old (mean: 49.3 ± 13.8 years), and predominantly female. Patients received bone block grafts either autologous (n = 48) (AUBB) or allografts (ABB) (n = 19). Implants were inserted 4-7 months (autografts) or 5-6 months (allografts) after bone grafting. The Pink Esthetic Score (PES) as well as radiographic and subjective assessments were employed for the outcome analysis. The PES was assessed twice within one month based on digital photographic images that were randomly rearranged between evaluations by three independent, experienced investigators. Results: Across all observations and investigators, the average PES was 7.5 ± 2.6 without differences between implants inserted in auto- and allografted bone, respectively. Patients assessed the allograft procedures as less painful and would have repeated it more often. The intra-rater reliability was excellent (correlation coefficients 0.7-0.9). The inter-observer agreement was lower (correlation coefficients 0.6-0.8). Conclusions: Bone grafting with ABB allografts yields equivalent results to autologous grafting, and patients appreciate the omission of bone harvesting. The PES is a reliable method but should be performed by the same individual.

This case series evaluated the graft stability and resorption of a modified shell technique for horizontal ridge augmentation. Autogenous bone shells of 1-mm thickness were fixed with microtitanium screws with the gaps between the shells and ridge filled with autogenous bone chips. In 22 patients, 30 cases were performed to augment 50 regions. Forty-two implants were inserted after a healing period of 5.5 (± 1.0) months. Preoperatively, the mean width of the crest was 2.7 mm (± 0.9), after bone grafting, 6.7 mm (± 0.8), and during implant placement, 5.9 mm (±0.7), and the mean resorption was 0.8 mm (± 0.5) (P < .001). This technique showed promising results. However, due to slight resorption, the ridge should be over contoured.

Thin facial soft tissue may lead to visible soft tissue discoloration around implants and therefore to esthetic deficiencies. The aim of this article is to present a surgical approach to peri-implant soft tissue discoloration caused by the shinethrough effects of restorative materials in the anterior maxilla. A clinical case is used to illustrate the approach. A minimally invasive tunneling approach and connective tissue graft are used. The optical outcome is documented in an objective and standardized manner using a spectrophotometer after a follow-up of 12 months. The presented technique clearly improved the clinical condition and esthetic outcome. Spectrophotometric follow-up revealed a soft tissue color difference between the implant and adjacent tooth (control) that was clearly less than initially presented. In the area 3 mm apical to the soft tissue margin, this difference was beneath the clinically perceptible threshold of 3.7.

Abutment material selection may have an effect on the color of the peri-implant soft tissue, especially in thin mucosa. The objective of this in vitro study was to investigate the effect of titanium, zirconia, and dyed fluorescent zirconia on the color of 1.5-mm-thick mucosa. Ten pig maxillae were used to simulate thin mucosa according to a previously published setup. Three different abutment materials were placed under the mucosa, and the color of the soft tissue was evaluated using a spectrophotometer. The test area without underlying material was used as a control. Whereas titanium induced visible color change values of ΔE7.3, significantly above the threshold level of ΔE3.7 (P < .05, Student t test), the changes after insertion of zirconia ( ΔE3.7) and dyed fluorescent zirconia (3.5) were not statistically different from the visible threshold of ΔE3.7 (P < .05, Student t test). The difference between the two zirconia specimens was not statistically significant, although the dyed zirconia material was darker; the color difference was ΔE10.35 between the two. In contrast to titanium, neither nondyed zirconia nor dyed fluorescent zirconia changed the gingival coloration. Moreover, shading of white zirconia with a fluorescent dye leads to an all-ceramic abutment material that mimics the optical properties of natural teeth.

Objectives Precise implant-supported prosthodontics requires accurate impressions. Many in vitro studies comparing different implant impression techniques were performed. The purpose of this in vivo study was to compare the discrepancy of two different impression techniques of implants clinically. Material and methods Four implants were inserted nearly bilateral in ten edentulous jaws. From each jaw, two different impressions (A, transfer; B, splinted pick-up) were taken. Respectively two stone casts of each jaw were produced and scan bodies were mounted on the lab analogues to digitize the casts. One scan body of the digitized casts was each superimposed and the deviations of the remaining three scan bodies were measured three dimensionally. The fit of the suprareconstructions was evaluated clinically on both casts and in the mouth. Results The mean discrepancy of scan body 2 was 192 μm (±96), 282 μm (±97) for scan body 3, and 366 μm (±114) for scan body 4. The discrepancies between two scan bodies were statistically significant (p≤0.010; ANOVA test). Comparing the data with the span between the scan bodies, a linear regression line could be drawn to show the dependency between the misfit and the length of the span. Clinically, the fit on the cast produced by the splinted pick-up technique was favorable. Conclusions The discrepancy between the splinted pick-up impression technique and the transfer technique were in a range with clinical influence. Clinical relevance For better accuracy of implant-supported prosthodontics, the splinted pick-up technique should be used for impressions of four implants evenly spread in edentulous jaws.

The principle of guided tissue and bone regeneration has long been established for treating bone and periodontal defects. In addition to nonabsorbable barriers, various collagens have become accepted as membrane materials for separating the graft from soft tissue. However, collagen membranes differ significantly in their barrier function and biocompatibility. The objective of this pilot study was to examine, in vitro and in vivo, a novel native collagen membrane extracted from porcine pericardium.The morphologic structure of two different native collagen membranes (Remotis, Thommen Medical; Bio-Gide, Geistlich Biomaterials) was examined using a scanning electron microscope. For biocompatibility testing, membranes were incubated with SaOs-2 osteoblastlike cells. After 2 hours, 3 days, and 7 days, proliferation of the cells on the membranes was determined. Evaluation of the biodegradation pattern was performed in a dog model with simultaneous bone augmentation with Bio-Oss (Geistlich Biomaterials) or Cerabone (Botiss Biomaterials) in the lateral anterior maxilla in eight animals with histologic examination after 4, 8, 12, and 24 weeks.An interconnective pore system was identifiable for Remotis, while Bio-Gide displayed a more fibrous structure. In vitro, Remotis showed considerable cell proliferation, which was significantly superior to that observed with Bio-Gide, especially after 7 days (2,910 ± 1,273 and 707 ± 706, respectively). In vivo, both membranes integrated into the surrounding tissue without any inflammatory reaction. Both membranes allowed early vascularization. However, considerable biodegradation was noted within 4 to 8 weeks with Bio-Gide, while Remotis resorbed generally within the first 8 to 12 week. Both membranes supported underlying bone formation.Both examined membranes indicate a high level of biocompatibility. Both are resorbed without inflammation within 8 weeks (Bio-Gide) or 12 weeks (Remotis). The compact interconnective pericardium collagen of Remotis may have stabilized the resorption process.

Objective The purpose of this study was to determine and measure the wear of the interface between titanium implants and one-piece zirconia abutments in comparison to titanium abutments. Methods 6 implants were secured into epoxy resin blocks. The implant interface of these implants and 6 corresponding abutments (group Zr: three one-piece zirconia abutments; group Ti: three titanium abutments) were examined by a microscope and scanning electron micrograph (SEM). Also the implants and the abutments were scanned by 3D-Micro Computer Tomography (CT). The abutments were connected to the implants and cyclically loaded with 1,200,000 cycles at 100 N in a two-axis fatigue testing machine. Afterwards, all specimens were unscrewed and the implants and abutments again were scanned by microscope, SEM and CT. The microscope and SEM images were compared, the CT data were superimposed and the wear was calculated by inspection software. The statistical analysis was carried out with an unpaired t -test. Results Abutment fracture or screw loosening was not observed during cyclical loading. Comparing the microscope and SEM images more wear was observed on the implants connected to zirconia abutments. The maximum wear on the implant shoulder calculated by the inspection software was 10.2 μm for group Zr, and 0.7 μm for group Ti. The influence of the abutment material on the measured wear was statistically significant ( p ≤ 0.001; Levene-test). Significance Titanium implants showed higher wear at the implant interface following cyclic loading when connected to one-piece zirconia implant abutments compared to titanium abutments. The clinical relevance is not clear; hence damage of the internal implant connection could result in prosthetic failures up to the need of implant removal.

In addition to osseointegration and restoration of function, patient satisfaction is a key element in the success of implant therapy. Especially in the esthetic zone, an essential part of the procedure aims at creating a definitive implant restoration that cannot be distinguished from the adjacent natural teeth. The present patient shows that, after localized ridge defects are reconstructed during implant surgery, a favorable esthetic and functional result can be achieved employing the keyhole access expansion technique for stage-two surgery, which is easy to perform, safe, and minimally invasive.

Introduction Within the last decades, collagen types I and III have been established as a sufficient biomaterial for GBR and GTR procedures. They might also be an adequate matrix for soft tissue augmentations. However, collagen materials differ significantly regarding resorption time, biodegradation pattern and the invasion of inflammatory cells. The aim of the present study was to compare the biodegradation and tissue integration of native, differently processed and cross-linked collagen scaffolds in rats. Methods Four experimental porcine collagen matrices of 1.0 mm thickness, developed for soft tissue augmentation procedures, were tested. Based on the same native dermal Type I and III collagen, native (ND, Mucoderm® prototype), specifically defatted (DD), ethylene dioxide cross-linked (ECL) and dehydrothermally cross-linked (DCL) dermis collagen (AAP/Botiss Biomaterials, Berlin, Germany) were evaluated. Two specimens of 1 × 1 cm were fixed around a non-absorbable spacer using non-absorbable sutures. After rehydration, specimens (N = 8) were randomly allocated in unconnected subcutaneous pouches on the back of 40 Wistar rats. Rats were divided into five groups (1, 2, 4, 8 and 12 weeks), including eight animals each. After each period, eight rats were sacrificed and explanted specimens were prepared for histological analysis. The following parameters were evaluated: membrane thickness as a sign of biodegradation and volume stability, cell ingrowth, vascularization, tissue integration and foreign body reaction. Results Biodegradation pattern of the non cross-linked collagen scaffolds differed only slightly in terms of presence of inflammatory cells and cell invasion into the matrix. In terms of biodegradation, ECL displayed a considerable slower resorption than ND, DCL and DD. Chemical cross-linking using ethylene dioxide showed a significant higher invasion of inflammatory cells. Conclusion Within the limits of the present study it was concluded that the processing techniques influenced the collagen properties in a different intensity. Dehydrothermal cross-linking and special defatting did not notably change the biodegradation pattern, whereas cross-linking using ethylene dioxide led to significant higher volume stability of the matrix. However, ECL showed an increased inflammatory response and compromised tissue integration. Therefore, ethylene dioxide seems to be not suitable for stabilization of collagen matrices for soft tissue augmentation procedures.

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.

Forty patients (12 men, 28 women; mean age 44.9 +/- 13.95 years) with inadequate bone volume for implant placement in either the maxilla or the mandible were scheduled for bone-grafting procedures. Bone grafts were harvested with a piezoelectric surgical device (Piezosurgery, Mectron) from 45 donor sites and grafted into recipient sites prior to implant placement. After healing of the grafted sites, 109 implants were placed. Clinical evaluations were performed to assess the size and quality of the obtained grafts, complications at the donor and recipient sites, integration of the grafts, bone quality, resorption of the grafts, and ability to properly place implants. Piezosurgery allowed precise, clean, and smooth cutting with excellent visibility. Mean graft size was 1.15 cm3 (SD 0.5), with a maximum of 2.4 cm3. The quality of the obtained grafts was mainly cortical (71%), 42 of the 45 donor sites healed uneventfully (93.33%), and 50 of the 52 grafted sites healed uneventfully (96.15%).