3D assessment after maxillary sinus grafting with a porcine, a bovine and a synthetical bone substitute material. A randomized controlled clinical trial.

AIM: This randomized controlled clinical study focused on graft volume alterations after sinus floor augmentation with a deproteinized bovine bone mineral (DBBM, Geistlich Bio-Oss®), deproteinized porcine bone mineral (DPBM, THE GRAFT®) or a biphasic calcium phosphate (BCP, OSOPIA®). MATERIAL AND METHODS: 28 patients with edentulous situations in the posterior maxilla with less or equal to 5 mm of residual bone height received a two- staged external sinus grafting procedure with DBBM, DPBM or BCP. CBCT scans were performed prior surgery (CBCT1), directly after surgery (CBCT2) and after a healing period of 4-6 months prior implant placement (CBCT3). CBCT scans were used to analyze volumetric alterations of the sinus grafts by virtual 3D model matching of CBCT1- CBCT2 (situation after sinus grafting) and CBCT1 and CBCT2 (situation prior implant placement). RESULTS: The volume of the bone graft in the maxillary sinus (volume (VOL%) directly after grafting rated as 100%) was stable after the healing period in the DBBM (VOL%: 103±4%) and the PBBM groups (VOL%: 112± 23) with no statistically significant differences concerning 3D measurements. In the BCP group, the grafted volume declined to 66± 25% (VOL%), statistically inferior to the DBBM and DPBM groups. CONCLUSION: Concerning bone graft stability/ 25 volume DBBM and DPBM show comparable outcomes. Due to resorption, BCP showed inferior bone graft volume after healing (statistically significant) compared to DBBM and DPBM.

A clinical trial: Aqualizer ™ therapy and its effects on myopathies or temporomandibular dysfunctions. Part II: Subjective parameters.

OBJECTIVE: Temporomandibular dysfunction (TMD) reduces patients' quality of life (QoL). The aim was to assess the effects of initial Aqualizer™ therapy. METHODS: Group 1 (initial Aqualizer™ therapy) before definitive splint therapy or Group 2 (no initial therapy). Patients with arthrosis, partial/total prosthesis, or were undergoing splint therapy were excluded. Subjective parameters were evaluated: duration and intensity of pain, influence on wellbeing, changes in the head/neck area, handling and improvement of the Aqualizer™, improvement in QoL. The statistical significance level was 5% (p < 0.05). RESULTS: In 53 patients (Group 1 n = 25; Group 2 n = 28), the improvement in patients' well-being and intensity of pain in both groups was significant (p < 0.001). An improvement in QoL was found in 84% of patients in Group 1 and 75% in Group 2. CONCLUSION: Initial Aqualizer™ therapy can decrease the intensity of pain and increase patients'.

A Retrospective Data Analysis for the Risk Evaluation of the Development of Drug-Associated Jaw Necrosis through Dentoalveolar Interventions.

This study aimed to analyse the development of medication-related osteonecrosis of the jaw (MRONJ) in patients who underwent surgical intervention to identify potential risk factors between three different groups sorted by the type of oral surgery (single tooth extraction, multiple extraction, osteotomy). Data from patients with this medical history between 2010 and 2017 were retrospectively analysed. The following parameters were collected: sex, age, medical status, surgical intervention location of dentoalveolar intervention and form of medication. A total of 115 patients fulfilled the criteria and underwent 115 dental surgical interventions (female n = 90, male n = 25). In total, 73 (63.47%) of them had metastatic underlying diseases, and 42 (36.52%) had osteoporotic ones. MRONJ occurred in 10 patients (8.70%) (female n = 5, male n = 5). The occurrence of MRONJ was significantly correlated (p ≤ 0.05) with the mandible site and male sex. Tooth removal at the mandible site remains the main risk factor for the development of MRONJ. The risk profile of developing MRONJ after dentoalveolar interventions could be expected as follows: tooth osteotomy > multiple extractions > single tooth extraction.

Kobra Surgery Simulator-A Possibility to Improve Digital Teaching? A Case-Control Study.

Computer-aided simulations have long been of great importance in university teaching; however, to date, there is limited use of such simulations in the dental surgical sector. For this purpose, an oral surgery simulator, "Kobra", was implemented in student training and was evaluated for dental education. Dental students (group 1, third-year and group 2, fourth-year) and dentists of the faculty (control group) were trained to use the simulator. The outcomes for group 1 (apicoectomy of an upper lateral incisor with Kobra), group 2 (removal of an impacted lower wisdom tooth with Kobra) and the control group (both procedures with Kobra) were evaluated. For evaluation purposes, subjective parameters (improvement of practical skills, comparison between conventional training and Kobra simulation, and implementation of simulation-based teaching) and objective parameters (removal of bone, tooth substance and soft tissue measured while performing the Kobra simulation) were assessed using questionnaires with a scale ranging from 1-5. A total of 49 students (third-year n = 29, with 22 women and 7 men; fourth-year n = 20, with 17 women and 3 men) and 10 dentists (women n = 5 and men n = 5) participated. Compared to the Kobra simulation, the conventional training method with plastic models was still favored (the difference was non-significant). Compared to the dentists, the simulation data showed a less precise surgical performance of the students (the difference was not significant). The Kobra simulation may offer an additional method to conventional surgery training using plastic models, with benefits for students and faculty staff.

A clinical trial: Aqualizer ™ therapy and its effects on myopathies or temporomandibular dysfunctions. Part I: Objective parameters.

OBJECTIVE: Symptoms of temporomandibular dysfunction (TMD) may include pain in the muscles or restrictions opening the mouth. The aim of this study was to assess the effects of initial Aqualizer™ therapy. METHODS: Group 1 received initial Aqualizer™ therapy before definitive hard splint; Group 2 received no initial therapy. Patients with arthrosis, partial/total prosthesis or undergoing splint therapy were excluded. Objective (temporomandibular joint palpation, temporomandibular joint auscultation, palpation of the chewing muscles, and mobility of the lower jaw) parameters were evaluated. The level of statistical significance was 5% (p < 0.05). RESULTS: In 53 patients (Group 1 n = 25; Group 2 n = 28), a significant improvement (p < 0.001) was found in Group 1 in pain on palpation (masseter muscle, temporal muscle, post-mandibular region, lateral pterygoid muscle, and suboccipital region), but no significant differences in jaw mobility were found. CONCLUSION: Aqualizer™ therapy produces significant improvement of primary symptoms.

Free Gingival Graft and Collagen Matrix Revascularization in an Enoral Open Wound Situation.

PURPOSE: Vestibuloplasty with free gingival grafting is a frequently performed surgical procedure to generate sufficient keratinized mucosa (KM) around dental implants. Avascular porcine collagen matrices (CM) have been proclaimed to be sufficient substitutes as alternatives to free gingival grafts (FGGs). However, the process of graft integration and vascularization is still incompletely understood. METHODS: In 18 patients a vestibuloplasty in the lower edentulous jaw situation was performed during implant exposure, either with FGGs from the palate or a porcine CM (mucoderm). Tissue perfusion of the soft tissue grafts was measured using laser-doppler-spectrophotometer intraoperatively and on postoperative days 2, 5, 10, 30 and between days 60 and 90. With graft perfusion expressed by oxygen saturation [SO2%], the relative amount of hemoglobin [rHb], blood flow, and velocity [AU] was detected and compared between groups and the surrounding mucosa. RESULTS: Healing was uneventful in both groups, with mature KM around dental implants after healing. Blood flow and velocity significantly increased until postoperative day 10, comparable to perfusion values of the surrounded mucosa. Intergroup comparisons revelated no significant differences concerning the flow between CM and FGGs. Oxygen saturation also significantly increased within the first 5 postoperative days in both groups. Hemoglobin content did not show any differences during the investigated period. CONCLUSIONS: The perfusion mainly progresses within the first postoperative week with only minimal further detectable alterations until the final investigation, comparable in both groups. Although integration of FGGs (revascularized) and the CM (new tissue formation) is biologically different, both transplants show comparable perfusion patterns, leading to sufficient KM.

Volumetric soft tissue alterations in the early healing phase after peri- implant soft tissue contour augmentation with a porcine collagen matrix versus the autologous connective tissue graft: A controlled clinical trial.

AIM: This study evaluates the early volumetric changes after buccal soft tissue contour augmentation around implants with a porcine collagen matrix (CM) vs. the subepithelial connective tissue graft (SCTG) from the palate. MATERIALS AND METHODS: 14 patients were enrolled after early implant placement with simultaneous contour augmentation and persistent buccal tissue deficits. At implant exposure, buccal soft tissues were thickened with the CM (n = 7) or the SCTG (n = 7). Impressions were taken before and after surgery, after ten days, one, three and six months. Impressions were digitized and augmented regions 3D evaluated (soft tissue volume (mm3 , %)/thickness (mm)). RESULTS: Volume increase (mm3 ) after 6 months was 19.56 ± 8.95 mm3 (CM) and 61.75 ± 52.69 mm3 (SCTG) (insignificant, p = .058). In percentage, this was a volume loss of the initially augmented soft tissue volume (100%) of 81.76% in the CM group and 56.39% in the SCTG group (6 months). The mean soft tissue thickness increase (mm) in the buccal contour after 6 months was 0.30 ± 0.16 mm (CM) and 0.80 ± 0.61 mm (SCTG) (insignificant, p = .071). CONCLUSION: The early healing phase is associated with a significant volume loss of the soft tissues. The SCTG shows insignificant superiority compared to the CM.

Gingiva thickening with a porcine collagen matrix in a preclinical dog model: Histological outcomes.

AIM: To compare 10-month histological and immunohistological outcomes after soft tissue thickening around teeth with a porcine collagen matrix (CM) versus a subepithelial connective tissue graft (SCTG). MATERIAL AND METHODS: In eight beagle dogs, soft tissue thickening of the buccal gingiva of upper canines was performed with the SCTG or the CM. Connective tissue thickness (CTT) was histomorphometrically measured in the augmented regions. The augmented connective tissues were also histologically characterized and the collagen I and vascular endothelial growth factor (VEGF) expressions immunohistologically quantified. RESULTS: CTT significantly differed between groups (SCTG: 1.32 mm ± 0.44 mm; CM: 1.06 mm ± 0.27 mm; p = .008). Descriptive histological analyses revealed mature connective tissue that did not differ between groups. Immunohistological quantification of collagen I and VEGF expressions in the connective tissue also revealed no significant inter-group differences (collagen I: SCTG, 32.64% ± 7.09% vs. CM, 30.57% ± 7.83%; VEGF: SCTG, 39.06% ± 7.27% vs. CM, 37.15% ± 9.80%). CONCLUSION: SCTG is superior to CM with regard to CTT in this experimental model. The CM and the SCTG lead to comparable connective tissue quality ten months after connective tissue thickening.

Collagen Matrix Vascularization in a Peri-Implant Vestibuloplasty Situation Proceeds Within the First Postoperative Week.

PURPOSE: Vestibuloplasty is a frequently performed surgical procedure to create or increase soft tissue mucosal sealing around dental restorations. Collagen matrices have exhibited comparable clinical results as free gingival grafts in the context of intraoral tissue augmentation. However, the process of matrix vascularization, the basic requirement for local healing, is incompletely understood. Therefore, this study investigated collagen matrix perfusion in a clinical intraoral setting. MATERIALS AND METHODS: In a prospective cohort study, vestibuloplasty was performed during implant exposure using prefabricated collagen matrices. Matric perfusion was determined intraoperatively and at days 2, 5, 7, 14, 30, and 90 using a laser Doppler spectrophotometer measuring oxygen saturation, relative amount of hemoglobin, blood flow, and blood velocity as primary outcome variables. These parameters were compared with perfusion of the oral mucosa surrounding the matrices. Statistical analysis was performed by applying variance and regression models. RESULTS: In 10 patients (average age, 60.9 yr), vestibuloplasty was performed exclusively in the anterior mandible. Blood flow and tissue oxygen saturation in the augmented zones markedly increased until postoperative day 5 and approximated perfusion values of the adjacent mucosa at the following 2 time points. Likewise, matrix oxygen saturation markedly increased until day 7 and subsequently converged to perfusion parameters of the surrounding mucosa at the following time points. CONCLUSION: Flow signals in incorporated collagen matrices occurred on day 2 after vestibuloplasty and further increased until days 5 to 7. Therefore, matrix perfusion mainly occurs within the first postoperative week, converging to perfusion levels of the surrounding mucosa with minimal alterations during the following course.

Oral implant survival in patients with bisphosphonate (BP)/antiresorptive and radiation therapy and their impact on osteonecrosis of the jaws. A systematic review.

AIM: In this systematic review, we aimed to assess the impact of endosseous implants on the formation of an osteonecrosis of the jaw, as well as implant survival rates for patients under bisphosphonate (BP), antiresorptive and radiation therapy. MATERIALS AND METHODS: An electronic search was performed using PubMed, Embase, and Medline databases with the logical operators: "dental implant", "antiresorptive", "bisphosphonate", "irradiation", "radiotherapy", "radiation", "necrosis" and "survival". The search was limited to articles published up to 15 December 2016. Recent publications were also searched manually to find any relevant studies that might have been missed using the search criteria noted above. The outcome variables were the implant survival rate and the frequency of osteonecrosis of the jaws. RESULTS: In total, 18 studies addressing oral implants in patients with BP or antiresorptive therapy and 23 with radiation therapy met the inclusion criteria and were included in this systematic review. Most of the studies had a retrospective design with a level of evidence (LoE) of III (moderately high risk of bias). Implant survival rate ranged from 92.86% to 100% in patients with BP/antiresorptive therapy (all due to osteoporosis) and 38.5% to 97.9% in patients with radiation therapy. For BP patients, osteonecrosis in relation to oral implants more frequently occurred in patients taking BPs due to malignant diseases. In patients with radiation therapy, an "implant triggered" necrosis is also a potential complication. The lack of data in the current literature concerning this issue does not allow a proper risk assessment to date. CONCLUSIONS: Within the limits of this systematic review, implant treatment concepts seem to be a valuable approach in patients with radiation therapy and patients with BP therapy due to an osteoporosis. In patients taking BPs due to a malignant disease, implant treatments are not recommended due to the high number of reported implant-related necrosis in this patient cohort. Outcomes of this review should, however, be regarded with caution due to the low level of evidence of the currently existing data.

Treatment of enucleated odontogenic jaw cysts: a systematic review.

OBJECTIVES: In this systematic review, we aimed to assess the impact of filling or not filling enucleated odontogenic jaw cysts on bony defect consolidation. In terms of filling, we aimed to assess which is the best filling material based on current evidence. STUDY DESIGN: An electronic search was performed using PubMed, Embase, and MEDLINE databases with the logical operators: "odontogenic cysts" AND "jaw cysts" AND "treatment AND therapy." RESULTS: Thirteen studies with primary enucleation (6 with filling and 7 without filling) were included. In terms of filling, either synthetic bone substitutes or autologous bone were used. The primary outcome was bony regeneration judged by radiographic follow-up measurements. Two-dimensional (2-D) radiographic follow-up measurements (densitometry) revealed a bone density increase and comparable bone regeneration in both groups. CONCLUSIONS: Because of the low number of studies and the heterogeneity of the included data, evidence-based treatment recommendations cannot be given at this time. Also, outcomes based on 2-D measurements should be interpreted with caution. However, the following factors are suggested as having an impact on bony defect consolidation: defect size, defect configuration, the preservation of the periosteum, and localization (upper or lower jaw). Prospective comparable clinical studies with a 3-dimensional follow-up are needed.

Soft tissue volume alterations after connective tissue grafting at teeth: the subepithelial autologous connective tissue graft versus a porcine collagen matrix - a pre-clinical volumetric analysis.

AIM: This study evaluates a porcine collagen matrix (CM) for soft tissue thickening in comparison to the subepithelial connective tissue graft (SCTG). MATERIAL AND METHODS: In eight beagle dogs, soft tissue thickening was performed at the buccal aspects of the upper canines (SCTG and CM). Impressions were taken before augmentation (i1), after surgery (i2), after one (i3), three (i4) and ten month (i5). Casts were optically scanned with a 3D scanner and each augmented region (unit of analysis) evaluated (primary outcome variable: volume increase in mm(3) ; secondary outcome variables: volume increase in percent, mean and maximum thickness increases in mm). RESULTS: 3D tissue measurements after surgery revealed a significant higher volume increase in the CM (86.37 mm(3)  ± 35.16 mm(3) ) than in the SCTG group (47.65 mm(3)  ± 17.90 mm(3) ). After 10 months, volume increase was non-significant between groups (SCTG:11.36 mm(3)  ± 9.26 mm(3) ; CM: 8.67 mm(3)  ± 13.67 mm(3) ). Maximum soft tissue thickness increase (i1-i5) was 0.66 mm ± 0.29 mm (SCTG) and 0.79 mm ± 0.37 mm (CM) with no significant difference. CONCLUSIONS: Ten months after soft tissue thickening, the CM is statistically non-inferior to the SCTG in terms of soft tissue volume and thickness increase. Further 3D studies are needed to confirm the data.

In vivo evaluation of biofunctionalized implant surfaces with a synthetic peptide (P-15) and its impact on osseointegration. A preclinical animal study.

OBJECTIVES: The overall aim of the study was to investigate a biofunctionalized implant surface with electrochemically deposition of hydroxyapatite and the synthetic peptide (P-15) and its effect on osseointegration. MATERIAL AND METHODS: Three modified implant types of ANKYLOS® C/X implants were used; (1) machined implants used as negative control (M, n = 20), (2) implants with the FRIADENT® plus surface (grit blasted and acid-etched) used as positive control (P, n = 20), and (3) implants with a biomimetic surface consisting of hydroxyapatite and the synthetic 15 aminoacids containing peptide P-15 (BP, n = 40). The implants were randomly inserted in the mandibles of 10 beagle dogs following 4 months after tooth extraction (P1-P4). Three animals were sacrificed 2 and 7 days after implant insertion, respectively, and four animals were sacrificed 6 months post implant insertion. Bone-to-implant contacts (BICs) were analyzed via histomorphometrical analyses at five different region of interests (ROIs); two at the middle part on either side of the implant (ROI 1/4), two at the apical part of the implant at each side (ROI 2/3), and one at the tip of the implant (ROI 5). RESULTS: All implant surfaces showed a high level of osseointegration and osteoconductivity. The cumulative implant survival rate (CSR) was 93.8%, 100% in the M, 85% in the P, and 95% in the BP group. No statistical difference in BICs at ROI 1/4, 2/3, and 5 could be shown between implant types following 2 and 7 days of healing. BIC values increased in all groups over time. After 6 months of healing the BP group showed superiority in BIC in ROI 2/3 (73.2 ± 15.6%) compared to the P (48.3 ± 10.6%) and M group (66.3 ± 30.2%) with a significant difference between BP and P (P = 0.002). CONCLUSION: It is hypothesized, that the surface biofunctionalization improves peri-implant bone formation and remodeling, leading to an increased bone-to implant contact. However, within the limitations of the study set-up no benefit in the early phase of osseointegration could be established for dental implants with P-15 containing surface in this study.

Long-term outcomes after vestibuloplasty with a porcine collagen matrix (Mucograft® ) versus the free gingival graft: a comparative prospective clinical trial.

OBJECTIVES: Porcine collagen matrices are proclaimed being a sufficient alternative to autologous free gingival grafts (FGG) in terms of augmenting the keratinized mucosa. The collagen matrix Mucograft® (CM) already showed a comparable clinical performance in the early healing phase, similar histological appearance, and even a more natural appearance of augmented regions. Predictability for long-term stability does not yet exist due to missing studies reporting of a follow-up >6 months. MATERIAL AND METHODS: The study included 48 patients with atrophic edentulous or partially edentulous lower jaw situations that had undergone an implant treatment. In the context of implant exposure, a vestibuloplasty was either performed with two FGGs from the palate (n = 21 patients) or with the CM (n = 27 patients). Surgery time was recorded from the first incision to the last suture. Follow-up examinations were performed at the following time points: 10, 30, 90, and 180 days and 1, 2, 3, 4, and 5 years after surgery. The width of keratinized mucosa was measured at the buccal aspect of each implant, and augmented sites were evaluated in terms of their clinical appearances (texture and color). RESULTS: The groups showed similar healing with increased peri-implant keratinized mucosa after surgery (FGG: 13.06 mm ± 2.26 mm and CM: 12.96 mm ± 2.86 mm). The maximum follow-up was 5 years (5 patients per group). After 180 days, the width of keratinized mucosa had decreased to 67.08 ± 13.85% in the FGG group and 58.88 ± 14.62% in the CM group with no statistically significant difference. The total loss of the width of keratinized mucosa after 5 years was significant between the FGG (40.65%) and the CM group (52.89%). The CM group had significantly shorter operation times than the FGG group. Augmented soft tissues had a comparable clinical appearance to adjacent native gingiva in the CM group. FGGs could still be defined after 5 years. CONCLUSIONS: The FGG and the CM are both suitable for the regeneration of the peri-implant keratinized mucosa with a sufficient long-term stability. With the CM, tissue harvesting procedures are invalid, surgery time can be reduced, and regenerated tissues have a more esthetic appearance.

Long-term outcomes of bone augmentation on soft and hard-tissue stability: a systematic review.

BACKGROUND: Peri-implant hard-tissue augmentation is a widely used clinical procedure. AIM: The present review aimed to analyse the current literature regarding medium- and long-term data concerning the stability of peri-implant tissues after hard-tissue augmentation prior or immediately with implant placement. MATERIAL AND METHODS: An electronic literature search was performed using Medline (PubMed) databases detecting clinical studies focusing on hard- and soft-tissue stability around dental implants placed either in augmented alveolar ridges or simultaneously with peri-implant bone grafting. The search was limited to articles published between 1995 and December 2014, focusing on clinical studies with a prospective study design assessing peri-implant bone and soft tissue stability over time with a minimum follow-up of 12 months. Recent publications were also searched manually to find any relevant studies that might have been missed using the search criteria noted above. RESULTS: Thirty-seven articles met the inclusion criteria and were included in this systematic review. Since the outcome measures and methods, as well as types of grafts and implants used were so heterogeneous, the performance of meta-analysis was impossible. The highest level of evidence was achieved by randomized clinical trials. CONCLUSION: Different hard-tissue augmentation procedures seem to show stable peri-implant tissues, although, up to now, long-term stability of the augmented buccal bone is assessed by only few studies. Further research should concentrate on combining three-dimensional radiographic data with non-invasive methods as digital surface measuring techniques or ultrasound evaluation.

Implant-based rehabilitation in oncology patients can be performed with high long-term success.

PURPOSE: Radiotherapy and compromised vital bone and/or surrounding soft tissue can be a challenge to the successful osseointegration of dental implants. We evaluated the long-term results of dental implants in patients with oral cancer. MATERIALS AND METHODS: To address the research purpose, we designed and implemented a retrospective cohort study that included patients with oral cancer who had received dental implants from 2003 to 2011. The data were collected from a clinical oncology database. The predictor variables included a set of heterogeneous variables grouped into logical sets of demographics, surgical treatment, dental rehabilitation, radiotherapy type, and tumor entity. The primary outcome variable was implant survival; the secondary outcome variable was peri-implantitis. The descriptive statistics, survival time analysis, Kaplan-Meier implant survival curves, and Cox hazard proportional modeling were computed. RESULTS: The study sample included 59 patients with oral cancer (20 women [33.9%], 39 men [66.1%]; mean age at tumor diagnosis, 55 years), who had had 272 implants placed during the study period. The mean follow-up period was 30.9 months (range 3 to 82). Of the 272 implants, 269 (98.9%) and 264 (97.1%) had survived for 2 and 5 years, respectively. During the observation period, 10 implants were lost (3.7%). Of the implant failures, 82% occurred in transplanted bone (4 fibula flaps, 4 iliac crests, and 2 native mandibles). We observed peri-implantitis caused by insufficiently attached gingiva and bone loss in 182 of the implants (67%). The factors associated with implant failure were peri-implantitis, insufficient soft and hard tissue, muscle dysfunction, and xerostomia. CONCLUSIONS: Implant-based rehabilitation in oncology patients can achieve a high long-term success rate, although risk factors such as impaired muscle function and a high frequency of peri-implantitis can affect healing.

Anorganic bovine bone (ABB) vs. autologous bone (AB) plus ABB in maxillary sinus grafting. A prospective non-randomized clinical and histomorphometrical trial.

OBJECTIVES: This investigation focused on histological characteristics and 5-year implant survival after sinus floor augmentation with anorganic bovine bone (ABB, Bio-Oss) and ABB plus autologous bone (AB) with a ratio of 1/1. MATERIAL AND METHODS: Nineteen consecutive patients with bony atrophy of the posterior edentulous maxilla and a vertical bone height ≤4 mm were prospectively included in this study. In the first surgical stage, the maxillary sinus was non-randomized either augmented with ABB alone (n = 12) or a 1/1 mixture of ABB and AB (n = 7). After a mean healing period of 167 days, biopsies were harvested in the region of the grafted sinus with a trephine burr and implants were placed simultaneously, ABB n = 18 and ABB + AB n = 12. The samples were microradiographically and histomorphometrically analyzed judging the newly formed bone (bone volume, BV), residual bone substitute material volume (BSMV), and intertrabecular volume (soft tissue volume, ITV) in the region of the augmented maxillary sinus. Implant survival was retrospectively evaluated from patient's records. RESULTS: No significant difference in residual bone substitute material (BSMV) in the ABB group (31.21 ± 7.74%) and the group with the mixture of ABB and AB (28.41 ± 8.43%) was histomorphologically determined. Concerning the de novo bone formation, also both groups showed statistically insignificant outcomes; ABB 26.02 ± 5.23% and ABB + AB 27.50 ± 6.31%. In all cases, implants were installed in the augmented sites with sufficient primary stability. After a mean time in function of 5 years and 2 months, implant survival was 93.75% in the ABB and 92.86% in the ABB + AB group with no statistically significant differences. CONCLUSION: The usage of ABB plus AB to a 1/1 ratio leads to an amount of newly formed bone comparable with the solitary use of ABB after grafting of the maxillary sinus. Considering that ABB is a non-resorbable bone substitute, it can be hypothesized that this leads to stable bone over time and long-term implant success. Importantly, in the sole use of ABB, bone grafting and therefore donor site morbidities can be avoided.

Performance of conical abutment (Morse Taper) connection implants: a systematic review.

In this systematic review, we aimed to compare conical versus nonconical implant-abutment connection systems in terms of their in vitro and in vivo performances. An electronic search was performed using PubMed, Embase, and Medline databases with the logical operators: "dental implant" AND "dental abutment" AND ("conical" OR "taper" OR "cone"). Names of the most common conical implant-abutment connection systems were used as additional key words to detect further data. The search was limited to articles published up to November 2012. Recent publications were also searched manually in order to find any relevant studies that might have been missed using the search criteria noted above. Fifty-two studies met the inclusion criteria and were included in this systematic review. As the data and methods, as well as types of implants used was so heterogeneous, this mitigated against the performance of meta-analysis. In vitro studies indicated that conical and nonconical abutments showed sufficient resistance to maximal bending forces and fatigue loading. However, conical abutments showed superiority in terms of seal performance, microgap formation, torque maintenance, and abutment stability. In vivo studies (human and animal) indicated that conical and nonconical systems are comparable in terms of implant success and survival rates with less marginal bone loss around conical connection implants in most cases. This review indicates that implant systems using a conical implant-abutment connection, provides better results in terms of abutment fit, stability, and seal performance. These design features could lead to improvements over time versus nonconical connection systems.

Vestibuloplasty: porcine collagen matrix versus free gingival graft: a clinical and histologic study.

BACKGROUND: A free gingival graft (FGG) is currently the gold standard for augmenting small areas of keratinized mucosa. The porcine collagen matrix (CM) represents an alternative to autologous tissue harvesting. This study aims to compare the CM versus FGGs for augmenting keratinized peri-implant mucosa based on clinical and histologic evaluations. METHODS: The study included 14 patients who underwent a vestibuloplasty with either a FGG from the palate (n = 7) or the CM (n = 7). An implant-fixed vestibular retention splint was inserted for 30 days. Follow-up examinations were performed at 4, 10, 30, and 90 days after surgery. Width of keratinized mucosa was measured in the region of each implant (days 10, 30, and 90). After 90 days, a biopsy was harvested for histologic and immunohistologic analyses. To characterize newly formed soft tissue, the authors stained for tissue-and differentiation-specific markers, cytokeratin (CK) 5/6, 13, and 14, to detect presence or absence of keratinization. RESULTS: The groups showed similar healing, with increased peri-implant keratinized mucosa. The CM group had overall significantly shorter operation times than the FGG group. Both groups showed similar overall shrinkage (32.98% CM versus 28.35% FGG). All biopsies showed a multilayered, keratinized, squamous epithelium. CKs 5/6 and 14 were detected in the basal and suprabasal layers, and spots of CK 13 were detected in the suprabasal layer. CONCLUSIONS: During the whole observation period, both groups showed comparable clinical and histologic outcomes. Within the limitations of the present study, CM seems to be a promising alternative for the regeneration of keratinized mucosa without tissue harvesting. Comparative long-term studies are needed to investigate changes over time.