Insertion Of Dental Implants Research Articles

Removal of dental implants displaced into the maxillary sinus: a retrospective single-center study

BackgroundThe use of dental implants in the prosthetic rehabilitation of the posterior atrophic maxilla might be a challenge procedure because of low bone quantity and quality. This study aimed to report cases of implant displacement or migration into the maxillary sinus treated from 2008 to 2021.Materials and methodsAll patients with unintentional insertion and/or displacement of dental implants into the maxillary sinus cavity that underwent surgical removal were included. Variables assessed included the patients’ characteristics, past medical history, clinical and radiological findings at presentation, surgical approach (transoral, transnasal, combined), and outcome.ResultsA total of forty patients (23 male, 17 female) underwent surgical removal of dental implant displaced in the maxillary sinus. The mean age was 52,3 + 11,3 years. Seven patients presented with oro-antral fistula (OAF). In 15 cases, an ostium obstruction was diagnosed. Twenty-five patients underwent transoral surgery under local anesthesia. Eleven patients were treated solely via transnasal endoscopic approach, and four patients who had an associated OAF underwent surgery through a combined transnasal and transoral approach. All patients healed uneventfully without complications.ConclusionThese results and recent literature validate that transoral and transnasal approach, or a combination of these procedures, can be used safely to treat complications following displacement/migration of dental implants in the maxillary sinus. Early surgical removal minimizes sinus inflammation and prevents more invasive procedures. Each procedure presents specific indications that must be carefully evaluated prior to treatment choice to optimize intervention outcomes.

Insertion and removal torque of dental implants placed using different drilling protocols: An experimental study on artificial bone substitutes.

The aim of this in vitro study was to measure the insertion and removal torque values of dental implant replicas inserted into artificial bone blocks using different surgical burs and drilling protocols. Four types of artificial, polyurethane bone blocks were used with different thicknesses (1 and 2mm) and densities (soft-1 mm, soft-2 mm, dense-1 mm, and dense-2 mm) of the simulated cortical and cancellous bone, respectively. Each bone construct was drilled with Straumann and Densah drills in both clockwise and counterclockwise directions for a total of 16 experimental conditions. For every scenario, 38 implant replicas were inserted and then removed after 1 min. Outcomes of interest were the insertion and removal torque values which were recorded by a torque meter. ANOVA and Tukey HSD tests were used to assess differences across each combination of drill, direction, and bone type. Densah counterclockwise registered statistically greater values for both insertion and removal torque, followed by Densah clockwise, Straumann counterclockwise, and Straumann clockwise. Increasing insertion and removal torque values were progressively reported for bone type (soft-1mm, dense-1mm, soft-2mm, and dense-2mm). The mean values of insertion and removal torque were significantly different (p < 0.05) across the four bone types, different burs, and with the two drilling modalities. Densah bur resulted in significantly greater values of torque compared to the Straumann drills for all the experimental conditions. The thickness of the cortical layer and the counterclockwise drilling direction play a significant role in determining the implant insertion torque.

Measures of Corticalization.

After the insertion of dental implants into living bone, the condition of the peri-implant bone changes with time. Implant-loading phenomena can induce bone remodeling in the form of the corticalization of the trabecular bone. The aim of this study was to see how bone index (BI) values behave in areas of bone loss (radiographically translucent non-trabecular areas) and to propose other indices specifically dedicated to detecting corticalization in living bone. Eight measures of corticalization in clinical standardized intraoral radiographs were studied: mean optical density, entropy, differential entropy, long-run emphasis moment, BI, corticalization index ver. 1 and ver. 2 (CI v.1, CI v.2) and corticalization factor (CF). The analysis was conducted on 40 cortical bone image samples, 40 cancellous bone samples and 40 soft tissue samples. It was found that each measure distinguishes corticalization significantly (p < 0.001), but only CI v.1 and CI v.2 do so selectively. CF or the inverse of BI can serve as a measure of peri-implant bone corticalization. However, better measures are CIs as they are dedicated to detecting this phenomenon and allowing clear clinical deduction.

The Heath of The Peri-Implant Phenotype after Immediate Insertion and Loading of One-Piece and Two-Piece Dental Implants in the Anterior Region. A Clinical and Cone-Beam Computed Tomographic Study

AbstractObjective This study aimed to provide an inclusive comparison between the peri-implant phenotype of immediately placed in fresh extraction socket one-piece and two-piece implants with immediate loading in the anterior region.Materials and Methods Twenty-two patients with a mean age of 36 ± 4.6 (4 males and 18 females)) were randomly allocated to the one-piece and the two-piece groups. Each patient had one immediate implant placement with immediate loading by provisional restorations. Gingival Index, Peri-implant Probing depth, Papilla Presence Index, and, Implant Quality Score were recorded at 3, 6, 9 months, and 18 months. Cone beam computerized tomography is utilized to assess peri-implant bone for 1 year.Statistical analysis A two-sample t-test was used to compare the two groups.Results Both groups showed similar clinical presentations. For group two, Gingival Index, Papilla Presence Index, Peri-implant Index, Implant Quality Score, and eri-implant bone level showed statistically significant improvement. Group one showed a non-significant increase in bone density.Conclusions The peri-implant phenotype showed more predictable treatment outcomes in the context of health and esthetics in two-pieces than in one-piece.

Clinical Outcomes After Primary Implantation into Modified One-and-a-Half-Barrel Fibula Free Flap Reconstructed Mandible.

The aim of this study was to introduce and evaluate a modified one-and-a-half-barrel fibular technique guided by occlusion for functionally reconstructing mandibular defects. Fifteen patients underwent mandibular reconstruction with the modified one-and-a-half-barrel technique and simultaneous insertion of dental implants. A vascularized fibular segment was used to reconstruct the alveolar ridge of the neomandible with dental implants loaded simultaneously. The inferior border was reconstructed with a nonvascularized segment. Panoramic radiographs were taken 1 week, 6 months, and 12 months after the surgery to measure the vertical height of the fibular segment, calculate the bone resorption rate at different time points, and observe the implant marginal bone loss and crown-to-implant ratio. The OHIP-14 questionnaire was employed to evaluate the perceived outcomes of oral rehabilitation. The vertical height of the vascularized and nonvascularized fibular segments 1 week, 6 months, and 12 months after the surgery was 14.51 ± 1.93, 14.19 ± 1.88, and 13.81 ± 1.78 mm; and 8.65 ± 0.98, 7.72 ± 0.94, and 7.25 ± 0.93 mm, respectively. The bone resorption rate of vascularized and nonvascularized fibular segments was 2.20% ± 1.04% and 10.69% ± 5.73%, respectively, in the first 6 months, and 2.67% ± 1.44% and 6.16% ± 2.75%, respectively, in the latter 6 months, showing a significantly higher resorption rate in the nonvascularized segment (P < .05). The implant marginal bone loss after functional loading was significantly greater than that before dental rehabilitation (P = .001). The OHIP-14 total scores were 20.07 ± 10.24, 19.00 ± 7.82, and 3.93 ± 1.87 before surgery, at 6 months, and at 12 months after surgery, respectively (P = .000). The proposed technique not only guarantees the esthetic appearance of patients but also achieves a suitable vertical height to facilitate the placement of the implant at the same time.

The Effect of Mandibular Angulation on Preoperative Assessment of Dental Implant Insertion at Premolar Region: CBCT Study.

Backgrounds This study investigated the effect of mandibular angulation on the perioperative evaluation of the implant placement at the premolar region on panoramic reconstructed images using cone beam computed tomography (CBCT). Methods A total of six dried anonymous human mandibles was included. Two implants were inserted in the left and right first premolar region. CBCT scans were obtained from each mandible at the standard position, +20° extension, and -20° flexion. The distance of the implant from the anterior loop of the inferior alveolar nerve and mental foramen was measured. Mean absolute error (MAE) of the distance of the implant from both anatomical landmarks was measured. The Wilcoxon matched-pair signed-rank test was used for the comparison of the measurements. All data were analyzed with the Stata program (version 15.1). Results No statistically significant differences were found between the distance of the implant from the mental foramen and the anterior loop of the inferior alveolar nerve up to 20° extension and flexion at both sides of the mandible. (All p > 0.1) However, a variable range of MAE (SD) in the distance of the implant from different anatomical landmarks was found (0.9 ± 0.7 to 3.3 ± 2.1). Conclusions We found no statistical difference in measurements of the distance of the implant from two anatomical landmarks at different head positions up to 20° extension and flexion. However, clinically, variable range in the distance of the implant from anatomical landmarks should be considered. Our findings could alert dentists of the possibility of error up to 20° extension and flexion on the perioperative evaluation of dental implant placement.

Zygomatic implants using dynamic navigation

Over the decades, surgeons innovated a myriad of methods to assist patients with the replacement of missing teeth with fewer complications and accurate placement. A review of the literature confirmed that zygomatic implants are effective in maxillary reconstruction. Recently, dynamic navigation has proven effective in guiding the insertion of dental implants through the real-time tracking of the surgical instruments during surgery in relation to the planned position on the CBCT of the patients. This method helped improve the accuracy of insertion of dental implants. A prospective randomized control trial was conducted on zygomatic implants inserted using dynamic navigation. A test group and a control group with 20 implants each group were set. In the test group, dynamic navigation guided insertion of zygomatic implants with the reflection of the mucoperiosteal flap was performed. In the control group, flapless insertion of the zygomatic implants was performed. Flapless surgery is associated with less swelling, edema, erythema, and alteration in sensation. The patient could eat and maintain oral hygiene immediately from the very next day. No infections were reported postoperatively. Dynamic navigation-guided insertion of zygomatic implants was effective in maxillary rehabilitation.

The Characterization of Titanium Particles Released from Bone-Level Titanium Dental Implants: Effect of the Size of Particles on the Ion Release and Cytotoxicity Behaviour

Many studies are being carried out on the particles released during the implantoplasty process in the machining of dental implants to remove bacterial biofilms. However, there are no studies on the release of particles produced by the insertion of bone-level dental implants due to the high compressive frictional loads between the rough titanium implant and the bone tissue. This paper aims to characterize the released particles and determine the release of titanium ions into the physiological environment and their cytocompatibility. For this purpose, 90 dental implants with a neck diameter of 4 mm and a torque of 22 Ncm were placed in 7 fresh cow ribs. The placement was carried out according to the established protocols. The implants had a roughness Ra of 1.92 μm. The arrangement of the particles in the bone tissue was studied by micro-CT, and no particle clusters were observed. The different granulometries of 5, 15, and 30 μm were obtained; the specific surface area was determined by laser diffraction; the topography was determined by scanning electron microcopy; and the particles were chemically analysed by X-ray energy microanalysis. The residual stresses of the particles were obtained by X-ray diffraction using the Bragg-Bentano configuration. The release of titanium ions to the physiological medium was performed using ICP-MS at 1, 3, 7, 14, and 21 days. The cytocompatibility of the particles with HFF-1 fibroblast and SAOS-2 osteoblast cultures was characterized. The results showed that the lowest specific surface area (0.2109 m2/g) corresponds to the particles larger than 30 μm being higher than 0.4969 and 0.4802 m2/g of those that are 5 and 15 μm, respectively, observing in all cases that the particles have irregular morphologies without contamination of the drills used in the surgery. The highest residual stresses were found for the small particles, −395 MPa for the 5 μm particles, and −369 for the 15 μm particles, and the lowest residual stresses were found for the 30 μm particles with values of −267 MPa. In all cases, the residual stresses were compressive. The lowest ion release was for the 30 μm samples, as they have the lowest specific surface area. Cytocompatibility studies showed that the particles are cytocompatible, but it is the smallest ones that are lower and very close to the 70% survival limit in both fibroblasts and osteoblasts.

Guided bone regeneration through autogenous laminated bone blocks

Implant–prosthetic rehabilitation of edentulous patients with various forms of bone atrophy is a current challenge in oral implantology. The aim of the study is to evaluate the bone volume obtained after grafting procedures using cortical blocks according to the Khoury technique. Material and methods: The study was focused on 10 patients with atrophies of the alveolar ridges that required procedures to create the bone supply for implant– prosthetic rehabilitation. The latter were performed using the Khoury technique, using laminated blocks installed at a distance from the recipient area, filling the space created with autogenous bone (50% of cases) and in combination with xenograft (50% of cases). Following the analysis of the data calculated on CBCT, the presence of a bone ridge with a thickness of 4.54±0.28mm (at 1mm apical from the top of the ridge) and 6.5±0.4mm (at a depth of 4mm) was determined. In 8 out of 10 patients, the implants were inserted in the same session, due to the possibility of fixing them in the apical part. Results: Following the surgery, the obtained thickness of the ridge was assessed at the same levels determined preoperatively, which constituted on average 9.5±0.26mm (at 1mm subcrestal) and 10.85±0.29mm (at 4mm depth) . At the end of the healing period, at the same levels the width of the ridge decreased by 0.51±0.14mm and 0.63±0.17mm (p&gt; 0.05), and was obtained 8.99±0.28mm and 10.22± 0.26mm. Conclusions: Following the analyzed data, the creation of bone supply through autogenous blocks (Khoury technique) allows to obtain predictable results and a suitable bone bed for the insertion of dental implants. If the alveolar ridge is atrophied (thin) only in the coronary portion (in 8 cases out of 10), and the apical portion is thick enough, the insertion of dental implants simultaneously with the grafting procedure does not affect the graft integration.

Comparison of Stress Distribution in Surrounding Bone during Insertion of Dental Implants on Four Implant Threads under the Effect of an Impact: A Finite Element Study

The design of an implant thread plays a fundamental role in the osseointegration process, particularly in low-density bone. It has been postulated that design features that maximize the surface area available for contact may improve mechanical anchorage and stability in cancellous bone. The primary stability of a dental implant is determined by the mechanical engagement between the implant and bone at the time of implant insertion. The contact area of implant-bone interfaces and the concentrated stresses on the marginal bones are principal concerns of implant designers. Numerous factors influence load transfer at the bone-implant interface, for example, the type of loading, surface structure, amount of surrounding bone, material properties of the implant and implant design. The purpose of this study was to investigate the effects of the impact two different projectile of implant threads on stress distribution in the jawbone using three-dimensional finite element analysis.

Патофизиологические аспекты регенерации костной ткани при увеличении ширины тонкого альвеолярного гребня челюстей с применением пьезохирургической техники

One of the main problems that impede dental rehabilitation with the use of dental implants is the limited amount of bone tissue in cases of its pronounced atrophy. According to a number of authors, about 50% of patients need additional osteoplastic operations before or at the stage of dental implantation. Objective. The aim of the paper is to assess the effectiveness of piezosurgical apparatus for splitting the alveolar crest of the jaw in the insertion of dental implants. Materials and methods. Forty adult patients (15 men and 25 women) aged 36 to 49 years who had undergone surgery for partial tooth loss on one and/or both jaws were evaluated. All in all, 48 implants were placed against the narrow alveolar crest of the jaws, which was surgically split using microsaws (Group 1- 11 patients), thin dental drills (Group 2 -15 patients) and piezosurgery apparatus (Group 3, 14 patients). The postoperative follow-up period was 4 to 6 months before the orthopaedic treatment. Results. During crestal splitting, the smallest bone reduction was obtained using piezosurgical technique, which was 0.84±0.22 mm, while with microsaws and dental drills, this figure was slightly higher, 0.93±0.21 mm (p≥0.05) and 1.23±019 mm (p≤0.05), respectively. One of the properties of a piezosurgical instrument is the effect on protein molecules, namely, their denaturation. This reduces the number of postoperative complications. Conclusion. The technique of alveolar crest splitting with a piezosurgical instrument works according to the absolutely natural and unique mechanism of bone healing - the mechanism of fracture repair. This technique uses the local bone resource and avoids or significantly reduces the use of foreign bone grafting materials. There is a tendency to a better rate of restoration of the lost width of the alveolar crest of the jaw when using the piezosurgical apparatus, in contrast to the use of microsaws and dental drills.

Effects of Dental Implants on Diabetic Patients

Diabetes mellitus is a chronic condition which produces an inflammatory response in hosts leading to accelerated periodontal destruction and subsequent tooth loss. There is substantial evidence of a dose-response relationship between glycemic control and periodontal health in diabetes. Diabetes and edentulism are especially found to coexist in the elderly. Edentulism in diabetic individuals restricts dietary choices causing reduced consumption of nutrient-dense foods in favor of a soft, starch rich diet. Dental implants restore functional tooth loss, enhancing chewing ability and comfort, speaking ability and facial appearance, consequently improving patient satisfaction and oral health related quality of life. Peri-implant disease is an important consideration in dental implant maintenance therapy in diabetic individuals due to slow wound healing, and increased susceptibility to microbial plaque accumulation and periodontal inflammation. There is evidence of improved glycemic control after insertion of dental implants due to improved masticatory function allowing stimulation of satiety centers in the brain as well as improved nutrition from selection of healthier dietary choices in patients undergoing dietary counseling. Current literature supports the use of implant supported dentures in diabetic patients experiencing poor tissue health and treatment satisfaction despite conventional denture therapy.

Bone Damage during Dental Implant Insertion: A Pilot Study Combining Strain Gauge and Histologic Analysis

Besides alveolar bone quality, the drilling protocol applied in conjunction with the design of an implant are the major determinants of primary implant stability. Surgical trauma and bone compression resulting from implant insertion may constitute one cause for marginal bone resorption. Inserting two current bone-level implant designs (Astra; Straumann; n = 5) in bovine ribs, primary stability, strain development on the buccal bone plate and histologic signs of bone damage were recorded. Besides comparing the implant designs (Welch t-tests), all measurement parameters were checked for potential correlations (Pearson product moment correlation coefficients) with the level of significance set at α = 0.05. Considerable numbers of crack formation and plastic deformation of bone were observed after implant insertion. Straumann implants showed slightly greater values for insertion torque (p = 0.772), strain development (p = 0.893) and implant stability (p = 0.642). Significantly greater bone to implant contact (cortical p = 0.014; trabecular p = 0.016) was observed in Straumann implants, while Astra implants caused a significantly greater number of microcracks in cortical bone (p = 0.020). In Straumann implants, insertion torque correlated with bone to implant contact in the cortical area (p = 0.029) and the number of macrocracks in trabecular bone correlated with bone to implant contact (p = 0.029). In Astra implants, insertion torque and bone to implant contact in the trabecular area correlated (p = 0.007) as well as the number of macrocracks in trabecular bone and implant stability (p = 0.016). Additionally, in the area of cortical bone, the number of macrocracks correlated with bone to implant contact (p = 0.019). Implant placement results in bone damage of varying magnitude, which is governed by the drill protocol, implant macrodesign and bone quality.

Nanostructured surface dental implants, a modern solution for the treatment of patients with chronic systemic diseases.

AbstractIntroduction. In modern dentistry the oral rehabilitation of patients with the help of dental implants has a very high success rate. However, the problem is the situation of patients with serious chronic diseases in which the insertion of dental implants is problematic or dental procedures can complicate or aggravate the patients’ disease.Case report. We presented the case of a patient with associated chronic diseases who benefited from the insertion of implants with a nanostructured surface. The nanotube surface of the dental implant has been loaded with anti-inflammatory drugs to promote healing and stimulate the process of osteogenesis.Conclusions. Within the limitations of this study, we consider the therapy with avant-garde nanostructured dental implants to represent a viable treatment option for patients with a medical history with complicated chronic diseases.

Bone augmentation with autologous tooth shell in the esthetic zone for dental implant restoration: a pilot study

ObjectivesTo investigate the outcome and short-term follow-up of autogenous tooth shell (TS) grafting for bone augmentation in the esthetic zone, as well as stability and esthetics of implant-supported restoration.Materials and methodsA total of 8 patients with 11 implants in 11 sites were enrolled in this study. All the horizontal and/or vertical bone defects in the esthetic zone were augmented by tooth shells, which were fixed laterally to the residual bone with osteosynthesis screws. The gap between the shell and residual bone was filled with Bio-Oss® granules. Four months after bone augmentation, dimensionally sufficient dental implants were inserted and implants-supported prostheses were made 3 months later. The esthetic outcome was evaluated by pink esthetic score (PES) and white esthetic score (WES) one year after prosthetic restoration. Horizontal ridge width (HRW) was assessed before and immediately after bone augmentation, as well as 4 and 19 months post-augmentation by radiography. The stability and absorption of TS grafts were evaluated at the 4th and 19th months post-augmentation.ResultsThough wound dehiscences occurred in 3 cases, secondary healings were obtained after TS modification and irrigation. The other 5 cases went through uneventful healing during the whole observation period. Radiographic examination showed that HRW was 8.01 ± 0.93 mm (median: 7.80, 95% CI 7.38, 8.64) 4 months after TS augmentation, which was statistically different compared to HRW (2.72 ± 1.73 mm) at the baseline. Mean HRW gain was 5.29 ± 2.03 mm (median: 4.60, 95% CI 3.92, 6.66). Three-dimensional bone volume in all the augmented sites was sufficient for dental implants insertion and prosthetic restoration. Follow-up of one year showed stable marginal bone around dental implants. The implant survival rate was 100%. HRW losses were 0.65 ± 0.43 mm (the 4th month) and 1.05 ± 0.54 mm (the 19th month) compared to HRW immediately after augmentation. The PES and WES of final prosthetic restorations were 8.09 ± 0.70 and 8.91 ± 0.54, respectively.ConclusionsAutogenous tooth shell grafting is a reliable approach for bone augmentation in the esthetic zone for dental implant treatment, allowing for favorable stability and esthetic outcome of implant-supported prosthesis within the one-year follow-up period.

Viability of Amnion-Chorion membrane with the trophoblast layer in augmented posterior extraction sockets

Augmentation of the extraction sockets with bone and a membrane prior to dental implants insertion has been an integral part of the dental practice due to the advantages of providing adequate hard and soft tissue support essential for the implant emergence profile. Several bone graft materials and membranes have been recommended for the socket preservation however most of the commercially available resorbable membranes dissolve prematurely when exposed resulting in loss of the graft material. With the introduction of the human placental membranes into the dental field expedited wound healing was demonstrated even when exposed due to the abundance of growth factors. In this study Amniotic membrane which processed in a way to preserve the trophoblast layer has been tested on top of augmented extraction sockets . Clinically this membrane was easier to handle due to the increased thickness as a result of combining amnion chorion and trophoblast layer , it has also shown expedited healing through tissue formation on top of the bone graft mass as soon as two weeks. The histological examination demonstrated a considerable layer of fully matured epithelized tissue covering the bone in a short period of time. The results confirmed the viability of the Amnion Chorion and trophoblast membrane in generating epithelized tissue is a short period of time when used in covering bone grafts in extraction sockets.

Guided bone regeneration in the anterior maxilla after tooth extraction and implant removal with sticky bone and L-PRF membrane in two surgical approaches

The main requirement for the insertion of dental implants is a good bone and gum condition and guided bone regeneration (GBR) combines grafts and membranes to increase such parameters in tissue deficiencies and thus achieve treatment success. This clinical case reports the oral rehabilitation of the anterosuperior area by the association of bone graft, autologous membrane and implantodontic therapy. Female patient, 45 years old, normosystemic, reported aesthetic complaint and implant mobility in the maxilla. Upon clinical and radiographic examination, an implant was diagnosed in the region of tooth 11 with unfavorable esthetics, mobility, inadequate prosthesis and bone loss, and tooth 22 with suppuration, fracture line and periapical radiolucency. The treatment consisted of removal of the implant and tooth 22, with immediate GBR using filling with Bio-Oss® and liquid leukocyte- and platelet-rich fibrin (L-PRF) and coating with L-PRF membrane. After 7 months, the second GBR was performed with the installation of 2 dental implants. After 6 months, healers were placed and 20 days after the adaptation of the provisional implant-supported single prostheses. There was a good gain in thickness and mucogingival limit, bone dimensions in height and thickness, and the case continues to be followed up until the final prosthesis is completed. This case suggests that sticky bone and L-PRF membrane can contribute to multiple GBR in the anterior maxillary region, favoring bone gain and osseointegration.

Evaluation of Implant Stability Following Sinus Augmentation Utilizing Bovine Bone Mixed with Platelet-Rich Fibrin

Background: Lateral sinus augmentation and simultaneous insertion of dental implants is a highlypredictable procedure and associated with high rate of implants success.Aims: To evaluate implant stability changes following maxillary sinus augmentation utilizing deproteinizedbovine bone alone or mixed with platelet-rich fibrin.Materials and Methods: A total of 34 lateral sinus augmentation procedures were performed and 50 dentalimplants simultaneously installed. The lateral sinus augmentation cases were allocated randomly into 3groups: Group A comprised 13 procedures and 21 dental implants utilizing solely deproteinized bovine bone.Group B involved 10 cases and 16 dental implants using deproteinized bovine bone mixed with leukocyteand platelet-rich fibrin. Group C included 11 operations and 13 dental implants employing deproteinizedbovine bone mixed with advanced platelet-rich fibrin. Resonance frequency analysis test was performedimmediately after implant installation and 24 weeks postoperatively for the measurement of the implantstability.Results: Implant stability quotient values increased significantly for all study groups 24 weeks after dentalimplants installation (P= 0.001). The implant stability quotient at T1 (day of implant installation) was 56.93±12.01 for group A, 58.34 ±12.82 for group B, and 61.35 ±8.47 for group C. The implant stability quotientat T2 (24 weeks after implant insertion) was 69.17 ±5.10, 69.43 ±5.32, and 68.50 ±7.44, respectively.Conclusion: The addition of leukocyte and platelet-rich fibrin or advanced platelet-rich fibrin to the bovinebone for sinus floor augmentation did not increased the implant stability quotient value in comparison to thebovine bone alone.

Knöcherne Rekonstruktionen des Ober- und Unterkiefers – Grundprinzipien, virtuelle Planung und intraoperative Umsetzung

Particularly after ablative surgery for head and neck cancer, microvascular free flaps represent the gold standard in reconstructive surgery. The increasing demand for improved postoperative quality of life requires a high standard of functional and esthetic reconstructive results. Depending on the nature of the defect, a huge variety of different free flaps are suitable for reconstruction. In oral and maxillofacial surgery, bony reconstruction is essential for restoring critical functions including speech, mastication, and swallowing. Here, virtual surgical planning and its translation to the operation using prefabricated surgical resection or osteotomy guides in combination with patient-specific implants has contributed to a high level of accuracy, leading to more precise prediction of the reconstructive result. Usually, complete dental rehabilitation after bony reconstruction includes insertion of dental implants, a process which can often take a significant amount of time before the definitive prosthetic restoration can be attached. Hence, the jaw-in-a-day concept provides the possibility of full dental rehabilitation simultaneously with the bony reconstruction. However, this promising tool requires careful patient selection and remains to be evaluated in the long term.

Effects of insertion torque on the structure of dental implants with different connections: Experimental pilot study in vitro.

ObjectiveDuring the insertion of dental implants in the bone tissue, different torque values can be applied. However, the high applied torque can cause damage to the implant connection. Our study sought to evaluate, by measuring the angle of rotation of the insertion drive and, later microscopic observation, possible changes in the structure of implants of different diameters with 3 different types of connections after the application of 4 different torque intensities.Materials and methodsThree hundred tapered dental implants and three hundred insertion drivers were used in the present study. Implants of 3.5 and 4 mm in diameter with 3 connection models were tested: external hexagon (EH), internal hexagon (IH) and Morse taper (MT). Then, sis groups were performed: EH3 group, EH4 group, IH3 group, IH4 group, MT3 group and MT4 group. The samples were submitted to the torque/torsion force at 4 intensities (n = 10 samples per group and intensity): 60, 80, 100 and 120 Ncm. The turning angle of the insertion driver was measured in each test. In addition, in 10 samples from each group, the maximum torque value supported by each implant model was measured. After the tests, all samples were inspected microscopically to describe the observed changes.ResultsThe maximum torque supported by the different implant models showed statistically significant difference (p < 0.0001). The values of the measured angles showed statistically significant differences between the torque values applied within each group (p < 0.001) and between groups with the same torque value (p < 0.001).ConclusionsWithin the limitations of the present study in vitro, the results showed that high torque values cause mechanical damage to the implants.