Crestal Bone Resorption Research Articles

Biological and mechanical effect of different types of attachments on supporting structures in implant retained mandibular overdenture a Randomized clinical study

Objective: To compare between implant retained overdenture with two different attachments by measuring : Retention. Bone changes by radiographic evaluation. Subjects and Methods: Eight completely edentulous patients were selected from the Outpatient Clinic of the Prosthodontic Department; Faculty of Dental medicine, Al Azhar University and classified into two equal groups. Each patient in two groups received two implants placed in the mandibular canine-premolar region bilaterally. Group (1): four patients received two implants using equator attachments. Group (2): four patients received two implants with using magnet attachments. and the study was randomized controlled trial with Calculated samples. type of randomization in that study was Block randomization and The out comes was assessor blinded as the investigators didn’t know the type of the attachment before measuring retention or amount bone resorption Results: Results revealed that, there was no statistically significant difference in bone loss between equator and magnet during the follow up period, and there were no statistically significant mean retention values in the two groups at base line and after 3 months. But 6 months; Magnet attachment showed statistically significantly lower mean retention values than Equator attachment. By time there was a statistically significant decrease in mean retention values of magnet rather than locator attachment. Conclusion: The use of equator and magnet attachments with two implant supported mandibular overdentures leads the same effect on crestal bone resorption. At the beginning the two attachment have the same retention quality by time magnet attachment loss some of its retention rather than locator attachment

A Comparative Radiographic Evaluation of Crestal Bone Resorption in Single Implant versus Two Implant Retained Mandibular Overdentures – A Randomised Controlled Trial

A Comparative Radiographic Evaluation of Crestal Bone Resorption in Single Implant versus Two Implant Retained Mandibular Overdentures – A Randomised Controlled Trial

Influence of Moderate Cigarette Smoking on the Peri-Implant Clinicoradiographic Inflammatory Parameters Around Cement- and Screw-Retained Dental Implants.

The aim of this study was to assess the influence of moderate cigarette smoking on the clinical (bleeding on probing [BoP] and probing depth [PD]) and radiographic (crestal bone resorption [CBR]) parameters around cement- and screw-retained dental implants at 5-year follow-up. A questionnaire was used to collect information about age, gender, smoking history, duration of implants in function, jaw location of the implant, and daily toothbrushing and flossing. Peri-implant BoP, PD, and CBR were measured in all groups. Group comparisons were performed using 1-way analysis of variance, and for multiple comparisons, the Bonferroni post hoc adjustment test was performed. The level of significance was set at P < .05. Forty-eight patients (25 smokers and 23 nonsmokers) had cement-retained dental implants, and 48 (24 smokers and 24 nonsmokers) had screw-retained dental implants. Among patients with cement- and screw-retained dental implants, PD (P < .05) and CBR (P < .05) were significantly higher among smokers than nonsmokers. The peri-implant sites that demonstrated BoP were statistically significantly higher among nonsmokers (P < .05) than smokers among patients with cement- and screw-retained dental implants. There was no statistically significant difference in peri-implant PD and CBR among smokers with cement- and screw-retained dental implants. Among nonsmokers with cement and screw-retained dental implants, there was no statistically significant difference in BoP, PD, or CBR. Cigarette smoking is associated with an increased PD and CBR around cement- and screw-retained dental implants. Cigarette-smoking increases peri-implant soft-tissue inflammation as well as loss of crestal bone, and this relationship is independent of the type of implant retention protocol used. The author recommends that cement- and screw-retained dental implants are suitable for prosthesis restoration in nonsmokers. Further studies on dual smokers (individuals smoking cigarettes and other forms of tobacco products) are needed related to the clinicoradiographic inflammatory parameters around cement- and screw-retained dental implants.

Digital vs. Freehand Anterior Single-Tooth Implant Restoration.

Replacing a single tooth in the anterior maxilla is one of the greatest challenges in dentistry. Both functional and aesthetic results are to be strictly pursued. Planning and executing such a case through a totally digital methodology eventually guarantee many advantages, above all patient's operative and postoperative comfort. To ascertain this, a BOP analysis was performed which allowed us to evaluate soft tissues health, and more; crestal bone resorption was measured to evaluate hard tissues stability. This assumption was studied through four cases in which patients were alternatively treated with analogic and digital techniques. Four homogeneous patients were recruited. They all needed to extract one of the upper incisors, due to different clinical reasons, and then to replace it with an implant. Each patient was treated with an immediate postextractive implant which was immediately loaded, and finally, analogical and digital techniques were compared. All patients underwent a preoperative CBCT examination. After surgery, patients were checked by the surgeon after 10 days and one month to evaluate the progress of healing and to exclude any prosthetic problem. At 6 months (T1), one year (T2), and three years (T3), intraoral x-rays were performed using customized centring devices, according to the parallel beam technique. All data have been collected in a table and statistically processed; mean and standard deviation were measured. All patients entered an oral hygiene program with six months recall. Dental hygienist checked the BOP at T1, T2, and T3. At every step, similar levels of BOP were recorded. About interproximal bone loss, all patients showed an initial moderate loss (between T1 and T2), followed by stable values between T2 and T3. Despite the important limitations of a study with few cases, these results show a similar outcome comparing digital and analogical methods.

Effect of low level laser therapy on crestal bone levels around dental implants-A pilot study.

Implant success is affected by initial bone resorption at the implant surface. Continuous efforts have been made to reduce the peri-implant crestal bone loss. Limited information is available regarding the influence of low level laser therapy (LLLT) on interaction between the bone and implant surface. The aim of this pilot study was to assess the effect of LLLT on peri-implant crestal bone levels. Twenty implants were placed in 20 patients who were randomly assigned to two groups. Group I patients' received no adjunctive treatment and group II patients' were administered LLLT using 980 nm diode laser at 0.1 W output power following implant placement. The energy density of 4 J/cm2 was delivered at six sites for a duration of 10 seconds per site. Crestal bone levels were evaluated primarily using digital intraoral periapical (IOPA) radiograph. The measurements were made immediately (T0) and 6 weeks (T1) post implant placement; and 6 months (T2) and 1 year (T3) post prosthetic loading time intervals and compared using repeated measures ANOVA test. Crestal bone levels at baseline were statistically not significant between groups (P = .880). At T3 time interval, the mean change in crestal bone levels around all anatomical implant sites measured was 0.81 (SE 0.04) mm for irradiated group and 0.97 (SE 0.04) mm for nonirradiated group. Intergroup analysis revealed statistically significant (P = .020) less crestal bone loss in group that received LLLT. Under the conditions of this study, LLLT reduced the crestal bone resorption surrounding dental implants. The present clinical trial was not registered.

Three years follow up study of the effect of implant abutment connection on bone resorption around implants placed at different crestal levels

Statement of problem: Implant abutment connection may affect the stresses and strains induced at the peri-implant area and influence crestal bone resorption around implants at different levels of crestal placement. Materials and Methods: Implants were divided into two groups: internal hexagon (Legacy™ 2, Implant Direct) and conical hybrid connection (AnyRidge; MEGAGEN). Each group was further subdivided into three subgroups depending on the location of surgical placement (subcrestal, crestal, or supracrestal) of the implant platform. Each case was evaluated radiographically and linear measurements of bone resorption were made from the implant's apex to the first point of bone-to-implant contact at prostheses loading and after 6, 12, 24 and 36 months. Data were collected, tabulated and statistically analyzed using t Student test and ANOVA test followed by Tukey’s test. Results: No Statistical significant differences were found between the main tested two groups (P ≥ 0.05), however there were statistical significant differences between the position groups with the conical hybrid subcrestal group showing the lowest values of peri-implant bone after three years of prostheses insertion. Conclusions: Conical hybrid implant abutment connection showed less crestal bone resorption around implants than internal hexagon implant abutment connection in any position of placement. Subcrestal implant surgical positioning showed the less crestal bone resorption followed by supracrestal. Crestal implant positioning should be avoided whenever possible.

RADIOGRAPHIC EVALUATION OF CRESTAL BONE RESORPTION DURING HEALING &amp; LOADING PERIOD IN IMPLANT SUPPORTED OVERDENTURE BY PLACING IMPLANT THROUGH FLAP TECHNIQUE- IN VIVO STUDY

Aim: The aim of this study was to detect the effect of flap technique on crestal bone resorption during healing and loading period in implant supported overdentures.&#x0D; Material and Methods: A total of 8 patients, 5 male and 3 female, ranging from 50 to 70 years of age, having completely edentulous maxillary and mandibular arches were selected for the study the whole study was conducted in 4 phases. In the 1st phase Clinical Diagnosis, Treatment Planning &amp; Denture Fabrication was done. The selected subjects will be diagnosed and treatment planning for new denture fabrication was done. In the 2nd phase the denture insertion was done and if required occlusal correction was be performed. After initial recall visit, patient was recalled again after one week of denture usage. In this visit 1st stage of implant surgery was conducted. Dental implant in the mid symphyseal region was placed following all the surgical protocols. Immediately after surgery first IOPA with RVG was taken. After the surgery the denture was relieved at the surgical site and patient was asked to use the same denture. Subsequently after 4 weeks and after 12 weeks of healing the second and third IOPA with RVG was taken. The computer software was used for measuring the bone level. After 3 months of Osseointegration period in phase 3, the loading of the implant was done by incorporating O ring attachment. Again after 4 weeks and after 12 weeks of loading the fourth and fifth IOPA with RVG was taken. The magnification error was checked. The data obtained was saved using Paint software used in Microsoft 8.1. The data so obtained for measuring the bone levels with the help of computer software (RVG 5100) was tabled and statistical analysis was done.&#x0D; Results: The mean rate of crestal bone loss with time was more during first month (0.35mm) then it decreased in 3rd month (0.51mm) and further decreased during 4th month (0.59mm) and 6th month (0.70mm) follow up period.&#x0D; Conclusion: The concept of single implant supported overdentures provides another option for completely edentulous elderly patients with severely resorbed mandibular ridge &amp; with economic constraints in developing countries.&#x0D; Keywords: Dental implants, Overdenture, Residual Alveolar Ridge, Crestal Bone loss, Intraoral Digital Radiography (RVG 5100).

Efficacy of Nonsurgical Mechanical Debridement With and Without Adjunct Low-Level Laser Therapy in the Treatment of Peri-Implantitis: A Randomized Controlled Trial

We hypothesized that in the long term (6-month follow-up), nonsurgical mechanical debridement (NSMD) with adjunct low-level laser therapy (LLLT) is more effective for the treatment of peri-implantitis than NSMD alone. The aim of the present 6-month follow-up convenience-sample cohort study was to assess the efficacy of LLLT as an adjunct to NSMD in the treatment of peri-implantitis. A questionnaire was used to collect demographic information. Patients with peri-implantitis in the test and control groups underwent NSMD with and without adjunct LLLT, respectively. Randomization was done by tossing a coin. In the test group, the laser was applied perpendicular to the periodontal pocket for 20 seconds at a constant distance of 15 mm and with a continuous wavelength (3.41 J/cm2 delivery with a 1.76 cm2 spot and average output of 0.3 W). In both groups, peri-implant probing depth, bleeding upon probing, and crestal bone resorption were assessed at baseline and at the 3-month and 6-month follow-up. Group comparisons were performed, and P < .05 was considered statistically significant. Sixty-seven individuals with peri-implantitis were included. The mean age of participants who underwent NSMD with adjunct LLLT and NSMD alone was 46.5 ± 3.4 and 45.3 ± 1.1 years, respectively. At the 3- and 6-month follow-up, peri-implant (P < .05), bleeding upon probing (P < .05), and probing depth (P < .05) were significantly higher among patients who underwent NSMD alone compared with patients who underwent NSMD with adjunct LLLT. There was no significant difference in crestal bone resorption in all patients up to the 6-month follow-up. In the short term, NSMD with adjunct LLLT was a useful treatment protocol for the treatment of peri-implant soft-tissue inflammation.

Clinical and Radiological Evaluation of Marginal Bone Loss around Dental Implants Restored with Zirconium vis-à-vis Porcelain Fused to Metal: An In Vivo Study

Abstract Introduction Marginal bone level is the criterion for implant success. Patient expectations for more natural looking implant restorations created the need to restore implants with more esthetically pleasing materials like Zirconia rather than conventional porcelain-fused to-metal (PFM) crowns. The aim of this study was to evaluate marginal bone loss around dental implants clinically and radiographically when restored with Zirconia and PFM prosthesis. Materials and Methods Two groups (control and test) were formed with 14 patients each. In the control group, the subjects were rehabilitated with PFM crowns and in the test group, the subjects were rehabilitated with Zirconia crowns. Rehabilitation was done after the healing period of 3 months. Radiographic evaluation was done at regular (baseline, 3rd, 6th, and 12th month) intervals. Results The results were statistically analyzed. Keeping in mind the limitations of the study, it was revealed that the difference in the crestal bone resorption in both the groups was not significant.

GUIDED BONE REGENERATION IN IMPLANT DENTISTRY– A REVIEW THE PAST PRESENT &amp; FUTURE

Post-extraction crestal bone resorption and periodontal disease are common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, Guided Bone Regeneration has emerged as a predictable method to enhance the bone volume in deficient recipient sites prior to implant placement. It provides sufficient bone volume and adequate soft tissue thickness to enable implants to be placed at the most optimal position from a prosthetic point of view. In the past, nonabsorbable membranes with basic functions such as space maintenance were used with bone graft materials. Due to several limitations of the non-absorbable membranes, membranes of the second and third generation equipped with controlled absorbability, and a functional layer releasing growth factors or antimicrobials were introduced. Moreover, tissue engineering using biomaterials enabled faster and more stable tissue regeneration. The scaffold with three-dimensional structures manufactured by computer-aided design and manufacturing (CAD/CAM) showed high biocompatibility, and promoted cell infiltration and revascularization.

Titanium-Prepared Platelet-Rich Fibrin Versus Connective Tissue Graft on Peri-Implant Soft Tissue Thickening and Keratinized Mucosa Width: A Randomized, Controlled Trial

The health of peri-implant tissues is associated with the peri-implant soft tissue thickness (STT) and keratinized tissue width (KTW). Resorptive changes in the crestal bone around implant sites will be affected by the STT. The present randomized prospective study compared the effectiveness of titanium-prepared platelet-rich fibrin (T-PRF) with that of connective tissue graft (CTG) on peri-implant STT, KMW, and crestal bone level. Through simultaneous augmentation of the soft tissue using T-PRF or CTG, 30 implants were placed in 30 patients. The implants were placed in thin, soft tissue areas and thickened simultaneously with a T-PRF membrane in the test group and a CTG in the control group. During surgery (T0) and at 3months postoperatively (T1), the KTW and peri-implant STT were measured at 3 points: occlusal part of the alveolar crest (OAC), midbuccal mucosa level (MBML), and 1mm above the mucogingival junction (MGJ1). The crestal bone changes were evaluated from a periapical radiograph at 3months postoperatively. The baseline STT and KTW measurements showed no significant differences between the 2 groups (P<.05). Comparison of the T0 and T1 measurements from the 2 groups showed a significant increase in KTW and STT (P<.001). Compared with the test group, the control group showed a highly significant increase in the peri-implant STT at the MBML, MGJ1, and KTW levels (P<.05). No significant difference was found between the 2 groups in terms of the OAC changes (P>.05). No crestal bone loss was observed in any of the dental implants. Both groups experienced a greater increase in peri-implant STT at the OAC level, and T-PRF can be considered as an autogenous alternative to CTG. Also, peri-implant STT might prevent crestal bone resorption in the osseointegration period.

The Influence of Progressive Static Load on the Ability of Dental Implants to Withstand Overloading Forces: An Experimental Study in Dogs.

To examine the effect of controlled progressive orthodontic loading on bone around implants subjected to overloading forces. Bilateral edentulous alveolar ridges were created in the posterior maxilla of five beagle dogs and left to heal for an 8-week period, after which 40 implants were placed. In the overloading group (OL), 16 implants were inserted and left to osseointegrate for 16 weeks; impressions were made, and metal crowns were mounted on with supraocclusal contacts with the antagonist teeth. Implants were exposed to dynamic overloading for 16 weeks. In the progressive loading + overloading group (PL+OL), 16 implants were left to osseointegrate for 8 weeks, and custom abutment cores were fabricated and coupled by pairs with Ni-Ti orthodontic springs. Ascending static forces of 100g, 200g, and 300g were each applied for a 3-week period, for a total 9-week progressive loading period. Thereafter, metal crowns with supraocclusal contacts were adapted, and a 16-week overloading protocol for implants was followed as for the overloading group. In the unloaded control group (UL), eight implants were inserted and left uncovered and unloaded for 32 weeks, that is, until the end of the experimental period, at which point all 40 implants were removed with the surrounding bone. Histologic, histomorphometric, and statistical analysis followed. Higher bone-to-implant contact percentage was reported for the OL group (P = .006) and PL+OL group (P < .001) compared with the UL group. Between the OL and PL+OL groups, the addition of progressive loading did not increase the bone-to-implant contact percentage (P = .225). Bone density 1 mm and 2 mm distant to the threads did not differ significantly between the three groups. Significantly lower crestal bone resorption was detected around OL group implants (P = .006) and PL+OL group implants (P = .004) compared with the UL group implants. The implant success rate was 87.5% for the UL group, 67.5% for the OL group, and 87.5% for the PL+OL group. The application of controlled progressive orthodontic loading on osseointegrated implants preceding overloading forces did not increase bone-to-implant contact. When applied, overloading significantly increased bone-to-implant contact compared with the unloaded implants. A significantly higher implant success rate was reported in the PL+OL group compared with the OL group.

Comparative Evaluation of Stress Distribution around Various Threaded Implants with and without Platform Switch: A 3-D Finite Element Analysis

The purpose of this study was to compare the stress distribution around various thread design implants with or without platform switching in the maxillary posterior region. Stress-based performances of four different thread design implants (single, double, triple, and asymmetric thread design each with or without platform switching) were analyzed by the three-dimensional finite element method under a static load of 100 N at 15° oblique direction buccolingually at the central portion of the abutment. A geometric model of the posterior maxillary segment (first molar region) with an implant and abutment was modeled using the CATIA V5R19 software. Type IV bone quality was approximated and complete osseous integration was assumed. The von Mises stresses recorded around the neck of the fourthread design implants without platform switching were greater than the platform switching variety. The single-threaded implant with platform switching showed the lowest amount of von Mises stress. Additionally, total displacement or micromovement of single, triple, and asymmetric thread implants with platform switching was found to be greater than the without platform switching variety. Further, the total displacement of the single-threaded implant without platform switching was lowest. Implant surface design, platform switching, and site of placement affect load transmission mechanisms. Due to low crestal resorption, single thread design with platform switching is preferred. The success of an implant in the maxillary molar region is more challenging in terms of the density of bone and the worst load transfer mechanism. With the right kind of implant surface design selection, this can be reduced to a great extent by the preservation of crest of the ridge. Crestal bone resorption following implant placement is an important issue. An optimum implant design with a single thread having a platform switch could compensate for this issue to a great extent.

Evaluation of Crestal Bone Resorption around Dental Implants in Flapped and Flapless Surgical Techniques Depending on Cone Beam CT Scan (Comparative Study)

Background: The long term survival of dental implants is evaluated by the amount of crestal bone loss around the implants. Some initial loss of bone around dental implants is generally expected. There is reason to believe that reflecting a mucoperiosteal flap promotes crestal bone loss in the initial phase after an implant has been inserted. The surgical placement of a dental implant fixture is constantly changing and in recent years, there has been some interest in developing techniques that minimize the invasive nature of the procedure, with flapless implant surgery being advocated. The purpose of this study was to compare the radiographic level of the peri- implant bone after implant placement between traditional flapped surgery and flapless approach depending on CBCT during 24 weeks healing period. Materials and Methods: A total of 25 Iraqi patients with an age ranged of 20-60 years who received 46 implants. Were randomized into two groups: control group which involved 27 implants inserted by conventional flapped surgical approach and study group which involved 19 implants inserted by flapless surgical approach. The bone level was measured by CBCT for each implant at buccal and palata/lingual sides at two times, immediately after implant placement (base line data), and after 24 weeks healing period. Results: There was no significant difference between study (flapless) and control (flapped) groups in the mean of total crestal bone resorption for buccal and palatal side after 24 weeks from implant placement (P= 0.393 for buccal side and P= 0.214 for palatal side). There was highly significant difference between buccal and palatal side regarding crestal bone loss around implants (P = 0.001) Conclusions: Bone resoption around dental implants placed with conventional flap surgery compared to flapless surgery does not seem to be influenced during the healing period before implant loading.

Evaluation of Effectiveness of Concentrated Growth Factors on Osseointegration Around Immediate Dental Implant

Aim: This study was designed to evaluate of using concentrated growth factors membrane (CGF) membrane mixed with concentrated growth factors (CGF) sticky bone around immediate implant versus immediate implant placement without any addition in mandibular molar area. Subjects and Methods: Twelve implant fixtures were inserted in 12 patients divided equally into two groups. The patients were selected from those attending outpatient clinic, Oral and Maxillofacial Surgery Department, at the Faculty of Dental Medicine, Cairo, Al-Azhar University (Cairo, Boys). Clinical examination was made to all patients by measuring of primary stability at time of implant placement and 6 months after implant placement as a secondary stability by ossttel device, Preoperative and after 6 months postoperatively cone beam CT for every patient to determine bone density between bony walls and implant surfaces. Data were collected, revised, coded and entered to the Statistical Package for Social Science (IBM SPSS) version 23. Results: The mean crestal bone resorption value in mesial and distal side of immediate implant placement with concentrated growth factor CGF membrane with CGF sticky bone around implant was 0.09±0.03mm & 0.43±0.23mm contrary to the immediate implant without any addition after 6 months follow up, which was 0.33±0.14mm & 1.56±0.77mm which was statistically significant. Conclusion: Immediate implant placement with CGF membrane/ CGF sticky bone show significant increase in secondary stability after six months.

Tapered Screw Implants With Different Machined Neck Designs: A 3-Year Split-Mouth Randomized Controlled Prospective Study.

Tapered Screw Implants With Different Machined Neck Designs: A 3-Year Split-Mouth Randomized Controlled Prospective Study.

A randomized controlled trial to compare aesthetic outcomes of immediately placed implants with and without immediate provisionalization.

There are mixed results regarding the aesthetic advantage of immediate provisionalization of dental implants. Therefore, this study aimed to compare facial mucosal level of single immediately placed implants with and without immediate provisionalization. Single implants were immediately placed to replace a hopeless maxillary anterior or premolar tooth in 40 subjects. Each implant was randomly assigned to receive a non-occluding temporary crown or a healing abutment after implant placement. At 4months, these implants were permanently restored and followed up for 12months. Clinical and radiographic parameters were measured and compared. The implant survival rate at 12months in the test and control group was 90% and 100%, respectively. Mid-facial mucosal marginal level and papilla height changes were minimal within groups, and no significant differences were found between the two groups. The amount of marginal bone remodelling was modest, with no significant difference between the two groups. Radiographic bone changes were not statistically different between the groups, except for the vertical crestal bone resorption. Immediate implant placement with or without provisionalization can achieve stable vertical soft tissue level for 12months as compared to pre-extraction level. However, immediate provisionalization was not able to improve the aesthetic outcome further.

Concepts for prevention of complications in implant therapy.

The use of dental implants is nowadays a well-accepted and highly predictable treatment modality for restoring the dentition and reestablishing the masticatory function of edentulous and partially edentulous patients. Despite the high predictability and excellent long-term survival rates reported for implant therapy, complications may still occur and can jeopardize both short- and long-term success. The present paper provides an overview on the most important aspects related to the etiology, prevention, and management of complications associated with implant therapy. Data from the literature indicate that a number of factors, such as surgical trauma, implant diameter, type of implant-abutment connection, abutment disconnection and reconnection, presence of microgap, and implant malpositioning, can substantially influence the biologic processes of bone remodeling and biofilm formation, thus increasing the rate of short- and long-term hard- and soft-tissue complications. Other factors, such as excess cement at cement-retained prosthetic restorations, abutment mobility, and infections (e.g. peri-implant mucositis and peri-implantitis) caused by bacterial biofilm, are further causes for complications and failures. More recent evidence also indicates that besides the need for sufficient bone volume surrounding the implant, the presence of an adequate width and thickness of attached mucosa may improve biofilm control and limit crestal bone resorption. Furthermore, emerging evidence points also to the pivotal role of human factors as one of the most important causes of complications in implant dentistry. It can be concluded that clinicians need to consider all biologic and biomechanical factors affecting implant placement and survival, as well as undergo adequate training to improve their surgical skills to control and prevent implant complications. Careful patient selection and control of environmental and systemic factors, such as smoking, diabetes etc., coupled with an accurate surgical and prosthetic planning, enable a better prevention and control of infections.

Biomechanical Effects of Diameters of Implant Body and Implant Platform in Bone Strain around an Immediately Loaded Dental Implant with Platform Switching Concept

Dental implants designed with platform switching have been used clinically to reduce crestal bone resorption. The aim of this study was to determine the biomechanical effects of loading types, diameter of platform, and implant diameter in bone strain around immediately loaded implants with platform switching concept. Platform-switching features of dental implants with various diameters of implant body and implant platform (named as RP5.0, RP4.3, and NP3.5) were inserted into artificial bone blocks. The initial implant stability was confirmed using a Periotest device before the loading test. Rosette strain gauges were placed on the alveolar region around the implants, and peak values of the bone strain during a 190-N vertical load or 30-degree lateral load were measured by a data acquisition system. The Kruskal-Wallis test and post-hoc pairwise comparisons were performed as statistical analyses. The median Periotest values of the RP5.0, RP4.3, and NP3.5 implants ranged from −6.59 to −7.34. The RP5.0 implant always showed the lowest bone strain around the implant, regardless of whether a vertical or lateral load was applied. Relative to the RP4.3 and NP3.5 implants, the RP4.3 implant produced a higher bone strain (by approximately 8%) under a vertical load but a lower bone strain (by approximately 25%) under a lateral load. This study confirmed that using a wider implant could relieve the bone strain around an immediately loaded implant with platform switching concept especially under lateral loading.

Covalently-Linked Hyaluronan versus Acid Etched Titanium Dental Implants: A Crossover RCT in Humans.

Biochemical modification of titanium surfaces (BMTiS) entails immobilization of biomolecules to implant surfaces in order to induce specific host responses. This crossover randomized clinical trial assesses clinical success and marginal bone resorption of dental implants bearing a surface molecular layer of covalently-linked hyaluronan in comparison with control implants up to 36 months after loading. Patients requiring bilateral implant rehabilitation received hyaluronan covered implants in one side of the mouth and traditional implants in the other side. Two months after the first surgery, a second surgery was undergone to uncover the screw and to place a healing abutment. After two weeks, the operator proceeded with prosthetic procedures. Implants were evaluated by periapical radiographs and the crestal bone level was recorded at mesial and distal sites—at baseline and up to 36 months. One hundred and six implants were positioned, 52 HY-coated, and 48 controls were followed up. No differences were observed in terms of insertion and stability, wound healing, implant success, and crestal bone resorption at any time considered. All interventions had an optimal healing, and no adverse events were recorded. This trial shows, for the first time, a successful use in humans of biochemical-modified implants in routine clinical practice and in healthy patients and tissues with satisfactory outcomes.