Peri-implant Crestal Bone Levels Research Articles

Clinical efficacy of two vertical soft tissue augmentation techniques for peri-implant crestal bone level stability: A randomized clinical trial.

This study aimed to compare the efficacy of two techniques-acellular dermal matrix (ADM) grafting and tenting technique (TT)-for soft tissue height (STH) augmentation simultaneous to implant placement to minimize peri-implant crestal bone level (CBL) changes. Forty patients with a healed single mandibular posterior edentulous site with a thin soft tissue phenotype were enrolled. Twenty patients received simultaneously to implant placement ADM grafting, while the others received submerged healing abutment (TT). Clinical peri-implant soft tissue height and radiographic CBL changes were measured at restoration delivery and 1-year follow-up. Both techniques effectively increased soft tissue thickness, resulting in a final average STH of 3.4 ± 0.5 mm after augmentation. On average, soft tissue increased by 1.6 ± 0.5 mm in group ADM and by 1.8 ± 0.4 mm in group TT after augmentation. In Group ADM, mesial CBL decreased from 0.4 ± 0.3 mm to 0.1 ± 0.2 mm, and distal CBL decreased from 0.5 ± 0.3 mm to 0.2 ± 0.3 mm over 1 year. In Group TT, mesial CBL remained stable at 0.3 ± 0.2 mm, while distal CBL reduced slightly from 0.5 ± 0.5 mm to 0.3 ± 0.2 mm. Both groups showed minimal changes in CBL, indicating great stability (pmesial = 0.003, pdistal = 0.004). TT was particularly effective in preventing mesial bone loss (pmesial = 0.019). The mesial CBL changes significantly differed between groups (p = 0.019), and not significantly at distal sites (p = 0.944). Neither treatment exhibited significant bone remodeling below the implant shoulder. This study suggests that both techniques were successful in STH augmentation, and they may effectively reduce peri-implant crestal bone level changes, with TT being slightly superior. TT was more prone to post-surgical complications. This RCT was not registered before participant recruitment and randomization.

Efficacy of customized crown-level position jig in measuring peri-implant crestal bone level on periapical radiographs: An in vitro study

Background/purposeAccuracy of using implant length on periapical radiographs as calibration reference for measurements has not been verified. This study aimed to verify the measurements of peri-implant crestal bone level (piCBL) on periapical radiographs taken by the paralleling technique and using the implant length for calibration; and to propose a customized crownlevel position (CLP) jig to improve the measurement accuracy of piCBL. Materials and methodsA typodont installed an implant and a screw-retained crown at maxillary central incisor was used. To simulate piCBL, a metal post was placed near the implant at the same height of implant platform. The CLP jig was designed and 3-dimensionally printed out to allow implant projected orthogonally on periapical film. Thirty periapical radiographs were taken using paralleling technique with and without the jig by three examiners. The implant axis and implant length on radiographs were acquired by image segmentation. The discrepancy of piCBL determination (ΔD) from these measurements were compared and further analyzed when using the implant length for calibration. ResultsThe piCBL measurement errors were smaller when the jig was used for all examiners (P < 0.001). The inter-rater differences were insignificant. After calibration, ΔD with and without jig were 0.09 (0.07–0.11) and 0.43 (0.38–0.49) mm, respectively. ConclusionConventional long-cone paralleling technique using true implant length for calibration demonstrated imprecise piCBL measurement on periapical radiographs. Transferring the implant axis to the CLP jig allowed orthogonal projection of radiography which provided reliable measurements of piCBL with an accuracy of less than 0.1 mm.

Correlation of implant position and crestal bone loss in 2-implant mandibular overdentures with immediate loading protocols: A prospective clinical study

Statement of problemThe 2-implant mandibular overdenture (2IMO) is a popular treatment for patients with an edentulous mandible, but information on the effect of the optimum implant position on the peri-implant crestal bone level with immediate loading protocols is lacking. PurposeThe purpose of this prospective clinical study was to evaluate correlations between different implant positions and crestal bone loss and between interimplant distance and the crestal bone loss in patients with 2IMOs with immediate loading protocols at 1-year follow-up. Material and methodsA total of 24 participants (13 men, 11 women, mean ±standard deviation age 63.25 ±10.76 years) were treated with 2IMOs (48 Ti-Zr implants) by a single operator between August 2015 and October 2020. The implant diameters (3.3 mm or 4.1 mm) and lengths (10 mm or 12 mm) were selected based on the crestal bone width, and the implants were placed, if possible, in the canine regions. Implant positions and interimplant distance (mm) were measured intraorally with dividers. Prefabricated mandibular dentures were immediately loaded with the LOCATOR-attachments by using a direct intraoral pickup procedure. Crestal bone-level changes were measured with a software program on the mesial and distal sides of each implant from periapical radiographs made with a paralleling technique (at baseline and 1-year follow-up). The measurement values were normalized. The Spearman rho correlation test and paired samples t tests were used for data analysis (α=.05). ResultsThe mean ±standard deviation position of the implants from the midline was 8.78 ±2.25 mm (9.00 ±2.22 mm right side, 8.56 ±2.31 mm left side), and the mean interimplant distance was 16.94 ±4.03 mm. At 1-year follow-up, the mean ±standard deviation crestal bone loss was 0.50 ±0.47 mm (n=48) (0.57 ±0.65 mm mesial, 0.43 ±0.53 mm distal). The mean ±standard deviation crestal bone loss was 0.46 ±0.4 mm with Ø3.3-mm implants (n=42) and 0.9 ±0.8 mm with Ø4.1-mm implants (n=6) (P=.005). Implant positions were negatively correlated (rs=-0.37) with the crestal bone loss, and the correlation was significant (P=.009). Interimplant distances were also negatively correlated with crestal bone loss (rs=-0.60; P=.002). Bone loss on the mesial side was positively correlated with that on the distal side rs=0.20; however, the correlation was not significant (P=.16). ConclusionsA weak and negative correlation was found between the implant position from the midline and the crestal bone loss and also between the interimplant distance and crestal bone loss in patients provided with 2IMOs with immediate loading protocols.

The Effect of Locator Attachment and Ball-O-Ring Attachment on Bone Height Change in Implant Retained Overdenture

Objectives. This study was conducted to evaluate and compare the effect of locator attachment and Ball-O-ring attachment on the peri-implant crestal bone level changes in edentulous patients rehabilitated with implant retained lower over denture. Methods. Twenty edentulous patients (male) were participating in this study, they were rehabilitated by mucosa supported maxillary complete denture and implant retained mandibular over denture by two implants installed in the canine region, patients were divided into two equal groups according to the type of attachment used, the locator attachment was used for group I and Ball-O-ring attachment was used for group II. Peri-implant crestal bone level changes were assessed using intra-oral radiographs taken with the standardized long cone paralleling technique using custom made acrylic template and the Rinn-xcp system. Periapical radiographs were taken every six months to complete a period of 18 months follow up period. The marginal bone loss at different intervals was obtained by calculating the difference in bone height at that interval from the base line measurement and statistically analyzed (t-test P &lt; 0.05). Results. The result of this study showed that the time has significant effect on the mean values of the peri-implant bone height on both groups. Moreover, group I had significantly less bone resorption from insertion to twelve months in compare to group II. Conclusion. The insignificant difference observed between comparing the peri-implant bone loss between the two groups indicates that the two treatment modalities are effective for the rehabilitation of lower denture. Locator attachments have the ability to control the amount bone loss. It could be advantageous in cases where the retention of implants retained overdentures is compromised.

Estimation of Soft and Hard Tissue Revolutionization Surrounding Dental Implant: A 2-Year Retrospective Study.

A dental implant is an idyllic mode of operandi for oral rehabilitation for complete and partially edentulous patients. The success of an implant is based on the health of its surrounding tissues. Therefore, the biological and clinical aspects of implant prosthesis and their surrounding tissues must persist to be investigated. A two-year retrospective clinical-radiological study was conducted to estimate peri-implant soft and hard tissue revolutionization after the placement of implants. A clinical-radiological investigation was carried out to determine the amount of soft and hard tissue revolutionization that occurred following the implantation of 200 implants. From October 2020 to March 2021, the research was carried out in the College of Dentistry at King Khalid University in Saudi Arabia. It was decided to conduct this study using a retrospective clinical record, which involved gathering information about patients who had previously received dental implants within the previous two years. Plaque index (PI), gingival index (GI), bleeding index (BI), peri-implant probing depth (PD), and peri-implant crestal bone level were measured at baseline and three months after implant placement in adult patients ranging in age from 20 to 50 years. The results were compared to the full-mouth index (FMI). Ethical clearance and written informed consent were obtained from all the study participants. The statistical analysis was done by using Statistical Package for Social Sciences (SPSS-23.0 version) (IBM; Chicago). The present study concluded that plaque accumulation, gingival bleeding, and probing depth were increased around implants during the follow-up, but it would not affect crestal bone loss. Still, it is essential to conduct a similar study with a larger sample size and a long follow-up period to give more precise results.

Radiographic Evaluation of Crestal Bone Level Changes for Allografts or Xenografts Placed during Implant Placement: A Retrospective Study

The aim of this study was to evaluate initial peri-implant crestal bone level changes when the allografts and xenografts were placed simultaneously during the implant placement. This retrospective study was planned with the convenient sampling total of 77 implant sites that were bone grafted either with allografts (group I) or xenografts (group II). Using the periapical radiographs obtained after placement of bone grafts as baseline, the changes in the alveolar crestal bone around the implants were evaluated by comparing periapical radiographs taken at 3 months and 6 or 8 months after the surgery. The alveolar bone loss at crestal region at the time of placement of bone grafts were -1.85 ± 1.26 mm at the xenograft sites and -1.75 ± 1.51 mm at allograft sites, respectively (p = 0.791). At the time of reentry, 3 months after tooth extraction and ridge preservation, the bone dimensions were 1.17 ± 0.83 mm for xenograft and 1.00 ± 1.14 mm for allograft (p = 0.523). At the final reentry, bone-grafted sites were divided into after 6 months and after 8 months postoperatively. After 3 months, the allografts showed lesser bone resorption (0.9 ± 0.52 mm) as compared with the xenografts (1.25 ± 1.00 mm). The bone loss after 8 months for the allografts was spiked to 1.83 ± 0.42 mm as compared with the xenografts 1.37 ± 1.12 mm with no statistically significant difference (p >0.05). Both allografts and xenografts present comparable crestal bone level changes around dental implants when simultaneously placed during implant placement surgery. Both allografts and xenografts are suitable for the preservation of the alveolar ridge regarding crestal bone level changes. Selection of allografts and xenografts may not be carried out based upon the crestal bone level changes.

Do postoperative antibiotics influence one-year peri-implant crestal bone remodelling and morbidity? A double-blinded randomized clinical trial.

ObjectivesThe primary objective of this study was to assess whether giving postoperative antibiotics to healthy patients after straightforward platform‐switched implant placement would influence peri‐implant crestal bone levels and postoperative morbidity after 1 year.MethodsThirty‐eight healthy individuals were recruited in this pilot, randomized, double‐blinded, placebo‐controlled clinical trial. The intervention group (n = 18) received two grams of amoxicillin one hour before implant placement followed by a 7 days postoperative regimen (500 mg tid). The control group (n = 20) took the same preoperative dose of amoxicillin and an identical placebo postoperatively. Mesial and distal peri‐implant crestal bone levels were measured at baseline, four months and one year later with standardized periapical radiographs. Postoperative pain severity was assessed through self‐administered questionnaires for 7 days. Surgery‐associated morbidities were evaluated after one, three, 16 weeks and 1 year. Descriptive and bivariate analyses were used.ResultsThirty‐seven participants completed the trial. At the one‐year follow‐up, the mean combined peri‐implant crestal bone changes for the intervention (n = 18) and control (n = 19) groups were ‐ 0.44 ± 0.41 mm and ‐ 0.27 ± 0.56 mm, respectively. The difference between the groups (intervention–control) for mean combined crestal bone level changes was not statistically significant. There were no significant differences in surgery‐associated morbidities between the intervention and control groups. The one‐year implant survival rate was 100% in both groups.ConclusionsStudy results suggest that a routine postoperative antibiotic regimen for healthy patients undergoing straightforward platform‐switched implant placement might not be necessary to prevent postoperative peri‐implant bone loss and complications.

Tomographic Assessment of reinforcement of acrylic resin denture base for palateless implant locator retained maxillary over denture.

Objectives: This study was conducted to evaluate the effect of metallic (cobalt chromium), glass fiber and nano zirconia oxide reinforcement of acrylic resin denture base on the peri-implant crestal bone level changes in palateless locator retained maxillary over denture. Materials and Methods: Twenty-one completely edentulous male patients with maladaptive experience to maxillary dentures were selected to participate in this study. For all patients maxillary four implant-retained overdenture was constructed following the same basic principles. Every patient received four implants, two in the canine region with (3.6 mm in diameter & 12mm in length), and two in the second premolar region with ( 4.5 mm in diameter & 8mm in length); (Tiologic® Implants, Dentaurum, Ispringen, Germany) . Metal (cobalt chromium) reinforced over denture was constructed for the first group , while 5% fiber reinforced acrylic resin denture was constructed for the second group and Overdenture was reinforced using 5% of nano ZrO2 for the group three patients. . Follow up visits were scheduled twelve and twenty four after implant loading for inspection of the prosthesis and radiographic evaluation Peri-implant crestal bone level changes were assessed using intra-oral radiographs taken . Results: The findings of the present study demonstrates that all the studied denture base reinforcement materials individually showed significance bone loss around implants (p < 0.05) after 12 months follow up period. Conclusion: Within the limitations of this study, reinforcement of polymethyl methacrylate denture base with glass fiber or nano zirconia oxide should be considered in palateless implant retained maxillary over denture.

Immediate and early loading of hydrothermally treated, hydroxyapatite-coated dental implants: a 7-year prospective randomized clinical study

BackgroundExisting research on marginal bone stability around hydroxyapatite (HA)-coated implants often lacks adequate long-term follow-up. The purpose of this randomized prospective study was to evaluate the 7-year outcome of patients with immediate and early loaded single-tooth restorations supported by implants with plasma-sprayed, partially HA-coated surfaces. Forty-two patients in need of 50 single implants were treated in in the Postgraduate Periodontics Clinic of Louisiana State University School of Dentistry. Implants were randomly divided into 2 groups: Group A was immediately loaded, and Group B was early loaded. Continuous follow-up with periodic maintenance care and radiographic evaluations was performed. The primary outcome of interest was implant survival, characterized using the Kaplan–Meier method. Secondary study outcome consisted of peri-implant crestal bone level changes. Data on age, sex, bone quality, implant location, length and diameter, and prior augmentation of the site were collected. Multiple regression analyses were conducted to determine whether the independent variables were associated with bone loss.ResultsOne implant failed to maintain stability and was removed at 3 weeks. Thirty-four patients (14 males, 20 females with a total of 42 implants) completed the 7-year follow-up visit. Average age of evaluable patients was 52 in Group A and 55 in Group B. No significant difference was observed regarding sex and age distribution between the 2 groups. No significant difference was detected in the distribution of implant locations, types of bone, implant length, implant diameter, and augmentation status of the bone between the 2 groups. After 7 years of functioning for the 42 implants examined, implant survival rate was 100% for Group A and 95.5% for Group B. The results from this study of 50 implants showed that HA-coated Zimmer Tapered Screw-Vent Implants were clinically effective, with an overall cumulative 7-year survival rate of 98.0%. When comparing radiographic bone levels between 2-year and 7-year follow-ups, no significant differences in bone loss were found between Group A and Group B.ConclusionsAfter 7 years in function, implants partially coated with plasma-sprayed and hydrothermally treated HA were clinically predictable when restored in occlusion immediately after or 3 weeks after implant placement.

Root Resorption of Central Incisor by Impacted Canine in Unusual Transposition: Orthodontics and Implant Rehabilitation: 3-Year Follow-Up

This case presents an unusual transposition of an impacted canine on the central incisor that provides a multidisciplinary approach to its resolution. The patient comes to the consultation for mobility of the central incisor. Clinically, tooth mobility was confirmed with tooth crowding and persistence of the temporary canine. Cone beam tomography (CBCT) observed the atypical position of the permanent canine that caused root resorption of the ipsilateral central incisor and the need to extract both teeth. The conservative treatment of the bone structures during the dental enucleation of the impacted canine carried out by odontosection and the immediate bone grafting of the defect projected an acceptable regeneration of the bone volume for the insertion of the implant. The orthodontic treatment managed to correct the bite, position the upper premolar in the place of the canine tooth and maintain the space to place the implant in the central incisor. The three-year follow-up shows maintenance of the peri-implant crestal bone level, the success of orthodontic treatment with recovery of the patient’s function and aesthetics.

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.

Effect Of Polyetheretherketone (PEEK) As Denture Base Material On Peri-Implant Bone Level Changes In Implant Bar Retained Overdenture Using CAD/CAM Technology

Objectives: This research was carried out to evaluate the effect of Polyetheretherketone (PEEK) as denture base material on peri-implant crestal bone level changes in edentulous patients rehabilitated with implant-supported primary-secondary bar overdenture and retained attachments attached the body of the bar constructed by CAD / CAM technology. Materials and Methods: Twenty completely edentulous patients complaining from insufficient retention of their mandibular denture were selected to participate in this study. All the patients were rehabilitated with an implant-supported bar overdenture. For All patients three implants (3.7mm) in diameter (11mm) in length were inserted in the interforamenal region using computer guided surgical template. Four months later, Cast bar with two semi precession attachment at the distal ends of the bar was constructed, The cast bar was scanned using bench laser scanner to obtain virtual model with the bar, the housing on the top of the bar and the female part of the attachment was designed using computer aided designing (CAD) the meld into wax by computer aided manufacturing (CAM). The CAD/ CAM wax pattern of housing and the female part of the attachments were transferred into acetal resin using the injection molded technique. Overdentures were constructed for all patients following the conventional technique. According to the denture base material, a toss coin was made to randomly divided the patients into two equal groups; group I received mandibular implant-retained overdenture were processed using heat cured acrylic resin, following the long curing cycle (heated at 78C° for eight hours), while for group II Polyetheretherketone (PEEK) lower overdenture was constructed, using the injection-molding technique. Radiographic evaluation of peri-implant bony changes was made using standardized long cone paralleling technique with custom made acrylic template and the Rinn-xcp at insertion, six, twelve and twenty four months were measured and statistically analyzed. The significant level was set at P ≤ 0.05P . ANOVA for repeated measures test was used to compare between follow up periods within groups and when statistically significant it was followed by simple main effect analysis with Bonferioni correction. One way ANOVA test was used to compare between groups at different follow up periods. Results. Both groups showed a statistically insignificant increase loss in crestal bone height around the implants. Although the data obtained from table1 revealed increase in the amount of bone changes for group I and Group II compared to group I during the follow up period statistical analysis of the data using ANOVA test for repeated measures revealed no significance difference(P ≥ 0.05) .Conclusion: CAD/ CAM technology and use of Polyetheretherketone (PEEK) as denture base material should be considered whenever possible to preserve the implant supporting structures in implant bar retained overdenture.

Efficacy of mechanical debridement with adjunctive probiotic therapy in the treatment of peri-implant mucositis in cigarette-smokers and never-smokers.

Efficacy of mechanical debridement (MD) with adjunctive probiotic therapy (PT) in the treatment of peri-implant mucositis (PiM) in cigarette-smoking and never-smoking subjects remains uninvestigated. The aim was to assess the efficacy of MD with adjunctive PT in the treatment of PiM in cigarette-smoking and never-smoking individuals. Patients with (group I) and without PiM (group II) were included. Demographic data was collected using a questionnaire. Treatment-wise, patients in groups I and II were subdivided into: (a) Patients that underwent MD with adjunct PT (using Lactobacillus reuteri); and (b) MD alone. In all groups, probing depth (PD), plaque index (PI), and bleeding on probing (BOP) were measured at baseline and compared after 3- and 6-months. Baseline peri-implant crestal bone levels were also measured. Sample-size estimation was performed, and statistical comparisons were done using one-way analysis of variance and Bonferroni post-hoc adjustment tests. P values under .05 were deemed significant. Eighty individuals (group I: 40 cigarette-smokers and group II: 40 never-smokers) with PiM participated in this study. At all-time intervals, no significant difference in PD, PI, and BOP were observed in all patients in group I. At 3-months' follow-up, the differences in BOP (P < .05), and PI (P < .05) were significantly higher in group II that underwent MD + PT than MD alone. At 6-months' follow-up, there was no difference in the changes in BOP and PI among subjects that underwent MD with and without adjunct PT. On a short-term basis, MD with adjunct PT is more effectual in the treatment of PiM than MD alone in never-smokers. Cigarette-smoking compromises peri-implant soft tissue healing following MD with or without adjunct PT.

Implant-Assisted Removable Partial Denture Prostheses: A Critical Review of Selected Literature.

A critical review of selected relevant publications assessed clinical efficacy and effectiveness of implant-assisted removable partial dentures (IARPDs) with implant survival and failure rates, biologic and technical complications, and maintenance and patient satisfaction after rehabilitation as outcomes. Screening of three databases (Medline [PubMed], Embase [OVID], and the Cochrane Library [CENTRAL]) and a manual search of related articles were performed. Reports on outcomes from human studies conducted between 1 January 1980 and 31 May 2016 were considered. A quality assessment of the identified full-text articles was performed to assess risk of bias and to evaluate heterogeneity. Only nine studies were included, and all nine demonstrated high risk of bias. The mean observation period ranged from 1 to 10 years, and only four studies included at least one control group. The studies reported implant survival rates of 91.7% to 100%, abutment tooth survival rates of 79.2% to 100%, and prosthesis survival rates of 90% to 100%. Approximal peri-implant crestal bone level changes (ΔCBL) ranged from -0.17 to -2.2 mm. IARPDs were associated with a higher frequency of technical complications and maintenance interventions than biologic complications. Only two question-based studies assessed patient satisfaction before and after treatment, and both reported marked improvement. A meta-analysis was not possible because of substantial heterogeneity in study design. Limited availability of robust publications related to the selected review topic precluded significant conclusions. Nonetheless, the preliminary assessment suggests that IARPDs are a simple and cost-effective approach to providing symmetric prosthesis support and stability, plus improved patient satisfaction.

CRESTAL BONE LOSS USING DIFFERENT STUD ATTACHMENTS IN DISTAL EXTENSION CASES

The duality of support that characterizes distal extension removable partial dentures is often characterized by time-dependent adverse changes in both the abutment teeth and edentulous areas. Consequently, adjunctive implant has been proposed for mandibular class I and II removable partial denture designs. This current study evaluated the effect of locator attachment system and ball abutment with O-ring female metal housings in implant retained mandibular partial overdenture by measuring peri-implant crestal bone level. Twenty partially edentulous male patients exhibiting bilateral distal extension edentulous areas were selected. Two implants were installed in the first molar region following the two stage surgical technique. Patients were randomly divided into 2 equal groups; Group 1 locator attachments were used and Group 2 ball attachments were used. The mesial, distal, buccal and lingual marginal bone height around the implants was evaluated using cone beam CT. The measurements were carried out at insertion, six and twelve months post insertion. The results of this study showed a statistically significant increase in crestal bone height loss around the implants in both groups during the follow up period. In conclusion, ball -retained mandibular overdenture are associated with more marginal bone compared to locator abutments.

RANDOMIZED CONTROL TRIAL FOR RADIOGRAPHIC ASSESSMENT OF TWO DIFFERENT ATTACHMENT MATERIAL RETAINING BAR SUPPORTED OVERDENTURE

Objectives: this research was carried out to evaluate two different attachment material retainers bar supported overdenture regarding the peri-implant crestal bone level changes. materials and methods: Twenty edentulous female patients participated in this study For each patient 3 endosteal implants were inserted in the interforamenal region using computer guided surgical Stent. Four month later implants were uncovered, healing abutments were secured and then transfer coping with long heads were used to make open tray impression technique. Plastic abutments were secured to implant analogue then plastic bars was attached to plastic abutments using durallay with two semi precision attachments at the distal ends of the bar. Then the bar was casted. Patients were divided into two groups. Group one the CAD CAM wax pattern of housing and the female part of the attachments were casted using nickel chrome alloy. Group two patients the CAD CAM wax pattern of housing and the female part of the attachments were transferred into Acetal resin using the injection molded technique. Then per implant crestal bone level were assessed using long cone parallel technique after six, twelve and twenty four months and then statistically analyzed. Results: This study showed that there was a statistically insignificant difference in between follow up periods for each group and between groups in between follow up period in interval 12-24 and significant difference between two groups after 24 months. Conclusion: Based on the results obtained from this study it can be concluded that acetal resin is favorable long term solution for implant retained mandibular overdentures

Crestal bone resorption in augmented bone using mineralized freeze-dried bone allograft or pristine bone during submerged implant healing: a prospective study in humans.

There is limited evidence on the crestal bone level changes around implants placed in bone augmented by guided bone regeneration (GBR) during submerged healing. The purpose of this study was to prospectively compare radiographic crestal bone changes around implants placed in augmented bone with changes around implants placed in pristine bone. Patients receiving dental implants in the augmented or pristine mandibular posterior edentulous ridge were included in the study. The digital standardized radiographs from the implant placement procedure were compared to the radiographs from the second-stage procedure to evaluate the peri-implant marginal bone level changes. The soft tissue thickness (ST), width of keratinized mucosa (wKM), and early cover screw exposure (eIE) were measured at the time of the second-stage procedure. A total of 29 implants in 26 patients, 11 in augmented bone (test group) and 18 in pristine bone (control group), were analyzed. The mean peri-implant bone loss (ΔBL) was 0.74±0.74mm (mean±SD) in the test group and 0.25±0.55mm (mean±SD) in the control group. The differences between the test and control groups in the mesial, distal, and mean peri-implant crestal bone level changes were statistically significant (P=0.009, P=0.004, and P=0.001, respectively). The confounding factors (ST, wKM, and eIE) were adjusted. More peri-implant crestal bone loss during the submerged healing period was observed in augmented bone than in pristine bone. Augmented bone may not exhibit the same characteristics as pristine bone during the implant submerged healing period.

Initial bone preparation followed by a 2-week delay before implant placement enhances the clinical and radiographic outcome: a randomized controlled trial

Initial bone preparation followed by a 2-week delay before implant placement enhances the biological activity at the osteotomy site, which may improve the treatment outcome. The aim of this study was to compare the clinical and radiographic outcomes of initial bone preparation and a 2-week delay in implant placement with the conventional method. Subjects were outpatients selected from a department of periodontology and oral implantology. The implant sites were randomly allocated to a test group and a control group (n=7 each). Test sites were treated with initial bone preparation followed by implant placement after a 2-week delay; control sites were treated with the conventional protocol. All sites were assessed over 12 months for the keratinized mucosa index, probing depth, implant mobility, and radiographic peri-implant crestal bone levels. A total of 14 implants were placed in 12 subjects (five males and seven females, mean age 31.5 years, range 18–45 years). The results showed a statistically significant reduction in peri-implant probing depth and crestal bone levels in the test group (P<0.01). This randomized controlled trial demonstrated better clinical and radiographic outcomes for initial bone preparation followed by a 2-week delay in implant placement; this may be an alternative to the conventional protocol.

Complications with Computer‐Aided Designed/Computer‐Assisted Manufactured Titanium and Soldered Gold Bars for Mandibular Implant‐Overdentures: Short‐Term Observations

Implant-overdentures supported by rigid bars provide stability in the edentulous atrophic mandible. However, fractures of solder joints and matrices, and loosening of screws and matrices were observed with soldered gold bars (G-bars). Computer-aided designed/computer-assisted manufactured (CAD/CAM) titanium bars (Ti-bars) may reduce technical complications due to enhanced material quality. To compare prosthetic-technical maintenance service of mandibular implant-overdentures supported by CAD/CAM Ti-bar and soldered G-bar. Edentulous patients were consecutively admitted for implant-prosthodontic treatment with a maxillary complete denture and a mandibular implant-overdenture connected to a rigid G-bar or Ti-bar. Maintenance service and problems with the implant-retention device complex and the prosthesis were recorded during minimally 3-4 years. Annual peri-implant crestal bone level changes (ΔBIC) were radiographically assessed. Data of 213 edentulous patients (mean age 68 ± 10 years), who had received a total of 477 tapered implants, were available. Ti-bar and G-bar comprised 101 and 112 patients with 231 and 246 implants, respectively. Ti-bar mostly exhibited distal bar extensions (96%) compared to 34% of G-bar (p < .001). Fracture rate of bars extensions (4.7% vs 14.8%, p < .001) and matrices (1% vs 13%, p < .001) was lower for Ti-bar. Matrices activation was required 2.4× less often in Ti-bar. ΔBIC remained stable for both groups. Implant overdentures supported by soldered gold bars or milled CAD/CAM Ti-bars are a successful treatment modality but require regular maintenance service. These short-term observations support the hypothesis that CAD/CAM Ti-bars reduce technical complications. Fracture location indicated that the titanium thickness around the screw-access hole should be increased.

Effect of Misfit of Cement-Retained Implant Single Crowns on Crestal Bone Changes

The purpose of this clinical study was to compare peri-implant crestal bone levels between misfitting (overhanging/open margin) cement-retained implant single crowns (SCs) vs accurately fitted implant SCs. Seventeen subjects were divided into two groups: test group (misfitting crowns, n = 10) and control group (accurately fitted crowns, n = 7). Crestal bone level changes were assessed using digital software. The average differences in mean bone loss within and between the two groups were statistically significant. Cement-retained implant SCs with marginal misfit resulted in more crestal bone loss than accurately fitted crowns after a mean of 3 years in function.