Search

Background/purpose: Information regarding agreements between periapical radiograph (PA) and cone beam computed tomography (CBCT) in detecting peri-implant defect is still scarce. The aim of this clinical study was to compare agreements between PA and CBCT in detecting peri-implant bone defect. Materials and methods: This retrospective clinical study enrolled 32 patients with both PA and CBCT filmed right after implant placement. Four modalities were used for film reading: PA1 (original), PA2 (enhanced brightness/contrast), CBCT1 (selected axial and mesial-distal direction images) and CBCT2 (all data with software). 2 experienced and 2 inexperienced observers scored all films. Intra- and inter-observer agreements were estimated with Cohen's kappa coefficient. Categorized agreements were compared and differences among four modalities were calculated. Results: Agreements of PA were better than CBCT when detecting peri-implant bone defects in inter-observer agreements (median kappa 0.471 vs. 0.192; p = 0.016). Moreover, agreements in experienced observers were better than inexperienced observers (median kappa 0.883 vs. 0.567; p

Introduction This meta-analysis of relevant animal studies was conducted to assess whether the use of porous-surface implants improves osseointegration compared to the use of non-porous-surface implants. Material and methods An electronic search of PubMed (MEDLINE) resulted in the selection of ten animal studies (out of 865 publications) for characterization and quality assessment. Risk of bias assessment indicated poor reporting for the majority of studies. The results for bone-implant contact (BIC%) and peri-implant bone formation (BF%) were extracted from the eligible studies and used for the meta-analysis. Data for porous-surface implants were compared to those for non-porous-surface implants, which were considered as the controls. Results The random-effects meta-analysis showed that the use of porous-surface implants did not significantly increase overall BIC% (mean difference or MD: 3.63%; 95% confidence interval or 95% CI: -1.66 to 8.91; p = 0.18), whereas it significantly increased overall BF% (MD: 5.43%; CI: 2.20 to 8.67; p = 0.001), as compared to the controls. Conclusion Porous-surface implants promote osseointegration with increase in BF%. However, their use shows no significant effect on BIC%. Further preclinical and clinical investigations are required to find conclusive evidence on the effect of porous-surface implants.

Background: This finite element analysis (FEA) evaluated stress distribution in implant-supported overdenture (ISO) and peri-implant bone using one extracoronal (ball) and two intracoronal (locator and Zest Anchor Advanced Generation (ZAAG)) attachment systems. Methods: In this in vitro study, the mandible was modelled in the form of an arc-shaped bone block with 33 mm height and 8 mm width. Two titanium implants were modelled at the site of canine teeth, and three attachments (ZAGG, locator, and ball) were placed over them. Next, 100 N load was applied at 90° and 30° angles from the molar site of each quadrant to the implants. The stress distribution pattern in the implants and the surrounding bone was analyzed, and the von Mises stress around the implants and in the crestal bone was calculated. Results: While minimum stress in peri-implant bone following load application at 30° angle was noted in the mesial point of the locator attachment, maximum stress was recorded at the distal point of the ball attachment following load application at 90° angle. Maximum stress around the implant following load application at 90° angle was noted in the lingual point of the ball attachment while minimum stress was recorded in the lingual point of the locator attachment following load application at 90° angle. Conclusions: According to the results, the locator attachment is preferred to the ZAAG attachment, and the ball attachment should be avoided if possible.

This study aimed to investigate the effects of the different dental implant neck designs, diameters, and inclinations, on the stress distributions at the mandibular crestal bone and implant-abutment complex, using three-dimensional (3D) finite element stress analysis (FEA) method. Finite element models of three-unit fixed partial dentures supported with two same length implants (10 mm), placed on the second premolar and second molar regions, were designed. Eight different models were designed according to the implants’ neck designs (platform switching/traditional), diameters (4.1 mm/4.8 mm) and the tilting angles of the posterior implants (0°/15°). The anterior implants’ widths were 4.1 mm and the neck design of the anterior implants matched the posterior implants. Two types of 100-N loads in vertical and 30° oblique directions were applied separately onto each central fossae and functional cusps of the fixed partial dentures crowns. Algor Fempro Software was used for the simulation and evaluation of the stress levels at the implant-abutment complex and the crestal bone. Stress levels measured at the crestal bone were found to be lower for the platform switching models. However, the platform switching design generated higher stress magnitudes within the implant-abutment complex. Inclined placement of posterior implants increased the amount of stress at the crestal bone around both implants. Biomechanically, selection of the largest diameter possible when using tilted platform switched implants may be recommended at the posterior mandible.

Introduction: The implant supported overdentures offered better chewing and masticatory functions. Locator attachment has more advantages than other attachment types. Aim: The aim of the study was to compare radio-graphically the effect of implant locator’s height on peri-implant bone height and density in mandibular over-denture. Patients and method: Twelve completely edentulous male patients had received con­ventional complete maxillary dentures and mandibular overdenture that retained by two implants that were inserted in the canine region by the help of CAD/CAM based surgical guides. The patients were divided randomly into two groups. Group I: the patients were received locator abutment with 1mm in height. Group II: the patients were received locator abutment with 3mm in height, a series of cone beam radiographs were taken at 0, 6, 12 and 18 months starting from the first day of lower over denture installation, peri-implant bone changes regarding height and density were estimated. Results: It was found that the mean marginal bone loss measurements were relatively higher for group I than group II with non-statistical significant difference. The aver­age difference in bone density measurements around the implants for both groups showing initial increase followed by marked decrease through the follow up periods. Conclusion: locator height has an effect on peri-implant bone height, bone density.

Item does not contain fulltext PURPOSE: To evaluate the effect of early bone loss (EBL), on long-term bone stability and future peri-implantitis development. MATERIALS AND METHODS: Patients referred for implant placement between 2005 and 2009 were consecutively treated and followed for 10 years. After 10 years, patients were invited for a scientific diagnostic visit to evaluate implant survival and bone loss. Bone level changes were compared with baseline. Non-parametric testing was performed in cross-tabs (Pearson Chi-square and Fishers's exact test). Kaplan-Meier-estimated survival curves were plotted for different thresholds for EBL at different timepoints. Generalized linear mixed models with binomial distribution and logit link for peri-implantitis were fitted. An adjusted logistic mixed model was made to evaluate peri-implantitis, in relation with smoking status, history of periodontitis, and EBL > 0.5 mm. RESULTS: Four hundred and seven patients (mean age of 64.86 years [range 28-92, SD 10.11]), with 1482 implants, responded to the 10-year recall invitation. After an average follow-up time of 10.66 years (range 10-14, SD 0.87), implant survival was 94.74%. Mean crestal bone loss after 10 years was 0.81 mm (SD 1.58, range 0.00-17.00). One hundred and seventy five implants in 76 patients had peri-implantitis (11.8% on implant level, 18.7% on patient level). EBL of 0.5, 1, and 2 mm were significant predictors for peri-implantitis and implant loss after 10 years. Implants with EBL ≥0.5 mm during the first year of function showed a 5.43 times higher odds for future peri-implantitis development. Probability in developing peri-implantitis was 52.06% when smoking, Periodontal history and EBL of >0.5 mm was combined. CONCLUSION: The present study suggests that EBL is a predictor for long-term peri-implant pathology, with a significant higher risk for peri-implantitis when early bone loss exceeds the thresholds of 0.5 and 1 mm, especially when additional risk factors such as smoking or susceptibility for periodontal disease prior to implant treatment are present. Clinical trial registration number B670201524796.

The treatment modality for completely edentulous arches has shifted from complete dentures to dental implants during the last 15-20 years. Tilting of implants has reduced the concern of resorbed posterior ridges in completely edentulous patients with “All-on-four” and “All-on-six” concept of dental implants. The purpose of this study is to compare the biomechanical behaviour of the “All-on-four”, “All-on-six” models with tilted distal implants at different angulations of 30 and 45 ° with four parallel placed implant-supported fixed prosthesis, and six parallel placed implant-supported fixed prosthesis models as controls using three-dimensional finite element analysis. The results showed that in all the models, in cancellous bone, cortical bone, implant and prosthesis – “All-on-four” model with distal implants tilted at an angulation of 30° showed stress values less than or equivalent to all the other models except on the implant in the presence of cantilever and on prosthesis during full mouth biting load where maximum stresses were observed. The study shows that All-on-four concept with tilted distal implants at an angulation of 30° showed stress values favourable for the rehabilitation of completely edentulous maxilla, but the presence of cantilever remains an area of concern.

Investigate the impact of resveratrol (RESV) on peri-implant repair and its effect on bone-related markers in rats with induced diabetes mellitus (DM).Ninety rats were divided into: DM + RESV (Higher counter-torque values were observed for implant removal in DM + RESV, DM + RESV + INS and Non-DM groups when compared to DM + PLAC (The therapy with RESV may favour peri-implant bone repair improving bone formation around implants.

Implantoplasty has been claimed as a promising strategy to treat peri-implantitis and prevent progressive peri-implant bone loss. Consequently, the aim of the present case series is to exhibit the clinical outcomes of a 3-year-follow-up resective and implantoplasty therapy applying a novel platform-switch concept to preserve peri-implant tissue integrity and counteract progressive bone loss. Four patients who underwent dental implant therapy and were diagnosed with peri-implantitis were treated through access flap surgery, a modified implantoplasty, bone recontouring, and surface decontamination. The radiographic and clinical parameters recorded before and during the 3-year follow-up were: marginal bone loss (MBL) as the primary endpoint, bleeding on probing index (BOP), probing depth (PD), presence of suppuration, pain, mobility, and fracture. The 3-year follow-up exhibited peri-implant bone stability in all cases (100%) showing radiographically an MBL reduction (mean) of 0.8 ± 0.5 mm (mesial) and 0.5 ± 0.3 mm (distal). Mean PD reduction was 4.75 ± 1 mm and mean BOP was reduced by 71%. Pain and suppuration were resolved in all cases. None of the cases reported implant fracture or mobility after the modified implantoplasty therapy. The present case series demonstrated that this modified implantoplasty can be more than a surface decontamination therapy where the narrow and smooth exposed implant surface can counteract peri-implantitis alterations providing favorable biologic conditions to maintain stability of peri-implant tissues.

Background/purpose: The use of osteotomes as a technique for densification and expansion of the residual ridge is one of the most widely used procedures to achieve adequate peri-implant bone quantity and density. The aim of this study was to evaluate the influence of time and the elastic deformation of peri-implant bone in the primary stability of implants placed using osteotomes. Materials and methods: In each of 10 fresh fragments of cow rib, two implants were placed using osteotomes. The insertion torque and initial implant stability quotient (ISQ) values were measured. In the control implants, the immediate removal torque was measured, while in the test implants, after 15 min of placement, ISQ values were measured again, and the removal torque was measured. Results: There were significant differences between the ISQ values and between the insertion torque and removal torque at 15 min. The ISQ values (perpendicular/parallel) increased between the initial moment (64.4 ± 9/70.3 ± 5.9) and 15 min (66/71.4 ± 6.4). The removal torque at 15 min (12.4 ± 5.8) was lower than the insertion torque (15.9 ± 5.9). Compression of the trabeculae in contact with the implant placed using osteotomes was observed, as well as a greater number of trabecular fractures in the implants placed using conventional drilling. Conclusion: There is an increase in ISQ values of dental implants placed using osteotomes after 15 min of placement. Keywords: Implant stability, Osteotomes, Resonance frequency analysis

뼈 재구성은 뼈를 제거하는 파골 세포, 그 후에 뼈를 생성하는 조골 세포, 기계적인 자극을 전달하는 골 세포를 중심으로 진행되며, 뼈 재구성의 과정 전체에 걸쳐서 뼈의 전반적인 밀도가 변하게 된다. 이 파골 세포 및 조골 세포에 의한 뼈 재구성의 미분 방정식을 Komarova가 제안하였다. 이번 연구에서는 제안된 미분 방정식을 활용하여 임플란트의 주변 뼈에 뼈 재구성을 적용하고 이를 통해 얻어진 다양한 조건하에서의 결과를 비교 및 분석한다. ABAQUS UMAT을 활용한 컴퓨터 해석이 임플란트가 심어진 하악골의 대구치 영역의 3D 모델에 적용될 것이다. 얻어진 결과는 임플란트의 구조, 저작력의 크기, 해면골의 밀도 등의 기계적, 생물적인 매개변수가 해면골의 뼈 재구성에 중요한 영향을 끼친다는 것을 보여준다.

Objectives The aim of this study was to assess the influence of transgingival compared with submerged healing on peri-implant bone maintenance around a novel, fully tapered implant in a healed crestal ridge in minipigs. Materials and methods In each of 12 minipigs, two implants (Straumann® BLX, Roxolid® SLActive®, Ø 3.75 × 8 mm) were placed. Implants were either left for submerged or for transgingival healing for 12 weeks. Measurements performed were bone-to-implant contact (BIC), first bone-to-implant contact (fBIC), bone area to total area (BATA), perpendicular bone crest to implant shoulder (pCIS), bone height change from placement, and bone overgrowth (for submerged implants). Results No significant differences were found between transgingival and submerged healing in any of the measured parameters, except for BATA on the buccal aspect in which significantly more bone formation was found for the transgingival healing group. For both groups, there was a gain in crestal bone height during the 12-week healing period. Conclusions Loaded compared with unloaded implants displayed comparable levels of osseointegration and equivalent marginal bone levels. This qualifies the implant placement protocol with respect to the osteotomy dimensions and subcrestal placement protocol for immediate loading. Clinical relevance The here presented results related to osseointegration and crestal bone maintenance after submerged or transgingival healing have demonstrated a high level of consistency in the used in vivo translational model. The obtained results support the translation of the novel implant type in conjunction with the developed surgical workflow and placement protocol into further clinical investigation and use.

Objective: To assess the effect of metal artifact reduction (MAR) algorithm of two cone-beam computed tomography (CBCT) software programs on the accuracy of peri-implant bone width measurements . Material and Methods: This in vitro study evaluated 35 bovine rib bone blocks measuring 8 x 8 x 11 mm. Titanium implants were inserted in bone blocks and placed in a wax model of mandible. CBCT scans were obtained with ProMax 3D and Cranex 3D CBCT systems with and without the MAR algorithm. The width of buccal and lingual bone plates surrounding the implant was measured on CBCT scans by two observers. The Cronbach’s alpha was calculated to assess inter-observer agreement. The area under the curve (AUC), sensitivity and specificity values were calculated and compared. Results: The two observers had an excellent agreement. The accuracy of Cranex 3D was higher than that of ProMax 3D (p

OBJECTIVE The aim was to assess the degree of radiographic peri-implant bone loss over a follow-up period up to 15 years. In addition, another aim was to identify risk indicators for peri-implant bone loss and for moderate-severe peri-implantitis at patient- and implant level. MATERIALS AND METHODS This is a cross-sectional clinical and radiological study of 147 patients with a total of 425 implants in combination with data collected retrospectively for baseline variables. To calculate the peri-implant bone loss (primary outcome variable), the radiographic bone level measurements from baseline were compared to the radiographic bone level measurements at the final radiographic measurement. Multilevel analyses were adopted with peri-implant bone loss and peri-implantitis as outcome variables. RESULTS The mean follow-up time was 12.5 years (range 10-15) and the mean age of the patients was 63 years (range 29-83). The mean peri-implant bone loss was 0.94 mm (S.D. 1.3). The prevalence of moderate-severe peri-implantitis at patient level was 17% and 8.9% at implant level. The peri-implant bone loss was significantly more pronounced in healthy implants if moderate-severe peri-implantitis was present in at least one implant within the same patient. The presence of moderate-severe peri-implantitis was significantly associated with general periodontitis Stages III or IV at follow-up and smoking. CONCLUSION The presence of moderate-severe peri-implantitis at patient level was found to be a risk indicator of peri-implant bone loss in healthy implants, while smoking and general periodontitis Stages III and IV were risk indicators of moderate-severe peri-implantitis.

The main biological and biophysical process that has made dental implant therapy predictably successful for replacing missing teeth is Osseointegration. Teeth extraction is done for several purposes, often without any consideration for the preservation of the alveolar ridge. Alveolar bone post-extraction changes have been estimated to cause a 50% decrease in alveolar bone buccolingual width, and a further loss in height. This review will go through various techniques of ARP and bone regeneration techniques and explore the best way to obtain the best outcomes after implant placement.

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.

PURPOSE To analyze peri-implant bone loss around six different types of implant-prosthetic connections over a 2-year follow-up period. MATERIALS AND METHODS A total of 120 implants were divided into six groups (n = 20), three with crestally and three with supracrestally placed implants, with different internal connections, placed in posterior sectors (molar and premolar), and bearing one-piece CAD/CAM restorations screwed directly to each implant's prosthetic platform. Bone height was measured from parallelized periapical radiographs taken at the moment of loading and 2 years later. RESULTS The patient sample included 61 subjects, 36 men and 25 women. Significant differences were found in bone loss between groups, the implant with internal hex and convergent transmucosal collar showing the least bone loss (P < .001) in comparison with the other designs. Supracrestally placed implants underwent less bone loss than crestally placed implants (P = .025). CONCLUSION Peri-implant bone loss is influenced by the level of implant placement in relation to the bone crest (crestal or supracrestal) and by the morphology of the prosthetic platform.

The purpose of this study was to assess the accuracy of high-frequency ultrasound (US) in the measurement of peri-implant bone defects in comparison with cone-beam computed tomography (CBCT) and micro-computed tomography (µCT). Bone defects were mechanically created around dental implants inserted into porcine ribs (n = 10). The bone samples were scanned by CBCT, µCT and US. Linear dimensions of the peri-implant defects were determined for supra-alveolar component, intra-bony component and width. The accuracy of measurements was evaluated with repeated-measures analysis of variance and the intra-class correlation coefficient at p ≤ 0.05. US underestimated the measurements for the supra-alveolar and intra-bony components in comparison to CBCT and µCT, and there were no statistically significant differences in the measurements of width. The intra-class correlation coefficient of US ranged from 0.96 to 0.98, whereas that for CBCT ranged from 0.77 to 0.97. US was accurate in measuring the width of peri-implant defects, although vertical measurements were underestimated by approximately 1 mm in comparison to those of CBCT and µCT.

The mechanism of the mineralization process induced by natural mineralized collagen (MC) has been investigated for decades. The purpose of this study was to investigate the efficacy of self-assembled MC for peri-implant bone defect reconstruction in a mini pig. A standardized peri-implant bone defect model was created using 14 mini pig mandibles. Two materials were evaluated, i.e. a mixture of hydroxyapatite and collagen (Type A, TA), and self-assembled MC (Type B, TB). Bio-Oss (BO) and untreated (blank control, BC) groups were used as controls. After 3- and 6-month healing periods, the mini pigs were sacrificed for histomorphometric and microcomputed tomography analysis. After 3 months of healing, the average alveolar ridge height was 3.27 ± 1.57 mm for group TA, 3.28 ± 2.02 mm for group TB and 3.37 ± 1.09 mm for group BO, while group BC showed the lowest height of 2.68 ± 0.47 mm. After 6 months of healing, the average alveolar ridge height was 2.64 ± 1.13 mm for group TA, 4.31 ± 1.80 mm for group TB and 3.87 ± 1.38 mm for group BO, while group BC showed the lowest height of 2.48 ± 1.80 mm. The experimental groups and control group showed similar bone volume density, bone complexity and histological reaction. The self-assembled MC (Type B) stimulated new bone formation in the reconstruction of deficient alveolar ridges around the dental implant; it also displayed excellent clinical operability compared with bone grafts without collagen.

Aim The purpose of this research is to compare peri-implant bone level in immediate and conventionally loaded implants using flap and flapless techniques. Materials and methods Forty patients were selected and were subjected into four groups. Group A: 10 patients with immediate loading (IL) by raising the flap. Group B: 10 patients with IL without raising the flap. Group C: 10 patients with conventional loading by raising the flap. Group D: 10 patients with conventional loading without raising the flap. Results It was observed that for most of the flapless techniques with IL cases, the bone loss settled at first thread or just below the implant collar after 6 months. Conclusion It was seen that the crestal bone height was reduced in both flap and flapless techniques by immediate and conventional loading, respectively. On comparing the bone loss, the flapless approach by IL showed statistically significant lesser reduction as determined by radiovisiography. Clinical significance Postoperative pain was less in the flapless technique as compared to the traditional flap technique. IL minimizes invasiveness, complexity, and also improves acceptance by patients.

Background This retrospective study investigates the change in the peri-implant bone level (PBL) during the 2nd decade of intraoral function in patients complying with a ‘supportive implant therapy’ (SIT) program. The results were statistically analyzed with respect to the implant abutment connection used. Methods In a private practice, only patients with 20-year SIT compliance were identified. Of these, all patients with 10- and 20-year radiographs available were selected. Therefore, no control group was possible and implant losses had to be excluded. Two experienced researchers assessed the peri-implant bone levels. As three different abutment connection concepts (bone-level butt-joint, bone-level conical and tissue-level conical) and two different implant surfaces (machined vs. roughened) were involved, statistical analyses were performed to detect potential differences. Results Ninety-three implants from 36 patients with 20-year SIT compliance and available radiographs were included in the study. At study baseline (10 years intraoral), a mean bone loss of − 1.7 mm (median − 1.2; standard deviation [sd] 1.4, range: 0 to − 7.2) was recorded. After 20 years, we found a mean bone loss of − 2.5 mm (median − 2.3, sd 1.79, range: − 0.5 to + 7.4). Furthermore, we found a mean bone loss of 0.8 mm in intraoral function from year 10 to year 20 (mean: 0.08 mm per year); this change was independent of the abutment connection type. Conclusions During the 2nd decade of function, peri-implant bone loss in patients with SIT compliance might be small in value and should not be expected in all implants.

Objective: The aim of this study was to assess, through biological analysis, the local effects and osseointegration of dental implants incorporating surface micro/nanofeatures compared to implants of identical design without surface treatment. Background: Known to impact bone cell behavior, surface chemical and topography modifications target improved osseointegration and long-term success of dental implants. Very few studies assess the performance of implants presenting both micro-and nanofeatures in vivo on the animal models used in preclinical studies for medical device certification. Methods: Implant surfaces were characterized in terms of topography and surface chemical composition. After 4 weeks and 13 weeks of implantation in sheep femoral condyles, forty implants were evaluated through micro-computed tomography, histopathologic, and histomorphometric analyses. Results: No local adverse effects were observed around implants. Histomorphometric analyses showed significantly higher bone-to-implant contact in the coronal region of the surface treated implant at week 4 and week 13, respectively 79.3$\pm$11.2% and 86.4$\pm$6.7%, compared to the untreated implant's 68.3$\pm$8.8% and 74.8$\pm$13%. Micro-computed tomography analyses revealed that healing patterns differed between coronal and apical regions, with higher coronal boneto-implant contact at week 13. Histopathologic results showed, at week 13, bone healing around the surface treated implant with undistinguishable defect margins while the untreated implant still presented bone condensation and traces of the initial drill defect. Conclusion: Our results suggest that the surface treated implant not only shows no deleterious effects on local tissues but also promotes faster bone healing around the implant. (word count: 241, Journal of Periodontal Research, Wiley, 2021

Objective: The aim of the present study was to evaluate radiographically the remodeling of the peri-implant bone crest in prosthetic friction morse cone implants, with platform switching, after 12 months of application of prosthetic load. Materials and Methods: 16 implants were installed, in 10 patients, rehabilitated with partial, single and multiple metal-ceramic prostheses, submitted to prosthetic function in the period of 12 months. Periapical radiographs to measure the distance between the mesial and distal marginal bone crest and the platform of each implant, were performed at the time of installing the prostheses and 12 months later. The images obtained at different intervals were digitized and analyzed using Image J software TD. Results: At the time of installing the prostheses, the averages of measurements on the distal and mesial surfaces were 0.57 mm (standard deviation 0.45) and 0.55 mm (standard deviation 0.41) respectively. After 12 months in function, the averages obtained were 0.59 mm (standard deviation 0.48) on the distal surface and 0.57 mm on the mesial surface, (standard deviation 0.34). Conclusion: In this radiographic evaluation, it was possible to observe that the implants with prosthetic connection of the frictional Cone Morse type with platform switching presented an average of 0.2mm of cervical bone remodeling, after 12 months in function, seeming to be a good alternative for periodic bone maintenance deploy. Objetivo: Evaluar radiográficamente la remodelación de la cresta ósea periimplantaria en implantes con conexiones protésicas de fricción cono Morse, después de recibir la carga protésica, inmediatamente después de la instalación de la prótesis y después de 12 meses de carga funcional. Materiales y métodos: se instalaron 16 implantes en 10 pacientes y se rehabilitaron con prótesis metalocerámicas parciales, unitarias o múltiples; sometido a la función masticatoria durante el período de 12 meses. Se realizaron radiografías periapicales para determinar la posición de la cresta ósea marginal mesial y distal en relación a la plataforma de cada implante, en el momento de la instalación de las prótesis y 12 meses después. Las imágenes obtenidas a diferentes intervalos fueron digitalizadas y analizadas mediante el software Image JTD. Resultados: En el momento de la instalación de las prótesis, los promedios de las medidas en las superficies distal y mesial fueron de 0,57 mm (desviación estándar 0,45) y 0, 55 mm (desviación estándar 0,41), respectivamente. Después de 12 meses en función, los promedios obtenidos fueron de 0,59 mm (desviación estándar 0,48) en la superficie distal y 0,57 mm en la mesial (desviación estándar 0,34). Conclusión: A través de la evaluación radiográfica se pudo observar que los implantes con plataforma switching ción y conexión protésica con cono morse de fricción mostraron un promedio de 0.2 mm de remodelado óseo cervical, luego de 12 meses en función, y pueden ser una buena alternativa para mantenimiento de los niveles óseos. Objetivo: Avaliar radiograficamente a remodelação da crista óssea peri-implantar em implantes com conexões protéticas do tipo cone morse fricicional, com plataforma switching, após 12 meses de carga protética. Materiais e Métodos: foram instalados 16 implantes, em 10 pacientes e reabilitados com próteses metalocerâmicas parciais, unitárias ou múltiplas; submetidos à função mastigatória durante o período de 12 meses. Radiografias periapicais para determinação da posição da crista óssea marginal mesial e distal em relação a plataforma de cada implante, foram realizadas no momento da instalação das próteses e 12 meses após. As imagens obtidas em diferentes intervalos foram digitalizadas e analisadas no software Image J TD. Resultados: No momento da instalação das próteses, as médias das medidas nas faces distal e mesial foram 0,57 mm (desvio padrão 0,45) e 0,55 mm (desvio padrão 0,41), respectivamente. Após 12 meses em função, as médias obtidas foram 0,59 mm (desvio padrão 0,48) na face distal e 0,57 mm na mesial (desvio padrão 0,34). Conclusão: Por meio da avaliação radiográfica, foi possível observar que os implantes com plataforma switching e conexão protética cone morse friccional apresentaram em média 0,2mm de remodelação óssea cervical, após 12 meses em função, podendo ser uma boa alternativa para manutenção dos níveis ósseos.

Objectives The aims of this study were (i) to compare the osteogenic impact of low-intensity pulsed ultrasound (LIPUS) and low-magnitude high-frequency (LMHF) loading achieved with whole-body vibration (WBV) on peri-implant bone healing and implant osseointegration in rat tibiae, and (ii) to examine their combined effect on these processes. Material and methods Titanium implants were inserted in the bilateral tibiae of 28 Wistar rats. Rats were randomly divided into four groups: LIPUS + WBV, LIPUS, WBV, and control. LIPUS was applied to the implant placement site for 20 min/day on 5 days/week (1.5 MHz and 30 mW/cm2 ). WBV was applied for 15 min/day on 5 days/week (50 Hz and 0.5 g). In the LIPUS + WBV group, both stimuli were applied under the same stimulation conditions as in the LIPUS and WBV groups. After 4 weeks of treatment, peri-implant bone healing and implant osseointegration were assessed using removal torque (RT) tests, micro-CT analyses of relative gray (RG) value, and histomorphometrical analyses of bone-to-implant contact (BIC) and peri-implant bone formation (BV/TV). Results The LIPUS + WBV group had significantly greater BIC than the WBV and control groups. Although there were no significant intergroup differences in RT, RG value, and BV/TV, these variables tended to be greater in the LIPUS + WBV group than the other groups. Conclusions The combination of LIPUS and LMHF loading may promote osteogenic activity around the implant. However, further study of the stimulation conditions of LIPUS and LMHF loading is necessary to better understand the osteogenic effects and the relationship between the two stimuli.

Dental implants report high survival rate for the treatment of patients with missing teeth and being one of the undeniable restoration techniques. However, peri-implant bone loss has recently arisen to be the highlight in contemporary implant therapy. Therefore, the possible causes that are detrimental to dental implants and surrounding tissues are important to be discovered. The present review focuses on the current etiologies of peri-implant bone loss and subsequent complications observed in clinical practices. A comprehensive literature search was conducted via PubMed, Scopus, and ScienceDirect databases using the related keywords. The literature reveals numerous etiological factors may initiate the loss of marginal bone in dental implant application: loading protocols, implant body placement, implant macro-design features, implant surface roughness, implantation site preparation, foreign body reaction, implant material particles detachment and contamination, and oral habit. Albeit the biomechanical, biological, or combination of factors are known to contribute in marginal bone resorption, the predictability of treatment modalities to handle the defect remains controversial and unclear. Further clinical trials and sophisticated quantitative assessment would be advantageous to help scrutinize the issue.

Purpose To evaluate and compare the effects of two restorative materials with different stiffness on peri-implant bone microstrain and implant micromovements during occlusal loading in implant-supported single and adjacent splinted crowns. Materials and methods Two 3 × 10-mm implants were inserted into the tibia of four rabbits. During the osseointegration process, prosthetic restorations were performed. Before suturing the flap, each implant's position and direction were obtained by fastening two splinted transfer abutments, onto which implant analogs were placed and fastened; the splinted transfer abutments were subsequently unfastened. Splinted transfer abutment/analog complexes were cast using type IV plaster to obtain eight different working models. Two single mandibular premolar crowns of monolithic zirconia and acrylate polymer composite were generated using CAD/CAM technology, and 16 adjacent splinted crowns (eight of each material) with the same design were also generated. After 6 weeks of implant osseointegration, the animals were sacrificed. Tibial sections with the implants were extracted, and prosthetic restorations (performed during implant osseointegration) were fastened to the implants. Static loading tests were performed with 100-N force application and an inclination of 6 degrees over the central fossa of the premolars. Implant micromovement was measured using an image analysis technique. Bone microstrain was quantified using two strain gauges placed on the crestal bone around the implants. Data were analyzed using two-way analysis of variance. Results The mean implant micromovement values were lower for monolithic zirconia single and splinted crowns (61.5 ± 26.3 μm and 57.7 ± 8.8 μm, respectively) than for acrylate polymer composite-based single and splinted crowns (78.9 ± 37.3 μm and 59.61 ± 11.5 μm, respectively). No significant differences between the materials were noted. Bone microstrain around the implants was lower for splinted crowns (303.7 ± 281.3 μe for acrylate polymer composite; 312.4 ± 226.8 μe for monolithic zirconia) than for single crowns (539.7 ± 8.8 μe for acrylate polymer composite; 574.6 ± 271.9 μe for monolithic zirconia). Conclusion Using restorative materials of different stiffness did not significantly affect the micromovement of already-osseointegrated implants supporting single or splinted crowns. Independent of material stiffness, single crowns transfer significantly more microstrain than splinted crowns.

Objective: To evaluate the influence of implant length on marginal bone loss, comparing implants of 4 mm, 6 mm, and &gt, 8 mm, supporting two splinted crowns after 36-month functional loading. Materials and Methods: this retrospective clinical trial evaluated the peri-implant behavior of splinted crowns (two per case) on pairs of implants of the same length placed in the posterior maxilla (molar area). Implants were divided into three groups according to length (Group 1: extra-short 4 mm, Group 2: short 6 mm, Group 3: conventional length &gt, 8 mm). Marginal bone loss was analyzed using standardized periapical radiographs at the time of loading and 36 months later. Results: 24 patients (19 women and 5 men) were divided into three groups, eight rehabilitations per group, in the position of the maxillary first and second molars. The 48 Straumann&reg, Standard Plus (Regular Neck (RN)/Wide Neck (WN)) implants were examined after 36 months of functional loading. Statistical analysis found no significant differences in bone loss between the three groups (p = 0.421). No implant suffered biological complications or implant loss. Long implants were associated with less radiographic bone loss. Conclusions: extra-short (4 mm), short (6 mm), and conventional length (&gt, 8 mm) implants in the posterior maxilla present similar peri-implant bone loss and 100% survival rates in rehabilitation, by means of two splinted crowns after 36 months of functional loading. Implants placed in posterior positions present better bone loss results than implants placed in anterior positions, regardless of the interproximal area where bone loss is measured. Conventional length (&gt, 8 mm) implants show better behavior in terms of distal bone loss than short (6 mm) and extra-short (4 mm) implants.

The development of effective methods to promote the osseointegration of dental implants by surface modification is an area of intense research in dental materials science. Exogenous metal ions present in the implant and surface modifications are closely related to the bone metabolism around the implant. In the complex oral microenvironment, the release of metal ions caused by continuous corrosion of dental implants has an unfavorable impact on the surrounding tissue, and then affects osseointegration, leading to bad results such as loosening and falling off in the late stage of the implant. Besides, these ions can even be distributed in distant tissues and organs. Currently, surface modification techniques are being developed that involve different processing technologies including the introduction of exogenous metal ions with different properties onto the surface of implants to improve performance. However, most metal elements have some level of biological toxicity and can only be used within a safe concentration range to exert the optimum biological effects on recipients. In this paper, we review the adverse effects of metal ions on osseointegration and highlight the emerging applications for metal elements in improving the performance of dental implants.

Background Clinical data on the restorative designs affecting the early progression of peri-implantitis are scarce. The aim of this retrospective study was to evaluate the influence of several restorative factors (e.g., restoration emergence angle, and internal screw length/diameter) on the marginal bone loss around implants with peri-implantitis. Methods Implants diagnosed with peri-implantitis having 1- (T1) and 2-year (T2) follow-ups were included. In addition, within 6 months pre-diagnosis (Tb), all cases required to have full documentation in which no evidence of peri-implantitis was not indicated. Changes in marginal bone levels (MBLs) from Tb to T1 and from T1 to T2 were evaluated. The effect of several variables on MBLs changes was assessed via univariate and multivariate generalized estimating equations. Results Eighty-three bone-level implants from 65 patients were selected. The mean follow-up before peri-implantitis diagnosis was 99.47 ± 47.93 months. The radiographic mean marginal bone loss was 1.52 ± 1.33 mm (Tb to T1) and 0.58 ± 0.52 mm (T1 to T2). Restoration emergence angle and frequency of maintenance visits significantly affected MBLs from Tb to T1. Besides, 66.3% of the included implants' bone levels were in a zone within 1 mm of the apical end of the internal screw at T1 and remained in this zone during the second follow-up year. Conclusions Significant marginal bone loss occurred in the early post-diagnosis period of peri-implantitis, which could be affected by the restoration emergence angle. Peri-implant MBLs were frequently located in a zone within 1 mm of the apical end of the internal screw.

Background Inactive human cathelicidin antimicrobial peptide is present in neutrophils, and proteinase 3 activates this peptide by producing active LL-37 peptide. LL-37 acts as a defensive peptide in the oral tissues. in the present study, the aim was to evaluate LL-37 and proteinase 3 levels in peri-implant sulcus fluid (PISF) in implants with and without peri-implantitis. Methods Patients who simultaneously had dental implants with peri-implantitis and without peri-implantitis were included in the study. Forty-four samples with peri-implantitis and 34 samples without peri-implantitis from 16 patients were obtained. Intraoral evaluations such as pocket depth, modified sulcus bleeding index, and modified plaque index were noted. Enzyme-linked immunosorbent assay was used for the evaluation of PISF LL-37 and proteinase 3 levels. Results PISF volume was significantly increased in the implants with peri-implantitis than those without peri-implantitis (p< 0.05). No difference was present between PISF LL-37 and proteinase 3 total amounts between the implants with and without peri-implantitis (p> 0.05). Pocket depths and PISF LL-37 and proteinase 3 levels were not correlated in the groups (p> 0.05). Conclusions PISF volume might be increased in response to peri-implant bone destruction. However, peri-implant tissue destruction caused by peri-implantitis does not seem to affect PISF LL-37 and proteinase 3 levels., Ege University Research FoundationEge University [2017-DIS-010], This study was supported by Ege University Research Foundation (2017-DIS-010).

Background: The aim of the present review was to assess the histological and histomorphometrical data from the paper published by our Laboratory on peri-implant bone in dental implants in different loading conditions. Methods: The papers published in different implant loading conditions, in dental implants retrieved from humans, and in the Hard Tissues Research Center of the University of Chieti-Pescara, Italy, were screened on MEDLINE/PubMed, Embase, Scopus, and other electronic databases until 31 December 2018. Only articles that reported the histological and histomorphometrical values of the Bone-Implant Contact (BIC) were selected. Results: The system selection provided a total of 155 papers. The manuscripts included for the narrative review were 57. These papers provided histological and histomorphometrical data. Conclusions: The bone remodeling around dental implants was found to be a dynamic process; loading changed the microstructure of the peri-implant bone; and implants were found to provide a successful function, over several decades, with different range of degrees of BIC in vivo (varying from a little more than 30% to a little more than 90%). Loaded implants presented a 10%−12% higher BIC values when compared to submerged, unloaded implants, and rougher surfaces had, on average, about a 10% higher BIC than machined surfaces.

We evaluated the response to peri-implant bone placed in the femoral condyle of osteoporotic rats, following intravenous zoledronate (ZOL) treatment in three settings: pre-implantation (ZOL-Pre), post-implantation (ZOL-Post), and pre- + post-implantation (ZOL-Pre+Post). Twenty-four female Wistar rats were ovariectomized (OVX). After 12 weeks, the rats received titanium implants in the right femoral condyle. ZOL (0.04 mg/kg, weekly) was administered to six rats 4 weeks pre-implantation and was stopped at implant placement. To another six rats, ZOL was given post-implantation and continued for 6 weeks. Additional six rats received ZOL treatment pre- and post-implantation. Control animals received weekly saline intravenous injections. At 6 weeks post-implantation, samples were retrieved for histological evaluation of the percentage of bone area (%BA) and of the percentage of bone-to-implant contact (%BIC). BA% for ZOL-Pre (29.6% &plusmn, 9.0%) and ZOL-Post (27.9% &plusmn, 5.6%) rats were significantly increased compared to that of the controls (17.3% &plusmn, 3.9%, p &lt, 0.05). In contrast, ZOL-Pre+Post rats (20.4% &plusmn, 5.0%) showed similar BA% compared to Saline controls (p = 0.731). BIC% revealed a significant increase for ZOL-Post (65.8% &plusmn, 16.9%) and ZOL-Pre+Post (68.3% &plusmn, 10.0%) rats compared with that of Saline controls (43.3% &plusmn, 9.6%, p &lt, 0.05), while ZOL-Pre rats (55.6% &plusmn, 19%) showed a BIC% comparable to that of Saline controls (p = 0.408). Our results suggest that receiving intravenous ZOL treatment before or after implant placement enhances peri-implant bone responses in terms of bone area. However, the effect of different ZOL treatment regimens on BIC% was found to be inconclusive.

OBJECTIVES To evaluate the impact on peri-implant bone support (as assessed on periapical radiographs) of the remodeling dynamics of varying graft biomaterials used for transcrestal sinus floor elevation (tSFE). METHODS The study is a multicenter, retrospective series of cases undergone tSFE (performed according to the Smart Lift technique) and concomitant implant placement. At operator's discretion, tSFE was performed with bone core (BC) alone or supplemented by deproteinized bovine or porcine bone mineral (DBBM and DPBM, respectively), synthetic hydroxyapatite in a collagen matrix (S-HA), or s-tricalcium phosphate (s-TCP). Immediately after surgery, at 6-12 months post-surgery, and at later (≥24 months) follow-up intervals, the percentage proportion of the implant surface in direct contact with the radiopaque area was calculated for the entire implant surface (totCON%). Also, the height of the graft apical to the implant apex (aGH) was assessed. RESULTS At 6-12 months following tSFE, median totCON% was 100%, with a median aGH of 1.4 mm. A tendency of aGH to decrease in height was observed at later follow-up intervals for sites treated with all grafting procedures. In all treatment groups, the majority of the implant surface was still surrounded by the radiopaque area at the longest follow-up visits. CONCLUSIONS Although the height of the peri-implant radiopaque area apical to the implant apex tends to reduce overtime at sites which have received tSFE, the peri-implant bone support seems to be maintained long term irrespective of the graft material used.

Low-magnitude, high-frequency (LMHF) loading plays an important role in bone healing. The present study aimed to evaluate the effect of LMHF loading applied directly to titanium dental implants on peri-implant bone healing and implant osseointegration.The mandibular premolars and molars were extracted from six male Beagle dogs. Three months post-extraction, each of the six dogs had three titanium implants (Aadva Standard Implant Narrow, Φ3.3×8mm) inserted into the mandibular premolar and molar area (three implants per side). In each animal, one side was randomly selected to undergo daily LMHF loading (treatment group), while the other side had no further intervention (control). The loading was applied directly to the implant abutment using an individual jig and a custom-made loading device (8μm, 100Hz). The implant stability quotient (ISQ) was tested every week. Three dogs were euthanized after 2 weeks, and three were euthanized after 8 weeks. Tissue samples were fixed and stained for micro-computed tomography (micro-CT) and histomorphometric analyses. Data were analyzed statistically, with significance set at p0.05.The treatment group had significantly increased peri-implant bone volume relative to tissue volume in region of interest 2 (100-500μm) compared with the control group after 2 weeks of loading (p0.05); however, there was no significant difference between groups after 8 weeks. The ISQ value and the micro-CT results did not differ between groups during the study period.LMHF loading positively influenced peri-implant bone healing in the early healing period.

The purpose of the present study was to evaluate the distribution and magnitude of stresses through the bone tissue surrounding Morse taper dental implants at different positioning relative to the bone crest.A mandibular bone model was obtained from a computed tomography scan. A three-dimensional (3D) model of Morse taper implant-abutment systems placed at the bone crest (equicrestal) and 2 mm bellow the bone crest (subcrestal) were assessed by finite element analysis (FEA). FEA was carried out on axial and oblique (45°) loading at 150 N relatively to the central axis of the implant. The von Mises stresses were analysed considering magnitude and volume of affected peri-implant bone.On vertical loading, maximum von Mises stresses were recorded at 6-7 MPa for trabecular bone while values ranging from 73 up to 118 MPa were recorded for cortical bone. On oblique loading at the equiquestral or subcrestal positioning, the maximum von Mises stresses ranged from 15 to 21 MPa for trabecular bone while values at 150 MPa were recorded for the cortical bone. On vertical loading,99.9vol.% cortical bone volume was subjected to a maximum of 2 MPa while von Mises stress values at 15 MPa were recorded for trabecular bone. On oblique loading,99.9vol.% trabecular bone volume was subjected to maximum stress values at 5 MPa, while von Mises stress values at 35 MPa were recorded for99.4vol.% cortical bone.Bone volume-based stress analysis revealed that most of the bone volume (99% by vol) was subjected to significantly lower stress values around Morse taper implants placed at equicrestal or subcrestal positioning. Such analysis is commentary to the ordinary biomechanical assessment of dental implants concerning the stress distribution through peri-implant sites.

The aim was to study the nature of the morphological changes over time in the bone tissue around the implants under the influence of low-intensity pulsed ultrasound in the experiment. Materials and methods. Experimental studies were carried out on rabbits of the chinchilla breed, with dental implants installed in the tibia – two experimental groups with ultrasound and one control group. The animals were withdrawn from the experiment at 1, 2, 4 and 8 weeks and histological examination of the sections of peri-implant tissues was carried out. Results. The processes of osseointegration of dental implants in all groups of animals occurred without disrupting the normal process sequence. In the early stages granulation tissue is formed, later it is replaced by fibrous-reticular and coarse-fibrous bone tissue, and at the end – by a more mature lamellar bone tissue. However, the timing and degree of maturation of bone tissue, as well as osseointegration of implants in groups using low-frequency low-intensity pulsed ultrasound and without it differed significantly. The study showed that ultrasound exposure to implants and surrounding tissues induces osteoreparation processes, stimulating neoangiogenesis in granulation and newly formed bone tissue. Conclusion. Application of ultrasound to implants and subsequent application to the peri-implant tissues during and after dental implantation promotes the formation of bone tissue, identical by the histostructure to the maternal bone.

Purpose The esthetic outcome of dental implants can be compromised when some degree of bone loss occurs around the implant. This may particularly affect the tissue-level (TL) design. Therefore, bone-level (BL) design implants may be preferable if a natural emergence profile is important. Notwithstanding the implant design, the gingival biotype has been identified as a crucial factor in the stability of crestal bone. The objective of this study was to investigate bone loss in patients with different gingival biotypes at TL and BL implant sites in the esthetic zone. Materials and methods In 41 patients, 20 TL and 22 BL implant procedures were carried out. Intraoral radiographs of all of the 42 sites were taken immediately after implant insertion as well as during the follow-up examination. The analysis of bone height was conducted using a computerized technique. The TRAN method was used to determine the gingival biotype. Results After a mean in situ period of 4.9 years in the TL group, 12 implants with a thick biotype had a mean bone loss of 0.21 mm (SD: 0.43 mm). The eight implants with a thin biotype had a loss of 0.05 mm (SD: 0.47 mm; P = .31). After a mean in situ period of 1.9 years, the 14 BL sites with a thick biotype showed a mean bone change of -0.03 mm (SD: 0.38 mm). In the eight implants with a thin biotype, a change of +0.09 mm (SD: 0.32 mm; P = .84) was noted. Conclusion Analysis of the obtained results did not reveal a dependency of bone height on implant design or on gingival biotype. However, prior to choosing an implant design, it may nevertheless be beneficial to screen for transparent soft tissues, where the BL design offers a more natural emergence profile. For this purpose, the TRAN method is clearly the fastest and easiest.

OBJECTIVES To evaluate the diagnostic value of cone-beam computed tomography (CBCT), intraoral radiography (IR), and dental magnetic resonance imaging (dMRI) for detecting and classifying peri-implant bone defects at zirconia implants. MATERIALS AND METHODS Forty-eight zirconia implants were inserted in bovine ribs, 24 of which had standardized defects (1-wall, 2-wall, 3-wall, 4-wall) in two sizes (1 and 3 mm). CBCT, IR, and dMRI were performed and analyzed twice by four readers unaware of the nature of the defects. Cohen's and Fleiss' kappa (κ), sensitivity, and specificity were calculated for the presence/absence of bone defects, defect size, and defect type. Cochran's Q-test with post hoc McNemar was used to test for statistical differences. RESULTS A high intra- and inter-reader reliability (κ range: 0.832-1) and sensitivity/specificity (IR: 0.97/0.96; CBCT: 0.99/1; dMRI: 1/0.99) for bone defect detection were observed for all three imaging methods. For defect type classification, intra- (κ range: 0.505-0.778) and inter-reader (κ: 0.411) reliability of IR were lower compared to CBCT (κ range intrareader: 0.667-0.889; κ inter-reader: 0.629) and dMRI (κ range intrareader: 0.61-0.832; κ inter-reader: 0.712). The sensitivity for correct defect type classification was not significantly different for CBCT (0.81) and dMRI (0.83; p = 1), but was significantly lower for IR (0.68; vs. CBCT p = 0.003; vs. dMRI p = 0.004). The sensitivity advantage of CBCT and dMRI for defect classification was smaller for 1-mm defects (CBCT/dMRI/IR: 0.68/0.72/0.63, no significant difference) than for 3-mm defects (CBCT/dMRI/IR: 0.95/0.94/0.74; CBCT vs. IR p = 0.0001; dMRI vs. IR p = 0.003). CONCLUSION Within the limitations of an in vitro study, IR can be recommended as the initial imaging method for evaluating peri-implant bone defects at zirconia implants. CBCT provides higher diagnostic accuracy of defect classification at the expense of higher cost and radiation dose. Dental MRI may be a promising imaging method for evaluating peri-implant bone defects at zirconia implants in the future.

OBJECTIVES To investigate the diagnostic accuracy of cone beam computed tomography (CBCT) for the diagnosis of peri-implant bone defects of titanium (Ti), zirconium dioxide (ZrO2 ) or titanium-zirconium (Ti-Zr) alloy implants. MATERIALS AND METHODS Ti, Ti-Zr or ZrO2 implants with two diameters (3.3 mm, 4.1 mm) and one length (10 mm) were inserted in the angle of the mandible of six fresh defrosted pig jaws. Out of the 12 implants inserted, 6 served in the test group with standardized buccal peri-implant bone defects, whereas 6 served as control without bone defects. CBCTs were performed with three acquisition protocols (standard, high and low dose) using two devices. Four observers analysed CBCTs as follows: (a) presence of a peri-implant defect; (b) presence of peri-implant artefacts and impact on defect diagnosis; and (c) linear measurements of buccal peri-implant defect including height and width (in mm). RESULTS CBCT device, CBCT settings, implant material, implant diameter and observer background did not significantly influence diagnostic accuracy. The sensitivity and specificity values were high for defect detection. ZrO2 led to a lower than average diagnostic accuracy (0.781). The linear measurements of peri-implant defect were underestimated by

Alveolar ridge remodeling post-extraction is a well-documented process. Alveolar bone is in a continuous state of remodeling even after implant placement, and this leads to changes in the contour of the peri-implant tissues over the years. A vast number of procedures have been described in literature to address and correct this resorption including procedures like socket grafting, dual zone grafting, socket shield (partial extraction therapy) and many more. Socket shield (partial extraction therapy) is a relatively new procedure described in the literature. This technique aims to try and slow down this remodeling and maintain the peri-implant tissues in a state near normalcy. The aim of this article is to assess a case where the possible cause of buccal bone loss around an integrated implant was an inappropriately prepared socket shield. It is recommended that an evidence-based consensus be put forth on both case selection and execution to minimize inappropriate execution of this technique by the average clinician.