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Objective: Two focused questions were addressed: Focused question (Q1) 1) Are there any differences between immediate and delayed placement in terms of (i) survival rate, (ii) success rate, (iii) radiographic marginal bone levels, (iv) height/(v)thickness of buccal wall, (vi) peri‐implant mucosal margin position, (vii) aesthetics outcomes and (viii) patient reported outcomes? Focused question 2 (Q2) What is the estimated effect size of immediate implant placement for all parameters included in Q1? Materials and methods: An electronic search (MEDLINE, EMBASE, The Cochrane Central Register of Controlled Trials and OpenGray) and hand search were conducted up to November 2019. Randomised controlled trials (RCT) with delayed implant placement as controls were eligible in the analysis for Q1. Immediate dental implant arms RCTs, controlled clinical trials (CCTs) and prospective case series of immediate implant placement were eligible in the analysis for Q2. Results: Six papers (RCTs) were included in the analysis for Q1 and 53 papers (22 RCTs, 11 CCTs and 20 case series) for Q2. Q1: Meta‐analyses did not show any significant difference in implant survival, but it did for bone levels and PES scores at 1 year post‐loading, favouring the immediate group. Q2: Meta‐analyses showed that immediate implants had a high survival rate (97%) and presented high PES scores (range 10.36 to 11.25). Information regarding marginal bone loss and gingival/papillary recession varied among all included studies. Conclusion: Similar survival rate was found between immediate and delayed implants. Immediate implants presented threefold early complications and twofold delayed complications. Success criteria should be reported more consistently, and the incidence/type of complications associated with immediate implants should be further explored. [ABSTRACT FROM AUTHOR]

Introduction: The remit of this working group was to update the existing knowledge base regarding bone augmentation for implant site development and soft-tissue grafting for esthetic outcomes. Four reviews from the working group formed the basis of this update. Moreover, clinical applications as well as suggestions for further research have been formulated. Materials and methods: The papers in the working group critically reviewed the literature. Four manuscripts were produced assessing (a) the outcomes of correcting dehiscence and fenestration defects at implant sites using various graft materials, (b) the outcomes of sinus floor augmentation at maxillary posterior sites with 6 mm or less residual bone height using various graft materials, (c) the association of the horizontal dimensions of buccal and interproximal bone with esthetic outcomes of implant-supported restorations, and (d) the outcomes of soft-tissue augmentations. Results: The results and conclusions of the review process are presented in the following papers. The group's consensus statements, clinical implications, and directions for future research are presented in this article. [ABSTRACT FROM AUTHOR]

In order to evaluate the level of evidence of factors influencing the survival of reconstructions, systematic reviews of the relevant literature were prepared by a group of rapporteurs. The review papers were circulated to the members of the group before the conference and formed the basis for group and panel discussions. Subsequently, modifications were added to the review papers, and suggestions for consensus statements concerning the following topics were prepared and again critically reviewed in the group and in the plenum: Impact of (i) periodontal disease on the survival of tooth-supported reconstructions, (ii) post-surgical factors as supportive therapy on the survival of implant supported reconstructions, (iii) technical and/or biological complications on the survival of different types of reconstructions, (iiii) material choice for reconstructions on the survival of single crowns and fixed dental prostheses. [ABSTRACT FROM AUTHOR]

Aim: To analyse possible effects of titanium surface topography on bone integration. Materials and methods: Our analyses were centred on a PubMed search that identified 1184 publications of assumed relevance; of those, 1064 had to be disregarded because they did not accurately present in vivo data on bone response to surface topography. The remaining 120 papers were read and analysed, after removal of an additional 20 papers that mainly dealt with CaP-coated and Zr implants; 100 papers remained and formed the basis for this paper. The bone response to differently configurated surfaces was mainly evaluated by histomorphometry (bone-to-implant contact), removal torque and pushout/pullout tests. Results and discussion: A huge number of the experimental investigations have demonstrated that the bone response was influenced by the implant surface topography; smooth ( Sa<0.5 μm) and minimally rough ( Sa 0.5–1 μm) surfaces showed less strong bone responses than rougher surfaces. Moderately rough ( Sa>1–2 μm) surfaces showed stronger bone responses than rough ( Sa>2 μm) in some studies. One limitation was that it was difficult to compare many studies because of the varying quality of surface evaluations; a surface termed ‘rough’ in one study was not uncommonly referred to as ‘smooth’ in another; many investigators falsely assumed that surface preparation per se identified the roughness of the implant; and many other studies used only qualitative techniques such as SEM. Furthermore, filtering techniques differed or only height parameters ( Sa, Ra) were reported. Conclusions: • Surface topography influences bone response at the micrometre level. • Some indications exist that surface topography influences bone response at the nanometre level. • The majority of published papers present an inadequate surface characterization. • Measurement and evaluation techniques need to be standardized. • Not only height descriptive parameters but also spatial and hybrid ones should be used. [ABSTRACT FROM AUTHOR]

Objectives: A thorough and exhaustive analysis of the available studies concerning placement of endosseous dental implants in diabetic subjects has not been previously published. The aim of the present study was to perform a comprehensive and critical review of experimental and clinical studies published in the international peer-reviewed literature in the English language regarding endosseous implant installation in diabetic subjects and to draw evidence-based conclusions on the effectiveness and predictability of dental implant therapy in diabetic patients. Material and methods: Literature search for articles published up to and including March 2005 in the English language was performed with a personal computer (PC) using The National Library Of Medicine ( ) and Cochrane Oral Health Group databases. Search strategy included a specific series of terms and key words. The reference lists of identified publications, relevant texts and previous workshops were also scanned. Data sources also included several hand-searched journals and contact with experts, when it was considered appropriate. Search was conducted independently by the three reviewers (S. K., I. K. K., I. F.). At the first phase of selection the titles and abstracts and at the second phase full papers were screened independently by the three reviewers. Disagreement regarding inclusion of full papers was resolved by discussion among the reviewers. Results: The search provided 227 potentially relevant titles and abstracts. At the first phase of evaluation, 199 publications were rejected based on title and abstract. At the second phase, the full text of the remaining 28 publications was retrieved for more detailed evaluation. These publications included 11 experimental studies and 16 clinical studies (one clinical study corresponded to two publications). Finally, 11 experimental and eight clinical studies were accepted. Clinical studies included four prospective and four retrospective studies. Because of the limited number of available studies and their heterogeneity, focusing on a specific predefined question to be answered by a systematic review was not feasible and therefore no meta-analysis was planned. Conclusion: Within the limits of the existing investigations, experimental studies seem to reveal an impaired bone healing response to implant placement in diabetic animals compared with non-diabetic controls, both quantitatively and qualitatively. The majority of clinical studies tend to indicate that diabetes is no contraindication for implant placement, on condition that it remains under metabolic control. However, definitive guidelines with objective criteria, such as type and duration of diabetes and glucosylated hemoglobin levels, need to be established in the future. [ABSTRACT FROM AUTHOR]

Objective The objective of this systematic review was to evaluate the ability of mechanical instruments to clean contaminated implant titanium surfaces. Materials and methods MEDLINE, Cochrane- CENTRAL and EMBASE databases were searched up to May 2013 to identify controlled studies on the cleaning efficacy of mechanical instruments on contaminated titanium surfaces. Results A comprehensive search identified 1893 unique potential papers. Fourteen studies met the inclusion criteria and were selected for this systematic review. Most of the studies were in vitro studies. Different surfaces and different contamination methods were used. Most studies used titanium discs, strips and cylinders. The air abrasive was the treatment mostly evaluated. The available studies had a high heterogeneity that precluded any statistical analysis of the data. Therefore, the conclusions are not based on quantitative data. Non-metal curettes and rubber cups were found to be ineffective. Positive results were reported for (ultra)sonic scalers with a metal tip on polished surfaces, (ultra)sonic scalers with a non-metal tip on smooth and sand-blasted and acid-etched ( SLA) surfaces, metal curettes and rotating titanium brushes on SLA surfaces. The air abrasive was found to be effective in cleaning machined, SLA and titanium plasma-sprayed ( TPS) surfaces. Conclusion The available data suggest that the air abrasive may remove plaque effectively from machined, SLA and TPS titanium surfaces. Positive results were also observed for rotating titanium brushes on SLA surfaces and ultrasonic scalers with non-metal tip on polished and SLA surfaces. However, the clinical impact of these findings requires further clarification. [ABSTRACT FROM AUTHOR]

Objective: To systematically collect and evaluate existing evidence on the effects of different mechanical instruments on the surface characteristics of smooth and rough titanium surfaces. Materials and methods: PubMed-MEDLINE, Cochrane-CENTRAL and EMBASE databases were searched up to December 2010 to identify appropriate studies. The eligible studies were controlled studies investigating titanium surface alterations following treatment with different mechanical instruments. Results: In total, 3275 unique papers were identified. A screening of the titles and abstracts resulted in 34 publications that met all of the eligibility criteria. Surface roughness was evaluated using scanning electron microscopy in most studies and using a profilometer in only 10 studies. The rough surfaces evaluated were titanium plasma sprayed and sandblasted and acid-etched surfaces only. Non-metal instruments were found to cause minimal or no damage to both smooth and rough titanium surfaces. Metal instruments were found to cause major damage to smooth surfaces. Burs seemed to be the instruments of choice, if smoothening of a rough surface was required. Conclusion: Non-metal instruments and rubber cups seem to be the instruments of choice for the treatment of smooth surfaces. Similarly, for rough implant surfaces, non-metal instruments and air abrasives are the instruments of choice, if surface integrity needs to be maintained. Metal instruments and burs are recommended only in cases requiring the smoothening of the surface roughness. The clinical impact of these findings requires clarification. [ABSTRACT FROM AUTHOR]

Objectives: Despite the availability of numerous animal models for testing the biological performance of dental and orthopedic implants, the selection of a suitable model is complex. This paper presents a new model for objective and standardized evaluation of bone responses to implants using the iliac crest in goats. Material and methods: The feasibility of the iliac crest model regarding anatomy and implant positioning was determined using two cadaveric specimens and the bone structure was evaluated and compared with that of the goat femoral condyle. Additionally, the validity of the model was tested by performing an in vivo study. Results: By means of a rather simple, safe, fast and reproducible surgical procedure, the iliac crest in goats could be approached and allowed the implantation of maximally five dental implants per iliac crest. Because of the bilateral implantation possibility, statistical comparisons between groups on either side of the goat could be performed, resulting in a high statistical power, and hence a reduction in the number of animals required to obtain significant data. Conclusions: In terms of surgical approach, anatomy and implant positioning, the iliac crest is the preferred model over the femoral condyle model. The iliac crest implantation model is suitable for evaluation of the osteogenic response to bone implant materials and represents a justified and deliberate alternative to the already existing animal models. To cite this article: Schouten C, Meijer GJ, van den Beucken JJJP, Spauwen PHM, Jansen JA. A novel implantation model for evaluation of bone healing response to dental implants: the goat iliac crest. Clin. Oral Impl. Res. 21, 2010; 414–423. doi: 10.1111/j.1600-0501.2009.01872.x [ABSTRACT FROM AUTHOR]

Objectives: The aim of this paper is to review current investigations on functional assessments of osseointegration and assess correlations to the peri-implant structure. Material and methods: The literature was electronically searched for studies of promoting dental implant osseointegration, functional assessments of implant stability, and finite element (FE) analyses in the field of implant dentistry, and any references regarding biological events during osseointegration were also cited as background information. Results: Osseointegration involves a cascade of protein and cell apposition, vascular invasion, de novo bone formation and maturation to achieve the primary and secondary dental implant stability. This process may be accelerated by alteration of the implant surface roughness, developing a biomimetric interface, or local delivery of growth-promoting factors. The current available pre-clinical and clinical biomechanical assessments demonstrated a variety of correlations to the peri-implant structural parameters, and functionally integrated peri-implant structure through FE optimization can offer strong correlation to the interfacial biomechanics. Conclusions: The progression of osseointegration may be accelerated by alteration of the implant interface as well as growth factor applications, and functional integration of peri-implant structure may be feasible to predict the implant function during osseointegration. More research in this field is still needed. To cite this article: Chang P-C, Lang NP, Giannobile WV. Evaluation of functional dynamics during osseointegration and regeneration associated with oral implants. Clin. Oral Impl. Res. 21, 2010; 1–12. [ABSTRACT FROM AUTHOR]

Aims: To assess the impact of different implant systems on the clinical conditions and the microbiota at implants, and whether the presence of bacteria at tooth sites was predictive of the presence at implant sites. Materials and methods: Subjects with either AstraTech or Brånemark in function for 7 years were enrolled. Sub-gingival bacterial samples at tooth and implant sites were collected with sterile endodontic paper points, and analyzed by the checkerboard DNA–DNA hybridization method (40 species). Results: Fifty-four subjects, 27 supplied with AstraTech ( n=132 implants) and 27 with Brånemark ( n=102) implants, were studied. Test tooth sites had significantly less evidence of bleeding on probing ( P<0.001) and presence of plaque ( P<0.001) than implant test sites. Implant sites presented with deeper probing pocket depth than tooth sites (mean difference: 1.1 mm, standard error of differences: 0.08, 95% confidence intervals (CI): 0.9–1.3, P<0.001). Tannerella forsythia ( P<0.05), Capnocytophaga sputigena ( P<0.05), Actinomyces israelii ( P<0.05) and Lactobacillus acidophilus ( P<0.05) were found at higher levels at tooth surfaces. No differences in bacterial load for any species were found between the two implant systems. The odds of being present/absent at tooth and implants sites were only significant for Staphylococcus aureus [odds ratio (OR): 5.2 : 1, 95% CI: 1.4–18.9, P<0.01]. Conclusions: After 7 years in function, implants presented with deeper probing depths than teeth. S. aureus was commonly present at both teeth and implants sites. S. aureus at tooth sites was predictive of also being present at implant sites. [ABSTRACT FROM AUTHOR]

Objectives: The outcome of implant treatment in periodontally compromised partially edentulous patients has not been completely clarified. Therefore, the aim of the present study was to perform, applying a systematic methodology, a comprehensive and critical review of the prospective studies published in English up to and including August 2006, regarding the short-term (<5 years) and long-term (≥5 years) prognosis of osseointegrated implants placed in periodontally compromised partially edentulous patients. Material and methods: Using The National Library Of Medicine and Cochrane Oral Health Group databases, a literature search for articles published up to and including August 2006 was performed. At the first phase of selection the titles and abstracts and at the second phase full papers were screened independently and in duplicate by the three reviewers (I. K. K., S. K., I. F.). Results: The search provided 2987 potentially relevant titles and abstracts. At the first phase of evaluation, 2956 publications were rejected based on title and abstract. At the second phase, the full text of the remaining 31 publications was retrieved for more detailed evaluation. Finally, 15 prospective studies were selected, including seven short-term and eight long-term studies. Because of considerable discrepancies among these studies, meta-analysis was not performed. Conclusions: No statistically significant differences in both short-term and long-term implant survival exist between patients with a history of chronic periodontitis and periodontally healthy individuals. Patients with a history of chronic periodontitis may exhibit significantly greater long-term probing pocket depth, peri-implant marginal bone loss and incidence of peri-implantitis compared with periodontally healthy subjects. Even though the short-term implant prognosis for patients treated for aggressive periodontitis is acceptable, on a long-term basis the matter is open to question. Alterations in clinical parameters around implants and teeth in aggressive periodontitis patients may not follow the same pattern, in contrast to what has been reported for chronic periodontitis patients. However, as only three studies comprising patients treated for aggressive periodontitis were selected, more studies, specially designed, are required to evaluate implant prognosis in this subtype of periodontitis. As the selected publications exhibited considerable discrepancies, more studies, uniformly designed, preferably longitudinal, prospective and controlled, would be important. [ABSTRACT FROM AUTHOR]

This paper reports a 5-year life-table analysis on wide neck (WN) ITI implants placed in a private practice. In 212 patients, 263 implants were placed in the posterior region; 97% rehabilitated the molar area. Implants in the mandible and in the maxilla were 61.2% and 38.8%, respectively; the mean implant length was 9.7 and 8.9 mm, respectively. Eighty-nine percent sites had both vestibular and buccal bone lamellae ≥1 mm, 9.1% had one of them <1 mm and 1.9% had both lamellae <1 mm. Sinus perforation during surgery occured in 52% of the maxillary implants. Prosthetic information was available for 249 implants; implants were involved in 157 single crowns (SC) and 80 fixed partial dentures (FPD). Radiographic analysis was performed on 102 implants that reached the 2-year control, and crestal bone loss (CBL) was measured. Results showed that five implants failed; the 5-year cumulative survival rate was 97.89%. The 1-year survival rate based on 259 implants was 98.8% and the 2-year survival rate based on 174 implants was 97.7%. In this 5-year timeframe, 94.3% of the SCs and 96.2% of the FPDs were free of complication. The mean CBL at the mesial and distal sides was 0.71 and 0.60 mm, respectively; bone losses >1 and >2 mm were recorded for 29.7% and 2.5% of the sides, respectively. This mid-term study showed that the WN ITI implants were highly predictable in private practice and that prosthetic complication in the molar area was an infrequent event. [ABSTRACT FROM AUTHOR]

Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clinical Oral Implants Research is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The integrity of connective tissues surrounding dental implants may be influenced by a balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The purpose of this study was to provide an overall assessment of TIMP-1, MMP-1 and -8 levels as well as collagenase activities during the wound healing process after implantation and in peri-implantitis lesions. Peri-implant crevicular fluid (PICF) was sampled with sterile paper strips from 10 osseointegrated implants of 6 subjects. Ten implants from 6 patients affected with peri-implantitis were also assessed. Gingival crevicular fluid (GCF) from 11 periodontitis-affected patients and 10 healthy volunteers served as controls. TIMP-1 and MMP-1 and -8 protein levels in the PICF were measured by ELISA, and active and APMA-activatable collagenase activities were determined by functional assays using image-analysis after SDS-PAGE. The experiment showed a significant increase in the TIMP-1 level at 1 week after implantation as compared with that in GCF from healthy periodontium. Four weeks after implantation it had reached the same level as that in the GCF of healthy subjects. The data has also disclosed a higher post-implantation collagenase activity level at 1 week than at weeks 2, 4, and 12. This may be due to the increase in MMP-1 and -8. Furthermore, peri-implantitis and periodontitis were shown to be similar inflammatory lesions in respect to MMP-1 and -8 and collagenase activities, even though the TIMP-1/MMP-1+MMP-8 ratio was significantly lower in peri-implantitis than in periodontitis. In conclusion, the over-production of TIMP-1 in the wound area after implantation could, to some extent, inhibit excessive tissue destruction and degradation of the neo-matrix in wound repair due to MMPs. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the efficacy of various interdental cleaning aids for artificial biofilm removal on different implant‐supported crown designs. Methods: Mandibular models with missing first molar were fabricated and installed with single implant analogs and loaded with crowns of different designs (concave, straight, and convex). Artificial biofilm was made with occlusion spray. Thirty volunteers (periodontists, dental hygienists, and laypersons) were asked to clean the interproximal areas. The crowns were unscrewed and photographed in a standardized setting. The outcome was measured by the cleaning ratio which represents the cleaned surfaces in relation to the area of the tested surface. Results: A significant difference in favor of concave crown (p <.001) on the basal surface was cleaned by all tools, except the water flosser. There was evidence of an overall effect of "cleaning tool," "surface," and "crown design" (p <.0001) except for the "participant" factor. The mean cleaning ratio for each cleaning tool and overall combined surfaces were (in%): dental floss: 43.02 ± 23.93, superfloss: 42.51 ± 25.92, electric interspace brush: 36.21 ± 18.78, interdental brush: 29.10 ± 15.95, and electric water flosser: 9.72 ± 8.14. Dental floss and superfloss were significantly better (p <.05) than other tools in removing plaque. Conclusions: Concave crown contour had the greatest artificial biofilm removal, followed by straight and convex crowns at the basal surface. Dental floss and superfloss were the most effective interdental cleaning devices for artificial biofilm removal. None of the tested cleaning devices were able to completely remove the artificial biofilm from the interproximal/basal surfaces. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate qualitative differences in the subgingival microbiota at titanium implants, ad modum Bråmnark, demonstrating clinical and radiographic signs of loss of supporting tissues )peri-implantitis) as compared to implants surrounded by healthy tissues. A total of 37 patients demonstrating 1 or more implants with bone loss ≥3 threads, bleeding on probing and/or suppuration and 51 patients with clinically healthy mucosa and no bone loss were recruited for the study. In each patient subgingival bacterial samples were obtained using paper-points, and subjected to microbiological analysis by culture. The two types of clinical conditions showed distinct bacterial profiles. For implants with peri-implantitis putative periodontal pathogens, such as Porphyuonmnas gingivulis, Prevotella intermedial Prevotella nigresscens and Actinobacillus actinomycetemcomitans , were found in 60% of the cases and microorganisms primarily not associated with periodontitis, such as Staphylococcus spp., enterics and Candida spp., were found in 55% of the peri-implant lesions. In contrast, implants surrounded by healthy tissue demonstrated a microbiota associated with periodontal health. The results indicate that the microbiota of the healthy peri-implant sulci is similar to that from corresponding conditions around teeth. However, in peri-implant areas staphylococci, enter& and yeasts were found almost as frequently as periopathogens indicating differences as compared to the microbiota around periodontitis affected teeth. A microbiological diagnosis may therefore be of guidance for the choice of antimicrobial treatment in patients with peri-implant infection. [ABSTRACT FROM AUTHOR]

A combined three-dimensional and axisymmetric finite element analysis was made of the effect upon the peak interfacial shear stress of providing an axially loaded mandibular dental implant with retention elements all the way up to the crest of the implant as opposed to a smooth neck. The effect of increased wall thickness of the implant and of using bi-cortical fixation as opposed to unicortical fixation was also studied. Retention elements at the implant neck were found to bring about a major decrease in the peak interfacial shear stress. Increased wall thickness and bi-cortical fixation also resulted in decreased peak interfacial shear stress but this effect was minor. The interpretation of this was that all these three measures increase the capacity of the implant to carry axial loads. Thus from a biomechanical viewpoint it appears to be advantageous to provide the neck of screw-shaped implants with retention elements, for example a rough surface of suitable micro-architecture and/or a microbhyphen;thread. It is furthermore suggested that retention elements at the implant neck will counteract marginal bone resorption in accordance with Wolff's law. This paper is a revision of: Hansson, S. (1997) Some steps to improve the capacity of dental implants to resist axial loads. In: Hansson, S., ed. Towards an optimized dental implant and implant bridge design: A bio-mechanical approach. Thesis. Göteborg; Chalmers University of Technology. [ABSTRACT FROM AUTHOR]

Purpose: The present retrospective clinical study was undertaken to evaluate the survival rate and marginal bone conditions around Nobel Direct one-piece implants. The purpose was also to compare the results with when these implants are used for immediate/early loading with implants allowed to heal before loading. Material and methods: Forty-three consecutive patients previously treated with 117 Nobel Direct implants at four different centres were evaluated. The implants had been used in both jaws for treatment after loss of single and multiple teeth. Immediate/early loading (within 2 weeks) with a provisional crown/bridge was applied to 95 implants, while 22 implants healed unloaded for 6 weeks to 6 months before loading. Calculations of marginal bone loss were performed in radiographs taken at placement and after an average of 10.2 months (range 1–18 months) of loading. Results: Six (5.1%) of the 117 implants were removed during the follow up. All failed implants belonged to the immediate/early loading group giving a failure rate of 6.3% for this group and 0% for two-stage implants. The failure rate was higher for flapless (7.9%) than for flap surgery (0%). The marginal bone loss was −2.4 mm (SD 1.5) for all implants, while 37.6% showed more than 3 mm of loss during the follow up. Bone loss increased with time of follow up. Implants subjected to immediate/early loading showed more bone loss than two-stage implants: −2.6 mm (SD 1.5) vs. −1.6 mm (SD 1.1). Moreover, 41.3% of immediately loaded and 22.7% of two-stage implants presented with more than 3 mm of bone loss. Conclusions: This short-term retrospective analysis showed a poor clinical outcome of Nobel Direct implants. Extensive marginal bone loss (>3 mm) was found around more than 1/3 of the implants evaluated. Less resorption and no failures were experienced when implants were allowed to heal from 6 weeks to 6 months before occlusal loading. Within the limitations of the present study design, data indicate that immediate loading, the use of this implant for multi-unit constructions and flapless surgery are risk factors for failure of Nobel Direct implants. [ABSTRACT FROM AUTHOR]

Purpose This systematic review aimed to evaluate the effect of implant length on peri-implant marginal bone loss ( MBL) and its associated influencing factors. Material and methods An electronic search of the PubMed and MEDLINE databases for relevant studies published in English from November 2006 to July 2012 was performed by one examiner ( AM). Selected studies were randomized clinical trials, human experimental clinical trials or prospective studies (e.g., cohort as well as case series) with a clear aim of investigating marginal bone loss of short dental implants (<10 mm) supporting fixed prostheses. A random-effect meta-regression model was used to determine the relationship between the effect size mean MBL and the covariate 'implant length.' Additionally, a subgroup analysis, by means of a random-effect one-way ANOVA model, comparing mean MBL values at different levels of each factor ('type of connection' and 'type of prostheses') was also performed. Results The meta-regression of mean MBL on the moderator 'implant length' was found to be insignificant ( P = 0.633). Therefore, it could not be concluded that implant length had an effect on peri-implant MBL. In addition, standardized differences in mean MBL on the subgroups short (<10 mm) and standard (≥10 mm) implants, as determined by the meta-analysis (random-effect model), were found to be statistically insignificant ( P = 0.222). Conclusions Within limitations of the present systematic review, it could be concluded that short dental implants (<10 mm) had similar peri-implant MBL as standard implants (≥10 mm) for implant-supported fixed prostheses. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the influence of instrumentation technique on the early osseointegration histomorphometrics and biomechanical fixation of fully laser-etched microgrooves implant surfaces in a sheep model. Material and Methods: Six sheep were subjected to bilateral hip surgeries 3 and 6 weeks before euthanasia. A total of 48 implants (ø4.5 mm, 8 mm in length) were distributed among four sites (8 per animal) and placed in bone sites drilled to 4.6 mm (reamer), 4.1 mm (loose), 3.7 mm (medium) and 3.2 mm (tight) in diameter. After healing, the animals were euthanized and half of the implants were biomechanically tested, while the remainder was subjected to non-decalcified histologic processing. The histomorphometric parameters assessed were bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). Statistical analysis was performed using a mixedmodel analysis of variance with significance level set at P < 0.05. Results: A general increasing trend is present from 3 to 6 weeks for most of the variables. The groups prepared to be press fit seemed to present higher values, which were maintained throughout the observation period. The reamer group presented the lowest BIC probably due to the drilling technique; however qualitatively, more new bone seemed to be in contact to the implant surface, at 3 weeks, whereas the implants placed in press-fit situations were mainly supported by cortical bone. Conclusion: The laser-etched microgrooved implant presented osteoconductive and biocompatible properties for all surgical procedures tested. However, procedures providing increasingly higher press-fit scenarios presented the strongest histomorphometric and biomechanical responses at 3 and 6 weeks. [ABSTRACT FROM AUTHOR]

Objectives To compare the implant size (width and length) planned with digital panoramic radiographs, cone beam computed tomography ( CBCT)-generated panoramic views, or CBCT cross-sectional images, in four implant systems. Material and methods Seventy-one patients with a total of 103 implant sites in the upper premolar and/or lower molar regions were examined with digital panoramic radiography (D- PAN) and ( CBCT). A metal ball 5 mm in diameter was placed in the edentulous area for the D- PAN. CBCT data sets were reformatted to a 10-mm thick CBCT panoramic view ( CBCT-pan) and 1-mm cross-sections ( CBCT-cross). Measurements were performed in the images using dedicated software. All images were displayed on a monitor and assessed by three observers who outlined a dental implant by placing four reference points in the site of the implant-to-be. Differences in width and length of the implant-to-be from the three modalities were analyzed. The implant size selected in the CBCT-cross images was then compared to that selected in the other two modalities (D- PAN and CBCT-pan) for each of the implant systems separately. Results The implant-to-be (average measurements among observers) was narrower when measured in CBCT-cross compared with both D- PAN and CBCT-Pan. For premolar sites, the width also differed significantly between D- PAN and CBCT-pan modalities. The implant-to-be was also significantly shorter when recorded in CBCT-cross than in D- PAN. In premolar sites, there were no significant differences in implant length among the three image modalities. It mattered very little for the change in implant step sizes whether CBCT-cross was compared to D- PAN or CBCT-pan images. Conclusion Our results show that the selected implant size differs when planned on panoramic or cross-section CBCT images. In most cases, implant size measured in cross-section images was narrower and shorter than implant size measured in a panoramic image or CBCT-based panoramic view. [ABSTRACT FROM AUTHOR]

Introduction Dental implant osseointegration can be impaired in medical conditions with low bone mass, such as glucocorticoid-induced osteoporosis. Intermittent human parathyroid hormone ( PTH) [1-34] administration has shown relevant anabolic bone activity in various animal models of osteoporosis. Therefore, we studied the effects of intermittent PTH [1-34] on bone response around titanium implants in experimental osteoporosis induced by ovariectomy and glucocorticoid administration. Methods Titanium dental implants were placed in the proximal tibia metaphysis in 38 animals. Twenty-eight rabbits had undergone bilateral ovariectomy and further methylprednisolone administration for 4 weeks to induce osteoporosis. Ten healthy rabbits were used as controls. At week 8, osteoporotic rabbits started saline vehicle or intermittent PTH administration for 12 weeks. Bone mineral density ( BMD) was assessed in peri-implant area, lumbar spine, and global and subchondral knee bone at baseline, and weeks 6 and 20. Animal sacrifice was carried out at week 21. Afterward, tibiae were removed for μ CT morphometry and undecalcified sections were evaluated by light and scanning electron microscopy. Results PTH increased bone-to-implant contact compared with control rabbits or vehicle administration in osteoporotic rabbits ( P < 0.005). PTH-induced new bone formation around external and internal surfaces of titanium implants led to a significant increase of BMD at peri-implant area in osteoporotic rabbits at week 20, when compared with vehicle ( P < 0.005). Likewise, PTH increased BMD in other analysed regions. Conclusions Intermittent administration of PTH [1-34] enhances the bone response around titanium implants in a rabbit model of ovariectomy and glucocorticoid-induced osteoporosis. [ABSTRACT FROM AUTHOR]

Objectives A better understanding of the biological processes controlling osseointegration at the bone-to-implant interface is needed. The aim of this study was to examine which are the molecular and biochemical variables that are significantly related to osseointegration, using multiple regression analysis. Materials and methods Titanium coins were placed into the tibial cortical bone of New Zealand White rabbits and evaluated using pull-out test after 4 and 8 weeks of healing. Correlations between pull-out and several markers from tissue fluid (Lactate dehydrogenase [ LDH] and Alkaline phosphatase [ ALP] activities and total protein content) and peri-implant bone tissue (total protein, RNA and DNA content, implant area covered with bone and gene expression of osteoblast, osteoclast and inflammation markers) were used to assess the importance of these parameters in bone healing and in relation to implant performance. Results Our results showed a negative correlation between the content of DNA, RNA and total protein at the peri-implant bone tissue and the pull-out force, indicating that as bone matures and implant becomes more osseointegrated, the organic content of bone decreases. The negative correlation found between pull-out force and ALP activity pointed to a delayed healing in implants with lower pull-out values and primary mineralization still ongoing. LDH activity and total protein content in the tissue fluid were as well negatively correlated with the pull-out force. Finally, a positive correlation was observed between the pull-out force and the expression of the osteoblast and the bone resorption markers, being osteocalcin and collagen-I the best predictive markers for osseointegration after 4 and 8 weeks of healing respectively. Conclusions These results suggest that the evaluation of these markers could be relevant for the assessment of new implant surfaces for rapid bone healing and improved implant performance. [ABSTRACT FROM AUTHOR]

Objectives Recently, guided implant surgery has been introduced and several studies verified its accuracy. While those studies reported on the accuracy of the entire procedure, this experiment wanted to evaluate the degree of deviation that can occur during the drilling procedure alone, due to the tolerance of the drill in the sleeve insert. Material and methods Drilling was executed in a plexi-glass box with a maximal inclination of the drills within the sleeve insert. Different sleeve inserts, sleeve positions, sleeve heights, sleeve insert heights and diameters were evaluated. Results The two tested sleeve inserts gave a maximum deviation in angulation of 5.2° and a maximum horizontal deviation of 1.3 mm at the implant shoulder and 2.4 mm at the apex for a 13 mm implant. These deviations decreased if the distance of the sleeve above the plexi-glass box became smaller and hand hold sleeve inserts gave less deviation than drill hold sleeve inserts. The deviation increased by longer implant length, larger drill key diameter, shorter sleeves and/or drill key heights. Conclusions For a minimal deviation during the surgery with a stereolithographic guide, it is very important to use the drill in a centric position, parallel to the cylinder. The use of longer drill keys and sleeves are critical for optimal accuracy. [ABSTRACT FROM AUTHOR]

Objectives The purpose of this study was to evaluate the biomechanical bone tissue response to novel microstructured zirconia implants in comparison to sandblasted and acid-etched ( SLA) titanium implants through the analysis of removal torque ( RTQ) measurements. Materials and methods Ti- SLA implants with a sandblasted, large-grit and acid-etched surface were compared with zirconia implants with an acid-etched surface. All implants had the same shape, a diameter of 4.1 mm and a length of 10 mm. A total of 136 implants were placed in the maxillae of 17 miniature pigs. Six animals were sacrificed after both 4 and 8 weeks and five animals were sacrificed after 12 weeks, thus providing a total of 102 implants for RTQ testing (34 implants were reserved for future histological analysis). The RTQ analysis was successfully performed, using a mixed model regression with P-values calculated using the nonparametric Brunner-Langer method, on 100 of the 102 implants, two were excluded from the analysis. Results The adjusted mean RTQ values for Ti- SLA implants were 131 Ncm (95% CI: 107-155) at 4 weeks, 128 Ncm (108-148) Ncm at 8 weeks, and 180 Ncm (153-207 Ncm) at 12 weeks of healing, whereas RTQ values for the zirconia implants were 110 Ncm (86-134), 97 Ncm (76-118) and 147 Ncm (121-174) at the corresponding time intervals. A comparison of the implant materials resulted in P-values of P = 0.114 at 4 weeks, P = 0.034 at 8 weeks and P = 0.105 at 12 weeks (significance set at P < 0.05). Conclusions Within the limits of the present study, it could be confirmed that the biomechanical bone-tissue response of the investigated zirconia implants is non-inferior to that of the well-documented, roughened titanium surface, at each time point, within the set tolerance. There were no statistically significant differences between the two materials after a healing period of 4 and 12 weeks. The RTQ values of both implant types increased significantly from the 8-week to the 12-week time point. [ABSTRACT FROM AUTHOR]

Objective Several theories have been presented to explain initial and secondary marginal bone loss around dental implants (e.g. microbial load, adverse loading, microbial leakage, compromised healing/adaptation of host-implant interface). Material and methods This study compared the long-term outcome (up to 12 years) of sleeping with loaded implants in the mandible via a split-mouth concept. Fourteen patients with overdentures were enrolled (10 women, mean age at implant insertion: 56 years [range: 33-71]). They presented with 28 loaded (position 33/43) and 14 sleeping implants (mostly position 31/41). At several follow-up visits, intra-oral radiographs (long-cone principle) were taken to observe marginal bone level changes. Results At each observation, compared with abutment connection, the submerged non-loaded implants showed less bone loss ( P-values: 1st year 0.007, 3 years 0.000, 5 years 0.002, 8 years 0.007, 12 years 0.000) than their neighbouring functional implants. This difference was primarily due to a more significant bone loss during the first year of loading (0.8 vs. 0.1 mm respectively), since afterwards, the bone level changes remained quite similar for both implant types. Conclusions Our data suggest that the first months of loading have a significant impact on the bone level (initial difference sleeping vs. loaded implants), followed by a more physiological bone level change afterwards. This initial difference might be explained by the adaptation of the surrounding bone to the loaded implant. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to calculate the volume of graft necessary for rehabilitation using varying lengths of implants, and to evaluate the usefulness of the planning dental software in determining the pre-operative volume of bone graft in maxillary sinus floor lifts. Material and methods Using the Compu Dent program, we calculated the volume of graft necessary for 62 sinus lifts. This volume was measured to raise the floor of each sinus to 13.4 and 15 mm in height. Results The average volume of graft to achieve a lift of 13.4 mm was 2.61 ± 0.69 cm³ for the right maxillary sinus, with the range of 1.38-4.1 cm³, and 2.68 ± 0.81 cm³ for the left maxillary sinus, with the range of 1.1-4.25 cm³. The average volume of graft to achieve a lift of 15 mm was 3.13 ± 0.75 cm³ for the right maxillary sinus, with the range of 1.59-4.81 cm³, and 3.29 ± 1.02 cm³ for the left maxillary sinus, with the range of 1.48-5.11 cm³. The statistical results showed a significant inversely proportional correlation between the average of the heights and the volume of graft in the right sinus. Conclusions The planning dental software is an effective tool in determining the volume of bone graft given the tool's simplicity, rapidness and possibility of standardization in all pre-surgical procedures. [ABSTRACT FROM AUTHOR]

Objectives Interforaminal implant surgery requires anatomical knowledge of the area and adequate information on the location of the various landmarks of significance such as the mental foramen, the anterior loop of the inferior alveolar nerve and the mandibular incisive canal. Cone beam computed tomography ( CBCT) is a relatively new imaging modality that provides a multi-dimensional view of the facial skeleton with, in most instances, lower radiation dose to the patient compared to medical CT. The present study aims to use CBCT to identify and measure variation in the presence and extent of the anterior loop of the inferior alveolar nerve. This information may be used to provide recommendations to the surgeon without access to a 3 D scan of the dento-alveolar region. Material and methods Ninety-three patients scanned with a Newtom VG device for a variety of clinical indications were included in this retrospective study. Using the multiplanar capabilities of the device's software the prevalence and length of the anterior loop was assessed. Results The results show that an anterior loop could be identified in 48% of the cases with a mean length (range) of 0.89 mm (0-5.7). Conclusions In almost half of the surveyed cases an anterior loop was present. Even though in 95% of the study cases the loop was <3 mm, a 100% safety margin in the placement of anterior mandibular implants, in the absence of a CBCT scan, would only be achieved with a distance of 6 mm between the anterior border of the mental foramen and the most distal interforaminal implant fixture. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to follow patient cases retrospectively in a longitudinal manner from the time of implant placement to the time they were diagnosed with peri-implant disease, and to identify associated clinical and microbiological features of peri-implant disease. Material and methods A total of 281 patient cases were chosen from the archives of the Oral Microbiological Diagnostic Laboratory, Gothenburg, Sweden, based on bacterial samples taken from diseased implants. A form was designed and filled in separately for each case including data on patient, implant and disease profile. Results Most cases were severe peri-implantitis cases (91.4%). In 41.3% of the patients, peri-implantitis was developed early, already after having implants in function less than 4 years. The type of implant surface was significantly associated with the time in years implants were in function, before disease was developed ( P < 0.05). The microbiological results by both culture and checkerboard analysis, although failed to fully correspond to the severity of the disease in terms of magnitude, proved to show that peri-implantitis is a polymicrobial anaerobic infection with increased number of AGNB (aerobic Gram-negative bacilli) in 18.6% of the patients. Conclusions Peri-implantitis is a biological complication of implants in function that poses a threat to their long-term survival. It may develop earlier around implants with rough surfaces and it may represent a true infection. Microbiological sampling methods should be improved and uniformed so as to fully unveil the microbiological profile of the disease. [ABSTRACT FROM AUTHOR]

Objective: The impact of the implant position on the restorative outcome could justify guided surgery even for the single implants particularly in the aesthetic zone and especially when a simplified concept is available. Material and methods: Based on a plaster model, on which the soft tissues were mimicked (according to the thickness measured on a Cone-Beam CT), a tooth-supported, surgical template was prepared. The latter guided all drills so that even flapless implant insertion became possible. All implants were placed by students of the master-after-master training program in Periodontology. Results: The prospective cohort included a total of 34 implants, all of AstraTech (Osteospeed®) type, which were successfully inserted in 29 patients, 16 flapless, 32 onestage. The marginal bone along the integrated implants remained stable over time, with 0.13 mm loss during the first year. The aesthetic parameters were reassuring. Conclusions: This simple model-based concept seems to be reliable for the guided placement of single implants and the pre-operative preparation of their restorations. To cite this article: Marcelis K, Vercruyssen M, Naert I, Teughels W, Quirynen M. Model-based guided implant insertion for solitary tooth replacement: a pilot study. Clin. Oral Impl. Res. 23, 2012; 999-1003 doi: 10.1111/j.1600-0501.2011.02242.x [ABSTRACT FROM AUTHOR]

Objectives: This study evaluated the histomorphometric and clinical outcomes of maxillary sinus floor elevation using deproteinized bovine bone mineral (DBBM). Material and methods: Maxillary sinuses with a residual vertical height of <5 mm were augmented with DBBM alone before implant placement 9 months later. At the time of implant surgery, trephine samples were removed and histological and histomorphometric analyses were performed to examine the percentage of bone and residual graft using point counting and software-aided analysis. Patients were recalled for clinical and radiographic examination up to 3 years later. Results: Twenty-five patient specimens were analysed. The percentages of regenerated bone and residual graft material were 19% and 40%, respectively. Software-aided analysis was comparable to point counting. Twelve patients attended for clinical follow-up. Implants placed into this regenerated bone exhibited success and survival rates of 100% after an average follow-up of 3 years. The average vertical height gained was 7.9 mm. Conclusions: The use of DBBM alone in maxillary sinus floor elevation is a predictable method to gain vertical bone height in the posterior maxilla. To cite this article: Lee DZ, Chen ST, Darby IB. Maxillary sinus floor elevation and grafting with deproteinized bovine bone mineral: a clinical and histomorphometric study. Clin. Oral Impl. Res. 23, 2012; 918-924 doi: 10.1111/j.1600-0501.2011.02239.x [ABSTRACT FROM AUTHOR]

Aim: To investigate bone-to-implant bonding for some novel surface modifications with a hierarchic structure and to correlate the in vivo results with surface roughness parameters. Materials and methods: Newly developed implants surfaces were tested in rabbits and compared with the commercially available OsseoSpeed™ (OS) implant. The blasted test samples were subjected to treatment in oxalic acid (AT-II), followed by subsequent etching in hydrofluoric acid (AT-I). Scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the surface topography and chemical composition of the implants. Biomechanical testing after 6 weeks of healing was complemented with the quantification of fluorochromes and the results were subjected to a multivariate statistical analysis. Results: The results show, both with biomechanical- and with histomorphometrical tests, that the AT-I implants with different surface roughness at the micro (blasting), submicro (shallow cavities) and nanolevels (precipitates) have a greater bone tissue integration compared with the AT-II- and OS implants. The 2D bone-to-implant contact (BIC) data were in accordance with the 3D removal torque (RTQ) results even if the former were deduced from implants located in spongeous-type bone and the latter in cortical bone. The increase in RTQ values for the test samples AT-I and AT-II compared with the reference complies with the slightly higher Sa values for these surfaces. Conclusions: Using a combination of conventional methods with novel quantification of florochrome and multivariate analysis, the influence of surface roughness on different levels could be discriminated. The RTQ and BIC values show that the most hierarchical structure with submicro cavities and nanoscale precipitates possesses the most favourable osseointegration properties. To cite this article: Johansson CB, Gretzer C, Jimbo R, Mattisson I, Ahlberg E. Enhanced implant integration with hierarchically structured implants: a pilot study in rabbits Clin. Oral Impl. Res. 23, 2012; 943-953 doi: 10.1111/j.1600-0501.2011.02233.x [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study was to compare the differences in the long-term clinical and radiologic effects for three different treatment strategies with implant-supported overdentures in the edentulous mandible, with a special emphasis on smoking. Materials and methods: In a randomized- controlled clinical trial, 110 edentulous patients participated. Thirty-six patients were treated with an overdenture supported by two implants with ball attachments (2IBA), 37 patients with an overdenture supported by two implants with a bar (2ISB) and 37 patients with an overdenture supported by four implants with a triple bar (4ITB). After a mean evaluation period of 8.3 years, the clinical and radiographic parameters were evaluated. Results: Ninety-four out of the original 110 patients (=85%) were evaluated. In the 2IBA group, the plaque index was significantly lower (vs. 2ISB, P=0.013; vs. 4ITB, P=0.001) than in the other groups, but there was no correlation with the other peri-implant parameters. In the 4ITB group, the marginal bone loss was significantly higher than that in the two implant groups. The maximal probing depth was correlated with peri-implant bone loss ( P=0.011). Smoking almost doubled marginal bone loss irrespective of the treatment strategy chosen. Conclusions: Patients with two implants show less marginal bone loss than those with four implants. Smoking is a risk factor for the survival of dental implants in the long run. To cite this article: Stoker G, van Waas R, Wismeijer D. Long-term outcomes of three types of implant-supported mandibular overdentures in smokers. Clin. Oral Impl. Res. 23, 2012; 925-929 doi: 10.1111/j.1600-0501.2011.02237.x [ABSTRACT FROM AUTHOR]

Objective: To evaluate the demographic, radiological and therapeutic parameters that influence the overall clinical performance of palatal implants subjected to orthodontic loading. Patients and methods: The data of all patients who had received an orthodontic palatal implant for skeletal anchorage between January 1998 and December 2007 were reviewed retrospectively. The primary endpoint was the implant loss. The following parameters were assessed by univariate (log-rank test) and multivariate (Cox's regression) analysis: (a) age and gender, (b) vertical bone height along the prospective implant axis, (c) surgeon's experience and (d) implant type. Results: Two-hundred and thirty-nine palatal implants were inserted in patients aged between 10 and 65 years. In all, 11/239 (4.6%) implants were lost: nine during the healing phase and two under functional loading. On univariate analysis, 'surgeon's experience' was associated with a better implant survival and vice versa ( P=0.0005; log-rank test). The significance of 'surgeon's experience' was confirmed by Cox's regression analysis ( P=0.001; Wald test). All other parameters had no impact on implant loss. Conclusions: The survival probability of palatal implants is not related to demographic and radiological parameters. Implant losses mainly occurred early in the healing phase of the palatal implant. According to our data, 'surgeon's experience' is the cornerstone of palatal implant success. [ABSTRACT FROM AUTHOR]

Aim This 1-year prospective RCT compared the outcome of minimally (turned) and moderately rough (TiUnite®) implant surfaces. Material and methods Two subgroups of patients were formed; one group ( n = 10) where all teeth had been extracted due to severe periodontitis, another group ( n = 8) with teeth in the antagonistic jaw with a history of periodontitis and some remaining medium pockets (4-6 mm). Implants ( n = 85, 43 turned & 42 TiUnite®) were installed randomly in each patient. After 3-6 months of submerged healing, healing abutments were connected, followed by final abutments 2 weeks later, all with the same surface characteristics as the supporting implant. Peri-implant parameters and intra-oral radiographs were recorded up to 1 year after abutment connection. Results Two turned implants failed in the partial edentulous group during the initial healing period ( CSR: 95%) and none of the TiUnite® ( CSR: 100%) surface. No statistically significant differences in clinical parameters could be observed between both surfaces. The partial edentulous subgroup showed more bone loss compared to the full edentulous subgroup. Conclusion Moderately rough implants have a similar clinical outcome (at 1 year of loading in periodontitis susceptible patients) compared to minimally rough implants. [ABSTRACT FROM AUTHOR]

Background Most current implants have a moderately rough surface (compared with older minimally rough 'turned' implants) to facilitate osseointegration. This randomized controlled trial ( RCT), with split-mouth design, examined whether this increased surface roughness influenced the initial subgingival plaque formation. Material and methods Ten fully edentulous and eight partially edentulous patients, all with a history of severe periodontitis, received 4-6 implants (mandible or maxilla). Per jaw, both minimally (turned) and moderately rough ( TiUnite) implants ( MKIII; Nobel Biocare) were alternated. Also, the healing and final abutments had similar surface characteristics. Subgingival biofilm formation was followed up for 1 year, and samples were analyzed by culture technique, qPCR and checkerboard Results Over the entire period, no statistically significant differences could be detected in subgingival microbiota between the minimally and moderately rough surfaces. In partially edentulous patients, the biofilm matured to a higher concentration of pathogens when compared with fully edentulous patients. The subgingival implant composition and concentration in partially edentulous patients were comparable to the subgingival microbiota along teeth. Conclusion The roughness of the more modern implants did not influence the biofilm formation during the first year of implant loading. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the effect of Si addition on a nanometer-scale roughness Ca and P implant surfaces in a canine tibia model by biomechanical and histomorphometric evaluations. Material and methods: The implant surfaces comprised a resorbable media CaP microblasted (control) and a CaP resorbable media+silica-boost microblasted (experimental) surfaces. Surfaces were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and optical interferometry (IFM) down to the nanometric level. The animal model involved the bilateral placement of control ( n=24) and experimental surface ( n=24) implants along the proximal tibiae of six dogs, remaining in vivo for 2 or 4 weeks. After euthanization, half of the specimens were torqued-to-interface failure, and the other half was subjected to histomorphologic and bone-to-implant contact (BIC) evaluation. Torque and BIC statistical evaluation was performed by the Friedman test at 95% level of significance, and comparisons between groups was performed by the Dunn test. Results: IFM and SEM observations depicted comparable roughness parameters for both implant surfaces on the micrometer and nanometer scales. XPS analysis revealed similar chemical composition, except for the addition of Si on the experimental group. Torque-to-interface failure and BIC mean values showed no significant differences ( P=0.25 and 0.51, respectively) at both 2- and 4-week evaluation points for experimental and control groups. Early bone healing histomorphologic events were similar between groups. Conclusions: The experimental surface resulted in not significantly different biomechanical fixation and BIC relative to control. Both surfaces were biocompatible and osseoconductive. To cite this article: Coelho PG, Granato R, Marin C, Jimbo R, Lin S, Witek L, Suzuki M, Bonfante EA. Effect of Si addition on Ca- and P-impregnated implant surfaces with nanometer-scale roughness: an experimental study in dogs. Clin. Oral Impl. Res. 23, 2012; 373-378. doi: 10.1111/j.1600-0501.2010.02150.x [ABSTRACT FROM AUTHOR]

Aim To evaluate the effect of mismatching abutments on implants with a wider platform on the peri-implant hard tissue remodeling and the soft tissue dimensions. Material and methods Mandibular premolars and first molars of six Labrador dogs were extracted bilaterally. After 3 months of healing, one tapered implant was installed on each side of the mandibular molar region with the implant shoulder placed at the level of the buccal alveolar bony crest. On the right side of the mandible, an abutment of reduced diameter in relation to the platform of the implant was used, creating a mismatch of 0.85 mm (test), whereas an abutment of the same diameter of the implant platform was affixed in the left side of the mandible (control). The flaps were sutured to allow a non-submerged healing. After 4 months, the animals were sacrificed and ground sections were obtained for histometric assessment. Results All implants were completely osseo-integrated. Bone levels were superior at the test than at the control sites. However, statistically significant differences were found only at the buccal and proximal aspects. The soft tissue vertical dimension was higher at the control compared with the test sites. However, statistically significant differences were demonstrated only at the buccal aspects. Conclusions A mismatch of 0.85 mm between the implant and the abutment yielded more coronal levels of bone-to-implant contact and a reduced height of the peri-implant soft tissue (biologic width), especially at the buccal aspect, if the implant shoulder was placed flush with the level of the buccal alveolar bony crest. [ABSTRACT FROM AUTHOR]

To compare panoramic and conventional cross-sectional tomography for preoperative selection of implant size for three implant systems (Brånemark, Straumann, 3i). Presurgical panoramic (Pan) and cross-sectional tomograms (Tomo) of 121 implant sites in 121 patients scheduled for single-tooth implant treatment were recorded; in 70 of the Pans (Pan-B), a metal ball was placed in the edentulous area. By means of dedicated software, an implant with subjectively determined proper dimensions for the respective site was outlined by manually placing four reference points in each image by three observers. Additionally, four reference points corresponding to the margins of the metal ball were manually placed in Pan-Bs. The length and width of the implant were calculated after calibration to the reference ball (true magnification) in Pan-Bs and to a 'standard' calibration method in all images (magnification factor 1.25 in Pans and 1.7 in Tomos). Based on the corrected dimensions, the nearest, smaller implant size was selected among those available in each of the three implant systems. When comparing Pans with Tomos, selected implant size differed in on average 89% of the cases. The length differed in 69% and the width in 66%. Implants planned on Tomos were longer than those planned on Pans in 47% and narrower in 30% (<10% in posterior regions). The Straumann system, with the smallest range of available implant sizes was significantly less affected by the radiographic method compared with the other two systems. The selected implant size differed considerably when planned on panoramic or cross-sectional tomographs. Schropp L, Stavropoulos A, Gotfredsen E, Wenzel A. Comparison of panoramic and conventional cross-sectional tomography for preoperative selection of implant size. Clin. Oral Impl. Res. , 2011; 424-429. [ABSTRACT FROM AUTHOR]

While many studies have focused on the hazardous effects of smoking, there is little direct evidence regarding the specific detrimental effects of the nicotine on the osseointegration of implants. To understand the effects of nicotine on gene expression and osseointegration of titanium implants in rats. Forty-four rats were administered with nicotine or saline for a period of 8 weeks. The femurs were then harvested and analyzed using a three-point bending test. Osseointegration level was determined using bone/implant contact ratio at 2 or 4 weeks after implants were placed. Expression levels of bone matrix-related genes were measured by quantitative real-time polymerase chain reaction. The results of the three-point bending showed that there was no significant difference detected in stiffness between control and nicotine groups at 8 weeks post-saline/nicotine delivery ( P=0.705). The bone/implant contact ratio in nicotine-delivered group was significantly decreased compared with those in the control group at 4 weeks ( P<0.05). Also, expression levels of osteopontin, type II collagen, bone morphogenic protein-2, bone sialoprotein, and core-binding factor α-1 were significantly down-regulated in the nicotine-delivered group compared with the control. Although systemic exposure to nicotine did not affect rat bone development, bone wound healing around the implant after placement was affected. These findings suggest that nicotine might inhibit the bone matrix-related gene expressions required for wound healing and thereby diminish implant osseointegration at late stage. Yamano S, Berley JA, Kuo WP, Gallucci GO, Weber HP, Sukotjo C. Effects of nicotine on gene expression and osseointegration in rats. Clin. Oral Impl. Res. , 2010; 1353-1359. doi: 10.1111/j.1600-0501.2009.01955.x [ABSTRACT FROM AUTHOR]

To compare the remodeling of the alveolar process at implants installed immediately into extraction sockets by applying a flap or a 'flapless' surgical approach in a dog model. Implants were installed immediately into the distal alveoli of the second mandibular premolars of six Labrador dogs. In one side of the mandible, a full-thickness mucoperiosteal flap was elevated (control site), while contra-laterally, the mucosa was gently dislocated, but not elevated (test site) to disclose the alveolar crest. After 4 months of healing, the animals were sacrificed, ground sections were obtained and a histomorphometric analysis was performed. After 4 months of healing, all implants were integrated ( n=6). Both at the test and at the control sites, bone resorption occurred with similar outcomes. The buccal bony crest resorption was 1.7 and 1.5 mm at the control and the test sites, respectively. 'Flapless' implant placement into extraction sockets did not result in the prevention of alveolar bone resorption and did not affect the dimensional changes of the alveolar process following tooth extraction when compared with the usual placement of implants raising mucoperiosteal flaps. Caneva M, Botticelli D, Salata LA, Souza SLS, Bressan E, Lang NP. Flap vs. 'flapless' surgical approach at immediate implants: a histomorphometric study in dogs. Clin. Oral Impl. Res. , 2010; 1314-1319. doi: 10.1111/j.1600-0501.2009.01959.x [ABSTRACT FROM AUTHOR]

Aim: To study osseointegration and bone-level changes at implants installed using either a standard or a reduced diameter bur for implant bed preparation. Material and methods: In six Labrador dogs, the first and second premolars were extracted bilaterally. Subsequently, mesial roots of the first molars were endodontically treated and distal roots, including the corresponding part of the crown, were extracted. After 3 months of healing, flaps were elevated and recipient sites were prepared in all experimental sites. The control site was prepared using a standard procedure, while the test site was prepared using a drill with a 0.2 mm reduced diameter than the standard one used in the contra-lateral side. After 4 months of healing, the animals were euthanized and biopsies were obtained for histological processing and evaluation. Results: With the exception of one implant that was lost, all implants were integrated in mineralized bone. The alveolar crest underwent resorption at control as well as at test sites (buccal aspect ∼1 mm). The most coronal contact of bone-to-implant was located between 1.2 and 1.6 mm at the test and between 1.3 and 1.7 mm at the control sites. Bone-to-implant contact percentage was between 49% and 67%. No statistically significant differences were found for any of the outcome variables. Conclusions: After 4 months of healing, lateral pressure to the implant bed as reflected by higher insertion torques (36 vs. 15 N cm in the premolar and 19 vs. 7 N cm in the molar regions) did not affect the bone-to-implant contact. To cite this article: Pantani F, Botticelli D, Garcia IR Jr., Salata LA, Borges GJ, Lang NP. Influence of lateral pressure to the implant bed on osseointegration: an experimental study in dogs. Clin. Oral Impl. Res. 21, 2010; 1264-1270. doi: 10.1111/j.1600-0501.2009.01941.x [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the influence of implant size and configuration on osseointegration in implants immediately placed into extraction sockets. Material and methods: Implants were installed immediately into extraction sockets in the mandibles of six Labrador dogs. In the control sites, cylindrical transmucosal implants (3.3 mm diameter) were installed, while in the test sites, larger and conical (root formed, 5 mm diameter) implants were installed. After 4 months of healing, the resorptive patterns of the alveolar crest were evaluated histomorphometrically. Results: With one exception, all implants were integrated in mineralized bone, mainly composed of mature lamellar bone. The alveolar crest underwent resorption at the control as well as at the test implants. This resorption was more pronounced at the buccal aspects and significantly greater at the test (2.7±0.4 mm) than at the control implants (1.5±0.6 mm). However, the control implants were associated with residual defects that were deeper at the lingual than at the buccal aspects, while these defects were virtually absent at test implants. Conclusions: The installment of root formed wide implants immediately into extraction sockets will not prevent the resorption of the alveolar crest. In contrast, this resorption is more marked both at the buccal and lingual aspects of root formed wide than at standard cylindrical implants. To cite this article: Caneva M, Salata LA, de Souza SS, Bressan E, Botticelli D, Lang NP. Hard tissue formation adjacent to implants of various size and configuration immediately placed into extraction sockets: an experimental study in dogs. Clin. Oral Impl. Res. 21, 2010; 885–895. doi: 10.1111/j.1600-0501.2010.01931.x [ABSTRACT FROM AUTHOR]