A 10-year Retrospective Clinical Study to Identify Risk Indicators for Peri-Implant Bone Loss and Implant Failure.

AIM: To evaluate long-term survival and success of dental implants and evaluate indicators affecting the long-term outcome. MATERIALS AND METHODS: Implant survival, success and crestal bone loss (BL) over time were evaluated. For covariates at patient level, Kaplan-Meier estimates of implant survival were compared between groups with the log-rank test. Observed mean bone loss (MBL) was plotted as a function of time. Cumulative frequencies of BL were plotted for different post-op times. Uni- and multivariate analysis was performed. Simple linear mixed and multiple linear mixed models for BL at 1, 5 and 10 years were fitted. RESULTS: 407 patients (221 women, 186 men; mean age 64.86 years (range 28-92, SD 10.11)), with 1482 implants, responded. Absolute implant survival was 94.74%; MBL was 0.81 mm (SD 1.58, range 0.00-17.00) after an average follow-up of 10.66 years (range 10-14, SD 0.87). Implant survival was influenced on implant level by smoking, implant width and early bone loss (EBL) > 0.5 mm; on patient level by a history of periodontitis. Indicators influencing MBL after the 1st year were abutment height, type of surgery and implant width, while after 5 and 10 years of function were abutment height, EBL > 0.5 mm and smoking. CONCLUSION: Implant survival was significantly affected by a history of periodontitis on patient level and by smoking, implant width and EBL > 0.5 mm on implant level. Late bone loss was significantly affected by abutment height, EBL > 0.5 mm and smoking. TRIAL REGISTRATION: B670201524796.

"Longitudinal Oral Health-Related Quality of Life in maxillary mini dental implant overdentures after 3 years in function".

OBJECTIVES: Longitudinal evaluation of Oral Health-Related Quality of Life (OHRQoL) during treatment of flaplessly placed, one-piece mini-dental-implants (MDIs) for maxillary overdentures is rarely investigated, nor is the impact of MDI failures. MATERIAL AND METHODS: This multicenter prospective cohort study evaluated the 3-year outcome of 5-6 MDIs in the edentulous maxilla in patients above 50 years with dentate mandible. Provisional dentures were provided before final prosthetic connection was established at 6 months. Postoperative discomfort was assessed using a visual analogue score (VAS). OHRQoL was investigated using the Oral Health Impact Profile (OHIP)-14 at baseline (preoperatively), postoperatively, post-prosthetic connection and after 3 years in function. RESULTS: 164 (78.4%) of the 204 placed MDIs were still in situ after 3 years, in 29/31 patients. Two patients lost 5/6 MDIs resulting in two prosthetic failures (6.45%). With regard to pain, a score of 4.1/10 (SD 2.8) was recorded on day 1, and 1.1/10 (SD 1.7) on day 7. A decrease in total OHIP-14 scores was observed postoperatively (15.6; SD 12.8) as compared to baseline (21.3; SD 13.1), with improvement of OHRQoL. Furthermore, this was statistically significant at connection of the final prosthesis (7.3; SD 6.7) (p = .006). The OHIP-14 improved less (p = .011) when experiencing one or more implant losses (9.5; SD: 9.85), in comparison with no implant loss (20.7; SD: 13.97). A failure of one MDI did not affect OHIP-14 score (p = .658); however, multiple failures did (p = .007). CONCLUSION: Maxillary MDI overdenture treatment yields significant OHRQoL improvement when at least 5 MDIs survive, preserving functional comfort.

A controlled study on the diagnostic accuracy of panoramic and peri-apical radiography for detecting furcation involvement.

BACKGROUND: The aims of this study were (1) to determine the accuracy, sensitivity, and specificity of panoramic and peri-apical radiographs in diagnosing furcation involvement, as well as (2) to evaluate the possible impact of clinical experience on these diagnostic parameters. METHODS: An existing radiographic dataset of periodontitis patients requiring implant surgery was retrospectively examined for furcation involvement. Criteria for inclusion were the presence of a CBCT, panoramic and peri-apical radiograph of the site of interest within a one-year time frame. All furcation sites were classified using the CBCT, which was considered as the gold standard, according to Hamp's index (1975). Ten experienced examiners and 10 trainees were asked to assess furcation involvement for the same defects using only the corresponding panoramic and peri-apical radiographs. Absolute agreement, Cohen's weighted kappa, sensitivity, specificity and ROC-curves were analyzed. RESULTS: The study sample included 60 furcation sites in 29 multi-rooted teeth from 17 patients. On average, 20/60 furcations were correctly classified according to the panoramic radiographs, corresponding to a weighted kappa score of 0.209, indicating slight agreement. Similarly, an average of 19/60 furcations were correctly classified according to the peri-apical radiographs, corresponding to a weighted kappa score of 0.211, also indicating slight agreement. No significant difference between panoramic and peri-apical radiography was found (P = 0.903). When recategorizing FI Grades into 'no to limited FI' (FI Grade 0 and I) and 'advanced FI' (FI Grade II and III), the panoramic and peri-apical radiography showed low sensitivity (0.558 and 0.441, respectively), yet high specificity (0.791 and 0.790, respectively) for identifying advanced FI. The ROC-curves for the panoramic and peri-apical radiographs were 0.79 and 0.69 respectively. No significant difference was found between experienced periodontists and trainees (P = 0.257 versus P = 0.880). CONCLUSION: Panoramic and peri-apical radiography are relevant tools in the diagnosis of FI and provide high specificity. Ideally, they are best used in combination with furcation probing, which shows high sensitivity. Furthermore, clinical experience does not seem to improve the accuracy of a radiological diagnosis of furcation sites. TRIAL REGISTRATION: Patient radiographic datasets were retrospectively analyzed.

Cost-effectiveness analysis of two attachment systems for mandibular overdenture.

OBJECTIVES: This study analysed the cost-effectiveness of two different attachments for the 2-implant overdenture (2IOD) in edentulous mandibles. MATERIALS AND METHODS: When considering alternative treatments, cost-effectiveness analysis is an important factor for stakeholders (patient, clinician, social security, insurance company, etc.). A general practice population (n = 116) was treated between 2003 and 2013 with a mandibular 2IOD with 2 different ball/stud attachment systems, one spherical (Group D) and one cylindrical (Group L). Patient well-being was assessed with OHIP-14-Total (OHIP-14-T), at intake and annually up to 5 years, to calculate the health effect. Initial and maintenance costs of both treatments were inventoried. The cost-effectiveness was compared. Annual discount rates of 4% and 1.5% were applied to future costs and health outcomes, following Dutch guidelines. Prices were adjusted to the year 2003. To offset the uncertainty in relevant input parameters, a sensitivity analysis was performed using bootstrap analysis. Significance was set at p < .05. RESULTS: The health effect was 6.36 (SD 5.32) for Group D and 8.54 (SD 5.63) for Group L. The sum of the discounted costs up to 5 years was EUR 4,210.98 (SD 634.75) for the D and EUR 3,840.62 (SD 302.63) for the Group L (p = .005). The bootstrapping reports that L abutment clearly dominates the D abutment in terms of cost-effectiveness. CONCLUSIONS: The 2IOD on the L abutment is dominant compared to the 2IOD on D abutment, in a 5-year perspective.

Biomaterials and regenerative technologies used in bone regeneration in the craniomaxillofacial region: Consensus report of group 2 of the 15th European Workshop on Periodontology on Bone Regeneration.

BACKGROUND AND AIMS: To review the regenerative technologies used in bone regeneration: bone grafts, barrier membranes, bioactive factors and cell therapies. MATERIAL AND METHODS: Four background review publications served to elaborate this consensus report. RESULTS AND CONCLUSIONS: Biomaterials used as bone grafts must meet specific requirements: biocompatibility, porosity, osteoconductivity, osteoinductivity, surface properties, biodegradability, mechanical properties, angiogenicity, handling and manufacturing processes. Currently used biomaterials have demonstrated advantages and limitations based on the fulfilment of these requirements. Similarly, membranes for guided bone regeneration (GBR) must fulfil specific properties and potential biological mechanisms to improve their clinical applicability. Pre-clinical and clinical studies have evaluated the added effect of bone morphogenetic proteins (mainly BMP-2) and autologous platelet concentrates (APCs) when used as bioactive agents to enhance bone regeneration. Three main approaches using cell therapies to enhance bone regeneration have been evaluated: (a) "minimally manipulated" whole tissue fractions; (b) ex vivo expanded "uncommitted" stem/progenitor cells; and (c) ex vivo expanded "committed" bone-/periosteum-derived cells. Based on the evidence from clinical trials, transplantation of cells, most commonly whole bone marrow aspirates (BMA) or bone marrow aspirate concentrations (BMAC), in combination with biomaterial scaffolds has demonstrated an additional effect in sinus augmentation and horizontal ridge augmentation, and comparable bone regeneration to autogenous bone in alveolar cleft repair.

Five-year study of mandibular overdentures on stud abutments: Clinical outcome, patient satisfaction and prosthetic maintenance-Influence of bone resorption and implant position.

OBJECTIVES: This prospective study analyses the 5-year clinical outcome, patient satisfaction and the technical outcome of a 2-implant overdenture on stud abutments. In addition, the influence of mandibular resorption and implant position on these outcomes was assessed. MATERIAL AND METHODS: Patients received two implants in a one-stage delayed protocol. Final prosthesis on stud abutments was finalized after 3 months. Implant survival, bone loss, plaque and sulcus bleeding index, OHIP-14, technical outcome and costs were assessed after 5 years. The Cawood-Howell classification defined the mandibular resorption. Inter-implant distances and angles (frontal, sagittal) were digitally measured. The significance level was p < .05. RESULTS: Fifty-six patients, 23 female and 33 males (mean age = 66.3, range 41-82), completed the follow-up. No implants were lost. Radiographical crestal bone loss was on average 1.25 mm (standard deviation SD 1.06), bleeding index was 0.75 (SD 0.73), and plaque index was 1.15 (SD 0.75) and higher for low mandibles (p = .001). The OHIP-14 reduction post-connection and after 5 years was significant (p < .001). Five-year maintenance required on average 6.7 (SD 4.8, range 0-25) interventions per patient. A larger inter-implant distance was associated with fewer replacement of retention inserts (p = .034) and less interventions (p = .006). Larger frontal (p = .023) and sagittal (p = .046) inter-implant angles (non-parallelism) required more inserts. The maintenance cost negatively influences the patient satisfaction (p = .004). 83% of the stud abutments showed wear. CONCLUSION: The implant overdenture on cylindrical stud abutments is a good and stable solution, irrespective of the resorption profile of the mandible. OHIP-14 improved permanently up to 5 years but is negatively influenced by complication cost. A small inter-implant distance, more frontal, sagittal inter-implant divergence increased maintenance.

Speech evaluation during maxillary mini-dental implant overdenture treatment: A prospective study.

Large proportions of patients are edentulous and wear removable dentures leading to reduced functional comfort and less oral health-related quality of life. Satisfaction with the oral situation after implantation depends on the outcome in eating comfort, speech comfort and aesthetics. Modification in form and location of the teeth may affect speech. The aim of this study is to determine speech, oromyofunctional behaviour, satisfaction with the treatment and the impact on quality of life of the horse-shoe overdenture retained by mini-dental implants (MDIs) in the maxilla. This prospective multicentre cohort study included 32 patients for treatment. 5 to 6 implants were placed, traumatically piercing the mucosa. Patients were evaluated three times during treatment (pre-operatively with conventional prosthesis including full palatal coverage (CD), post-operatively with provisionally relined CD and with horse-shoe overdenture on MDI). The assessment included a phonetic evaluation, examination of oromyofunctional behaviour, evaluation of the impact on quality of life (OHIP-14) and a rating of satisfaction with the treatment and speech on a visual analogue scale. Several speech sounds are found to be disturbed before treatment. In the next two stages of the treatment, the number of speech issues decreases. In the final stage, ten people show minor speech problems, especially with the /s/ sound. In this stage, seven people still present with oromyofunctional problems, especially whistling problems. In this last stage, people are very satisfied with the treatment (83%) and with speech (84%). The impact on quality of life is low (8.23/56).

Adapting the vertical position of implants with a conical connection in relation to soft tissue thickness prevents early implant surface exposure: A 2-year prospective intra-subject comparison.

AIM: To evaluate the effect of soft tissue thickness on bone remodelling and to investigate whether implant surface exposure can be avoided by adapting the vertical implant position in relation to the soft tissue thickness. MATERIALS AND METHODS: Twenty-five patients received two non-splinted implants supporting an overdenture in the mandible. Soft tissue thickness was measured using bone sounding and ultrasonically. One implant was installed equicrestally (control), and the vertical position of the second implant was adapted to the site-specific soft tissue thickness (test). Crestal bone levels were determined on digital peri-apical radiographs and compared with baseline (implant placement). RESULTS: Twenty-five patients were consecutively treated. No implants failed during the follow-up. A significant correlation was observed between soft tissue thickness and bone level alterations after 6 months (ultrasound ICC = 0.610; bone sounding ICC = 0.641) with inferior bone levels for equicrestal implants when thin tissues are present. Subcrestal implants showed significantly better bone levels after 6-month (n = 24, 0.04 mm versus 0.72 mm; p < .001), 1-year (n = 24, 0.03 mm versus 0.77 mm; p < .001) and 2-year follow-up (n = 24, 0.04 mm versus 0.73 mm; p < .001). CONCLUSION: Initial bone remodelling was affected by soft tissue thickness. Anticipating biologic width re-establishment by adapting the vertical position of the implant seemed highly successful to avoid implant surface exposure.

How do peri-implant biologic parameters correspond with implant survival and peri-implantitis? A critical review.

OBJECTIVES: The aim of this critical review was to evaluate whether commonly used biologic diagnostic parameters correspond to implant survival and peri-implantitis prevalence. MATERIALS AND METHODS: Publications from 2011 to 2017 were selected by an electronic search using the Pubmed database of the US National Library of Medicine. Prospective and retrospective studies with a mean follow-up time of at least 5 years and reporting prevalence of peri-implantitis as well as mean bone loss and standard deviation were selected. The correlation between reported prevalence of peri-implantitis and reported implant survival, mean follow-up time, mean bone loss, mean probing depth, and mean bleeding on probing was calculated. Mean bone loss and standard deviation were used for estimation of proportion of implants with bone loss exceeding 1, 2, and 3 mm. RESULTS: Full-text analysis was performed for 255 papers from 4,173 available ones, and 41 met all the inclusion criteria. The overall mean weighted survival rate was 96.9% (89.9%-100%) and the reported prevalence of peri-implantitis ranged between 0% and 39.7%, based on 15 different case definitions. The overall weighted bone loss was 1.1 mm based on 8,182 implants and an average mean loading time ranging from 5 to 20 years. No correlation was found between mean bone loss and the reported prevalence of peri-implantitis. The estimated prevalence of implants with bone loss above 2 mm was 23%. The overall weighted mean probing depth was 3.3 mm, and mean weighted bleeding was 52.2%. Only a weak correlation was found between survival and function time (r = -0.49). There was no relation between the probing depth or bleeding and the mean bone loss, mean follow-up time, and reported prevalence of peri-implantitis. CONCLUSION: Biologic parameters mean probing depth and mean bleeding on probing do not correlate with mean bone loss and this irrespective of follow-up. Case definition for peri-implantitis varied significantly between studies indicating that an unambiguous definition based on a specified threshold for bone loss is not agreed upon in the literature.

Biological aspects: Summary and consensus statements of group 2. The 5th EAO Consensus Conference 2018.

OBJECTIVES: This publication reports the EAO Workshop group-2 discussions and consensus statements which provided the scientific evidence on the influence of biological parameters on implant-related clinical outcomes. MATERIAL AND METHODS: The first publication was a systematic review on the biological effects of abutment material on the stability of peri-implant marginal bone levels and the second, a critical narrative review on how peri-implant diagnostic parameters correspond with long-term implant survival and success. The group evaluated the content of both publications, made corrections and recommendations to the authors and agreed on the consensus statements, clinical recommendations and recommendations for future research, which are described in this consensus report. RESULTS: Tested abutment materials can be considered appropriate for clinical use according to the observation period studied (mean 3.5 years). Mean peri-implant bone loss and mean probing pocket depths are not adequate outcomes to study the prevalence of peri-implantitis, while the reporting of frequency distributions is considered more appropriate. CONCLUSIONS: Titanium is currently considered the standard of care as abutment material, although other materials may be more suitable for aesthetic locations. Peri-implantitis should be diagnosed through composite evaluations of peri-implant tissue inflammation and assessment of marginal bone loss with different thresholds.

Dental implant register: Summary and consensus statements of group 2. The 5th EAO Consensus Conference 2018.

OBJECTIVES: This publication reports the EAO Workshop group-2 and consensus plenary discussions and statements on a narrative review providing the background and possible facilities and importance of a dental implant register, to allow for a systematic follow-up of the clinical outcome of dental implant treatment in various clinical settings. It should be observed that the format of the review and the subsequent consensus report consciously departs from conventional consensus publications and reports. MATERIAL AND METHODS: The publication was a narrative review on the presence and significance of quality registers regarding select medical conditions and procedures. The group discussed and evaluated the publication and made corrections and recommendations to the authors and agreed on the statements and recommendations described in this consensus report. RESULTS: Possible registrations to be included in an implant register were discussed and agreed as a preliminary basis for further development, meaning that additional parameters be included or some be deleted. CONCLUSIONS: It was agreed to bring the idea of an implant quality register, including the presented results of discussions and proposals by the group- and plenary sessions, to the EAO Board for further discussion and decision.

Assessment of periodontal bone level revisited: a controlled study on the diagnostic accuracy of clinical evaluation methods and intra-oral radiography.

OBJECTIVES: The accuracy of analogue and especially digital intra-oral radiography in assessing interdental bone level needs further documentation. The aim of this study was to compare clinical and radiographic bone level assessment to intra-surgical bone level registration (1) and to identify the clinical variables rendering interdental bone level assessment inaccurate (2). MATERIALS AND METHODS: The study sample included 49 interdental sites in 17 periodontitis patients. Evaluation methods included vertical relative probing attachment level (RAL-V), analogue and digital intra-oral radiography and bone sounding without and with flap elevation. The latter was considered the true bone level. Five examiners evaluated all radiographs. RESULTS: Significant underestimation of the true bone level was observed for all evaluation methods pointing to 2.7 mm on average for analogue radiography, 2.5 mm for digital radiography, 1.8 mm for RAL-V and 0.6 mm for bone sounding without flap elevation (p < 0.001). Radiographic underestimation of the true bone level was higher in the (pre)molar region (p ≤ 0.047) and increased with defect depth (p < 0.001). Variation between clinicians was huge (range analogue radiography 2.2-3.2 mm; range digital radiography 2.1-3.0 mm). CONCLUSION: All evaluation methods significantly underestimated the true bone level. Bone sounding was most accurate, whereas intra-oral radiographs were least accurate. Deep periodontal defects in the (pre)molar region were most underrated by intra-oral radiography. CLINICAL RELEVANCE: Bone sounding had the highest accuracy in assessing interdental bone level.

A 5-year prospective study on regenerative periodontal therapy of infrabony defects using minimally invasive surgery and a collagen-enriched bovine-derived xenograft.

AIM: The primary objective of this study was (1) to evaluate the 5-year clinical outcome of regenerative periodontal therapy (RPT) using minimally invasive surgery and a collagen-enriched bovine-derived xenograft and (2) to identify predictors for clinical attachment level (CAL) gain and vertical radiographic bone (RB) gain. MATERIALS AND METHODS: Ninety-five non-smoking patients with ≤ 25% full-mouth plaque and bleeding presenting ≥ 6 months after initial periodontal therapy with ≥ 1 isolated interdental infrabony defect were recruited. Minimally invasive surgery (MIST or M-MIST) and a collagen-enriched bovine-derived xenograft were used in all patients. Patients were surgically treated by the same clinician and evaluated up to 5 years of follow-up. Multivariate analyses were used to identify predictors for CAL gain and RB gain. RESULTS: Before surgery, mean probing depth (PD) was 7.8 mm, CAL was 10.0 mm, and defect depth amounted to 5.2 mm. Seventy-one patients (33 men, 38 women, mean age 52) could be evaluated at 5 years. Mean PD reduction was 3.3 mm (SD 2.2), CAL gain was 3.0 mm (SD 2.1), and RB gain was 57% (SD 38). Forty-five percent showed ≥ 4 mm CAL gain, whereas 24% were considered failures (≤ 1 mm CAL gain). Forty-eight percent showed considerable RB gain (≥ 75%). Regression analyses showed that plaque was a significant predictor for CAL gain (p = 0.001) and RB gain (p = 0.005). Patients' compliance had a significant impact on RB gain (p < 0.001). CONCLUSION: Only patients with perfect oral hygiene and excellent compliance should be considered for RPT. Especially, the latter can only be assessed after sufficient follow-up following initial periodontal therapy. CLINICAL RELEVANCE: RPT failed in 24% of the patients after 5 years. Regression analyses demonstrated a significant impact of plaque and patients' compliance on the long-term outcome. Only patients with perfect oral hygiene and excellent compliance should be considered for RPT. Patients should not be treated too soon following initial therapy, since compliance can only be reliably assessed after sufficient follow-up.

Impact of crestal bone resorption on quality of life and professional maintenance with conventional dentures or Locator-retained mandibular implant overdentures.

STATEMENT OF PROBLEM: The influence of the mandibular resorption profile on clinical outcome after converting a conventional complete denture into a Locator-retained implant overdenture is unknown. PURPOSE: The purpose of this prospective study was to assess the oral health-related quality of life (OHRQoL) and prosthetic maintenance of mandibular overdentures on 2 Locator abutments in relation to the resorption degree of the edentulous mandible. MATERIAL AND METHODS: Twenty-five participants were treated and classified according to the Cawood and Howell (CAW-H) resorption classification for the resorption profile of the mandible, CAW-H group III-IV (n=14) and CAW-H group V (n=11). Participants received conventional complete dentures (CDs) before implant placement and immediate nonfunctional loading on Locators with a resilient liner. After 3 months, the attachments were functionally activated. Assessments were made using the Oral Health Impact Profile 14 (OHIP-14) questionnaires with existing CDs and new CDs at 1, 3, and 15 months after loading. Prosthetic maintenance (repairs, rebasings, replacement of retention parts) and biological prosthetic aftercare were assessed. For comparison between groups, the Kruskal-Wallis and Mann-Whitney U tests were applied for continuous and ordinal variables and the chi-square test for cross-tabulations. To analyze repeated OHIP-14 scores, the Friedman test was used for ordered alternatives to test whether the measurements differed (overall significance level α=.05). Then the Wilcoxon signed rank test was conducted to detect specific differences (α=.05). RESULTS: OHIP-14 scores decreased significantly after implant placement and functional connection for the whole population (P<.001) and for both sub groups, the CAW-H group III-IV (P<.001) and the CAW-H group V (P=.013). CAW-H group V participants needed more retention inserts than CAW-H group III-IV participants (26 versus 3, respectively; P=.006). The incidence of repair and rebasing was limited for both groups, and biological aftercare and pain relief were comparable. CONCLUSIONS: Changing a CD to an overdenture significantly improved ORLQoL regardless of the resorption degree, but heavily resorbed mandibles require more replacements of retention inserts.

Modern implant dentistry based on osseointegration: 50 years of progress, current trends and open questions.

In the 1960s and 1970s, implant-supported prostheses based on subperiosteal or blade implants had a poor reputation because of questionable clinical outcomes and lack of scientific documentation. The change to a scientifically sound discipline was initiated by the two scientific pioneers of modern implant dentistry, Professor P. I. Brånemark from the University of Gothenburg in Sweden and Professor André Schroeder from the University of Bern in Switzerland. Together with their teams, and independently of each other, they laid the foundation for the most significant development and paradigm shift in dental medicine. The present volume of Periodontology 2000 celebrates 50 years of osseointegration. It reviews the progress of implant therapy over the past 50 years, including the basics of implant surgery required to achieve osseointegration on a predictable basis and evolving innovations. The development of bone-augmentation techniques, such as guided bone regeneration and sinus floor elevation, to correct local bone defects at potential implant sites has increased the indications for implant therapy. The paradigm shift to moderately rough implant surfaces resulted in faster and enhanced bone integration and led to improvements in various treatment protocols, such as immediate and early implant placement in postextraction sites, and made various loading protocols possible, including immediate and early implant loading. In the past 15 years, preoperative analysis and presurgical planning improved as a result of the introduction of three-dimensional imaging techniques. Hereby, cone-beam computed tomography offers better image quality with reduced radiation exposure, when compared with dental computed tomography. This opened the door for digital planning and surgical modifications. Over the last 50 years this evolution has facilitated tremendous progress in esthetic outcomes with implant-supported prostheses and improved patient-centered outcomes. This volume of Periodontology 2000 also discusses the current trends and open questions of implant dentistry, such as the potential of digital implant dentistry in the surgical and prosthetic field, the trend for an increasing average age of implant patients and the related adaptations of treatment protocols, and the second attempt to establish ceramic implants using, this time, zirconia as the implant material. Finally, some of the hottest controversies are discussed, such as recent suggestions on bone integration being a potential foreign-body reaction and the evidence-based appraisal of the peri-implantitis debate.

Current state of the art of computer-guided implant surgery.

The invention of computerized axial tomography (now known as computerized tomography) and developments of interactive software to allow virtual planning, with the aim to guide the surgery precisely toward a specific target, has dramatically improved general, as well as oral, surgery. Virtual dental implant planning allows for a prosthetically driven approach, resulting in the best possible design of the prosthesis, better esthetics, optimized occlusion and loading. This approach has also changed the surgical paradigm of using extensive flaps to obtain a proper view of the surgical area because flapless implant surgery, with or without immediate loading, has become more predictable. Two types of guided implant surgery protocols - static and dynamic - are described in the literature. The static approach, better known as computer-guided surgery, refers to the use of a tissue-supported surgical template. This reproduces the virtual implant position directly from computerized tomographic data and this information can be converted to guide templates to be used during surgery, with or without raising a mucoperiosteal flap. Dynamic guided surgery, also called navigation, reproduces the virtual implant position directly from computerized tomographic data and uses motion-tracking technology to guide the implant osteotomy preparation. As the technology developed further, different levels of evidence were presented that showed various degrees of accuracy. Several protocols for guided surgery are available in the literature and are distinguished by different guide production techniques, methods of support and drilling/placement protocols. Currently, implant planning software using cone-beam computerized tomography data has made it possible to plan the optical implant position virtually the optimal implant position, taking the surrounding vital anatomic structures and future prosthetic requirements into consideration. This paper summarizes the evolution and ongoing trends in digital and virtual planning and in implant surgery. The purpose of this overview was to clarify the different concepts in guided surgery and their respective advantages, disadvantages and limitations. The outcome of guided surgery is assessed in terms of implant survival, precision and complications. Clinical cases are given to demonstrate briefly the workflow and clinical guidelines for safe use of these approaches.

Esthetic assessments in implant dentistry: objective and subjective criteria for clinicians and patients.

In recent years the scientific community has shown a clear interest in the esthetic outcome of implant treatment. The present paper provides an overview of the esthetic ratings that have been used in implant dentistry. A distinction can be made between objective evaluations by clinicians and subjective evaluations by patients. The former mainly include: midfacial and interproximal soft-tissue levels; two-dimensional/three-dimensional soft-tissue alterations; assessment of the color match between the natural dentition, on the one hand, and the peri-implant tissues and the reconstruction, on the other hand; and ordinal indices, such as the pink and white esthetic score. Patient's needs and judgment may differ from objective indicators of implant success and esthetics. As a result, assessing treatment on the basis of patient-reported outcomes measures should be considered important. Validated questionnaires have been used that mainly assess the impact of oral health on the overall well-being of individuals. The esthetic judgment of patients is usually based on nonstandardized questions with varying scoring methods, including visual analog scales, Likert and other category scales and open questions. The heterogeneity in scoring systems between studies may compromise proper comparison of objective and subjective esthetic outcomes between studies and therapeutic concepts.

Implant surface roughness and patient factors on long-term peri-implant bone loss.

Dental implant placement is a common treatment procedure in current dental practice. High implant survival rates as well as limited peri-implant bone loss has been achieved over the past decades due to continuous modifications of implant design and surface topography. Since the turn of the millennium, implant surface modifications have focused on stronger and faster bone healing. This has not only yielded higher implant survival rates but also allowed modifications in surgical as well as prosthetic treatment protocols such as immediate implant placement and immediate loading. Stable crestal bone levels have been considered a key factor in implant success because it is paramount for long-term survival, aesthetics as well as peri-implant health. Especially during the past decade, clinicians and researchers have paid much attention to peri-implant health and more specifically to the incidence of bone loss. This could furthermore increase the risk for peri-implantitis, the latter often diagnosed as ongoing bone loss and pocket formation beyond the normal biological range in the presence of purulence or bleeding on probing. Information on the effect of surface topography on bone loss or peri-implantitis, a disease process that is to be evaluated in the long-term, is also scarce. Therefore, the current narrative review discusses whether long-term peri-implant bone loss beyond physiological bone adaptation is affected by the surface roughness of dental implants. Based on comparative studies, evaluating implants with comparable design but different surface roughness, it can be concluded that average peri-implant bone loss around the moderately rough and minimally rough surfaces is less than around rough surfaces. However, due to the multifactorial cause for bone loss the clinical impact of surface roughness alone on bone loss and peri-implantitis risk seems rather limited and of minimal clinical importance. Furthermore, there is growing evidence that certain patient factors, such as a history of periodontal disease and smoking, lead to more peri-implant bone loss.

Accuracy of digital impressions of multiple dental implants: an in vitro study.

INTRODUCTION: Studies demonstrated that the accuracy of intra-oral scanners can be compared with conventional impressions for most indications. However, little is known about their applicability to take impressions of multiple implants. AIM: The aim of this study was to evaluate the accuracy of four intra-oral scanners when applied for implant impressions in the edentulous jaw. MATERIAL AND METHODS: An acrylic mandibular cast containing six external connection implants (region 36, 34, 32, 42, 44 and 46) with PEEK scanbodies was scanned using four intra-oral scanners: the Lava C.O.S. and the 3M True Definition, Cerec Omnicam and 3Shape Trios. Each model was scanned 10 times with every intra-oral scanner. As a reference, a highly accurate laboratory scanner (104i, Imetric, Courgenay, Switzerland) was used. The scans were imported into metrology software (Geomagic Qualify 12) for analyses. Accuracy was measured in terms of trueness (comparing test and reference) and precision (determining the deviation between different test scans). Mann-Whitney U-test and Wilcoxon signed rank test were used to detect statistically significant differences in trueness and precision respectively. RESULTS: The mean trueness was 0.112 mm for Lava COS, 0.035 mm for 3M TrueDef, 0.028 mm for Trios and 0.061 mm for Cerec Omnicam. There was no statistically significant difference between 3M TrueDef and Trios (P = 0.262). Cerec Omnicam was less accurate than 3M TrueDef (P = 0.013) and Trios (P = 0.005), but more accurate compared to Lava COS (P = 0.007). Lava COS was also less accurate compared to 3M TrueDef (P = 0.005) and Trios (P = 0.005). The mean precision was 0.066 mm for Lava COS, 0.030 mm for 3M TrueDef, 0.033 mm for Trios and 0.059 mm for Cerec Omnicam. There was no statistically significant difference between 3M TrueDef and Trios (P = 0.119). Cerec Omnicam was less accurate compared to 3M TrueDef (P < 0.001) and Trios (P < 0.001), but no difference was found with Lava COS (P = 0.169). Lava COS was also less accurate compared to 3M TrueDef (P < 0.001) and Trios (P < 0.001). CONCLUSIONS: Based on the findings of this in vitro study, the 3M True Definition and Trios scanner demonstrated the highest accuracy. The Lava COS was found not suitable for taking implant impressions for a cross-arch bridge in the edentulous jaw.

Oral health-related quality of life changes after placement of immediately loaded single implants in healed alveolar ridges or extraction sockets: a 5-year prospective follow-up study.

OBJECTIVES: The impact of single implants on oral health-related quality of life (OHRQoL) is scarcely investigated, especially when combined with immediate placement and loading in extraction sockets. The aim was to describe prospectively the changes of OHRQoL with single implants placed in the esthetic zone in healed ridges or in extraction sockets after 5 years. MATERIAL AND METHODS: Ninety-six patients, enrolled at three clinical centers, received 102 single implants placed in a healed ridge (n = 54 implants/50 patients) or in extraction sockets (n = 48 implants/46 patients). Implants were immediately provisionalized, and permanent crowns were cemented after 12 weeks. Oral health impact profile questionnaires (OHIP-14) were completed before surgery, after 1 (provisional crown), 6 (permanent crown), 12 and 60 months, respectively. The overall OHIP-14 score pertains to seven domains with two items each and was assessed on a Likert scale of 0-4 (0 = never and 4 = very often). The evolution of the total OHIP-14 score and changes within all OHIP domains over time and between groups were assessed with a linear mixed-effect model analysis. RESULTS: After 5 years, overall implant survival was 98%. The total OHIP-14 score for both groups combined decreased from 0.50 at baseline to 0.17 at 6 months (P < 0.001), indicative of improvement. For both groups, this remained stable up to 5 years (P = 0.41). However, after 5 years, the total OHIP-14 score revealed a statistically significantly higher improvement in the healed group compared with the extraction group (P = 0.027). CONCLUSION: Missing a single tooth in the maxillary esthetic zone leads to limited OHRQoL problems as reflected by a low overall OHIP score. However, OHRQoL improves less in the extraction group, reflecting that replacing a missing tooth is perceived as more beneficial than replacing a present tooth.