Periodontal regeneration risk assessment in the treatment of intrabony defects.

BACKGROUND: Regenerative approaches performed in periodontics seems to be efficient in treating intrabony defects. There are, however, many factors that may affect the predictability of the regenerative procedures. The present article aimed to propose a new risk assessment tool for treating periodontal intrabony defects by regenerative therapy. METHODS: Different variables that could affect the success of a regenerative procedure were considered based on their impact on (i) the wound healing potential, promoting wound stability, cells, and angiogenesis, or (ii) the ability to clean the root surface and maintain an optimal plaque control or (iii) aesthetics (risk for gingival recession). RESULTS: The risk assessment variables were divided into a patient, tooth, defect, and operator level. Patient-related factors included medical conditions such as diabetes, smoking habit, plaque control, compliance with supportive care, and expectations. Tooth-related factors included prognosis, traumatic occlusal forces or mobility, endodontic status, root surface topography, soft tissue anatomy, and gingival phenotype. Defect-associated factors included local anatomy (number of residual bone walls, width, and depth), furcation involvement, cleansability, and number of sides of the root involved. Operator-related factors should not be neglected and included the clinician's level of experience, the presence of environmental stress factors, and the use of checklists in the daily routine. CONCLUSIONS: Using a risk assessment comprised of patient-, tooth-, defect- and operator-level factors can aid the clinician in identifying challenging characteristics and in the treatment decision process.

Increasing the margin of patient safety for periodontal and implant treatments: The role of human factors.

Early complications following periodontal and dental implant surgeries are typically attributed to technique or poor biological response, ignoring the possibility of the human element. Interestingly, significant experience is not correlated with increased success, whereas evidence supports the impact of clinical behavior on patient outcome. This is the result of errors, much like those scrutinized in other high-risk technical fields, such as aviation. What can be surprising is that those who make these errors are very well acquainted with best practices. Given this, how is it possible for the conscientious practitioner to fail to apply protocols that are nonetheless very well known? Recently, the concepts of human and organizational factors have been translated to medicine, though dentistry has been slow to recognize their potential benefit. This review lists specific human factor behaviors, such as use of checklists and crew resource management, which might improve postsurgical outcome.

Importance of keratinized mucosa around dental implants: Consensus report of group 1 of the DGI/SEPA/Osteology Workshop.

OBJECTIVES: To assess the literature on (i) the relevance of the presence of a minimum dimension of keratinized peri-implant mucosa (KPIM) to maintain the health and stability of peri-implant tissues, and; (ii) the surgical interventions and grafting materials used for augmenting the dimensions of the KPIM when there is a minimal amount or absence of it. MATERIAL & METHODS: Two systematic reviews complemented by expert opinion from workshop group participants served as the basis of the consensus statements, implications for clinical practice and future research, and were approved in plenary session by all workshop participants. RESULTS: Thirty-four consensus statements, eight implications for clinical practice, and 13 implications for future research were discussed and agreed upon. There is no consistent data on the incidence of peri-implant mucositis relative to the presence or absence of KPIM. However, reduced KPIM width is associated with increased biofilm accumulation, soft-tissue inflammation, greater patient discomfort, mucosal recession, marginal bone loss and an increased prevalence of peri-implantitis. Free gingival autogenous grafts were considered the standard of care surgical intervention to effectively increase the width of KPIM. However, substitutes of xenogeneic origin may be an alternative to autogenous tissues, since similar results when compared to connective tissue grafts were reported. CONCLUSION: Presence of a minimum width of KPIM should be assessed routinely in patients with implant supported restorations, and when associated with pathological changes in the peri-implant mucosa, its dimensions may be surgically increased using autogenous grafts or soft-tissue substitutes with evidence of proven efficacy.

Impact of timing of dental implant placement and loading: Summary and consensus statements of group 1-The 6th EAO Consensus Conference 2021.

OBJECTIVES: This publication reports on the EAO workshop group 1 summaries, discussions and consensus statements based on four systematic reviews evaluating the impact of timing of dental implant placement and loading. MATERIALS AND METHODS: The first of the systematic reviews was on the influence of the timing of implant placement and loading in the biological outcomes of implant-supported fixed partial dentures. The second systematic review evaluated the influence of the timing of implant placement and loading on the aesthetic outcomes in single-tooth implants. The third systematic review was on the long-term outcomes of maxillary single-tooth implants in relation to timing protocols of implant placement and loading and the fourth on patient's perception of timing concepts in implant dentistry. The group evaluated these systematic reviews, provided comments and additions as required and agreed on the relevant consensus statements as well as on clinical and research recommendations. RESULTS: Different timings of implant placement/loading presented with high implant survival rates. The systematic reviews evaluated from this working group provided a number of conclusions based on the available/current literature. However, the specific topic of timing is an area that further research is required in order to provide detailed guidelines for the different protocols to be employed.

Immediate Loading of Two Unsplinted Implants in Edentulous Patients with Mandibular Overdentures: A 10-year Retrospective Review of Patients from a Previously Conducted 1-year Cohort Study

PURPOSE: This 10-year retrospective study aimed to report implant bone changes in completely edentulous patients after a mandibular immediate loading protocol using two ball attachments. MATERIALS AND METHODS: This study was initially designed as a prospective 1-year cohort study, then extended with a 10-year retrospective evaluation of implant bone change. In the first part of the study, 43 edentulous patients wearing satisfactory maxillary and mandibular dentures for at least 3 months were included. Two interforaminal implants (Brånemark system, Nobel Biocare) were placed symmetrically in the anterior mandible using a surgical template and a torque greater than 40 Ncm. Immediately following surgery, 2.25-mm-diameter ball abutments were screwed to the implants, and their matrices (Dalbo Plus, Cendres et Métaux) were incorporated in the denture base. In an initial 1-year study, clinical recalls were scheduled 3, 6, and 12 months after implant placement with a team of two investigators. The follow-up consisted of a clinical examination and a standardized radiographic assessment of the vertical bone change. Implant stability was then monitored. The patient satisfaction was evaluated with a questionnaire before and 3 months after loading. The second part of the study occurred 10 years after the inclusion, as patients were recalled for an implant bone change monitoring. RESULTS: The included patients were 28 to 80 years of age (mean: 61 ± 11.4 years). Three out of 86 implants failed during the healing phase (survival rate of 96.5% [90.1%, 99.2%]). Implant stability was maintained all along the 1-year follow-up (Δ = 73.33, 95% CI [72.39 to 74.26], P = .032). The mean radiographic bone loss was 0.27 ± 0.35 mm at 3 months after surgery, 0.47 ± 0.42 mm after 1 year, and 0.95 ± 0.98 mm after 10 years. General visual analog scale satisfaction was increased by 25 units with the treatment. No patients were lost to follow-up at 1 year, but five were lost at 10 years. CONCLUSION: This protocol of immediate loading of two unsplinted mandibular implants in overdenture patients using ball attachments is a clinically viable treatment with a high implant success rate and improved satisfaction.

Biomechanical aspects: Summary and consensus statements of group 4. The 5th EAO Consensus Conference 2018.

OBJECTIVES: The aim of the present publication was to report on the EAO Workshop group-4 discussions and consensus statements on the five reviews previously prepared. These reviews provided the scientific evidence on the effect of crown-to-implant ratio, on reconstructions with cantilevers in fully and partially edentulous patients, on biological and technical complications of tilted in comparison with straight implants, and on the effects of osseointegrated implants functioning in a residual dentition. MATERIAL AND METHODS: The group discussed, evaluated, corrected where deemed appropriate, and made recommendations to the authors regarding the following five reviews submitted: (a) Is there an effect of crown-to-implant ratio on implant treatment outcomes?; (b) Implant-supported cantilevered fixed dental rehabilitations in fully edentulous patients; (c) and in partially edentulous patients; (d) Biological and technical complications of tilted implants in comparison with straight implants supporting fixed dental prostheses; (e) What are the adverse effects of osseointegrated implants functioning among natural teeth of a residual dentition? Based on the five manuscripts and the discussion among the group as well as the plenum members, the major findings were summarized, consensus statements were formulated, clinical recommendations were proposed, and areas of future research were identified. RESULTS: Crown-to-implant ratios ranging from 0.9 to 2.2 did not influence the occurrence of biological or technical complications also in single-tooth restorations. Reconstructions with cantilevers for the rehabilitation of fully and partially edentulous jaws showed high implant and reconstruction survival rates. In contrast, the rate of complications-in particular associated with veneering material-was high during the observation period of 5-10 years. The data reported were primarily derived from studies with high risk of bias. The data for single-implant reconstructions were small. There was no evidence that distally tilted implants were associated with higher failure rates and increased amounts of marginal bone loss. The data supporting these findings, however, were at high risk of bias and frequently incompletely reported. Frequent positional changes occurred between the natural teeth and the implant-supported restorations. These changes were more pronounced in younger individuals, and even though they were reduced with age, they still occurred in adult patients. Even though these changes were frequent, potential implications for the patient are unclear. CONCLUSIONS: The use of single-tooth restorations with crown-to-implant ratio in between 0.9 and 2.2 may be considered a viable treatment option. Multiunit reconstructions with cantilevers are a viable treatment option in fully and partially edentulous patients. Clinicians and patients should be aware, however, that complications are frequent and primarily related to resin material used for veneering. There is some evidence that tilting an implant does affect stability of the implant and the surrounding bone. Treatment options to tilted implants should carefully be considered, as the effect on soft tissues and on prosthesis behavior is poorly reported for tilted implants. Positional changes in the dentition in relation to implant-supported restorations occur frequently. The patient should be informed about the possible need for a treatment related to these changes in the long term.

Treatment of class III multiple gingival recessions: Prognostic factors for achieving a complete root coverage.

BACKGROUND: This report is intended to present a supplemental analysis of data from a prior report (Aroca et al., ) to investigate factors associated with a complete root coverage at 1 year. The purpose of the prior report was to investigate at 1 year the adjunction effect of EMD for the treatment of Miller's class III recession defects using a coronally advanced modified tunnel/CTG technique with (test group) or without (control group). The purpose of this report was to investigate additional factors associated with root coverage in the same data set. MATERIALS AND METHODS: On the 138 observations collected from 20 patients, a regression model was used to highlight the relationship between the percentages of root coverage (RC) and three following covariates: the distance from the tip of the papilla and the contact point (DCP) at baseline, the group membership (control vs. test) and tooth position in the mouth (maxillary vs. mandibular). RESULTS: The statistical analysis showed that there was a significant effect of the DCP at baseline (p = 0.01) and of the tooth type (p < .001) on the percentage of RC at 1 year, whereas no significant difference between the two techniques (group membership effect) was shown (p = 0.69). CONCLUSION: The probability to obtain a complete root coverage decreases when the DCP at baseline increases. Moreover, maxillary teeth are more likely to give better RC than mandibular teeth. However, in this analysis similar to the last, there was no group effect.

Are "Human Factors" the Primary Cause of Complications in the Field of Implant Dentistry?

Complications in medicine and dentistry are usually analyzed from a purely technical point of view. Rarely is the role of human behavior or judgment considered as a reason for adverse outcomes. When the role of human factors is considered, these are usually described in general terms rather than specifically identifying the factors responsible for an adverse event. The impact of cognitive and behavioral factors in the explanation of adverse events has been studied in other high-stakes areas such as aviation and nuclear power. Specific protocols have been developed to reduce rates of human error, and, where human error is unavoidable, to lessen its impact. This approach has dramatically reduced the incidence of accidents in these fields. This article aims to review how a similar approach may prove valuable in the reduction of complications in implant dentistry.

[Is human behavior the leading cause of complications in medical practice?]. / Le comportement humain : première cause de complication en pratique médicale ?

Medical errors and the resulting complications are most often analyzed from a purely technical viewpoint. The impact of human behavior is very seldom raised among the major causes of severe undesirable events (SUE) in the medical field. When human responsibility is advanced, the thrust is always negative and critical, i.e. the "culprit" did not comply with the rules. However, in other risk-related human activities, such as aeronautics or the nuclear energy sector, the influence of human behavior in triggering SUEs has been examined and is now acknowledged to be one of the main causes of complications and problems. Specific protocols have been devised to reduce the number of mistakes made and to eliminate repercussions when errors inevitably occur. This novel approach has considerably reduced the accident rate in this type of industry. The aim of this article is to show that the same approach can be adopted in medicine and that taking human factors into account when analyzing medical practices can lead to significant improvements in safety and security.

Early Implant Failures Related to Individual Surgeons: An Analysis Covering 11,074 Operations Performed during 28 Years.

BACKGROUND: Compared with knowledge on patient and implant component factors, little knowledge is available on surgeons' role in early implant failures. PURPOSE: To report incidence of early implant failures related to total number of operations performed by individual surgeons. MATERIALS AND METHODS: Early implant failures (≤1 year of implant prosthesis function) were reported after a total of 11,074 implant operations at one specialist clinic during 28 years of surgery. Altogether, 8,808 individual patients were treated by 23 different dentists, of whom 21 surgeons were specialists in oral surgery or periodontology. Recorded failures were related to total numbers of performed operations per surgeon, followed by statistical comparisons (χ2 ) between surgeons with regard to type of treated jaw and implant surface. RESULTS: Altogether, 616 operations were recorded with early implant failures (5.6%), most often observed in edentulous upper jaws after placing implants with a turned surface (p < .05). Significant differences between surgeons, gender of surgeon, type of treated jaws by the surgeon, and implant surface used by the surgeon could be observed (p < .05). CONCLUSIONS: Early implant failures are complex, multifactorial problems associated with many aspects in the surgical procedure. A stochastic variation of failures for individual surgeons could be observed over the years. Different levels of failure rate could be observed between the surgeons, occasionally reaching significant levels as a total or for different jaw situations (p < .05). The surgeons reduced their failure rates when using implants with moderately rough surfaces (p < .5), but the relationship of failure rate between the surgeons was maintained.

Short implant in limited bone volume.

Rehabilitation of severely resorbed jaws with dental implants remains a surgical and prosthetic challenge for clinicians. The purpose of this review was to evaluate the available data on short-length implants and discuss their indications and limitations in daily clinical practice. A structured review of MEDLINE and a manual search were conducted. Thirty-two case series devoted to short-length implants, 14 reviews and 3 randomized controlled trials were identified. Of this group of papers, we can conclude that short-length implants can be successfully used to support single and multiple fixed reconstructions in posterior atrophied jaws, even in those with increased crown-to-implant ratios. The use of short-length implants allows treatment of patients who are unable to undergo complex surgical techniques for medical, anatomic or financial reasons. Moreover, the use of short-length implants in daily clinical practice reduces the need for complex surgeries, thus reducing morbidity, cost and treatment time. The use of short implants promotes the new concept of stress-minimizing surgery, allowing the surgeon to focus more on the correct three-dimensional positioning of the implant.

Impact of implant length and diameter on survival rates.

INTRODUCTION: Despite the high success rates of endosseous oral implants, restrictions have been advocated to their placement with regard to the bone available in height and volume. The use of short or nonstandard-diameter implants could be one way to overcome this limitation. MATERIAL AND METHODS: In order to explore the relationship between implant survival rates and their length and diameter, a Medline and a hand search was conducted covering the period 1990-2005. Papers were included which reported: (1) relevant data on implant length and diameter, (2) implant survival rates; either clearly indicated or calculable from data in the paper, (3) clearly defined criteria for implant failure, and in which (4) implants were placed in healed sites and (5) studies were in human subjects. RESULTS: A total of 53 human studies fulfilled the inclusion criteria. Concerning implant length, a relatively high number of published studies (12) indicated an increased failure rate with short implants which was associated with operators' learning curves, a routine surgical preparation (independent of the bone density), the use of machined-surfaced implants, and the placement in sites with poor bone density. Recent publications (22) reporting an adapted surgical preparation and the use of textured-surfaced implants have indicated survival rates of short implants comparable with those obtained with longer ones. Considering implant diameter, a few publications on wide-diameter implants have reported an increased failure rate, which was mainly associated with the operators' learning curves, poor bone density, implant design and site preparation, and the use of a wide implant when primary stability had not been achieved with a standard-diameter implant. More recent publications with an adapted surgical preparation, new implant designs and adequate indications have demonstrated that implant survival rate and diameter have no relationship. DISCUSSION: When surgical preparation is related to bone density, textured-surfaced implants are employed, operators' surgical skills are developed, and indications for implant treatment duly considered, the survival rates for short and for wide-diameter implants has been found to be comparable with those obtained with longer implants and those of a standard diameter. The use of a short or wide implant may be considered in sites thought unfavourable for implant success, such as those associated with bone resorption or previous injury and trauma. While in these situations implant failure rates may be increased, outcomes should be compared with those associated with advanced surgical procedure such as bone grafting, sinus lifting, and the transposition of the alveolar nerve.

Short implants in the severely resorbed maxilla: a 2-year retrospective clinical study.

BACKGROUND: Although the predictability of endosseous dental implants is well documented, the restoration of the posterior region of the maxilla remains a challenge. The placement of short implants is one therapeutic option that reduces the need for augmentation therapy. PURPOSE: The purpose of this retrospective study was to assess the survival rates of 6 to 8.5 mm-long implants in the severely resorbed maxilla following a surgical protocol for optimized initial implant stability. MATERIALS AND METHODS: The study included 85 patients with 96 short (6-8.5 mm) implants (Brånemark System, Nobel Biocare AB, Göteborg, Sweden) supporting single-tooth and partial reconstructions. The implants had a machined (54) or an oxidized (TiUnite, Nobel Biocare AB) (42) surface. A one-stage surgical protocol with delayed loading was used. The patients were followed for at least 2 years after loading (average follow-up period 37.6 months). The marginal bone resorption was assessed by radiographic readings. RESULTS: Five implants were lost during the first 9 months, and four implants were lost to follow-up. The cumulative survival rate was 94.6%. Four of the failed implants had a machined surface, and one had an oxidized surface. The mean marginal bone resorption after 2 years in function was 0.44 +/- 0.52 mm. CONCLUSION: This study demonstrates that the use of short implants may be considered for prosthetic rehabilitation of the severely resorbed maxilla as an alternative to more complicated surgical techniques.

Influence of implant length and bicortical anchorage on implant stress distribution.

BACKGROUND: Short implants present superior failure rates for everybody. PURPOSE: The aim of this theoretic study was to assess to what extent implant length and bicortical anchorage affect the way stress is transferred to implant components, the implant proper, and the surrounding bone. MATERIALS AND METHODS: Stress analysis was performed using finite element analysis. A three-dimensional linear elastic model was generated. All implants modeled were of the same diameter (3.75 mm) but varied in length, at 6, 7, 8, 9, 10, 11, and 12 mm (Brånemark System, Nobel Biocare AB, Gothenburg, Sweden). Each implant was modeled with a titanium abutment screw and abutment, a gold cylinder and prosthetic screw, and a ceramic crown. The implants were seated in a supporting bone structure consisting of cortical and cancellous bone. An occlusal load of 100 N was applied at a 30 degrees angle to the buccolingual plane. RESULTS: With the selected model and bone properties, the coronal cortical anchorage was dominating, and the bone stress concentrated to that area. CONCLUSIONS: The maximum bone stress was virtually constant, independent of implant length and bicortical anchorage. The maximum implant stress, however, increased somewhat with implant length and bicortical anchorage.