Biological mechanisms underlying complications related to implant site preparation

Digital workflow of labial guides for alveolar ridge reduction during implant-supported full-arch rehabilitation

This article presents a technique for fabricating two-piece labial guides using resin and cobalt-chromium for guided alveoloplasty, implant placement, and immediate full-arch implant-supported fixed complete denture placement. This technique reduces tissue damage and overcomes the negative effect of the anatomical position of the palatal neuropore and mobility of the tissue flap on the positioning and stability of the guide. The use of labial retention metal guides with improved mechanical properties of cobalt-chromium and fixation plugs allows the unilateral placement of the guide. Thus, minimally invasive implant surgery can be performed owing to the absence of large palatal flap elevation and obstruction. Such a design provides better stability of the guides and clear visual access during surgery.

History of periodontitis as a risk factor for implant failure and incidence of peri-implantitis: A systematic review, meta-analysis, and trial sequential analysis of prospective cohort studies

INTRODUCTION

Dental implants are widely employed as dependable replacements for lost teeth. However, it is crucial to establish, solely through prospective cohort studies, whether a history of periodontitis indeed constitutes a significant risk factor for implant failure.

METHODS

A systematic literature search was conducted in October 2022 in several electronic databases with subsequent manual updates. Only original prospective cohort studies evaluating the implant (loss) rate ≥1 year after implant loading were included. Logarithmic risk ratio and weighted mean differences were calculated. Study results were summarized using random effects meta-analyses evaluated by trial sequential analyses. The Newcastle-Ottawa scale evaluated study bias and the GRADE approach assessed the certainty/quality of the evidence.

RESULTS

A total of 14 publications reporting on 12 prospective cohort studies were included. Low evidence certainty/quality evidence due to the absence of randomized clinical trials revealed significantly greater odds of failure in patients with a history of periodontitis at follow-ups both after ≤5 years (RR = 1.62; 95% CI: 1.71-2.37; p = 0.013) and >5 years (RR = 2.26; 95% CI: 1.12-4.53; p = 0.023). The incidence of peri-implantitis (RR = 4.09; 95% CI: 1.93-8.58; p < 0.001) and the weighted mean (WM) of marginal bone loss (WM difference = 0.75 mm; 95% CI: 0.18-1.31; p < 0.05) were statistically significantly greater in the periodontally compromised group, whereas there was no significant difference between the two groups for peri-implant probing depth.

CONCLUSION

A history of periodontitis can be considered a significant risk factor for incident implant failure, peri-implantitis, and greater marginal bone loss.

Modeling of a New Percutaneous Orthopedic Implant System to Control the Post-surgery Osseointegration Process

This study presents a mechanical model of a novel medical device designed to optimize the osseointegration process in upper and lower limb amputees, leading to the promotion of optimal rehabilitation. The medical device is developed to reduce the risk of implant failure, leading to re-amputation above the implant. The proposed model serves several purposes: 1) to guide the osseointegration process by providing electrical endo-stimulation directly to the bone-implant contact site, using an invasive electrical stimulation system, which is implanted in the bone permanently, 2) to locally transmit stem cells after implantation, without the need for opening the skin or perforating the bone, which is particularly useful for regenerative medicine after partial healing of the implant, 3) to transmit necessary nutrients from the bone, also without opening the skin or puncturing the bone, and 4) to combat infections by locally administering drugs after implantation.

"Compression Necrosis" - A Cause of Concern for Early Implant Failure? Case Report and Review of Literature

Purpose

Compression necrosis refers to bone tissue damage that can occur when excessive pressure or force is applied to surrounding bone during implant placement. This pressure can compromise blood supply to the bone, leading to necrosis. Compression necrosis is a concern, because it can affect the stability and long-term success of dental implant.

Patients and Methods

This case report highlights a case of early bone loss and implant failure possibly due to compression necrosis. Clinical data, photographs, radiographs, blood examination report and histology were presented to document the early failure of an implant placed in the mandibular left posterior region of a 33-year-old female patient.

Results

Radiograph taken six weeks after implant placement showed severe angular defect. Therefore, the implant was surgically removed. Histological examination of the area showed bony trabeculae with an absence of osteoblastic riming, suggestive of necrotic bone.

Conclusion

Using excessive torque values when placing implants in dense bones can increase the risk of implant failure due to bone over compression. Dental professionals must follow the manufacturer's instructions and employ quality surgical techniques during implant placement into dense cortical bone to minimise risks.

Development and validation of a specialized system for self-tapping medical bone screw testing

A specialized system for accurate self-tapping medical bone screw testing is developed, fully meeting the requirements of ASTM F543-A4 (YY/T 1505-2016). The onset of self-tap is identified automatically according to a change in the slope of the torque curve. Precise load control is applied to determine the self-tapping force accurately. A simple mechanical platform is embedded to ensure the automatic axial alignment of a tested screw with the pilot hole in a test block. In addition, comparative experiments are conducted on different self-tapping screws to verify the system's effectiveness. By the automatic identification and alignment method, both torque curves and axial force curves for each screw exhibit significant consistency. The self-tapping time point derived from the torque curve agrees well with the turning point of the axial displacement curve. The determined self-tapping forces' mean values and standard deviations are both small, which are proved to be effective and accurate in the insertion tests. This work contributes to improving the standard test method for accurate determination of the self-tapping performance of medical bone screws.

Marginal Bone Loss Compared in Internal and External Implant Connections: Retrospective Clinical Study at 6-Years Follow-Up

The aim of this study was to assess and compare the marginal bone loss between two different categories of implants (Winsix, Biosafin, Ancona, Italy) having the same diameter and belonging to the Torque Type^® (TT^®) line, in the internal hexagon version (TTi, Group A) and in the external hexagon configuration (TTx, Group B). Patients with one or more straight implants (insertion parallel to the occlusal plane) in the molar and premolar regions in association with tooth extraction at least 4 months prior to implant insertion, who have a fixture diameter of 3.8 mm, who followed up for at least 6 years, and whose radiographic records were available were enrolled in this study. Depending on implant connections (externally or internally), the sample was divided into groups A and B. For externally connected implants (66), the marginal resorption was 1.1 ± 0.17 mm. The subgroup of single and bridge implants showed no statistically significant differences with a marginal bone resorption of 1.07 ± 0.15 mm and 1.1 ± 0.17 mm, respectively. Internally connected implants (69) showed an overall marginal resorption of 0.91 ± 0.17 mm, while the subgroup of single and bridge implants showed resorption of 0.90 ± 0.19 mm and 0.90 ± 0.17 mm, respectively, with no statistically significant differences. According to the obtained results, internally connected implants showed less marginal bone resorption than externally connected implants.

Influence of different surgical techniques on primary implant stability in the posterior maxilla: a randomized controlled clinical trial

BACKGROUND AND OBJECTIVE

Primary stability (PS) is remarkable for secondary stability and implant success. Surgical technique modifications seem to improve primary stability, especially in poor quality bone. The aim of this study was to compare the insertion torque (IT) and implant stability quotients (ISQ) of implants placed with underpreparation, expanders, and standard surgical instrumentation in different bone types.

MATERIAL AND METHODS

This randomized controlled clinical trial enrolled 108 patients (n=108 implants) distributed in three study groups: group 1 (n=36) underpreparation technique, group 2 (n=36) expander technique, and group 3 (n=36) conventional drilling. IT was recorded with a torque indicator. ISQ was recorded with resonance frequency analysis immediately after surgery.

RESULTS

ISQ values were associated with the patient's bone quality and were higher in bone quality type II (76.65) and type III (73.60) and lower in bone quality type IV (67.34), with statistically significant differences (p<0.0001). Lower stability results were obtained when conventional drilling (69.31) was used compared to the use of underpreparation (74.29) or expanders (73.99) with a level of significance of p=0.008 and p=0.005, respectively.

CONCLUSIONS

The surgical technique influences the PS when there is low-quality bone. In low-quality bones, conventional drilling obtains lower ISQ values.

CLINICAL RELEVANCE

Replace the conventional drilling technique for an alternative, underpreparation or expanders, in low-quality bone in order to achieve greater primary stability.

Evaluation of Change in Radiographic Fractal Dimension around Dental Implants Placed with Low-Speed Drilling and Standard Drilling Protocols

Osseointegration is a process that depends on a multitude of factors, including the type of drilling, whether biological or conventional. Objective: Establish box-counting dimension values for radiological images in patients with implants placed with both drilling methods. Material and method: The sample included 129 implants corresponding to 50 patients. A double-blind study of data collection was carried out with the subsequent analysis of the fractal dimension as a comparative value of the state of the trabecular architecture. Results: We found no significant differences (p ≥ 0.05) between the two study groups comparing both drilling techniques. The values for the conventional drilling technique are 0.24 ± 0.07 and for biological drilling: 0.19 ± 0.11 with a p-value of 0.767. Conclusions: The drilling technique does not influence the success of the procedure and the osseointegration process.

The effect of preoperative clindamycin in reducing early oral implant failure: a randomised placebo-controlled clinical trial

OBJECTIVES

To assess the effect of preoperative oral clindamycin in reducing early implant failure in healthy adults undergoing conventional implant placement.

MATERIALS AND METHODS

We conducted a prospective, randomised, double-blind, placebo-controlled clinical trial in accordance with the ethical principles and Consolidated Standards of Reporting Trials statement. We included healthy adults who underwent a single oral implant without previous infection of the surgical bed or the need for bone grafting. They were randomly treated with a single dose of oral clindamycin (600 mg) 1 h before surgery or a placebo. All surgical procedures were performed by one surgeon. A single trained observer evaluated all patients on postoperative days 1, 7, 14, 28, and 56. Early dental implant failure was defined as the loss or removal of an implant for any reason. We recorded the clinical, radiological, and surgical variables, adverse events, and postoperative complications. The study outcomes were statistically analysed to evaluate differences between the groups. Furthermore, we calculated the number required to treat or harm (NNT/NNH).

RESULTS

Both the control group and clindamycin group had 31 patients each. Two implant failures occurred in the clindamycin group (NNH = 15, p = 0.246). Three patients had postoperative infections, namely two placebo-treated and one clindamycin-treated, which failed (relative risk: 0.5, CI: 0.05-5.23, absolute risk reduction = 0.03, confidence interval: - 0.07-0.13, NNT = 31, CI: 7.2-∞, and p = 0.5). One clindamycin-treated patient experienced gastrointestinal disturbances and diarrhoea.

CONCLUSIONS

Preoperative clindamycin administration during oral implant surgery in healthy adults may not reduce implant failure or post-surgical-complications.

CLINICAL RELEVANCE

Oral clindamycin is not efficacy.

TRIAL REGISTRATION

The present trial was registered (EudraCT number: 2017-002,168-42). It was approved by the Committee for the Ethics of Research with Medicines of Euskadi (CEIm-E) on 31 October 2018 (internal code number: 201862) and the Spanish Agency of Medicines and Medical Devices (AEMPS) on 18 December 2018.

Accuracy of Augmented Reality-Assisted Navigation in Dental Implant Surgery: Systematic Review and Meta-analysis

BACKGROUND

The novel concept of immersive 3D augmented reality (AR) surgical navigation has recently been introduced in the medical field. This method allows surgeons to directly focus on the surgical objective without having to look at a separate monitor. In the dental field, the recently developed AR-assisted dental implant navigation system (AR navigation), which uses innovative image technology to directly visualize and track a presurgical plan over an actual surgical site, has attracted great interest.

OBJECTIVE

This study is the first systematic review and meta-analysis study that aimed to assess the accuracy of dental implants placed by AR navigation and compare it with that of the widely used implant placement methods, including the freehand method (FH), template-based static guidance (TG), and conventional navigation (CN).

METHODS

Individual search strategies were used in PubMed (MEDLINE), Scopus, ScienceDirect, Cochrane Library, and Google Scholar to search for articles published until March 21, 2022. This study was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and registered in the International Prospective Register of Systematic Reviews (PROSPERO) database. Peer-reviewed journal articles evaluating the positional deviations of dental implants placed using AR-assisted implant navigation systems were included. Cohen d statistical power analysis was used to investigate the effect size estimate and CIs of standardized mean differences (SMDs) between data sets.

RESULTS

Among the 425 articles retrieved, 15 articles were considered eligible for narrative review, 8 articles were considered for single-arm meta-analysis, and 4 were included in a 2-arm meta-analysis. The mean lateral, global, depth, and angular deviations of the dental implant placed using AR navigation were 0.90 (95% CI 0.78-1.02) mm, 1.18 (95% CI 0.95-1.41) mm, 0.78 (95% CI 0.48-1.08) mm, and 3.96° (95% CI 3.45°-4.48°), respectively. The accuracy of AR navigation was significantly higher than that of the FH method (SMD=-1.01; 95% CI -1.47 to -0.55; P<.001) and CN method (SMD=-0.46; 95% CI -0.64 to -0.29; P<.001). However, the accuracies of the AR navigation and TG methods were similar (SMD=0.06; 95% CI -0.62 to 0.74; P=.73).

CONCLUSIONS

The positional deviations of AR-navigated implant placements were within the safety zone, suggesting clinically acceptable accuracy of the AR navigation method. Moreover, the accuracy of AR implant navigation was comparable with that of the highly recommended dental implant-guided surgery method, TG, and superior to that of the conventional FH and CN methods. This review highlights the possibility of using AR navigation as an effective and accurate immersive surgical guide for dental implant placement.

Heat Accumulation in Implant Inter-Osteotomy Areas-An Experimental In Vitro Study

To examine the influence of the distance between adjacent implant osteotomies on heat accumulation in the inter-osteotomy area, two experimental groups with 15 pairs of osteotomies in Type II polyurethane blocks were compared: 7 mm inter-osteotomy separations (Group A, n = 15) and 14 mm inter-osteotomy separations (Group B, n = 15). An infrared thermographic analysis of thermal changes in the inter-osteotomy area was completed. A one-way analysis of variance (ANOVA) and Fisher post-test were used to determine group differences. Higher temperatures were recorded in Group A at the coronal and middle levels compared to the apical level in both groups. The temperature reached max temperatures at T80s and T100s. In Group A, the threshold for thermal necrosis was exceeded. Meanwhile, Group B did not reach the threshold for thermal necrosis. Preparing adjacent implant osteotomies in dense bone with a 7 mm separation between their centers increases the temperature in the inter-osteotomy area, exceeding the threshold for bone thermal necrosis; meanwhile, increasing the distance between osteotomies reduces the thermal accumulation and the risk for thermal necrosis.

Surgical safety checklists for dental implant surgeries-a scoping review

OBJECTIVES

In both elective surgeries and aviation, a reduction of complications can be expected by paying attention to the so-called human factors. Checklists are a well-known way to overcome some of these problems. We aimed to evaluate the current evidence regarding the use of checklists in implant dentistry.

METHODS

An electronic literature search was conducted in the following databases: CINHAL, Medline, Web of Science, and Cochrane Library until March 2022. Based on the results and additional literature, a preliminary checklist for surgical implant therapy was designed.

RESULTS

Three publications dealing with dental implants and checklists were identified. One dealt with the use of a checklist in implant dentistry and was described as a quality assessment study. The remaining two studies offered suggestions for checklists based on literature research and expert opinion.

CONCLUSIONS

Based on our results, the evidence for the use of checklists in dental implantology is extremely low. Considering the great potential, it can be stated that there is a need to catch up. While creating a new implant checklist, we took care of meeting the criteria for high-quality checklists. Future controlled studies will help to place it on a broad foundation.

CLINICAL RELEVANCE

Checklists are a well-known way to prevent complications. They are especially established in aviation, but many surgical specialties and anesthesia adopt this successful concept. As implantology has become one of the fastest-growing areas of dentistry, it is imperative that checklists become an integral part of it.

Risk Characteristics of Peri-Implant Infections: A Retrospective Evaluation in a University Consultation Setting

Peri-implantitis is a common biological complication in dentistry. The aim of the present study was to retrospectively analyze risk characteristics in a group of patients referred to a university-based consultation for peri-implantitis. In all, 190 initial cases from 2010 to 2019 were evaluated and descriptively summarized. The evaluation included various parameters such as periodontitis, smoking and oral hygiene status, implant position, type of prosthetic restoration and retention, mucosal quality, and further anamnestic and clinical findings related to the potential risk of developing peri-implantitis. Peri-implantitis was diagnosed in 83% of the cases, with peri-implant mucositis alone in 16% of cases; furthermore, 38% of the patients were diagnosed with active/instable periodontitis, while 14% had stable periodontitis. Residual cement was considered as a potential co-factor of peri-implant inflammation in 43% of cases. Suboptimal implant positioning was found in 19% of patients. Peri-implantitis or peri-implant mucositis was present in about one-third of patients in the absence of smoking and periodontitis factors. Of note, 6% showed no identifiable risk factors. Factors related to an increased risk of peri-implantitis should be taken into consideration when planning implant treatment. Adequate prosthetic implant position, restoration, and cleanability remain important for long-term success.

Dental Implant Placement in Focal Osteoporotic Bone Marrow Defect: a Case Report and Treatment Recommendations

BACKGROUND

Focal osteoporotic bone marrow defect is asymptomatic radiolucent area usually discovered incidentally during radiographic examination of the jaws. This bone condition can lead to clinical complications during dental implant placement or during osseointegration process.

METHODS

A 54-year-old woman was referred to private dental implant centre for a dental implant rehabilitation treatment in May 17, 2016. Oral examination revealed a healthy mucosa with no visible pathology. Adentia of tooth #46 and moderate atrophy of the edentulous alveolar process were found. Panoramic radiography of the jaws showed 2 cm x 2 cm radiolucency with irregular borders located in tooth #46 region. The margins of the bone defect were uneven, single trabeculae were visible, and the cortical layer was not deformed. In the absence of signs of pathology, it was decided to perform a dental implant surgery in the edentulous jaw segment #46.

RESULTS

The osteoporotic focus was filled with natural bovine bone substitute Cerabone^®. The granules were gently condensed to the sides - to the buccal and lingual walls until they filled the entire cavity. A 10 mm long, 4.1 mm diameter Straumann^® Tissue Level implant was surgically placed with the shoulder of the implant resting on the margins of the osteotomy. It was proposed six steps protocol for surgical dental implant installation in focal osteoporotic bone marrow defect in mandible.

CONCLUSIONS

A six-step protocol for surgical placement of dental implants in focal osteoporotic bone marrow defects may be a useful tool for clinicians in implant dentistry.

Comparative analysis of lateral maxillary sinus augmentation with a xenogeneic bone substitute material in combination with piezosurgical preparation and bony wall repositioning or rotary instrumentation and membrane coverage: a prospective randomized clinical and histological study

OBJECTIVES

The present randomized controlled clinical study aimed to investigate if, in lateral maxillary sinus augmentation, the repositioned bony wall or the application of a collagen membrane results in more preferable new hard tissue formation.

MATERIALS AND METHODS

Forty patients were divided into two study groups. Both groups received a xenogeneic bone substitute material (BSM) during lateral sinus augmentation. In the bony wall group (BW), following piezosurgery, the retrieved bony wall was repositioned. In the collagen membrane group (CM), following rotary instrument preparation, collagen membrane coverage was applied. After 6 months, biopsies were taken to histologically analyze the percentage of BSM, connective tissue (CT), and newly formed bone (NFB) following both approaches.

RESULTS

Forty implants were placed and 29 harvested biopsies could be evaluated. Duration of surgery, membrane perforations, and VAS were detected. Histomorphometrical analysis revealed comparable amounts of all analyzed parameters in both groups in descending order: CT (BW: 39.2 ± 9%, CM: 37,9 ± 8.5%) > BSM (BW: 32.9 ± 6.3%, CM: 31.8 ± 8.8%) > NB (BW: 27.8 ± 11.2%, CM: 30.3 ± 4.5%).

CONCLUSIONS

The results of the present study show that the closure of the access window by means of the retrieved bony wall or a native collagen membrane led to comparable bone augmentation results.

CLINICAL TRIAL

clinicaltrials.gov NCT04811768.

CLINICAL RELEVANCE

Lateral maxillary sinus augmentation with the application of a xenogeneic BSM in combination with a native collagen membrane for bony window coverage represents a reliable method for surgical reconstruction of the posterior maxilla. Piezosurgery with bony window repositioning delivers comparable outcomes without membrane coverage.

It is all about peri-implant tissue health

Healthy peri-implant tissues have become synonymous with implant success and a major challenge in contemporary implant dentistry. Numerous local and systemic factors, as well as iatrogenic and other hitherto underappreciated factors of potential clinical relevance may influence the outcome of implant therapy. In this volume of Periodontology 2000, a group of outstanding experts has elaborated on the latest insights on the prevention and management of major surgical, biological and technical complications, to facilitate the establishment and maintenance of peri-implant health. This volume focusses on factors affecting early and late implant loss and the potential role of systemic diseases and local conditions. It comprehensively discusses the implementation of guided implant surgery to facilitate the cleansibility of implant-supported restorations, as well as iatrogenic factors related to bone augmentation/sinus grafting procedures. The challenges associated with soft-tissue grafting and the prevention of esthetic complications are also reviewed as the paradigm of success in implant dentistry shifts from implant survival towards a greater focus on patient-reported outcomes. Prosthetic failures remain a significant challenge and are discussed in light of new evidence, as is the relevance of the structural dimensions of the peri-implant mucosa. The volume closes with detailed and well-illustrated appraisals of the surgical management of peri-implantitis, the management and sequelae of dental implant removal, and the latest evidence for the oral health related quality of life in patients treated with dental implants.