Complications and treatment errors in peri-implant soft tissue management.

Inadequate quality, quantity, or aesthetics of the peri-implant soft tissues can result from a combination of factors related to the outcome of treatments performed before, during, or after implant placement. In this paper, we describe in detail the treatment errors that can pave the way for the onset of mucositis or give rise to soft tissue complications such as peri-implant soft tissue discoloration or dehiscence, graft exposure, or scar formation. By tracing the error back to the planning or surgical stage, clinical insights on surgical soft tissue management are provided to avoid or treat complications that affect the status of the peri-implant soft tissues. Mastering the learning curve and knowing the limitations of each technique are fundamental for preventing added treatment failures that can result in increased patient morbidity and overall discontent.

Avoiding implant-related complications in medically compromised patients with or without unhealthy lifestyle/Elevated oxidative stress.

Increased human life expectancy broadens the alternatives for missing teeth and played a role in the widespread use of dental implants and related augmentation procedures for the aging population. Though, many of these patients may have one or more diseases. These systemic conditions may directly lead to surgical complications, compromise implant/bone healing, or influence long-term peri-implant health and its response to biologic nuisances. Offering patients credible expectations regarding intra- and postoperative complications and therapeutic prognosis is an ethical and legal obligation. Clear identification of potential types of adverse effects, complications, or errors is important for decision-making processes as they may be related to different local, systemic, and technical aspects. Therefore, the present review structures the underlying biological mechanisms, clinical evidence, and clinical recommendations for the most common systemic risk factors for implant-related complications.

How to avoid intraoperative and postoperative complications in maxillary sinus elevation.

Maxillary sinus floor elevation, via the lateral approach, is one of the most predictable bone augmentation procedures performed in implant dentistry. but both intra- and postoperative complications can occur, and some of them are severe. Our aim is as follows: To review the pertinent literature on the topic, especially assessing the risk factors related to complications. To give clinical recommendations to minimize intra- and postoperative complications with the ultimate scope of improving the standard of clinical care and patient safety.

Gingival phenotype assessment methods and classifications revisited: a preclinical study.

OBJECTIVE: To compare gingival phenotype assessment methods based on soft tissue transparency on different backgrounds and assessor experience levels. METHODS: For this purpose, 24 gingival specimens were retrieved from pig jaws with tissue thicknesses from 0.2 to 1.25 mm. Three methods were assessed: periodontal probe PCP12 (thin/thick), double-ended periodontal probe DBS12 (thin/moderate/thick) and colour-based phenotype probe CBP (thin/moderate/thick/very thick). Each sample was photographed with each probe underneath and categorized whether the probe was visible or not using different coloured backgrounds. To measure experience level influence, dentists, dental undergraduate students and laypersons (n = 10/group) performed the evaluation. RESULTS: PCP12 probe showed a threshold between 0.4 and 0.5 mm. To distinct between thin and moderate thick gingiva, a comparable range for DBS12 was found while moderate thickness was between 0.5 and 0.8 mm and for thick above 0.8 mm. CBP also showed a comparable threshold of 0.5 mm for thin versus moderate as compared with the other methods; above 0.8 mm, predominantly a very thick tissue was measured. In general, the background colour had a minor impact on PCP12 and DBS12, and investigator experience showed no clear influence on GP assessment. CONCLUSION: Based on probe transparency and within the limitation of a preclinical study, we suggest GP differentiation into three entities: thin (< 0.5 mm; high risk), moderate (0.5-0.8 mm; medium risk) and thick (> 0.8 mm; low risk). CLINICAL RELEVANCE: All three GP assessment methods are easy to perform and seem to have a high predictive value with a three entities classification for DBS12 and CBP.

A Retrospective Multicenter Study on Short Implants With a Laser-Microgrooved Collar (≤7.5 mm) in Posterior Edentulous Areas: Radiographic and Clinical Results up to 3 to 5 Years.

PURPOSE: We aimed to retrospectively evaluate the radiographic and clinical results and the success rate of short implants with a laser-microgrooved collar (≤7.5 mm) placed in the posterior areas after up to 3 to 5 years of function and the possible influence of several variables-such as gender, periodontitis, smoking habit, location, implant stability at placement, and prosthetic fixation design-on implant marginal bone loss (MBL). MATERIALS AND METHODS: A chart review was used for this multicenter study, which involved 5 private dental clinics. All patients had been treated with short dental implants with a laser-microgrooved collar from January 2012 to December 2015. RESULTS: A total of 174 patients (99 male and 75 female patients; mean age, 51.6 ± 2.8 years) with 254 implants were evaluated. Seven short implants failed. The cumulative success rate was 97.2%, without a statistically significant difference between implants placed in the posterior maxilla and mandible. The mean MBL was 0.18 ± 0.7 mm at the mesial aspect and 0.19 ± 0.6 mm at the distal aspect. No statistical relationships were found between MBL and gender, periodontitis, smoking habit, location, implant stability at placement, and prosthetic fixation design. CONCLUSIONS: At the end of the 3- to 5-year follow-up period, short implants with a laser-microgrooved collar (≤7.5 mm) in the posterior areas yielded a relatively high cumulative success rate. The laser-microgrooved collar implant maintained stable marginal bone levels. No investigated variable was statistically associated with MBL.

Risk factors in lateral window sinus elevation surgery.

Maxillary sinus augmentation is the most predictable of the pre-prosthetic surgical procedures. There are, however, known and well-documented complications that can and do occur. The most common are the intraoperative complications of sinus membrane perforation and bleeding, and the postoperative complications of sinus graft infections, sinus infections, and sinusitis. The majority of these complications can be prevented, or their incidence greatly reduced, through a thorough understanding of maxillary sinus anatomy, the multifaceted etiologies of these conditions, and the steps that can be taken to avoid them. This volume of Periodontology 2000 will discuss both the preoperative and intraoperative procedures that will prevent these untoward outcomes and the necessary treatment modalities that will limit their adverse effects.

Self-assessed neurological disturbances after surgical removal of impacted lower third molar: a pragmatic prospective study on 423 surgical extractions in 247 consecutive patients.

OBJECTIVES: The aim of this study was to assess the combined role of current radiographic risk indicators and patient age in predicting lower lip sensitivity disturbances after surgical removal of impacted lower third molars. The question was which combinations indicate low or high risk. MATERIALS AND METHODS: A prospective study was implemented involving 247 consecutive outpatients who underwent 423 surgical extractions. The predictor variables were patient age and risk indicators observed on panoramic radiographs. The outcome variable was the incidence of self-assessed lip sensitivity alterations. The extractions were subdivided into four groups according to the predictors. RESULTS: Two hundred forty-five teeth were extracted in patients younger than 25 years and 178 in patients 25 years old or older; radiographic risk indicators were associated with 226 out of 423 teeth (53.43%). No permanent neurological damage was observed. Transient lip sensitivity alterations were observed in five cases (1.18%; 95% confidence interval = 0.4 to 2.7%), all in the older group with radiographic risk indicators. CONCLUSIONS: The data indicate a low overall incidence of transient lip sensitivity impairment that occurred only in the presence of radiographic risk indicators in patients aged ≥ 25 years. CLINICAL RELEVANCE: Informed consent should include the possibility of inferior alveolar nerve injury in mature patients with radiographic risk indicators. Prophylactic removal of impacted teeth with radiographic signs of risk may be indicated when the patient is not yet aged 25 years.

Implant placement in the esthetic area: criteria for positioning single and multiple implants.

Patient expectations from implant treatment have changed over the years and esthetics plays an important role in defining what is now called success of rehabilitation. Of the many factors that influence the outcome of the rehabilitation, the two main ones are the bone and soft-tissue deficiencies at the intended implant site. Many surgical approaches are described in terms of timing of implant placement and management of regenerative procedures. The aim of this article is to discuss the different implant placement alternatives in the esthetic area, in particular: (i) the timing of implant placement/regenerative procedures/skeletal growth/altered passive eruption; (ii) the correct three-dimensional position of the fixture between the cuspids and in the premolar area; (iii) multiple missing teeth in the esthetic area with single tooth/pontic or cantilevered options/prosthetic compensation; (iv) placement of implants into infected sites; and (v) the influence of abutment and crown morphology on implant position. Combining our long-standing clinical experience and the pertinent literature, the following conclusions can be drawn: Immediate implant placement can be a successful procedure in terms of esthetics but it is technique sensitive and requires an experienced team. Immediate placement is less traumatic to the patient as fewer surgical procedures are involved and patients tend to prefer this clinical approach with regards to quality of life. The diagnostic phase is of utmost importance, with not only bone and soft tissue deficiencies being addressed but also: skeletal growth, dental/implant soft tissue parameters such as altered passive eruption and the morphology of the roots adjacent to the edentulous area. Post-extraction immediate loading is feasible in infected sites. The correct position of the fixture should follow widely accepted guidelines but the abutment morphologies play a role in the vestibular/palatal position of the implant. The long axis of the implant, aiming at the incisal edge of the future restorations, is the most appropriate implant position when a shoulder-less abutment is used and allows a restorative crown morphology with a cervical contour resembling a natural tooth. The use of a shoulder-less abutment gives more space for the tissue to grow compared with the traditional abutment with shoulder finish line.

Immediate implant placement and provisionalization of maxillary anterior single implants.

An inevitable loss of soft and hard tissue after tooth extraction often results in a compromised site for anterior implant esthetics in both vertical and horizontal dimensions. Immediate implant placement and provisionalization has been a viable option for replacing failing maxillary anterior teeth as it preserves the vertical existing osseous and gingival architecture. With the simultaneous addition of soft- and hard-tissue grafts, the peri-implant horizontal tissue topography can also be maintained. The esthetic success of immediate implant placement and provisionalization procedures is influenced by a number of factors that can be identified as patient-dependent or clinician-dependent. This article describes in detail the process of patient selection, indications, contraindications, diagnosis, treatment planning and treatment execution required to achieve functional and esthetic success with immediate implant placement and provisionalization.

Implants With and Without Laser-Microtextured Collar: A 10-Year Clinical and Radiographic Comparative Evaluation.

INTRODUCTION: This article reports, after at least 10 years of follow-up, the comparative data of marginal bone loss (MBL) and periimplant soft tissue parameters, around implant with and without laser-microtextured (L) collar surface, previously reported at 3 years of follow-up. MATERIALS AND METHODS: Twenty implants with L collar surface (test) were placed adjacent to 20 control implants with machined (M) collar surface in 15 partially edentulous patients, who were followed up for at least 10 years as part of a prospective longitudinal study. The plaque score, bleeding on probing (BoP) score, and probing depth (PD) were recorded at baseline and at each year follow-up examination. Mucosal recession (MR), and radiographic MBL were assessed at baseline and after at least 10 years. RESULTS: Four patients were lost during follow-up, so the number of implants that have been followed for at least 10 years was 32 (16 tests and 16 controls). At the end of the follow-up period, no significant differences were found between the study groups regarding the presence of plaque and BoP (P > 0.05). A statistically significant difference between test and control implant was found for mean PD (2.3 ± 0.7 mm vs 3.8 ± 0.8), MBL (1.23 ± 0.21 mm vs 2.8 ± 0.9 mm), and mean MR (1.08 ± 0.4 mm vs 2.46 ± 0.3 mm). CONCLUSION: Results suggest that after at least 10 years of function, implants with laser-microtexturing (L) collar surface, compared with implants with machined surface, lead to lower MBL and PD.

Analysis of Forces Applied During Transalveolar Sinus Lift: A Preliminary Clinical Study.

PURPOSE: To introduce a novel modality that enables the measurement of forces applied during a transalveolar sinus floor elevation (tSFE) and to investigate the influence of anatomical and surgical factors on the necessitated force in sinus membrane detachment. MATERIAL AND METHODS: A new endosinus probe, innovated with a calibrated load cell, was used to test the forces needed to perforate ten maxillary sinuses in 5 human cadavers. The same probe was also used to detach the Schneiderian membrane from the bony floor of 21 human subjects undergoing tSFE. RESULTS: The force needed to cause membrane perforation in the cadaver sample was on average 3.46 ± 1.04 N. The maximum force applied in vivo to a sinus membrane without perforation was 2.01 ± 0.67 N on average. Regression analysis showed that smoking (P < 0.001), as well as 3.0 mm osteotomy (P < 0.001), was significantly correlated to increased forces during membrane detachment. CONCLUSIONS: The maximum force needed to detach the membrane was found to be, on average, lower than the membrane breaking load in cadavers. Furthermore, because of smoking and a 3.0-mm osteotomy diameter demonstrating a high association with increased forces during membrane detachment, they may be considered as risk factors of membrane perforation.

Healing of Postextraction Sockets Preserved With Autologous Platelet Concentrates. A Systematic Review and Meta-Analysis.

PURPOSE: The true benefit of autologous platelet concentrates (APCs) for enhancing the healing of postextraction sites is still a matter of debate, and in recent years several clinical trials have addressed this issue. The purpose of this study was to determine the effectiveness of an APC adjunct in the preservation of fresh extraction sockets. MATERIALS AND METHODS: An electronic search was performed on Medline, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. Only controlled clinical trials or randomized clinical trials were included. Selected articles underwent risk-of-bias assessment. The outcomes were complications and adverse events, discomfort and quality of life, bone healing and remodeling assessed by histologic and radiographic techniques, and soft tissue healing. RESULTS: Thirty-three comparative studies were included. Nine articles had a parallel design and 24 had a split-mouth design. Twenty studies were considered to have a low risk of bias and 13 were considered to have a high risk. Overall, 1,193 teeth were extracted from 911 patients. Meta-analysis showed that soft tissue healing, probing depth at 3 months, and bone density at 1, 3, and 6 months were statistically better for the APC group. Qualitative analysis suggested that APCs might be associated with a decrease in swelling and trismus. However, no relevant difference among groups was found for probing depth at 1 month, incidence of alveolar osteitis, acute inflammation or infection, percentage of new bone, and indirect measurement of bone metabolism. CONCLUSION: APCs should be used in postextraction sites to improve clinical and radiographic outcomes such as bone density and soft tissue healing and postoperative symptoms. The actual benefit of APCs on decreasing pain in extraction sockets is still not quantifiable.

Immediate Versus Delayed Loading of Postextraction Implants: A Long-Term Retrospective Cohort Study.

PURPOSE: To compare the long-term clinical and radiographic outcomes between immediate loading (IL) and conventional loading of implants placed immediately in fresh extraction sockets. MATERIALS AND METHODS: Demographic data, implant details, and periapical radiographs of patients were collected. The long-term marginal bone level remodeling and implant survival rate were calculated. RESULTS: Twenty-one patients (mean age 52.55 ± 14.61 years) with 35 implants immediately inserted into postextraction sites (22 immediate loaded and 13 delayed loaded) were analyzed. The mean follow-up duration was 6 years (range 2-11 years). The implant cumulative survival rate was 96.5%. At the longest follow-up, the mean crestal bone level averaged 0.144 ± 0.705 for IL and 0.161 ± 0.877 for delayed loading, respectively. The mean implant aesthetic score was 7. CONCLUSIONS: IL does not negatively influence the long-term prognosis of implants inserted into fresh extraction sockets.

Risk Factors in Early Implant Failure: A Meta-Analysis.

BACKGROUND: Clinicians should be able to weigh the role of the main risk factors associated with early implant failure. PURPOSE: The aim of this meta-analysis was to assess the influence of different patient-related and implant-related risk factors on the occurrence of early implant failure. MATERIALS AND METHODS: In July, 2014 the main electronic databases were searched for studies reporting on early failures. Relevant papers were selected by 2 independent authors using predefined selection criteria. Three authors independently scored the included studies for quality assessment. The estimated odds ratios of the main risk factors from the selected papers were subjected to meta-analysis. RESULTS: Nine studies were included. A total of 18,171 implants were meta-analyzed, of which 10,921 were analyzed for smoking, 15,260 for implant diameter, 16,075 for implant length, and 16,711 for implant location (maxilla vs mandible). The main significant risk factors for early implant failures were the smoking habit (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.3, 2.3), implants shorter than 10 mm (OR, 1.6; 95% CI, 1.2, 2.2) and implants placed in the maxilla (OR, 1.3; 95% CI, 1.0, 1.6). CONCLUSIONS: Clinicians should be aware of the increased risk of early failure in the presence of smokers, implants with reduced length, and implant-supported maxillary rehabilitation.

Maxillary Sinus Grafting With Biphasic Bone Ceramic or Autogenous Bone: Clinical, Histologic, and Histomorphometric Results From a Randomized Controlled Clinical Trial.

PURPOSE: The present, randomized, controlled clinical trial compared the histologic and histomorphometric results from maxillary sinus augmentation with either biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% ß-tricalcium phosphate) or autogenous bone (AB) as bone-grafting materials. MATERIAL AND METHODS: Ten patients received bilateral sinus elevation surgery with intraoral AB chips (control group) on one side and BCP (test group) on the contralateral side. After a healing period of 6 to 8 months, implant sites were created and trephine cores were harvested for histological and histomorphometric analysis of the grafted areas. RESULTS: The histological examination of biopsies showed BCP particles interconnected by bridges of a vital newly formed bone. Histomorphometry demonstrated that the amount of newly formed bone in the control group (36.8%) was significantly greater than that in the BCP (28.2%) group (P = 0.0032). BCP and AB cores revealed an average of residual graft particles of 32.9% and 4.8%, respectively. The average percentage of soft tissue components was 38.9% in the BCP cores and 58.4% in the AB cores. CONCLUSIONS: Based on our findings, the amount of vital bone formation was significantly higher for AB than that for BCP. However, BCP seemed to be a biocompatible and osteoconductive material that can be used with success as a bone substitute in maxillary sinus procedures.

Periimplant Bone Response in Human-Retrieved, Clinically Stable, Successful, and Functioning Dental Implants After a Long-Term Loading Period: A Report of 17 Cases From 4 to 20 Years.

OBJECTIVE: This study aimed at a histologic and histomorphometric analysis of the periimplant tissues and bone-titanium interface reactions in successfully osseointegrated, clinically stable, and immobile human titanium dental implants retrieved after a long loading period. MATERIALS AND METHODS: In the last 30 months (2013-2015), 21 implants, retrieved from individuals for different causes after a loading period ranging from 4 to 20 years, were sent to the Implant Retrieval Center, University of Chieti-Pescara, Italy. In 4 cases, almost all the bone had been lost during the retrieval, whereas in the remaining 17 cases, mineralized bone was still present. RESULTS: Around the majority of the implants, mature compact bone with few marrow spaces was found. The trabecular bone, constituted by a few thin bone trabeculae, was in a periimplant location around only a few implants. A high percentage of bone-implant contact (BIC) (comprised between 32 ± 4.1% and 83 ± 2.9%) was present. In almost all implants, the space within the threads was almost completely filled by compact lamellar bone or by a thin layer of bone. Close and tight contact between bone and implant surface was observed in all specimens with no gaps or connective tissue at the interface. CONCLUSIONS: All implants appeared to be well integrated in the surrounding mineralized bone, and all of them showed adequate bone-to-implant contact percentages.

Maxillary Segmental Micro Osteotomy: A Human Cadaver Study on the Efficacy of the Technique.

PURPOSE: Ultrasonic bone cutting was recently introduced as a feasible alternative to the conventional tools of cranio-maxillofacial surgery because it offers improved precision and safety.This study examined the feasibility of minimally invasive orthodontic or preprosthetic surgery using a piezosurgery device for latero-posterior maxillary segmental osteotomy. MATERIALS AND METHODS: Four fresh cadaveric heads were obtained for this study. Maxillary posterior osteotomy was performed using piezoelectric surgery. To preserve the vascular supply, only 1 vestibular incision was made during surgery. The Mectron Piezosurgery unit is a multipurpose device that uses micrometric ultrasonic piezoelectric vibrations with a variable frequency and cutting energy. The strategy for maxillary osteotomy included 1 horizontal osteotomy, 2 vertical osteotomies, and 1 palatal osteotomy performed transantrally without incision of the mucoperiosteum. The osteotomies were performed using a piezodevice (OT7-type inserts: 0.55 and 0.35 mm). In total, 1 horizontal cut (3 mm above the roots of the teeth), 2 vertical bone cuts, and 1 palatal osteotomy were made without incision of the palatal mucoperiosteum.Gentle dissection of the buccal fat pad was used to promote the healing of hard and soft tissues in the osteotomized zone. RESULTS: No damage to soft tissues, including the palatal mucosa, occurred. The buccal fat pad was mobilized easily without requiring an additional incision. The osteotomic sites were linear and clean in the palatal aspect. The integrity of the vascular network was maintained because of the lack of damage to the palatal mucosa. No chisels were used during the osteotomies. DISCUSSION: This cadaveric study shows the feasibility of using piezosurgery for segmental maxillary osteotomy. This report outlines a new and simple application of segmental maxillary micro-osteotomy.

Buccolingual implant position and vertical abutment finish line geometry: two strictly related factors that may influence the implant esthetic outcome.

PURPOSE: Three-dimensional implant positioning has always been a highly debated topic especially in the esthetic zone due to many problems related to buccal bone resorption. A new concept in implant position, dictated by changing the abutment finish line, is presented in the following article. MATERIALS AND METHODS: The actual guidelines on implant position agree that in the bucco-palatal dimension, the implant should be placed more toward the palatal preserving at least 2 mm of buccal bone. However, changing the abutment finish line geometry from horizontal to vertical, the authors' geometry of choice, the surgical approach in the bucco-palatal direction has been modified accordingly to ensure final restorations that will guarantee long-term soft tissue stability. RESULTS: The emergence angle of the natural teeth has been the authors' guide to establish the implant position which should be located with the long axis of the implant corresponding to the incisal edge of the future restoration. Observation of the clinical results in the past years strongly supports this approach. CONCLUSIONS: The surgical and prosthetic concepts described in this article allow the clinician to recreate a pleasant and natural-looking esthetics while the patient can easily maintain a proper hygiene around the implant. However, despite the promising clinical results obtained by the authors, further clinical and randomized researches should be realized to validate the above-proposed approach.

Platelet-Rich Plasma and Deproteinized Bovine Bone Matrix in Maxillary Sinus Lift Surgery: A Split-Mouth Histomorphometric Evaluation.

PURPOSE: The purpose of this split-mouth controlled study was to evaluate and compare the amount of vital bone after lateral sinus lift surgery using either a mixture of pure platelet concentrate and deproteinized bovine bone mineral (test group) or solely deproteinized bovine bone as grafting material (control group). MATERIALS AND METHODS: Six patients with edentulous posterior maxilla and a residual ridge height of less than 4 mm were recruited in this study. Six months after grafting procedure, 2 bone biopsies per patient were taken bilaterally from the anterolateral sinus wall. Histological and histomorphometrical analysis was carried out. RESULTS: A total of 10 sinus surgeries in 5 patients were analyzed. The mean percentage of vital bone was 22.72% ± 9.21% (range, 11.45%-33.30%) in the control group and 30.70% ± 7.89% (range, 18.30%-39.99%) in the test group. CONCLUSION: The adjunct of pure platelet-rich plasma to deproteinized bovine bone mineral may enhance vital bone formation in the first 6 months after sinus floor augmentation. However, no statistically significant difference was found between groups (P = 0.18).