Factors influencing the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses: A multicenter cross-sectional study.

BACKGROUND: Peri-implantitis is widely recognized as a major cause of late implant failure, both in pristine and regenerated bone. The present study aims to evaluate the prevalence of peri-implantitis in implants inserted in augmented maxillary sinuses and to analyze possible risk factors. METHODS: A cross-sectional study was conducted in four centers including patients who underwent lateral or transcrestal sinus augmentation and received dental implants. Clinical and anamnestic data were collected using a standardized form. Univariate and multivariate logistic regression analyses have been performed for both implant-level and patient-level variables. Subsequently, a multilevel logistic mixed-effect model was built to analyze variables correlated with the occurrence of peri-implantitis. RESULTS: A total of 156 patients (61 males and 95 females; mean age: 60.9 ± 11.6 years) with 315 implants inserted into augmented maxillary sinuses with a follow-up ranging from 1 to 18 years were evaluated. Seven implants in seven patients were previously lost for peri-implantitis (2.2% and 4.5% at implant- and patient-level, respectively); 250 implants showed no signs of peri-implant diseases (79.4%), 34 implants presented mucositis (10.8%), and 24 implants exhibited peri-implantitis (7.6%). Corresponding data evaluated at patient-level were 125 (80.1%), 17 (10.9%), and 14 (9.0%), respectively. At the multilevel analysis, history of periodontitis, sinus elevation with lateral approach, and one-stage sinus floor elevation significantly correlated with the occurrence of peri-implantitis (P <0.001). CONCLUSIONS: History of periodontitis confirmed its well-known role as a risk factor for peri-implant pathologies. In addition, both lateral window technique and one-stage sinus floor elevation seemed to represent significant risk factors for peri-implantitis.

Dimensions of the healthy gingiva and peri-implant mucosa.

OBJECTIVE: To determine the dimensions of the soft tissue cuff present at various aspects of teeth and to compare these dimensions to those of the mucosa surrounding single implants. MATERIAL AND METHODS: Fifty volunteers were recruited that were ≥25 years of age and exhibited no signs of (i) untreated caries; (ii) loss of periodontal tissue support in the incisor, canine, and premolar regions; (iii) systemic or local disease. Furthermore, among the 50 patients recruited (iV), 27 had one single implant in the maxilla with teeth present mesial and/or distal to the implant. Probing pocket depth (PPD) and transmucosal sounding depth (TS) were assessed by five experienced, carefully calibrated examiners and with the use of a periodontal probe at the proximal (mesial, distal) and flat (facial, buccal and palatal/lingual) surfaces of all teeth/implants. The width of the keratinized mucosa (KM) was also determined. RESULTS: It was demonstrated that (i) PPD and TS were greater at proximal than at flat surfaces at both tooth and implant sites. In addition, both PPD and TS were deeper at implant than at tooth sites. The TS values documented that the cuff of healthy soft tissue that surrounded a tooth varied between 2 mm at flat surfaces and 4 mm at proximal surfaces, while at implant sites, the mucosa at proximal as well as flat surfaces was 1-1.5 mm greater. CONCLUSION: The probing pocket depth (PPD) and the transmucosal sounding depth (TS) values were greater at proximal than at flat, that is, facial/palatal (lingual) surfaces at tooth sites and frequently also at implant sites. Furthermore, the PPD and the TS dimensions were greater at implant than at adjacent tooth sites.

Intraoperative complications during sinus floor elevation using two different ultrasonic approaches: a two-center, randomized, controlled clinical trial.

PURPOSE: The aim of this study was to assess the prevalence of intraoperative complications during maxillary sinus elevation with lateral approach using a piezoelectric device with two different surgical techniques. MATERIALS AND METHODS: Antrostomies were randomly performed by outlining a window (group A, 36 patients) or by eroding the cortical wall with a grinding insert until the membrane was visible under a thin layer of bone, before outlining the window (group B, 36 patients). Occurrence of membrane perforation, laceration of vascular branches, and surgical time was recorded. RESULTS: Seventy-two patients underwent sinus floor elevation: four perforations (11.1%) were observed in group A (two occurred during elevation with hand instruments) and zero perforations in group B (p < .05). No evidence of vascular lacerations was registered in both groups. A clinically insignificant but statistically shorter surgical time was recorded in group A (9.2 ± 3.7 minutes) than in group B (13.3 ± 2.4 minutes; p < .05). CONCLUSIONS: Within the limits of the present study, it may be concluded that ultrasonic erosion of the lateral wall of the sinus is a more predictable technique than piezoelectric outlining of a bone window in preventing from accidental perforations of Schneiderian membrane during sinus augmentation procedures.

Marginal bone preservation in single-tooth replacement: a 5-year prospective clinical multicenter study.

BACKGROUND: Few long-term studies are available comparing immediate and conventional loading protocols of implant-supported single-tooth replacement. PURPOSE: The aim of the present randomized controlled clinical trial was to evaluate prospectively the 5-year clinical and radiological outcome of immediate functional loading implants used in single-tooth replacement. MATERIALS AND METHODS: One hundred fifty-one subjects, who required single-tooth rehabilitation in the area from position 15 to 25 and from 35 to 45, were enrolled in eight private clinics in Italy. A randomization protocol was applied to allocate the implants in three treatment groups: one control group and two test groups. In the control group, implant placement was performed according to a conventional drilling procedure, and the implants were submerged for 3 months before abutment connection and loading. Implants allocated in the test group 1 and 2 followed an immediate functional loading protocol. While in test group 1, implant placement was performed according to conventional drilling procedure, in test group 2, a modified implant installation procedure (osteotome technique) was applied. Clinical and radiographic examinations were performed during the 5-year follow-up, and technical and biological complications were registered. RESULTS: Although four implants (three in the test group 2 and one in the test group 1) were lost in the immediate functional loading groups in the first year of follow-up, no further implant loss occurred in any of the treatment groups in the following monitoring period up to 5 years. No significant differences on marginal bone level changes were observed between the treatment groups. About 52% of all implants showed bone gain in the period from 1-year to 5-year follow-up. The percentage of all implants that in the same interval of time showed bone loss was about 28%. Although few technical complications were recorded in the period of time up to 5 years, implants showing biological complication were 5.7%. CONCLUSION: It is suggested that implants installed with a conventional installation technique together with an immediate functional loading protocol may be considered as a valid treatment alternative in a long-term perspective when used in a single-tooth replacement in an esthetic area.

Alveolar antral artery isolation during sinus lift procedure with the double window technique.

The sinus lift technique, introduced in 1976 by Tatum and subsequently described by Boyne in 1980, is nowadays considered a safe and reliable procedure for the rehabilitation of the atrophic upper posterior maxilla. The alveolar antral artery (AAA) is anastomoses between the posterior superior alveolar artery (PSAA) and the infraorbital artery (IOA) and may be present in the sinusal antrostomy. The haemorrhage of this vascular bundle represents the second intra-operatory complication in term of frequency during sinus lift procedure. Purpose of this study was to illustrate and describe a new technique allowing the AAA isolation during sinus lift procedure in cases in which the artery is clearly present inside the surgical area, detectable through CT scan exam. Presence, course and possible identification of the alveolar antral artery are also discussed, according to the studies present in the literature.

A new method to evaluate volumetric changes in sinus augmentation procedure.

BACKGROUND: In sinus augmentation procedure, the assessment of volume changes of grafted materials is important both in the clinical practice and in dental research to evaluate the features of filling materials. PURPOSE: In this study, we assessed the repeatability of a new method proposed to evaluate volumetric changes following sinus lift augmentation procedure. MATERIALS AND METHODS: In 10 patients, maxillary sinus augmentation procedure with simultaneous implant placement was performed. Maxillary cone beam computer tomographies were taken 1 week after surgery (T1) and 6 months after surgery (T2). At each evaluation the gap inside the implant between the fixture and the bottom of the screw was used as reference point (Rp), and a standardized volume of interest (VOI) centered on the Rp was selected. Masks were chosen to select the graft and bone tissue within the VOI; the volume at T1, T2, and the difference of volume between T1 and T2 were computed. Expert and non-expert operators performed the analysis. Method errors were computed. RESULTS: The error of the method was 1% for both intra-operator and inter-operator measurements. Tissue contraction at T2 was 19 ± 4% of the total initial volume. CONCLUSIONS: The standardization of the method allows to obtain repeatable measurements.

Clinical and radiographic evaluation of early loaded narrow diameter implants - 1-year follow-up.

OBJECTIVE: To evaluate the clinical performance of Astra Tech OsseoSpeed TX 3.0S implants using one-stage surgical procedure and early loading in the anterior region. MATERIAL AND METHODS: This is a prospective, single arm, multi-centre study. Patients missing teeth at positions 12, 22 and 32-42 were eligible to enter the study. The implants (OsseoSpeed TX 3.0S) used in the study were of 3 mm diameter and of different lengths. One-stage surgery was performed, and healing abutments were used during the 6-10 weeks healing period. Clinical and radiographic examinations were assessed at implant installation, loading and at the 6- and 12-month follow-up visits. RESULTS: Ninety-seven implants were placed in 69 patients at six different study centres in Denmark, Germany, Italy, Spain, Sweden and the United Kingdom. The survival rate was 95.9%. No implants have been lost after loading (100% survival rate after loading). Mean marginal bone loss 1 year after installation was 0.065 mm (SD = 1.018). The frequency of bone loss ≥ 1 mm was 6.6% and 51.3% of the implants demonstrated no bone loss or even bone gain from the surgical visit to the first year follow-up visit. Mean probing pocket depth and gingival zenith score were stable from crown placement to the 6- and 1-year follow-up visits. CONCLUSION: Treatment with OsseoSpeed TX 3.0S implants is a safe and predictable option in the anterior region where physical space is limited. Minimal marginal bone loss was observed during the first year follow-up.

Clinical investigation of mucosal thickness stability after soft tissue grafting around implants: a 3-year retrospective study.

PURPOSE: To assess the long-term stability of gingival grafts placed around dental implants at the time of second surgery uncovering and to further investigate the association between mucosal thickness (MTh) by demographic variables and clinical investigation. MATERIALS AND METHODS: Fourteen patients with submerged dental implants covered by inadequate keratinized mucosa were studied. The subjects underwent a periimplant plastic surgery (PPS) at the second-stage dental implant surgery and free gingival autograft orsubepithelial connective tissue graft were used according to the patients' clinical situation. Clinical measurement of MTh was assessed by bone sounding with a periodontal probe using customized acrylic stents andthe values were recorded at baseline (day of graft) and at 0.5, 1.5, 4, 12, 24 and 36 months after grafting. RESULTS: At 12 months postoperatively, the mean MTh was 2.89 mm, with a mean additional increase of 1.75 mm when compared with baseline (P=0.0001). No statistically significant differences in MTh were found between the 12- and the 36-month observations (P=0.09). In addition, at 36 months, a thin mucosa was associated with a greater increase in the MTh compared with a thick mucosa (2.14 and 0.64 mm, respectively, P=0.006). Similarly, the mandibular sites were associated with a greater increase in the MTh in comparison with the maxillary sites (2.17 and 0.81 mm, respectively; P=0.02). CONCLUSIONS: Within the limitations of this investigation, the data suggest that PPS at the second-stage dental implant surgery could results in additional increases in MTh, especially when it is performed in areas where the mucosa is of a thin biotype.

Individual skeletal models and preoperative simulation in advanced osseointegration: a case report.

This article presents a new diagnostic and simulative method, PSM LAB-MACHINE, with the aim of the anatomic reproduction of skeletal components of the facial skeleton. The importance of surgical predetermination with the possibility of simulating the planned surgical strategies is here evaluated. The described clinical case demonstrates the importance of planning in the reconstructive surgery of the maxillofacial district, using solid structures as individual skeletal models. The usefulness of a solid structure as skeletal replica for the effectiveness of modeling corticocancellous bone grafts from the iliac crest with an impressive reduction of the work times is highlighted. The high precision of adaptation of grafts to the donor site after modeling is notable.