Stefano Salgarello

Determinants for success rates of temporary anchorage devices in orthodontics: a meta-analysis (n > 50)

INTRODUCTION The aim of this study was to review the literature and evaluate the failure rates and factors that affect the stability and success of temporary anchorage devices (TADs) used as orthodontic anchorage. METHODS Data were collected from electronic databases: MEDLINE database, Scopus, and Web of Knowledge. Four combinations of term were used as keywords: screw orthodontic failure, screw orthodontic success, implant orthodontic failure, and implant orthodontic success. The following selection criteria were used to select appropriate articles: articles on implants and screws used as orthodontic anchorage, data only from human subjects, studies published in English, studies with more than 50 implants/screws, and both prospective and retrospective clinical studies. RESULTS The search provided 209 abstracts about TADs used as anchorage. After reading and applying the selection criteria, 26 articles were included in the study. The data obtained were divided into two topics: which factors affected TAD success and to what degree and in how many articles they were quoted. Clinical factors were divided into three main groups: patient-related, implant-related, and management-related factors. CONCLUSIONS Although all articles included in this meta-analysis reported success rates of greater than 80 per cent, the factors determining success rates were inconsistent between the studies analysed and this made conclusions difficult.

Mechanical response of bone under short-term loading of a dental implant with an internal layer simulating the nonlinear behaviour of the periodontal ligament.

We consider a non-standard design for a fixed dental implant, incorporating a soft layer which simulates the presence of the periodontal ligament (PDL). Instead of being aimed at causing an a priori defined stress/strain field within the surrounding bone, upon loading, such a design simply tries to better reproduce the natural tooth–PDL configuration. To do this, the mechanical properties of the internal layer match those of the PDL, determined experimentally to be strongly nonlinear. Three-dimensional finite element analyses show that the presence of such a layer produces (i) a prosthesis mobility very similar to that of a healthy tooth, for several loading conditions, and (ii) a stress/strain distribution substantially different from that arising, upon loading, around a conventional implant. The lack of knowledge of the real mechanical fields existing, under loading, in the bone around a healthy tooth makes it very difficult to state that the stress distribution produced by the modified implant is “better” than that produced by the standard one. Nevertheless, the comparison of the results obtained here, with those of previous refined analyses of the tooth–PDL–bone system, indicates that the modified implant tends to produce a stress distribution in the bone, upon loading, closer to “natural” than that given by the standard one, within the limits imposed by the presence of threads coupling the implant with the bone.

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.

The diagnostic performance of dental maturity for identification of the circumpubertal growth phases: a meta-analysis

The present meta-analysis initially evaluates the reliability of dental maturation in the identification of the circumpubertal growth phases, essentially for determining treatment timing in orthodontics. A literature survey was performed using the Medline, LILACS and SciELO databases, and the Cochrane Library (2000 to 2011). Studies of the correlation between dental and cervical vertebral maturation methods were considered. The mandibular canine, the first and second premolars, and the second molar were investigated. After the selection, six articles qualified for the final analysis. The overall correlation coefficients were all significant, ranging from 0.57 to 0.73. Five of these studies suggested the use of dental maturation as an indicator of the growth phase. However, the diagnostic performance analysis uncovered limited reliability only for the identification of the pre-pubertal growth phase. The determination of dental maturity for the assessment of treatment timing in orthodontics is not recommended.

AQP1 expression in human gingiva and its correlation with periodontal and peri-implant tissue alterations

Aquaporins (AQPs) are a family of hydrophobic integral membrane proteins that function as transmembrane channels and play an important role in tissue homeostasis. Aquaporin-1 (AQP1), in particular, has been reported to be involved in several biological processes including inflammation, angiogenesis, wound healing and others. Periodontitis and peri-implantitis can be defined as inflammatory processes that affect the tissues surrounding a tooth or an osseointegrated implant, respectively. To date, there are limited data about the involvement of AQPs in these diseases. The aim of this study was to evaluate the possible link between the histomorphological alterations and the expression of AQP1 in healthy, pathological and healed periodontal and peri-implant gingival tissues. The results obtained showed that changes in organization of collagen fibers were observed in periodontitis and peri-implantitis, together with an increase in the percentage of area occupied by inflammatory cell infiltration and an increase of AQP1 immunostaining, which was located in the endothelial cells of the vessels within the lamina propria. Moreover, in healed periodontal and peri-implant mucosa a restoration of histomorphological alterations was observed together with a concomitant decrease of AQP1 immunostaining. These data suggested a possible link between the degree of inflammatory state and the presence of AQP1, where the latter could be involved in the chain of inflammatory reactions triggered at periodontal and peri-implant levels.