1,721,018 research outputs found
Accuracy of computer-aided template-guided oral implant placement : a prospective clinical study
No full textPurpose: The aim of the present study was to evaluate the in vivo accuracy of flapless, computer-aided implant placement by comparing the three-dimensional (3D) position of planned and placed implants through an analysis of linear and angular deviations. Methods: Implant position was virtually planned using 3D planning software based on the functional and aesthetic requirements of the final restorations. Computer-aided design/computer-assisted manufacture technology was used to transfer the virtual plan to the surgical environment. The 3D position of the planned and placed implants, in terms of the linear deviations of the implant head and apex and the angular deviations of the implant axis, was compared by overlapping the pre- and postoperative computed tomography scans using dedicated software. Results: The comparison of 14 implants showed a mean linear deviation of the implant head of 0.56 mm (standard deviation [SD], 0.23), a mean linear deviation of the implant apex of 0.64 mm (SD, 0.29), and a mean angular deviation of the long axis of 2.42° (SD, 1.02). Conclusions: In the present study, computer-aided flapless implant surgery seemed to provide several advantages to the clinicians as compared to the standard procedure; however, linear and angular deviations are to be expected. Therefore, accurate presurgical planning taking into account anatomical limitations and prosthetic demands is mandatory to ensure a predictable treatment, without incurring possible intra- and postoperative complications
Risk indicators related to peri-implant disease : An observational retrospective cohort study
Full text linkPurpose: The aim of the present study was to retrospectively investigate the influence of potential risk indicators on the development of peri-implant disease. Methods: Overall, 103 patients referred for implant treatment from 2000 to 2012 were randomly enrolled. The study sample consisted of 421 conventional-length (>6 mm) non-turned titanium implants that were evaluated clinically and radiographically according to pre-established clinical and patient-related parameters by a single investigator. A non-parametric Mann-Whitney U test or Kruskal-Wallis rank test and a logistic regression model were used for the statistical analysis of the recorded data at the implant level. Results: The diagnosis of peri-implant mucositis and peri-implantitis was made for 173 (41.1%) and 19 (4.5%) implants, respectively. Age (≥65 years), patient adherence (professional hygiene recalls <2/year) and the presence of plaque were associated with higher peri-implant probing-depth values and bleeding-on-probing scores. The logistic regression analysis indicated that age (P=0.001), patient adherence (P=0.03), the absence of keratinized tissue (P=0.03), implants placed in pristine bone (P=0.04), and the presence of peri-implant soft-tissue recession (P=0.000) were strongly associated with the event of peri-implantitis. Conclusions: Within the limitations of this study, patients aged ≥65 years and non-adherent subjects were more prone to develop peri-implant disease. Therefore, early diagnosis and a systematic maintenance-care program are essential for maintaining peri-implant tissue health, especially in older patients
Computer-aided flapless implant surgery and immediate loading : A technical note
No full textPurpose: The aim of the present technical note was to describe a prosthetic technique developed to increase the predictability of immediately loaded implants supporting a fixed prosthesis after computer-aided template-guided flapless implant placement. Methods: During a 2-year period, eight patients presenting partial edentulism underwent computer-aided template-guided implant placement. The presented technique was used during the prosthetic procedures to directly transfer the data obtained with the facebow to the surgical environment, allowing for accurate repositioning of the temporary prosthesis on the implants as previously planned with the digital software. Results: A total of 78 dental implants were immediately loaded with an implant-supported fixed prosthesis after flapless template-guided implant placement. A survival and success rate of 100 % was reported after a mean follow-up of 1 year from the prosthetic loading. Neither major complications nor dropouts were observed during the healing time. From both clinical and radiological evaluations, implants appeared stable with no signs of soft tissue inflammation or infection and no evidence of pathological peri-implant bone resorption. Conclusions: The proposed technique associated with computer-aided implant placement and immediate loading protocol provided a high implant and prosthetic survival and success rate. No complications were reported during the recalls, suggesting predictability and reliability of the present technique over a short-term period
Long-term survival rate of implants placed in conjunction with 246 sinus floor elevation procedures : results of a 15-year retrospective study
No full textObjectives The aim of the present long-term study was to retrospectively evaluate the survival rate of implants placed in regenerated maxillary sinuses and to assess the influence of hypothetical predictors of implant failure. Methods A database including 218 patients who received dental implants after sinus lift procedures was analyzed. The following variables were systematically included and evaluated: type of graft material used, number of surgeries performed, and use of membranes to cover the lateral antrostomy and/or to repair accidental Schneiderian membrane perforations. The Kaplan-Meier estimator was used for comparisons among the groups. Results A total of 589 dental implants were positioned in 246 grafted sinuses and were in function for 3-186 months. The Kaplan-Meier cumulative survival rate was 98.3% after 15.5 years of follow-up. All implant losses occurred within 52 months (4.3 years) after augmentation. According to the log-rank test, no statistically significant difference was shown between each patient/implant variable (p > 0.05). Conclusions Despite the limitations inherent in this type of study, no statistically significant differences between the groups could be found. Intraoperative Schneiderian membrane perforations did not affect the outcome of the implants positioned. Clinical significance The present long-term study is intended as a reference for clinicians approaching sinus floor elevation surgery in order to provide them with relevant operative findings. Since all the drawbacks occurred within the first 5 years, medium-term follow-up studies could be suitable for further retrospective evaluations
Alveolar ridge augmentation with titanium mesh. A retrospective clinical study
Full text linkAn adequate amount of bone all around the implant surface is essential in order to obtain long-term success of implant restoration. Several techniques have been described to augment alveolar bone volume in critical clinical situations, including guided bone regeneration, based on the use of barrier membranes to prevent ingrowth of the epithelial and gingival connective tissue cells. To achieve this goal, the use of barriers made of titanium micromesh has been advocated. A total of 13 patients were selected for alveolar ridge reconstruction treatment prior to implant placement. Each patient underwent a tridimensional bone augmentation by means of a Ti-mesh filled with intraoral autogenous bone mixed with deproteinized anorganic bovine bone in a 1:1 ratio. Implants were placed after a healing period of 6 months. Panoramic x-rays were performed after each surgical procedure and during the follow-up recalls. Software was used to measure the mesial and the distal peri-implant bone loss around each implant. The mean peri-implant bone loss was 1.743 mm on the mesial side and 1.913 mm on the distal side, from the top of the implant head to the first visible bone-implant contact, at a mean follow-up of 88 months. The use of Ti-mesh allows the regeneration of sufficient bone volume for ideal implant placement. The clinical advantages related to this technique include the possibility of correcting severe vertical atrophies associated with considerable reductions in width and the lack of major complications if soft-tissue dehiscence and mesh exposures do occur
Combined treatment of odontogenic keratocysts : initial marsupialization and successive enucleation with peripheral ostectomy plus Carnoy's solution application. A five-year follow-up experience
No full textTwo-stage surgical treatment protocol of keratocyst leads to complete healing, preservation of important anatomical structures and absence of recurrence.All patients were instructed in daily irrigation using chlorhexidine 0.2% during the period of marsupialization. After enucleation, good healing was obtained in all cases and from two up to five years of follow-up, there is no evidence of recurrence.Three cases of large KCOTs have been treated by initial marsupialization and, after a mean period of six months, successive enucleation with peripheral ostectomy and application of Carnoy's solution was performed.The odontogenic keratocyst (KCOT) is a locally aggressive, cystic jaw lesion with a high growth potential and a propensity for recurrence. Considering its neoplastic features, treatments of keratocysts are required and they are generally classified as conservative or aggressive. However, although in literature there are several studies, the choice of treatment strategies remains controversial. We report a two-stage protocol based on initial marsupialization and successive enucleatio
A retrospective evaluation of 192 implants placed in augmented bone : long-term follow-up study
No full textThe purpose of the present study was to assess the cumulative survival rate (CSR) of 192 implants placed in association with guided bone regeneration (GBR) procedures to evaluate the long-term predictability of this technique. Moreover, the Kaplan Meier survival analysis was applied to the data in order to evaluate predictors of implant failures, including the source of the graft, the type of membrane, and the timing of implant placement. The CSR of the sample was 95.6% over a mean follow-up period of 78 months (range, 1-175 months). Considering the source of graft, a 95.0%, 93.3%, and 97.7% CSR was obtained for demineralized bovine bone mineral (DBBM), autologous, and 1:1 ratio mixture of autologous and DBBM grafts, respectively. The CSR referred to bioabsorbable membranes was 96.5%, whereas 94.6% was the CSR reported for nonresorbable membranes. The CSR of simultaneous surgeries was 96.8%, whereas staged surgeries showed a CSR of 94.5%. According to the data, implants placed in conjunction with GBR procedures presented a satisfying survival rate even in the long term. All the procedures performed with different bone grafts and type of membranes guaranteed optimal results both in one-and two-stage approaches. No statistically significant differences could be detected among the groups; indeed, the use of DBBM associated with resorbable membranes may be suggested to reduce patients' morbidity and treatment time. Therefore, the dental implants placed in association with bone regenerative procedures presented safe and predictable long-term clinical results
The use of a collagenated porcine cortical lamina in the reconstruction of alveolar ridge defects. A clinical and histological study
No full textOBIETTIVO: La ricostruzione alveolare per mezzo di membrane riassorbibili e non-riassorbibili è stata proposta al fine di incrementare il volume dei tessuti duri nei siti deficitari. L’obiettivo del presente studio è stato quello di testare clinicamente e istologicamente l’impiego di una lamina corticale in collagene suino in caso di procedure di incremento osseo orizzontale e verticale, associato a innesto osseo suino particolato.
METODI: Complessivamente, sono stati reclutati 8 pazienti parzialmente edentuli (6 femmine e 2 maschi) con una età media di 45 anni, che necessitavano procedure di rigenerazione ossea al fine di eseguire un posizionamento implantare protesicamente guidato. Tutti i difetti alveolo-crestali sono stati rigenerati per mezzo di una barriera eterologa di osso corticale in combinazione con osso eterologo particolato. Le biopsie ossee sono state prelevate durante il rientro chirurgico.
RISULTATI: Un totale di 15 impianti sono stati posizionati sia simultaneamente che con procedura differita nei siti aumentati. Non sono occorse complicanze durante le successive fasi riabilitative. Da un punto di vista istologico, la lamina ossea è risultata essere ampiamente vascolarizzata ed integrata con i tessuti molli circostanti e l’osso nativo. La presenza di lacune osteoclastiche ha suggerito un rimodellamento attivo dell’innesto particolato e una graduale sostituzione con osso di neoformazione.
CONCLUSIONI: La ricostruzione alveolare per mezzo di lamina corticale collagenata ha dato risultati clinici e istologici incoraggianti. La rigidità e il lento pattern di riassorbimento hanno permesso la protezione del coagulo ematico anche in caso di difetti ossei verticali, evitando allo stesso tempo il rientro chirurgico per la sua rimozione.BACKGROUND: Alveolar ridge reconstruction by means of resorbable and non-resorbable membranes has been proposed to increase the hard tissue volume in deficient sites. The purpose of this study was therefore to clinically and histologically evaluate the use of collagenated porcine bone lamina in case of horizontal and vertical bone augmentation procedures in conjunction with particulate porcine xenograft. METHODS: Overall, 8 partially edentulous patients (6 females and 2 males) with a mean age of 45 years requiring bone regeneration procedures to achieve a prosthetically driven implant placement were enrolled. All ridge defects were augmented using a xenogeneic cortical bone barrier in combination with particulate heterologous bone. Bone biopsies were collected during the re-entry procedure. RESULTS: A total of 15 implants were placed both simultaneously or in a staged approach in the augmented sites. No complications occurred during the rehabilitation. Histologically, the bone lamina was widely vascularized and integrated with the surrounding soft tissues and the native bone. The presence of osteoclastic lacunae suggested an active remodeling of the particulate graft and a gradual substitution with the newly formed bone. CONCLUSIONS: Alveolar reconstruction by means of the collagenated cortical lamina gave promising clinical and histological results. The rigidity and the slow resorption pattern allowed for the blood clot protection even in case of vertical defects, avoiding at the same time the re-entry surgery for its removal
Long-term retrospective evaluation of dental implants placed in resorbed jaws reconstructed with appositional fresh-frozen bone allografts
No full textIntroduction: The aim of this study was to evaluate the outcome of fresh-frozen bone allografts in preprosthetic surgery for implant placement purposes. Materials and Methods: The cohort comprised 45 patients treated with fresh-frozen bone block grafts and dental implants. Clinical and radiological evaluations were performed to evaluate the survival rate. The data were statistically analyzed with the Kaplan-Meier estimator to assess the influence of possible predictors of implant failure on survival. Results: Overall, 262 implants were retrospectively analyzed. The survival rate was 90.84% over a mean follow-up of 50 months. Comparing the donor site and the position of the implants, no statistically significant differences could be detected (P = 0.7194 and P = 0.2901, respectively), whereas sex resulted in a marginally statistically significant difference (P = 0.0581). When considering age categorized on the median value (≤55/>55 years), age resulted in a statistically significant difference (P = 0.0340), with higher failures found in older people. Conclusion: Implant loss was strictly related to the lack of primary osseointegration. Female sex and old age were found to be risk factors, which could negatively influence implant survival
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