1,720,970 research outputs found
Potenzialità clinico-terapeutiche del lembo a riposizionamento coronale
No full textLa ricopertura delle recessioni gengivali è diventata una parte rilevante della terapia parodontale dal momento che è in continuo aumento la richiesta di un risultato estetico da parte dei pazienti. Il lembo a riposizionamento coronale permette di trattare efficacemente anche recessioni gengivali multiple in presenza di un'adeguata quantità di tessuto cheratinizzato apicalmente alle lesioni. Il caso presentato è stato trattato con due interventi di questo tipo in due settori diversi del cavo orale. Nel primo intervento, al lembo vestibolare è stato associato lo scollamento di un lembo palatino con la conservazione della papilla per trattare una tasca in quella zona; nel secondo intervento, il mese successivo, si è semplicemente abbinato al lembo un innesto di connettivo per compensare la perdita di sostanza dentaria radicolare associata alle recessioni.
Nel caso presentato a distanza di 12 mesi si è ottenuta la completa ricopertura delle recessioni trattate
Piezosurgical treatment of crestal bone: quantitative comparison of post-extractive socket outcomes with those of traditional treatment
No full textObjectiveThe study aimed to quantitatively compare, for the first time, the clinical outcomes of crestal bone volume resorption in sockets undergoing traditional extraction technique (TET) or piezosurgical extraction technique (PET), also considering the influence of buccal plate thickness.
Material and methodsIn this prospective study, 19 sockets were randomly treated with TET, and 18 sockets were randomly treated with PET. Furthermore, patients were split into subgroup A, with buccal bone plate thickness (BPT) 1mm, and subgroup B, with BPT>1mm. Buccal (BCH) and palatal (PCH) cortex height, bucco-palatal ridge (BPR) width were monitored at tooth extraction and after the 4-month post-extractive period of natural healing.
ResultsAfter 4months, BCH, PCH and BPR width decreased more in the TET than in the PET group, but only the BPR decrease was statistically significant (P=0.034) after ANOVA test. In both TET and PET groups, all B subgroup patients showed a lower decrease than A subgroup patients for both BCH, PCH and BPR, statistically significant for PCH (P=0.019) and BPR (P<0.001) of TET group, and BPR (P=0.002) of PET group, after ANOVA. Both A and B subgroups of PET showed a statistically significant lower decrease than the corresponding subgroups of TET, comparing A (P=0.005) and B (P=0.037) subgroups for BPR, after ANOVA.
ConclusionsWith both thin and thick buccal plates, the piezosurgical extraction technique of teeth significantly decreases the horizontal resorption of the hard tissue ridge, but not the vertical resorption. Moreover, buccal plate thickness seems to be a key factor in post-extractive bone resorption: the thinner the buccal plate the greater the horizontal crestal bone loss
Impianti ibridi in pazienti sani e parodontalmente compromessi: studio clinico e radiografico preliminare
No full textQuesto studio clinico e radiologico preliminare ha esaminato la sopravvivenza, la perdita di osso marginale (MBL) e l’influenza dell’altezza dell’abutment protesico (AH) sulla MBL intorno a impianti ibridi posizionati in due gruppi di pazienti parzialmente edentuli: pazienti parodontalmente sani (HP) e parodontalmente compromessi (PCP). In totale, sono stati trattati 93 pazienti che necessitavano di restauri implantari singoli o multipli, in entrambe le arcate, con applicazione di restauri protesici cementati. Sono stati posizionati 54 impianti (35 nell’arcata superiore e 19 in quella inferiore) in 45 HP e 56 impianti (31 nell’arcata superiore e 25 in quella inferiore) in 48 PCP. Tutti i 110 impianti ibridi posizionati in osso intatto hanno fatto registrare una percentuale di sopravvivenza del 100% sia negli HP sia nei PCP. Non sono state registrare differenze statistiche nel confronto dei valori di MBL dell’arcata superiore con quelli dell’arcata inferiore. In HP e PCP, è stata registrata una quantità similare e limitata di MBL ed è stato trovato che maggiore era l’AH, minore era la MBL. In conclusione, i risultati indicano che gli impianti ibridi esaminati possono ridurre il rischio di perimplantite dovuta alla superfici coronali macchinate e migliorare l’osteointegrazione grazie alle loro superfici apicali ruvide
Hybrid Implants in Healthy and Periodontally Compromised Patients: A Preliminary Clinical and Radiographic Study
Full text linkThis preliminary clinical and radiographic study examined the survival of, the marginal bone loss (MBL) around, and the influence of prosthetic abutment height (AH) on MBL around hybrid implants placed in two groups of partially edentulous patients: healthy (HPs) and periodontally compromised (PCPs) patients. A total of 93 patients requiring single or multiunit implant restoration, in the mandible or maxilla, were treated while undergoing cement-retained prosthetic restoration. A total of 54 implants (35 in the maxilla and 19 in the mandible) were placed in 45 HPs, and 56 implants (31 in the maxilla and 25 in the mandible) in 48 PCPs. All 110 hybrid implants positioned in pristine bone provided a 100% survival rate in both HPs and PCPs. No statistical differences were recorded comparing the MBL values of maxillae with those of mandibles. In HPs and PCPs, a similar and limited amount of MBL was recorded, and it was found that the higher the AH, the less MBL. In conclusion, results indicate that the hybrid implants examined could reduce the risk of peri-implantitis due to their coronal machined surfaces and improve osseointegration due to their apical rough surfaces
Hybrid and fully-etched surface implants in periodontally healthy patients: A comparative retrospective study on marginal bone loss
No full textBackground: Human studies on implants with the same design but with different surfaces are lacking at the present time. Purpose: The aim of this study was to compare the survival rate of and marginal bone loss (MBL) around 2 types of implants with the same design, but with different surfaces: fully "sandblasted and double-etched" (SDE) implants and hybrid (H) implants, with an apical SDE-surface and a coronal machined-surface. Materials and methods: The SDE- and H-surfaces were previously analyzed under SEM and profilometer. Implants were placed in partially edentulous periodontally healthy patients requiring single implant-restoration, in either mandible or maxilla, with cement-retained prosthetic restoration. Twelve months after prosthetic loading, MBL in relation to prosthetic abutment height (AH), calculated radiographically, was statistically analyzed. Results: SEM and profilometer analyses revealed no differences between the SDE-surfaces of either SDE- or H-implants. Transverse ridges and grooves characterized the machined portion of H-implants, clearly influencing the profilometer analysis. In 75 patients, 37 SDE and 38 H-implants were placed and all functioned completely after 12 months. In both SDE- and H-groups, MBL had a significant inverse relationship with AH, with greater intercept and negative slope for SDE-group and intersection of the 2 regression lines at AH=2 mm. Conclusions: A 100% survival rate was recorded for SDE- and H-implants placed in pristine bone of periodontally healthy patients; MBL was limited and similar in both SDE- and H-groups; the higher the prosthetic AH, the lesser the MBL around implants; H-implants could reduce bone loss most effectively with abutments lower than 2 mm, realistically exploitable on thin biotypes; SDE-implants could reduce bone loss most effectively with abutments greater than 2 mm, realistically exploitable on thick biotypes
Minimum Abutment Height to Eliminate Bone Loss: Influence of Implant Neck Design and Platform Switching
Full text linkPURPOSE:
This retrospective study quantitatively analyzed the minimum prosthetic abutment height to eliminate bone loss after 4.7-mm-diameter implant placement in maxillary bone and how grafting techniques can affect the marginal bone loss in implants placed in maxillary areas.
MATERIALS AND METHODS:
Two different implant types with a similar neck design were singularly placed in two groups of patients: the test group, with platform-switched implants, and the control group, with conventional (non-platform-switched) implants. Patients requiring bone augmentation underwent unilateral sinus augmentation using a transcrestal technique with mineralized xenograft. Radiographs were taken immediately after implant placement, after delivery of the prosthetic restoration, and after 12 months of loading.
RESULTS:
The average mesial and distal marginal bone loss of the control group (25 patients) was significantly more than twice that of the test group (26 patients), while their average abutment height was similar. Linear regression analysis highlighted a statistically significant inverse relationship between marginal bone loss and abutment height in both groups; however, the intercept of the regression line, both mesially and distally, was 50% lower for the test group than for the control group. The marginal bone loss was annulled with an abutment height of 2.5 mm for the test group and 3.0 mm for the control group. No statistically significant differences were found regarding marginal bone loss of implants placed in native maxillary bone compared with those placed in the grafted areas.
CONCLUSION:
The results suggest that the shorter the abutment height, the greater the marginal bone loss in cement-retained prostheses. Abutment height showed a greater influence in platform-switched than in non-platform-switched implants on the limitation of marginal bone loss
Maxillary sinus augmentation by crestal access: a retrospective study on cavity size and outcome correlation
No full textObjective: Cone-beam computed tomography (CBCT) and radiographic outcomes of crestal sinus elevation, performed using mineralized human bone allograft, were analyzed to correlate results with maxillary sinus size. Material and methods: A total of 60 sinus augmentations in 60 patients, with initial bone ≤5 mm, were performed. Digital radiographs were taken at surgical implant placement time up to post-prosthetic loading follow-up (12-72 months), when CBCT evaluation was carried out. Marginal bone loss (MBL) was radiographically analyzed at 6 months and follow-up time post-loading. Sinus size (BPD), implant distance from palatal (PID) and buccal wall (BID), and absence of bone coverage of implant (intra-sinus bone loss - IBL) were evaluated and statistically evaluated by ANOVA and linear regression analyses. Results: MBL increased as a function of time. MBL at final follow-up was statistically associated with MBL at 6 months. A statistically significant correlation of IBL with wall distance and of IBL/mm with time was identified with greater values in wide sinuses (WS ≥ 13.27 mm) than in narrow sinuses (NS < 13.27 mm). Conclusions: This study is the first quantitative and statistically significant confirmation that crestal technique with residual ridge height <5 mm is more appropriate and predictable, in terms of intra-sinus bone coverage, in narrow than in WS
Influence of abutment height and vertical mucosal thickness on early marginal bone loss around implants: A randomised clinical trial with an 18-month post-loading clinical and radiographic evaluation
No full textAbstract
Purpose: To investigate the influence of vertical mucosal thickness on marginal bone loss around implants with short and long prosthetic abutments and the marginal bone loss progression rate up to 18 months after prosthetic loading.
Materials and methods: Internal hex platform-switched implants were placed equicrestally using a two-stage protocol in the posterior mandible of two groups of patients with different vertical mucosal thickness, thin (≤ 2.0 mm) and thick (> 2.0 mm). Elevated prosthetic abutments of different heights (1 mm or 3 mm) were randomly assigned for single screw-retained crowns in both groups. Mesial and distal marginal bone loss were measured at implant placement (T0) and crown delivery (after 4 months [T1]), and after 6 (T2), 12 (T3) and 18 months (T4) of functional loading.
Results: Eighty implants were placed in eighty patients. Three patients dropped out at T2. At T4, 74 out of 77 implants were functioning, resulting in a 96% survival rate. Marginal bone loss (mean ± SE) at T2 was significantly greater in the 1-mm abutment groups (0.61 ± 0.09 mm with thin mucosa; 0.64 ± 0.07 mm with thick mucosa) than in the 3-mm abutment groups (0.32 ± 0.07 mm with thin mucosa; 0.26 ± 0.04 mm with thick mucosa). The marginal bone loss pattern over 18 months of loading showed that the greatest amount of marginal bone loss occurred during the first 6 months of function.
Conclusions: Internal hex platform-switched implants placed equicrestally and restored with 1-mm abutments presented greater marginal bone loss than identical implants with 3-mm abutments, with vertical mucosal thickness having no significant influence.
Keywords: abutment height; marginal bone loss; platform switching; vertical mucosal thickness
Minimally Invasive Management of Implant-Supported Rehabilitation in the Posterior Maxilla, Part II. Surgical Techniques and Decision Tree
No full textInsufficient crestal bone is a common feature encountered in the edentulous posterior maxilla due to atrophy of the alveolar ridge and maxillary sinus pneumatization. Numerous surgical techniques, grafting materials, and timing protocols have been proposed for implant-supported rehabilitation of posterior maxillae with limited bone height. In the majority of potential implant sites, residual bone height is less than 8 mm and the clinician has to select either a lateral or transcrestal sinus-elevation technique or placing short implants as the correct surgical option. Nevertheless, guidelines for selecting the best option remains mostly based on the personal experience and skills of the surgeon. The role of sinus anatomy in healing and graft remodeling after sinus floor augmentation is crucial. In addition to the evaluation of residual bone height, the clinician should consider that histologic and clinical outcomes are also influenced by the buccal-palatal bone wall distance. Therefore, three main clinical scenarios may be identified and treated with either a lateral or transcrestal sinus-elevation technique or short implants. This article introduces a new decision tree for a minimally invasive approach based on current evidence to help the clinician safely and predictably manage implant-supported treatment of the atrophic posterior maxilla
Intraoperative complications and early implant failure after transcrestal sinus floor elevation with residual bone height ≤5 mm: A retrospective multicenter study
Full text linkOBJECTIVE: Clinical indications for maxillary sinus floor elevation with transcrestal techniques have increased in recent years even in sites with minimal residual bone height (RBH). Nevertheless, limited information is currently available on incidence of intraoperative complications and early implant failure in these cases. MATERIAL AND METHODS: This retrospective multicenter study was performed on anonymized clinical and radiographic records of patients who underwent transcrestal sinus floor elevation in seven clinical centers. Influence of different factors related to patient, and sinus anatomy and surgical technique on the incidence of intraoperative complications and early implant failure rate after transcrestal sinus lift were investigated. RESULTS: A total of 430 patients treated with transcrestal sinus floor elevation for single‐implant insertion in sites with RBH ≤5 mm were included in the final analysis. After 1 year of loading, 418 implants of 430 were satisfactorily in function. Early implant failure was recorded in 12 cases (2.8%); results were significantly associated with the presence of large sinus cavities and with the occurrence of membrane perforation. The following adverse events were recorded: membrane perforation (7.2%), acute sinusitis (0.9%), implant displacement into the sinus cavity (0.7%), oro‐antral fistula (0.2%), and benign paroxysmal positional vertigo (0.5% of osteotome cases). A strong direct correlation between sinus membrane perforation and bucco‐palatal sinus width (p = .000) was demonstrated. CONCLUSIONS: Early implant failure after transcrestal sinus elevation showed significant direct correlation with bucco‐palatal maxillary sinus width and the presence of membrane perforation. Sinus membrane perforation was strongly associated with bucco‐palatal sinus width (extremely low perforation rate in narrow and much higher incidence in wide sinuses)
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