International Journal of Periodontics & Restorative Dentistry, Pre-Print
DOI: 10.11607/prd.6574, PubMed-ID: 37819852Sprache: Englisch
Ultrathin ceramic veneers are a viable therapeutic option to manage esthetic challenges in the anterior zone. Proper conditioning of the intaglio surface of porcelain veneers is essential to achieve an adequate bonding. In clinical practice, this is typically done with chemical etching using an acid-containing agent, such as hydrofluoric (HF) acid. While it is well established that the etching effect is time- and acid concentration-dependent, little is known regarding the impact of etching time and the veneer fabrication method. The purpose of this pilot study was to evaluate the effect that different etching time protocols have on the intaglio surface characteristics of ultrathin ceramic veneers fabricated with either the platinum foil technique or the refractory die technique using scanning electron microscopy (SEM). Several replicas of an ultrathin feldspathic ceramic veneer for a maxillary central incisor were fabricated. Individual specimens were processed according to different intaglio surface etching protocols: no etching, etching for 90 seconds, etching for 120 seconds, and etching for 150 seconds, using 9.6% HF acid. It was observed that the 120 seconds etching protocol resulted in a favorable microroughness surface pattern in the platinum foil group. This pattern was comparable to that obtained by etching the intaglio of veneers fabricated with the refractory die technique by applying HF acid for 90 seconds. Increasing the etching time to 150 seconds did not result in a more favorable roughness pattern.
International Journal of Periodontics & Restorative Dentistry, Pre-Print
DOI: 10.11607/prd.6809, PubMed-ID: 37471159Seiten: 1-26, Sprache: Englisch
The primary aim of this study was to evaluate the efficacy of alveolar ridge preservation (ARP) therapy compared with unassisted socket healing (USH) in attenuating interproximal soft tissue atrophy. Adult subjects that underwent maxillary single-tooth extraction with or without ARP therapy were included in this study. Surface scans and cone beam computed tomography were obtained to digitally assess interproximal soft tissue height changes and measure facial bone thickness (FBT), respectively. Logistic regression models were conducted to investigate the individual effect of demographic and clinical variables. Ninety-six subjects (USH=49; ARP=47) constituted the study population. Linear soft tissue assessments revealed a significant reduction of the interproximal soft tissue over time within and between groups (P<.0001). ARP therapy significantly attenuated interproximal soft tissue height reduction compared to USH (USH mesial: -2.0±0.9mm vs. ARP mesial: -1.0±0.5mm / USH distal -1.9±0.7mm vs. ARP distal: -1.1±0.5mm; P<.0001). Thin FBT (≤1mm) upon extraction was associated with greater interproximal soft tissue atrophy compared with thick FBT (>1mm), independently of the treatment received (P<.0001). Nevertheless, ARP therapy resulted in better preservation of interproximal soft tissue height especially in thin bone phenotype by a factor of 2 for the mesial site (+1.3mm) and a factor of 1.6 (+0.9mm) for the distal site. This study demonstrated that ARP therapy largely attenuates interproximal soft tissue dimensional reduction after maxillary single-tooth extraction compared with USH.
Schlagwörter: tooth extraction, bone resorption, alveolar ridge preservation, digital image processing, dental implants
International Journal of Periodontics & Restorative Dentistry, 3/2023
DOI: 10.11607/prd.2023.3.eSeiten: 278, Sprache: Englisch
The International Journal of Prosthodontics, 5/2021
DOI: 10.11607/ijp.7170Seiten: 567-577, Sprache: Englisch
Purpose: To evaluate the incidence of ultrathin ceramic veneer fractures with different preparation protocols over a period of 36 months and the possible relationship with local- and patient-related factors.
Materials and Methods: Adult patients who received ceramic veneers for improvement in smile esthetics were selected from a private practice pool. Restorations were grouped as conventional (prep) or ultrathin ceramic veneers following either a minimal preparation (min-prep) or no tooth preparation (no-prep) protocol. After veneer bonding, all patients were followed up at intervals of 6 months up to 36 months. A panel of clinical outcomes was recorded, and patient satisfaction was assessed at 36 months.
Results: The study sample was formed by 49 patients who received a total of 194 veneers. Twelve veneers were prep, 125 were min-prep, and 57 were no-prep. Total fracture occurrence was 9.8% in 13 participants. No fractures were observed in prep veneers, while 16 out of 125 min-prep and 3 out of 57 no-prep veneers had fractures. Most fractures (13 out of 19) occurred early, within the first 12 months after bonding. Out of 194 veneers, only 1 had a catastrophic failure (0.5%), 3 had large (≥ 1 mm) chippings (1.5%), and 15 had minor (< 1 mm) chippings (7.7%). A generalized estimating equation model revealed that the odds of veneer fracture were significantly higher in men (odds ratio [OR] = 11.29), in patients who exhibited tooth wear at baseline (OR = 5.54), and in central (OR = 13.56) and lateral (OR = 10.43) incisors compared to canines and premolars. All participants indicated that they would not change to a different restorative protocol in order to have a thicker restoration and possibly less risk of fracture.
Conclusion: Ultrathin ceramic veneers are a viable cosmetic dentistry treatment option that involve minimal or no tooth preparation. However, a tendency for increased early fractures was observed in the min-prep group.
International Journal of Periodontics & Restorative Dentistry, 3/2021
Seiten: 335-345, Sprache: Englisch
This study evaluated a panel of clinical, dimensional, volumetric, implant-related, histomorphometric, and patient-reported outcome measures (PROMs) following reconstruction of dehiscence defects in extraction sockets with a minimally invasive technique using particulate bone allograft and a nonresorbable dense polytetrafluoroethylene (dPTFE) membrane. Subjects (n = 17) presenting severe buccal dehiscence defects at the time of single-rooted tooth extraction participated in the study. The mean vertical dimension of the dehiscence defects at baseline was 5.76 ± 4.23 mm. Subjects were followed up at 1, 2, 5, and 20 weeks postoperatively. The dPTFE barrier was gently removed at 5 weeks. CBCT and intraoral scans were obtained at baseline and at 20 weeks. A bone core biopsy sample was harvested at 24 weeks (before implant placement). Linear radiographic measurements revealed a mean increase in buccal bone height from baseline to 20 weeks (5.66 ± 5.1 mm; P < .0001). A total alveolar bone volume gain of 9.12% was observed. Although approximately half of the sites required some degree of additional bone augmentation at the time of implant placement, all implants were placed in a favorable restorative position with adequate primary stability. Histomorphometric analyses revealed a mean mineralized tissue area of 31.04% ± 15.22%, and the proportions of remaining allograft material and nonmineralized tissue were 16.23% ± 10.63% and 52.71% ± 9.53%, respectively. All implants survived up to 12 months after placement. PROMs were compatible with minimal discomfort at different postoperative stages and a high level of overall satisfaction upon study completion. This study demonstrated that the reconstructive procedure employed was successful and predictable in treating large, postextraction alveolar ridge deformities to optimize tooth replacement therapy with implant-supported prostheses.
International Journal of Periodontics & Restorative Dentistry, 2/2021
Seiten: 245-251, Sprache: Englisch
This study aimed to assess how frequently the maxilla anatomy allows for lingualized immediate implants in the central incisor region with a screw channel that has an ideal distance of 1.5 mm from the incisal margin. The effect of abutments with angle correction on case selection will also be verified. A retrospective cross-sectional study of 181 CBCT scans was carried out. Using an implant-planning software, implant placement was simulated in the lingual aspect of the socket. The location of the prospective screw channel was registered as incisal, lingual, or facial. The angle between the actual screw channel and the position of the ideal one was calculated. The effect of angle correction on allowing an ideal screw channel configuration was computed. Out of 161 eligible cases, 144 presented favorable anatomy for an immediate implant. The screw channel had an incisal position in 40 cases (28%), a lingual position in 60 cases (42%), and a facial position in 44 cases (30%). The screw channel could be placed at the planned distance from the incisal edge in 35 cases (24%). The position was unfavorable in the remaining 109 cases. In 103 of these cases, an abutment with an angled screw channel could make the conditions feasible. Within the simulated conditions, a majority of maxillary central incisors present favorable ridge anatomy for lingualized immediate implant placement. Achieving a proper location of the screw channel requires abutments with angle correction in a majority of cases.
International Journal of Periodontics & Restorative Dentistry, 1/2021
Seiten: 141-148, Sprache: Englisch
This study aimed to characterize extraction sockets based on indirect digital root analysis. The outcomes of interest were estimated socket volume and dimensions of the socket orifice. A total of 420 extracted teeth, constituting 15 complete sets of permanent teeth (except third molars), were selected. Teeth were scanned to obtain STL files of the root complex for digital analysis. After digitally sectioning each root 2.0 mm apical to the cementoenamel junction (CEJ), root volume was measured in mm3 and converted to cc. Subsequently, a horizontal section plane was drawn at the most zenithal level of the buccal CEJ, and the surface area (in mm2) and buccolingual and mesiodistal linear measurements of the socket orifice (in mm) were computed. Maxillary first molars exhibited the largest mean root volume (0.451 ± 0.096 cc) and mandibular central incisors the smallest (0.106 ± 0.02 cc). Surface area analysis demonstrated that mandibular first molars presented the largest socket orifice area (78.56 ± 10.44 mm2), with mandibular central incisors presenting the smallest area (17.45 ± 1.82 mm2). Maxillary first molars showed the largest mean socket orifice buccolingual dimension (11.08 ± 0.60 mm), and mandibular first molars showed the largest mean mesiodistal dimension (9.73 ± 0.84 mm). Mandibular central incisors exhibited the smallest mean buccolingual (5.87 ± 0.26 mm) and mesiodistal (3.52 ± 0.24 mm) linear dimensions. Findings from this study can be used by clinicians to efficiently plan extraction-site management procedures (such as alveolar ridge preservation via socket grafting and sealing) and implant provisionalization therapy, and by the industry to design products that facilitate site-specific execution of these interventions.
International Journal of Periodontics & Restorative Dentistry, 5/2020
DOI: 10.11607/prd.4789, PubMed-ID: 32925996Seiten: 667-676, Sprache: Englisch
Orthodontic extrusion (OE) is an orthodontic tooth movement in a coronal direction to modify the tooth position and/or induce changes on the surrounding bone and soft tissue with a therapeutic purpose. Evidence emanating from clinical reports and case series studies indicates that OE is a predictable treatment option to manage a variety of clinical situations. Common indications include traction of impacted teeth, exposure of teeth presenting structural damage to facilitate restorative therapy, treatment of periodontal bony and papillary defects, and implant site development. Unfortunately, there is a paucity of established protocols and guidelines for its application in clinical practice. Controversy exists in regard to the definition of rapid and slow OE, use of circumferential supracrestal fiberotomy, and tooth stabilization protocols during and upon completion of orthodontic movement. This article provides a concise perspective on the topic of OE by discussing key biologic principles and technical aspects that are translated into guidelines for the management of different clinical scenarios.
International Journal of Periodontics & Restorative Dentistry, 1/2020
DOI: 10.11607/prd.4422, PubMed-ID: 31815974Seiten: 61-70, Sprache: Englisch
Adequate management of the implant-supported restoration has become an important task when trying to obtain optimal esthetic outcomes. The transgingival area must be developed to maintain or influence the final appearance of the peri-implant soft tissues. Two distinct zones within the implant abutment/crown can be identified: the critical contour and the subcritical contour. Their design and subsequent alteration may impact the peri-implant soft tissue architecture, including the gingival margin level and zenith, labial alveolar profile, and gingival color. Defining these two areas helps clarify how to process soft tissue contours and may additionally improve the necessary communication with the laboratory. Since there are many protocols for placing implants, it is worthwhile to determine similarities in the contouring and macrodesign of their corresponding provisional restorations. Therefore, the purpose of this paper is to discern the general characteristics of the critical and subcritical contours for provisional restorations made for immediate and delayed implants in order to obtain guidelines for daily clinical practice.
QZ - Quintessenz Zahntechnik, 2/2018
AbstractSeiten: 259-261, Sprache: Deutsch