| 1. |
- Haag, P., et al.
(författare)
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Porcelain bonding to titanium with two veneering principles and two firing temperatures
- 2013
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Ingår i: Swedish Dental Journal. - : Sveriges tandläkarförbund. - 0347-9994. ; 37:3, s. 143-152
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Tidskriftsartikel (refereegranskat)abstract
- Dental literature, as well as dental laboratories, has described problems with ceramic veneering of titanium, while clinical and in vitro studies have reported good results. The objective of this study was to investigate the effect of firing temperature, thermo cycling, and veneering methods on bond strength between porcelain and titanium. Eighty titanium specimens were prepared with one of two methods:a bonding agent firing or an oxidation firing. During veneering, half of the specimens in each group were fired at 30 C above and half at the manufacturer's recommended temperature. In the bonding agent group and in the oxidation group, half of each firing group was thermocycled. Bond strength was calculated in a three-point bending test. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the titanium and the porcelain fracture surfaces of one specimen from each subgroup was used in order to study the composition of the interface between titanium and porcelain surfaces after fracture. No significant difference in bond strength was found when firing at a higher temperature compared with firing at the recommended temperature. An oxidation firing before veneering yielded significantly higher bond strength in a three-point bending test than when firing with a bonding agent. SEM and EDS analyses indicated a higher frequency of titanium oxide fractures in the oxidation than in the bonding agent group. The main finding is that firing at 30 degrees C above the recommended temperature does not significantly affect bond strength between titanium and porcelain. SEM and EDS analysis indicate that fractures occur in the titanium oxide layer by oxidation firing and in the interface between titanium oxide layer and veneering material by bonding agent firing. This finding might indicate that three-point bending test is not a relevant method for determining bond strength in this case, since the firing methods might influence the ductility of the samples.
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| 2. |
- Larsson, Christel, et al.
(författare)
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All-ceramic two- to five-unit implant-supported reconstructions. A randomized, prospective clinical trial
- 2006
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Ingår i: Swedish Dental Journal. - 0347-9994. ; 30:2, s. 45-53
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Tidskriftsartikel (refereegranskat)abstract
- Syftet med denna studie var att kliniskt utvärdera helkeramiska två- till femleds rekonstruktioner på implantat, samt att jämföra två olika keramiska system, Denzir® (DZ) och In-Ceram Zirconia® (InZ). Arton patienter behandlades med totalt 25 två- till femleds rekonstruktioner på implantat. Nio patienter fick rekonstruktioner utförda i DZ och nio patienter fick rekonstruktioner utförda i InZ. Rekonstruktionerna cementerades med zinkfosfatcement på preparerbara titandistanser. Rekonstruktionerna utvärderades efter 6- och 12 månader. Vid uppföljning efter 12 månader var alla 25 rekonstruktioner i funktion, inga hade frakturerat. Ytliga kohesiva, sk. chip-off, frakturer noterades däremot hos 6 av 18 patienter (8 av 25 rekonstruktioner). Nio led i DZ-gruppen (7 av 13 rekonstruktioner) och ett led i InZ-gruppen (1 av 12 rekonstruktioner) uppvisade chip-off frakturer. Skillnaden mellan de båda grupperna var statisktiskt signifikant (p< 0.01). Kantanslutningen bedömdes som utmärkt vid 34 stöd (56%) och acceptabel vid 27 stöd (44%). Resultat från denna 12 månaders uppföljning indikerar att helkeramiska två- till femleds rekonstruktioner på implantat kan övervägas som behandlingsalternativ. Vid jämförelse mellan de båda keramiska systemen är slutsatsen att DZ-systemet uppvisar oacceptabelt många frakturer i ytporslinet och därför inte kan rekommenderas för den typ av behandling som utvärderats här. Fortsatta studier och långtidsuppföljningar är nödvändiga innan ovan nämda material och teknik kan rekommenderas för allmänt bruk.
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| 3. |
- Rosendahl, Kerstin, et al.
(författare)
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Implant periapical lesion. A case series report.
- 2009
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Ingår i: Swedish Dental Journal. - 0347-9994. ; 33:2, s. 49-58
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Tidskriftsartikel (refereegranskat)abstract
- One complication in implant dentistry is the implant periapical lesion-IPL--which is a lesion around the apex of a stable implant diagnosed radiographically as a radioluscency in the bone at the apical part of an implant.The IPL can perform with or without clinical symptoms such as tenderness, swelling, suppuration and fistulation. This report describes 4 cases of IPL which were treated surgically with sectioning and removal of the affected portion of a stable implant and thorough debridement of the granulomatous tissue around it. This treatment was, up to 4 years after treatment, successful in all 4 cases. It can also from this report be concluded that IPL is a rather rare condition and that it can occur at any stage of implant treatment, in these cases from 4 months up to 11 years after implant installation. Finally there is a discussion about the aetiology of IPL and a comparison to findings in other reports on IPL and it is concluded that it is difficult to claim that there is a single cause to IPL. Rather it is evident that the condition might be a sequel of the summation of many possible causes.This summation exceeds the local biological threshold for the individual patient.
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| 4. |
- Vult von Steyern, Per, et al.
(författare)
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Use of Abutment-teeth vs. Dental Implants to Support All-ceramic Fixed Partial Dentures : An In-vitro Study on Fracture Strength
- 2005
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Ingår i: Swedish Dental Journal. - 0347-9994. ; 29:2, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present in-vitro study was to compare the fracture strength of all-ceramic Fixed Partial Dentures supported by tooth-analogues and periodontal membrane with the same supported by dental implants. As ceramics are highly brittle, they cannot withstand deformations of more than 0.1% without fracturing. Hence, when planning an all-ceramic FPD, it is essential to evaluate abutment sup-port, as the fracture strength of all-ceramic constructions depends on the stability of the support to reduce strain in the beam of the prosthe-sis. The support provided by implants differs, however, from the sup-port provided by natural teeth as the implants are anchored directly in the bone with no intermediate tissue. One question that arises is whether strain and stress in the prosthesis are lower when the prosthe-sis is loaded on implants compared to natural teeth and hence if all-ceramic FPDs benefit from implant support. Twenty-four three-unit all-ceramic FPDs-12 supported by two dental implants and 12 by two tooth-analogues serving as end abutments-were made. All FPDs were subjected to preloading in a preloading procedure and subsequently subjected to load until fracture occurred. Load at fracture were regis-tered and comparisons between the two groups were made. The loads at fracture were statistically significant higher in the group supported by implants compared to the group supported by tooth-analogues (p = 0.003). Within the limitations of this in-vitro study, the following con-clusions can be drawn: All-ceramic fixed partial dentures can be used in combination with dental implants. The solid support gained from implants might thus be beneficial for the outcome of such treatment due to decreased strain and stress levels in the prosthesis when loaded on implants compared to when loaded on natural teeth. Clinical stud-ies are, however, needed to confirm these findings as there are more factors that influence the final clinical outcome.
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