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Biomedical subjects

L Zetterqvist

Publications and source records attributed to L Zetterqvist.

At least 19 recordsLinked to original sources
PubMed2005

A 3-year prospective follow-up study of implant-supported fixed prostheses in patients subjected to maxillary sinus floor augmentation with a 80:20 mixture of deproteinized bovine bone and autogenous bone Clinical, radiographic and resonance frequency analysis.

The purpose of this prospective clinical study was to evaluate the 3-year outcome of 30 maxillary sinus floor augmentations with an autogenous bone-deproteinized bovine bone mixture (20:80). A total of 108 dental implants were placed after 6 months of graft healing. After another 6 months, the occlusion was restored with fixed prostheses and followed for 3 years of functional loading. Clinical and radiographic examinations of the sinuses and implants, including computerized tomography (CT) were performed. The stability of the implants was evaluated by means of resonance frequency analyses (RFA). After 3 years of functional loading with fixed bridges, 15 of 108 implants were lost giving a cumulative survival rate (CSR) of 86%. All followed patients, except one, had fixed bridges in function after 3 years of loading. The mean marginal bone loss was 1.3+/-1.1 mm after 3 years. RFA showed a mean implant stability quotient (ISQ) value of 66+/-4.1 after 3 years with no significant difference between implants in grafted and residual bone. Examination with CT showed that 67% of the maxillary sinuses were healthy prior to treatment and 71% after 3 years of loading. It was concluded that grafting of the maxillary sinus with a mixture of autogenous bone and deproteinized bovine bone is a reliable procedure.

Aged↗
PubMed1998

A prospective multicenter study evaluating loading of osseotite implants two months after placement: one-year results.

Historically, the recommended time between placement and functional loading of machined-surface dental implants has been 3 months for the mandible and 6 months for the maxilla. However, such recommendations are a result of evaluating randomly chosen healing times during the initial phase of implant development and are based on the subsequent clinical outcome of either implant integration or mobility. In recent years, histologic and experimental studies have shown that specifically designed micro-topographic implant surfaces can result in increased bone-to-implant contact at earlier healing times than obtained with machined-surface implants. Histologic and clinical studies investigating early and immediate implant loading support the premise that implants can be placed into function earlier than previously recommended. With the development of specifically designed implant surfaces and the utilization of time-saving surgical (one-stage surgical protocol) and prosthetic (implant position indexing) techniques, patients are now being restored and returning to function sooner than previously thought possible. The purpose of this multicenter clinical investigation is to evaluate the efficacy of loading Osseotite dental implants (3i-Implant Innovations Inc., Palm Beach Gardens, Florida) at 2 months and to determine the effect of early loading on implant performance and survival. A total of 429 Osseotite implants were placed in 155 patients (87 females and 68 males; mean age 54.0 +/- 13.7 yr), at 10 study centers, and subsequently loaded 2.1 +/- 0.7 months following placement. A single-stage surgical protocol was followed, with implants indexed immediately or impressed 4 to 6 weeks following placement. Patient restorative treatments included placement of 83 single-implant provisional restorations and 129 splinted, two-, three-, and four-implant supported maxillary and mandibular provisional restorations. The mean time from prosthetic loading to the most recent follow-up evaluation was 10 +/- 1.3 months. Seven of the 429 implants did not integrate; of these, six were identified prior to loading and one was identified 1 month after loading. The cumulative implant survival rate was 98.5% at 12.6 months. The cumulative post-loading implant survival rate was 99.8% at 10.5 months. The preliminary results of this clinical investigation suggest that successful functional loading of the Osseotite dental implant is possible at 2 months following noncomplicated implant placement.

Adult↗
PubMed1995

Long-term results of amalgam versus glass ionomer cement as apical sealant after apicectomy.

A total of 67 teeth in 64 patients were treated with apicectomy and retrograde fillings. They were randomized to receive fillings of amalgam or glass ionomer cement in a comparative clinical study. Healing was evaluated clinically and radiographically after 1 and 5 years. Evaluation showed no difference in healing capacity between the two materials. Overall success rates in both groups were registered as 90% at 1 year and 85% at 5 years. Contamination with blood or saliva during insertion of the filling material did not affect healing adversely. The study shows that the 5-year follow-up result can be predicted in more than 95% of the cases at the 1-year follow-up. It can be concluded that glass ionomer cement is a valid alternative to amalgam as an apical sealant after apicectomy with equally good long-term clinical results.

Aluminum Silicates↗
PubMed1995

X-ray microanalytical and morphological observations of the interface region between ceramic implant and bone.

In 8 monkeys both the maxillary lateral incisors were extracted. In the 16 extraction sites an Al2O3-ceramic dental implant (Frialit) was immediately inserted. Eight implants were submerged under the oral mucosa and the other 8 were allowed to penetrate through the mucosa during the observation period. None of the implants was loaded during the observation periods. After experimental periods of 1, 2, 4 and 8 months, the interface region between the implant and bone was examined using scanning-electron microscopy, X-ray microanalysis, back scatter, microradiography and light microscopy. The results showed that osseointegration of Al2O3-ceramic dental implant was obtained. The newly formed bone around the implant filled exactly the contours of the implant. Newly formed bone had a mineral content and a phosphorus-to-calcium ratio similar to that of the adjacent older mature jaw bone. There were no differences in the osseointegration rate between the submerged and the nonsubmerged implants. No leakage of aluminium from the implant could be detected in the bone.

Aluminum Oxide↗
PubMed1994

Effect of low level energy laser irradiation on wound healing. An experimental study in rats.

In this randomized experimental study the wound healing process in rats was investigated after treatment with low level energy laser. In the caudal area of the back of 38 rats, standardized full thickness wounds were punched out bilaterally. The animals were randomly divided into two groups, A and B with 19 rats in each group. Group A was laser irradiated on one side wound (A1), leaving the contralateral side as a control of possible systemic effects (A2). Group B was given placebo irradiation (ordinary light) on one side (B1) and the contralateral side was left without treatment (B2). Two animals from each group were sacrificed continuously every second day from day 3. Neither the clinical nor the microscopical examination of the wound healing process revealed any differences between group A1, A2, B1 and B2, during the observation period. This study did not confirm that low level energy laser treatment would affect the wound healing process.

Animals↗
PubMed1992

Quantitative radioactive analysis of microleakage of four different retrograde fillings.

Sealing properties of four different retrograde filling materials were investigated in vitro. Radioactive isotopes were applied in the root canal, and leakage into an extraradicular fluid was measured at regular intervals. The method permitted repeated observation of the specimens over prolonged periods of time. Forty single-rooted human teeth were biomechanically instrumented and obturated using calcium-hydroxide paste. Following obturation, an apicectomy was performed and retrograde cavities were filled with four different materials: group 1, non gamma 2 amalgam (Amalcap); group 2, glass ionomer cement (Ketac Silver); group 3, calcium-hydroxide-based root canal sealer (Sealapex); group 4, composite resin (Palfique Light-S). After removal of the calcium hydroxide, the teeth were immersed in a fluid. An isotope solution was then placed in the root canals. Samples were taken from the fluid at 0, 3, 7, 28, 56, 105, 210, 285 and 376 days to determine the radioactivity. It was found that Sealapex and Palfique Light-S showed significantly less leakage than amalgam and glass ionomer cement, which had the highest apical leakage.

Analysis of Variance↗
PubMed1991

Apicectomy: a comparative clinical study of amalgam and glass ionomer cement as apical sealants.

Healing capacity after apicectomy was investigated in a randomized clinical study of 105 teeth apically sealed with either amalgam or glass ionomer cement. The results were evaluated clinically and radiographically after 1 year. The success rate was high for both materials: 91% for amalgam and 89% for glass ionomer cement. Contamination with moisture and blood adversely affected the outcome for both materials and was significantly more frequent in unsuccessful cases.

Apicoectomy↗
PubMed1991

Tissue integration of Al2O3-ceramic dental implants: an experimental study in monkeys.

The effect of two different treatment modalities on the tissue integration of Frialit implants was compared in an experimental study in 10 monkeys. The maxillary central incisors were extracted. In one extraction site, chosen by lot, a Frialit implant was immediately inserted, allowing the implant to penetrate the oral mucosa. In the contralateral extraction site, a modified Frialit implant was placed and allowed to heal under a mucoperiosteal flap. None of the implants used in the study was loaded during the observation periods. After experimental periods of 1, 3, 6, and 8 months, the implants were evaluated and monkeys were sacrificed. In situ and histological evaluation showed no significant difference between the two treatment modalities under nonloading conditions. In both cases the healing around the implants was uneventful and good tissue integration was achieved.

Aluminum Oxide↗
PubMed1990

Tissue integration of A12O3-ceramic dental implants (Frialit)--a case report.

The tissue intraosseous integration of A12O3-ceramic dental implants (Frialit) is studied in a patient case, where an implant-fracture made it necessary to remove the implant from a patient's jaw. The surgical removing of the apical part of the implant with the use of a Trepan bur made it possible to examine and visualize histologically and microradiographically the tissue adjacent to the implant. The results of both the histological and microradiographical studies showed that a good healing and osseointegration of the ceramic dental implant (Frialit) was obtained. A direct contact was established between the implant and the surrounding alveolar bone and the induced bone tissue fitted exactly to the contour of the implant. No evidence was found of formation of a connective tissue capsule between the implant and the adjacent alveolar bone nor of any inflammatory reaction in the interface zone. In summary it was evident from the result of the present study that the biocompatibility properties of pure aluminoxide ceramics (A12O3) are excellent and can be recommended as an acceptable alternative among the many different implants, that now are available on the market.

Adult↗
PubMed1989

A comparative experimental investigation in monkeys between three different implant materials.

To study the tissue integration of 2 new potential biomaterials (whisker silicon carbide, reinforced aluminum oxide, and zirconium oxide strengthened aluminium oxide) a comparative investigation between these ceramic materials and unalloyed titanium was performed on monkeys. Cylindrical implants (4 x 6 mm) were inserted in the femur of 10 adult monkeys. After observation periods ranging from 1 to 8 months the animals were killed and clinical and histological evaluations (microradiography and light-microscopy) were carried out. After 6-8 months, the implants were covered with bone and firmly attached, indicating an uneventful healing. Histologically, a close connection between bone and implant was observed. At some areas the implants were totally osseointegrated and at some areas there were soft tissue layers between implant and bone. No differences in bone repair with regard to the different materials could be observed.

Aluminum↗
PubMed1988

The effect of low-energy infra-red laser radiation on wound healing in rats.

The aim of this study was to evaluate the effect of low-energy infra-red laser treatment on wound healing in rats, both histologically as well as by gross observation. In the caudal area of the back of 14 rats, identical full thickness dermal wounds were punched out bilaterally. One wound in each rat was randomly selected for laser radiation. The contralateral wound was left untreated, serving as a control. All the laser-treated wounds and the untreated control wounds healed in the same way within the same period of time. No difference was observed concerning bleeding time, nor as to the formation and loss of crust. None of the wounds showed signs of infection during the observation period. Histological examination indicated no obvious morphological difference between the laser-treated and the untreated wounds. The present study did not confirm that the use of low-energy infra-red laser radiation could improve the wound healing process.

Animals↗
PubMed1988

Lymphocyte and IgG responses to different herpes simplex virus antigens in patients with frequent HSV-1 reactivations.

Seventeen patients with a history of frequent clinical herpes simplex (HSV) reactivations and 13 HSV seropositive controls were monitored for 6 months. The patients had 4-8 clinical reactivations during the study. No clinical HSV reactivations were observed in the controls. IgG subclasses directed against HSV-1 nucleocapsid, membrane and glycoprotein C (gC) antigens were determined after the study period. Anti-HSV IgG4 directed against gC was found more often in the patients (65%) than in the controls (8%, P less than 0.025). The same trend was seen for IgG4 against HSV nucleocapsid antigen (88 and 46%, n.s.) and HSV membrane antigen (82 and 38%, n.s.). In both patients and controls IgG3 was found more often against nucleocapsid antigen compared to membrane or gC antigens (P less than 0.001). Lymphocytes were stimulated with the different antigens and the anti-HSV IgG subclass responses and cellular proliferation were determined. Lymphocyte produced IgG4 against HSV nucleocapsid antigen was found more often in patients than in controls (47 and 8%, P = 0.05) and membrane antigen (41 and 0%; P less than 0.025). No differences were found in the magnitude of lymphocyte proliferation responses between patients and controls. Lymphocyte proliferation responses were stronger to nucleocapsid antigen than to membrane or gC antigens (P less than 0.01).

Adult↗
PubMed1987

Glass-ionomer cement as retrograde filling material. An experimental investigation in monkeys.

The tissue reaction following the use of glass-ionomer and amalgam, as retrograde filling materials was investigated in an experimental study using 8 monkeys. After apicectomy of the upper central incisors, amalgam and glass-ionomer cement was used at random as retrograde filling material. 2 animals at a time were sacrificed after 2 weeks, 1, 3 and 6 months. Irrespective of the length of time, the tissue reactions were similar for the 2 materials. 2 weeks after surgery, a vascular granulation tissue containing lymphocytes, plasma cells and polymorpho-nucleated leukocytes was observed close to the retrograde fillings. 1 month after surgery, good healing was found, the granulation tissue being replaced by new osteoid or bone formation. After 3 and 6 months, there was complete healing with no inflammatory reaction and a mature alveolar bone surrounding the apicectomized roots.

Animals↗