Reverse scan technique: A verification method for the implant position in intraoral scans.

This article describes a fully digital method of verifying and increasing the accuracy of the position of implants in extensive prosthetic restorations. This cost-effective, timesaving, and versatile procedure uses a laboratory scanner, a scannable implant analog, and a printed interim implant-supported prosthesis to refine the virtual definitive cast.

Marginal bone response of submerged and non-submerged osteoconductive alkali-etched implants in thick and thin biotypes: A 2-year clinical follow-up study.

PURPOSE: This follow-up study evaluated the implant success rate and marginal bone response of submerged and non-submerged osteoconductive two-piece implants with a moderately rough implant neck in thick and thin gingival biotypes. MATERIALS AND METHODS: The stability of the hard tissue surrounding the implants was evaluated, based on clinical and radiographic examinations performed after implant placement and every follow-up thereafter. The clinical data were processed via linear mixed-effects model statistics at the patient level. RESULTS: Forty-three edentulous and partially edentulous patients were treated with a total of 97 implants with an osteoconductive surface. After 2 years in function, all the implants and dental prostheses reached a 100% success rate according to predefined criteria. Taking implantation as a baseline, the mean change in the marginal bone level (ΔMBLp) after 2 years in function was -0.36 mm (SD: 0.55), and bone resorption higher than 1 mm and less than 2.5 mm was observed for seven implants. Taking dental prosthesis placement as a baseline, the ΔMBLp after 2 years of loading was -0.13 mm (SD: 0.39), and bone resorption higher than 1 mm and less than 2.0 mm was observed only for two implants. Statistically significant differences in mean marginal bone loss were observed in the gingival biotype (P = .006) and submersion (P < .05). Their influence on the dynamics of peri-implant bone loss during the process of biologic width restoration was analyzed. CONCLUSION: This study demonstrated the high stability of peri-implant hard tissue and the 100% success rate of the implant system with a moderately rough neck. The biotype and implant submersion were evaluated as factors having a significant influence on marginal bone loss.

Chronological Age as Factor Influencing the Dental Implant Osseointegration in the Jaw Bone.

The objectives of this study were to evaluate osseointegration of dental implant in the jaw bone in the young and elderly population and comparing the results to assess indicators and risk factors as age for the success or failure of dental implants. A retrospective study of 107 implants (Impladent, LASAK, Czech Republic) was prepared. The patients at implants surgery were divided in three groups. The patients were followed-up for a 7-year period. We evaluated osseointegration from long term point of view as a change of marginal bone levels close to dental implant. Marginal bone levels were recorded and analysed with regard to different patient- and implant-related factors. An influence of chronological age on change of marginal bone levels during 6-year retrospective study vas evaluated. The study examined 47 patient charts and 107 implants from the Second Faculty of Medicine, Charles University and University Hospital Motol. We proved that young healthy patients with long bridges or Branemarks have the same progression of marginal bone levels changes. The chronological age hasn't therefore direct influence on the osseointegration from long term point of view. But we found that the length of dental suprastrucure-prosthetic construction negatively influences marginal bone changes, though these results weren't statistically significant. More extensive dental implant suprastrucure undergoes smaller osseointegration. On the other hand the length of dental suprastrucure (prosthetic construction) negatively influences dental osseointegration in both groups of patient.

In Vitro Bioactivity Test of Real Dental Implants According to ISO 23317.

PURPOSE: The goal of this study was to compare the in vitro bioactivity in simulated body fluid (SBF) of commercially available dental implants. MATERIALS AND METHODS: Bioactivity, according to ISO 23317, of commercially available dental implants with various surface modifications (BIO-surface, SLA, SLActive, TiUnite, and OsseoSpeed) was tested in SBF for 1 and 3 weeks. Surface characterizations, especially calcium and phosphorus surface content before and after the immersion in SBF, were performed. The effect of surface treatment on bioactivity was studied. RESULTS: Differences between surfaces before immersion in SBF were confirmed by Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), energy-dispersive x-ray spectroscopy (EDX), and scanning electron microscope (SEM) analysis. Calcium and phosphorus surface content was increasing within the tested period in the case of two (BIO-surface and SLActive) of the five tested dental implants. Calcium-phosphate precipitation was observed by SEM, XPS, EDX, and x-ray micro­diffraction (µ-XRD) analysis. CONCLUSION: Two (BIO-surface from LASAK and SLActive from Straumann) of the five tested dental implants were found to be bioactive, according to ISO 23317. Although it is difficult to unambiguously determine the properties that have influence on the hydroxyapatite precipitation rate, multiple properties that the two surfaces have in common were found.

18 months of experiences with the biotitanium replacement (Implaspin) used in treatment of degenerative lumbar spine diseases.

Between 2007-2008 forty two patients neurosurgery department of the KNTB (Regional Hospital of T. Bat'a) Zlin underwent surgery using the bioactive replacement Implaspin. The group of 21 patient of the total of number of 42 patients was operated first time for diagnosis degenerative instability or spondylolisthesis gr I-II. In this group was the follow-up period of 18 months, the mean baseline Oswestry score was 57%. A value of 37% was achieved after 18 months during the evaluation of the clinical status using the Oswestry questionnaire. This result represented a improvement of the condition. No change of the position of the instruments occurred during the X-ray and CT, MRI controls. Therefore, the Implaspin replacement appeared to be a perfect alternative to other lumbar spine replacements combining the osteoconductive properties of the bioactive material with the rigidity of titanium.

Bioactive titan cage Implaspin in treatment of degenerative disease of the cervcal spine--the results from 2007 till 2008.

The authors present results of surgical treatment of cervical spine degenerative disease via Implaspin biotitanium replacement. Surgery was indicated for a group of 24 patients with symptoms of cervical spondylogenic myelopathy or the irritation decay root syndrome non-reacting to conservative treatment. Pre-surgery X-ray and MRI examinations showed spinal canal stenosis caused by the intervertebral disk osteochondrosis combined with prolapse or dorsal osteophytes. Clinical problems of the group of patients were evaluated through the JOA classification before surgery and during the 2nd, the 6th and month 12th after surgery. The surgery rate of success was evaluated in percentages during post-surgery examinations that took place in the 12th month. Based on the JOA classification, that rate of success falls into the good surgery results zone. The post-surgery X-ray examinations showed two sank replacements by 1/3 of its height into the surrounding vertebral bodies. In these cases we performed the control MRI. No signs of the new spinal compression were found and the spinal canal was free in the operated site. Based on our short-term experiences, the Implaspin bioactive replacement seems to be a suitable alternative to the other types of replacements designed for intervertebral fusion in the lower cervical spine area.

Changes in stability after healing of immediately loaded dental implants.

PURPOSE: To investigate the parameters that affect primary stability of dental implants, to determine how primary stability influences posthealing stability, and to ascertain the effect of primary stability and insertion parameters on marginal bone loss. MATERIALS AND METHODS: A total of 940 immediately loaded implants were considered. Using resonance frequency analysis, primary stability (primary implant stability quotient [pISQ]) and stability after 4 months (tISQ) were recorded. When the differences between pISQ and tISQ exceeded 5 units, marginal bone loss was measured. The implants were placed into three groups based on their primary stability: high (pISQ > 72), moderate, and low (pISQ < 68). Changes in stability after 4 months of loading were evaluated. The relationships between pISQ, insertion parameters, DISQ (ie, tISQ - pISQ), and marginal bone loss were analyzed. The Student t test, one-way analysis of variance, and Spearman nonparametric correlation coefficient were employed for statistical evaluation. RESULTS: Of the 940 implants, tISQ was recorded in 526 implants and marginal bone loss was measured in 76 implants. There was no statistical relationship between pISQ and insertion torque. Primary stability was influenced by implant diameter but not by implant length. There was a significant relationship between implant insertion torque and bone type. The low primary stability group showed a significant increase in stability during healing. However, high primary stability implants demonstrated a significant reduction in their stability. The linear regression analysis demonstrated that at a pISQ of 69.2, tISQ value would equal pISQ value. Correlations between marginal bone loss and final insertion torque and between marginal bone loss and DISQ values were observed. CONCLUSIONS: Stability of immediately loaded implants with high pISQ decreased significantly during the initial 4 months of healing. However, stability of implants with low primary stability increased significantly. DISQ and insertion torque showed correlation with marginal bone loss.

Secondary stability assessment of titanium implants with an alkali-etched surface: a resonance frequency analysis study in beagle dogs.

PURPOSE: This study was carried out to quantify the effect of an alkali-modified surface on implant stability during healing using an animal model. MATERIALS AND METHODS: A total of 24 screw-shaped, self-tapping, commercially pure titanium dental implants, divided into a test group (implants with an alkali-modified surface or "biosurface") and a control group (implants with a turned, machined surface) were inserted without pretapping in the tibiae of 3 beagle dogs. The resonance frequency analysis method was used to measure the implant stability quotient (ISQ) 0, 1, 3, 9, and 12 weeks after implantation. The animals were sacrificed after 2, 5, and 12 weeks, and the bone-implant contact (BIC%) was evaluated histomorphometrically. RESULTS: The difference in the osseointegration rates (deltaISQ/deltahealing time) between the implants with alkali-modified surface (biosurface) and those with a turned, machined surface was evaluated as a mean of 0.843 ISQ/week within the first 9 weeks of healing. The mean increase in the secondary implant stability was found to be proportional to the mean increase in the BIC at healing period earlier than 5 weeks. DISCUSSION: The characteristics that differed between the implant surfaces, ie, specific surface area, contact angle, and hydroxylation/hydration, may represent factors that influence the rate of osseointegration and the secondary implant stability. CONCLUSION: The alkali-treated surface enhances the secondary stability in the early stages of healing compared to the turned, machined surface, as a consequence of faster BIC formation.

Biomimetic apatite formation on chemically treated titanium.

Titanium treated in NaOH can form hydroxycarbonated apatite (HCA) after exposition in simulated body fluid (SBF). Generally, titanium is covered with a passive oxide layer. In NaOH this passive film dissolves and an amorphous layer containing alkali ions is formed on the surface. When exposed to SBF, the alkali ions are released from the amorphous layer and hydronium ions enter into the surface layer, resulting in the formation of Ti-OH groups in the surface. The released Na(+) ions increase the degree of supersaturation of the soaking solution with respect to apatite by increasing pH, and Ti-OH groups induce apatite nucleation on the titanium surface. The acid etching of titanium in HCl under inert atmosphere was examined as a pretreatment to obtain a uniform initial titanium surface before alkali treatment. Acid etching in HCl leads to the formation of a micro-roughened surface, which remains after alkali treatment in NaOH. It was shown by SEM, gravimetric and solution analysis that the apatite nucleation was uniform and the thickness of precipitated HCA layer increased continuously with time. The treatment of titanium by acid etching in HCl and subsequently in NaOH is a suitable method for providing the metal implant with bone-bonding ability.

Hydroxyapatite formation on alkali-treated titanium with different content of Na+ in the surface layer.

Titanium can form a bone-like apatite layer on its surface in SBF when it is treated in NaOH. When pre-treated titanium is exposed to SBF, the alkali ions are released from the surface into the surrounding fluid. The Na+ ions increase the degree of supersaturation of the soaking solution with respect to apatite by increasing pH. On the other hand, the released Na+ cause an increase in external alkalinity that triggers an inflammatory response and leads to cell death. Therefore, it would be beneficial to decrease the release of Na+ into the surrounding tissue. The purpose of this study was to evaluate the hydroxyapatite formation on alkali-treated titanium with different content of Na+ in the surface layer. Using SEM, gravimetric analysis and measurement of calcium and phosphate concentration, it was found that the rate of apatite formation was not significantly influenced by a lower amount of Na+ in the surface layer. Titanium with the lowest content of Na+ could be more suitable for implantation in the human body. The amount of alkali ions released in the surrounding tissue is lower and the rate of apatite formation is identical to titanium with the highest content of Na+ in the surface layer.