Surface modifications of dental implants

Dental implant surface technologies have been evolving rapidly to enhance a more rapid bone formation on their surface and hold a potential to increase the predictability of expedited implant therapy. While implant outcomes have become highly predictable, there are sites and conditions that result in elevated implant loss. This paper reviews the impact of macro-retentive features which includes approaches to surface oxide modification, thread design, press-fit and sintered-bead technologies to increase predictability of outcomes. Implant designs that lead to controlled lateral compression of the bone can improve primary stability as long as the stress does not exceed the localized yield strength of the cortical bone. Some implant designs have reduced crestal bone loss by use of multiple cutting threads that are closely spaced, smoothed on the tip but designed to create a hoop-stress stability of the implant as it is completely seated in the osteotomy. Following the placement of the implant, there is a predictable sequence of bone turnover and replacement at the interface that allows the newly formed bone to adapt to microscopic roughness on the implant surface, and on some surfaces, a nanotopography (<10⁻⁹m scale) that has been shown to preferably influence the formation of bone. Newly emerging studies show that bone cells are exquisitely sensitive to these topographical features and will upregulate the expression of bone related genes for new bone formation when grown on these surfaces. We live in an exciting time of rapid changes in the modalities we can offer patients for tooth replacement therapy. Given this, it is our responsibility to be critical when claims are made, incorporate into our practice what is proven and worthwhile, and to continue to support and provide the best patient care possible.     

Surface properties of endosseous dental implants after NdYAG and CO2 laser treatment at various energies.

OBJECTIVES: Dental lasers have been used for uncovering submerged implants as well as decontaminating implant surfaces when treating peri-implantitis. The objective of this study was to compare the possible alterations of the smooth surface and resorbable blast material (RBM) surface implants after using NdYAG and CO(2) lasers at various energies. MATERIALS AND METHODS: Ten smooth surface implants and 10 RBM surface implants were used. Two smooth surface implants and 2 RBM surface implants served as a control group that was not lased. The remaining implants were treated using NdYAG and CO(2) lasers. The surface of each implant was treated for 10 seconds on the second and third threads. The smooth surface implants (group 1) were treated using a pulsed contact NdYAG laser at power settings of 1, 2, 3.5, and 5 W, which are commonly used for soft tissue surgery; the corresponding energy and frequency were 50 mJ and 20 Hz, 100 mJ and 20 Hz, 350 mJ and 10 Hz, and 250 mJ and 20 Hz, respectively. The group 2 RBM implants were treated using a pulsed contact NdYAG laser. The group 3 smooth surface implants were treated using a pulsed wave non-contact CO(2) laser at 1, 2, 3.5, and 5 W, and the group 4 RBM implants were treated using a pulsed wave non-contact CO(2) laser. Data were analyzed using scanning electron microscopy. RESULTS: The control surface was very regular and smooth. After NdYAG laser treatment, the implant surface showed alterations of all the surfaces. The amount of damage was proportional to the power. A remarkable finding was the similarity of the lased areas on the smooth and RBM surfaces. CO(2) laser at power settings of 1.0 or 2.0 W did not alter the implant surface, regardless of implant type. At settings of 3.5 and 5 W, there was destruction of the micromachined groove and gas formation. CONCLUSION: This study supports that CO(2) laser treatment appears more useful than NdYAG laser treatment and CO(2) laser does not damage titanium implant surface, which should be of value when uncovering submerged implants and treating peri-implantitis.     

Combined periodontal treatment with dental implants

Implant treatment of partial edentulous periodontal compromised patients have led to a change in indication and therapy. After an adequate periodontal treatment for most of the patients there are no obstructions for implant treatment. However untreated periodontal disease and refractory periodontitis patients are at risk for complications. The diagnosis, treatment planning, treatment and maintenance of periodontal compromised patients need a multidisciplinary approach. A regular and tight maintenance program is essential to keep the periodontal and peri-implant tissues in a good condition.     

Surface characterization of SLActive dental implants

The aim of the study was to characterize the surface chemistry, hydration capacity, topography and roughness of the root part of a hydrophilic sandblasted and acid-etched titanium dental implant (SLActive). Implants as received (SAR), after water rinsing (SAW) and after ultrasonication in water (SAU) were subjected to x-ray photoelectron spectroscopy (XPS) elemental and binding state analysis. Scanning electron microscopy plus energy dispersive x-ray microanalysis (SEM/EDX), reflection Fourier transform infrared microspectroscopy (RFTIRM) and hydration/ dehydration cycling by environmental scanning electron microscopy (ESEM), were performed in SAR, whereas SAU implants were subjected to 3D-optical profilometry and SEM. For all the experiments, a conventional sandblasted and acid-etched implant (SLA ) of the same manufacturer was used as control. XPS showed lower mean C content in SAR than SLA, but not significantly different. In SAW, the C and O contents were increased. Significantly reduced C and increased Ti and O contents were found in SAU. Residual Na phases, other than NaCl, were traced in all SLActive groups. SAR demonstrated higher [-OH]/O2- ratio than SLA . EDX documented higher O, Na, Cl and lower Ti content in SAR. More -OH contributions were probed on SAR in comparison with SLA by RFTI RM. Ti-O peaks assigned to anatase, rutile and amorphous phases were found in both implant groups. The ESEM study revealed a full rehydration capacity in SAR, in contrast to SLA. No differences were found in the topography of SAU and SLA implant surfaces under the SEM. However, significantly greater values in spatial and functional roughness parameters were encountered in SAU. The increased surface hydroxylated titanium content and the greater spatial and functional roughness parameters, may explain the enhanced biological activity documented for SLActive in comparison with SLA.     

High accuracy measuring device for dental cast--using device with flat laser beam]

A new system has been developed for measuring the surface morphology of the occlusal material. The main characteristic of the system is utilizing a flat laser beam to produce high accuracy measuring and to enable measuring 200 points at the same time on a line of 30 mm in length. It takes 8 to 10 minutes to digitize the whole morphology of a dental cast. The system has a central processing unit that assembles a series of digitized points into a data file of the dental morphology. It is also able to recognize the graphical image of the numerically reconstructed morphology on the CRT. Application of this measuring system enables the approach to the qualitative and quantitative evaluation of the spatial relationship between the opposing teeth at near the occlusal contact.     

Combination syndrome: treatment with dental implants

Occlusal plane problems are often not evaluated adequately. They can be left untreated or improperly treated. This article reviews one such problem known as Combination Syndrome. The treatment method described involves using a fixed mandibular prosthesis over implants that have been placed immediately after dental extractions.     

Surface characterization of three titanium dental implants

PURPOSE: The aim of this study was to evaluate topographically and compositionally the rough surface of 3 different commercial titanium dental implants. MATERIALS: Bio Com Standard, Osseotite Implant, and Fixture MT Osseospeed were analyzed using scanning electron microscopy, atomic force microscopy, and energy dispersive spectroscopy. RESULTS: The scanning electron microscopy and atomic force microscopy analyses showed that the rough surface of Bio Com Standard presents numerous impressions superimposed by sharp pits, of Osseotite Implant many discrete sharp pits, and of Fixture MT Osseospeed a mixed feature appearance. The energy dispersive spectroscopy analysis of the rough implant surfaces revealed a small trace of Si found on the surface of Osseotite Implant. Fixture MT Osseospeed showed a nonhomogeneous distribution of the detected elements. CONCLUSION: The examined implants had a different rough surface topography, which was directly dependent on the type of treatment used. The differences concerning the surface morphology were leading in a characteristic nanotopography, which might influence the biologic activities at the implant-tissue interface. Surface oxygen concentrations also indicated differences in the oxide layer width between the examined implants, being minimal in Osseotite Implant and maximal in Fixture MT Osseospeed.     

Oral rehabilitation with dental implants after cancer treatment

Background: Patients who undergo surgical management of oral cancer may greatly benefit from an implant‐supported prosthesis. This study reports on the clinical experience of dental implant placement in patients following resection of oral cancer over a 15‐year period. Controversies including the use of dental implants in irradiated tissues, and hyperbaric oxygen treatment will also be discussed. Methods: Thirty‐one patients who had dental implants placed as part of their oral rehabilitation between 1992 and 2007 were investigated. Demographic data and factors including implant survival, type of prosthesis provided, radiotherapy and the hyperbaric oxygen therapy were analysed. Results: In this retrospective study, there was a retention rate of 110 implants from a total of 115 implants placed. A high rate of implant retention was found, with 5 implant failures from a total of 115 implants placed. The 5 failed implants occurred in free flap bone that had been irradiated. Conclusions: Dental implants provide an important role in the oral rehabilitation of oral cancer patients. There may be an increased risk of implant failure in free flap bone that has been irradiated.     

Surface characteristics of dental implants: A review

Objectives

During the last decades, several changes of paradigm have modified our view on how biomaterials’ surface characteristics influence the bioresponse. After becoming aware of the role of a certain microroughness for improved cellular contact and osseointegration of dental titanium implants, the likewise important role of surface energy and wettability was increasingly strengthened. Very recently, synergistic effects of nanoscaled topographical features and hydrophilicity at the implant/bone interface have been reported.

Consideration of biomechanical stress in treatment with dental implants

The most common implant complications, whether associated with the implant or prosthetic restoration, occur as a result of biomechanical stress. These complications include early implant failure, fracture of the prosthesis, abutment or prosthetic screw loosening, implant crestal bone loss, and problems with overdenture attachments. An engineering approach to resolve biomechanical problems involves determining the nature of complications and then designing an approach to eliminate their underlying causes. Treatment planning should incorporate methods to reduce stress and minimize its initial and long-term effects. The treatment plan is altered when forces are greater or bone is less dense than usual to minimize the negative impact of stress on the implant, bone, and restoration. Several parameters under the clinician's control can improve the transosteal environment relative to managing stress on the implant-restoration complex. The goal is to decrease the amount of force, or increase the implant-bone surface area, to decrease the chance of implant-restoration complications.+     

Surface area analysis of dental implants using micro-computed tomography

Objectives: In this study, we present and evaluate a micro‐computed tomography (micro‐CT)‐based method for the calculation of the potential bone/implant contact area (p‐BICA) on the surface of dental implants. Material and methods: For seven commercially available implants (Ankylos? implant, Brånemark System^®, Frialit CELLplus?, Replace^® Select Tapered, Straumann Solid screw?, XiVE S CELLplus?, 3i Osseotite XP? Threaded Miniplant^®), the p‐BICA surface is determined by means of three‐dimensional X‐ray computed‐tomography and computer‐based data processing. Measurements were repeated two times, and the stability and repeatability of the measurement method were evaluated. Results: Our analysis revealed a p‐BICA of 118 mm² for the XiVE S CELLplus? implant, 134 mm² for the Ankylos?, 136 mm² for the Frialit CELLplus?, 138 mm² for the Brånemark System^®, 139 mm² for the Replace^®, 159 mm² for the 3i Osseotite XP? and 199 mm² for the Straumann Solid screw? implant. The measurement method proved to be stable and led to reproducible results. Conclusions: The micro‐ and macrostructure of dental implants define the surface and the p‐BICA. Precise determination of this parameter can be achieved by means of the micro‐CT‐based method as presented in this study. The value of p‐BICA lies in the predictability of industrial design before preclinical and clinical testing. Based on this method, dental implant properties become comparable even if geometrical details are not disclosed by the manufacturer.