Biomedical subjects

George E Romanos

Publications and source records attributed to George E Romanos.

11 recordsLinked to original sources

PubMed2006

Effects of Er:YAG laser and ultrasonic treatment on fibroblast attachment to root surfaces: an in vitro study.

BACKGROUND: The aim of this study was to analyze the effects of erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser and ultrasonic treatment on fibroblast attachment to periodontally diseased root surfaces. METHODS: Thirty single-rooted human periodontally involved teeth were included in this study. A total of 60 specimens were obtained from all selected teeth and were randomly assigned to the following three groups: group A, untreated control group; group B, ultrasonic group; and group C, Er:YAG laser at 160 mJ/pulse at 10 Hz group. All of the specimens were incubated in petri dishes with fibroblast suspension and observed by scanning electron microscopy. RESULTS: Laser-treated specimens showed a significantly higher cell density number, with a mean+/-SD of 3,720+/-316 cells/mm2. The ultrasonically treated group showed a lower cell density number, with a mean+/-SD of 658+/-140 cells/mm2. The untreated control group showed the lowest cell density number, with a mean+/-SD of 130+/-80 cells/mm2. Differences between all groups were significant (P<0.0001). CONCLUSION: The results of the study indicate that untreated control surfaces and ultrasonically treated surfaces exhibited a significantly lower number of attached cells compared to laser-treated specimens, which showed a significantly higher cell density number.

Adult↗

PubMed2006

Immediate versus delayed functional loading of implants in the posterior mandible: a 2-year prospective clinical study of 12 consecutive cases.

The aim of this investigation was to evaluate the clinical success of immediately loaded implants versus implants loaded in a delayed fashion in the posterior mandible. Three implants were placed distal to the canines bilaterally in the edentulous distal mandibular ridges of 12 patients. One side was randomly selected for placement of three implants (delayed loading; control sites) with a progressive thread design for submerged healing, and after 3 months the implants were exposed and loaded with provisional splinted crowns, which were replaced 6 weeks later by the definitive restorations. Three additional implants (immediately loaded; test sites), of the same size were placed in the contralateral side of the mandible. The test implants had abutments placed and were loaded immediately using the same protocol as the control implants. After a mean loading period of 25.3 months, the patients showed normal mean clinical values without significant differences (P < 0.05) for test and control implants, respectively, as follows: Plaque Index: 0.4 versus 0.8; Sulcus Bleeding Index: 0.5 versus 0.3; probing pocket depth: 1.9 mm versus 2.1 mm; width of keratinized mucosa: 2.5 mm versus 3.3 mm; Periotest value: -3.7 versus -3.2. Twenty-nine of the examined sites showed no bone loss. After 2 years of loading in the posterior mandible, test and control implants had the same prognosis.

Bicuspid↗

PubMed2005

Histologic and histomorphometric findings from retrieved, immediately occlusally loaded implants in humans.

BACKGROUND: The immediate loading treatment concept can be successfully used in implant dentistry. Bone cells migrate onto the implant surface and establish a stable anchorage on the titanium surface. When implants are loaded immediately after surgery, there is a high long-term success rate of the implant-supported reconstruction. Based on histologic observations from different animal studies, the interface of immediately loaded implants can have a direct bone-to-implant connection without any fibrous tissue formation. Mature bone formation is dependent on the loading period. The aim of this study was to demonstrate a histologic analysis of retrieved, clinically stable immediately loaded implants with different implant designs and surfaces. An objective demonstration of the bone-implant interface was presented for the implant systems used. METHODS: A total of 29 implants with different implant designs and surfaces were retrieved from patients who were treated with implants using an immediate loading protocol and fixed immediate restorations placed the same day after surgery. The loading period was between 2 and 10 months. The bone-implant interface was examined histologically and histomorphometrically. RESULTS: A high bone-to-implant percentage of 66.8% (+/-8.9%) was found in the examined retrieved implants. Some marginal bone resorption was observed in the crestal part of the implants. CONCLUSION: According to the present histologic and histomorphometric evaluation of retrieved, clinically stable implants, immediate occlusal loading can present a high level of bone-to-implant contact in humans.

Alveolar Process↗

PubMed2005

Er:YAG laser in defocused mode for scaling of periodontally involved root surfaces: an in vitro pilot study.

BACKGROUND: The Er:YAG laser may be used on periodontally involved teeth in combination with conventional periodontal therapy in order to improve the efficacy of root instrumentation. The aim of this study was to compare the effect of hand instrumentation on root surfaces of periodontally involved teeth with Er:YAG laser application. METHODS: Thirty freshly extracted, non-carious, single-rooted, periodontally diseased human teeth from adult humans with advanced periodontal disease were used in this study. The teeth were divided into three groups of 10 specimens each. Group A was treated with scaling and root planing (SRP) with curets only (control). In group B, the root surfaces were scaled with curets and then lased with an Er:YAG laser (wavelength 2.94 microm). A handpiece with a water spray was used in non-contact mode (defocused) at a distance of 1 cm from root surface. Laser parameters were set at energy of 100 to 200 mJ/pulse, with 10 Hz of frequency. In group C, the root surfaces were lased only with power settings 250 to 300 mJ/pulse and 10 Hz frequency. An epon-araldite plastic embedding technique was used for light microscopic investigation. RESULTS: Histologic findings showed significant differences between the test and control sites. In control sites, after hand instrumentation, the surface was smooth, without a cementum layer, and the dentin layer presented opened tubules. Defects on the dentin layer were also present along root surfaces. In the test sites (B, C) root surfaces revealed no thermal damage; no cracking or tissue carbonization were observed. The superficial layers of lased surfaces appeared smooth and melted without alterations. CONCLUSION: Based on these findings, it appears that it may be feasible to use the Er:YAG laser for root instrumentation without prior root planing if the proper parameters are followed.

Adult↗

PubMed2004

Removal of epithelium in periodontal pockets following diode (980 nm) laser application in the animal model: an in vitro study.

OBJECTIVE: The purpose of this study was to examine the removal of the epithelium in the periodontal pocket using a diode (980 nm) laser in comparison with the conventional techniques in an animal experimental model. BACKGROUND DATA: The goal of periodontal therapy is to reduce the bacterial deposits in the pockets and to enhance the clinical attachment. Different surgical techniques have been used in the past, which control the epithelial migration and promote the connective tissue formation. MATERIALS AND METHODS: The buccal pockets of the posterior teeth in 10 freshly sacrificed adult pigs were scaled by three different examiners (with different levels of experience in periodontal surgery) using conventional curettes. The lingual pockets were treated using a diode (980 nm) laser. The laser was used in a continuous wave (c. w.) mode with two different power settings (2 and 4 Watts) with a 300-microm-thick glass fiber. The instrumentation period revealed 15 sec in all of the sites. Soft tissue biopsies of the instrumented sites were removed and examined histologically. RESULTS: In all of the lased sections, no epithelial remnants were found. The laser with a low power was able to remove the thin pocket epithelium in the same way regardless of the level of surgical experience of the examiner. A high-power setting presented significant damage to the underlying connective tissues. The sites, which were instrumented with the conventional curettes, demonstrated significant epithelial remnants in all of the tissues regardless of the level of periodontal surgical experience. CONCLUSION: The histological findings presented in this study showed that instrumentation of the soft periodontal tissues with a diode laser (980 nm) leads to a complete epithelial removal in comparison to conventional treatment methods with hand instruments (independent of the clinician's experience).

Animals↗

PubMed2004

Periodontal treatment with an Er:YAG laser compared to ultrasonic instrumentation: a pilot study.

BACKGROUND: The aim of the present study was to compare the effectiveness of an Er:YAG laser to that of ultrasonic scaling for non-surgical periodontal treatment. METHODS: Twenty patients with moderate to advanced periodontal disease were randomly treated in a split-mouth design with a single episode of subgingival debridement using either an Er:YAG laser device (160 mJ/pulse, 10 Hz) combined with a calculus detection system with fluorescence induced by 655 nm InGaAsP diode laser radiation (ERL), or an ultrasonic instrument (UI). Clinical assessments of full-mouth plaque score (FMPS), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL) were made at baseline and at 3 and 6 months following therapy. RESULTS: No differences in any of the investigated parameters were observed at baseline between the two groups. The mean value of BOP decreased in the ERL group from 40% at baseline to 17% after 6 months (P<0.0001) and in the UI group from 46% at baseline to 15% after 6 months (P<0.0001). The sites treated with ERL demonstrated mean CAL gain of 1.48 +/- 0.73 mm (P<0.001) and of 1.11 +/- 0.59 mm (P<0.001) at 3 and 6 months, respectively. The sites treated with UI demonstrated mean CAL gain of 1.53 +/- 0.67 mm (P<0.001) and of 1.11 +/- 0.46 mm (P<0.001) at 3 and 6 months, respectively. No statistically significant differences were observed between the groups (P>0.05). CONCLUSION: Within the limits of the present study, it can be concluded that both therapies led to significant improvements of the investigated clinical parameters.

Adult↗

PubMed2004

Surgical and prosthetic concepts for predictable immediate loading of oral implants.

Immediate loading of oral implants is an established concept for lower jaw restoration using four intraforaminal implants splinted together with a bar. There is a lot of misunderstanding in the literature and not exact definition of the term "immediate loading." Moreover, the number of implants to restore edentulous jaws is relatively high to compensate for the loading forces and dependent on the bone quality and quantity. This report presents the different surgical and prosthetic concepts for immediate loading to get long-term success in the upper and lower jaw. When the primary stability is adequate, only six implants may be loaded immediately after surgery, if the implants are splinted using a provisional fixed restoration. Using a number of six primary stable implants, it is possible to restore edentulous jaws independent on the clinical situation. This concept may be used successfully in the posterior part of the mandible when three implants are splinted with provisional crowns and loaded immediately. The biomechanical aspects, the implant design and surface seem to be of great importance for the long-term success in compromised and advanced surgical cases. In conclusion, immediate loading of oral implants may be successful if a primary stability as well as immobilization (splinting) immediately after surgery are taken care.

Dental Abutments↗

PubMed2003

Bone-implant interface around titanium implants under different loading conditions: a histomorphometrical analysis in the Macaca fascicularis monkey.

BACKGROUND: Bone healing around endosseous dental implants is associated with peri-implant loading conditions. Therefore, the aim of this study was to evaluate histomorphometrically the bone response around unloaded, delayed, and immediately loaded implants with a progressive thread design that were placed in the posterior regions of the lower jaw in monkeys. METHODS: Nine adult monkeys (Macaca fascicularis) were used in this study. After extraction of the second premolars and first and second molars in the mandible, the bone was allowed to heal for a period of 3 months. Forty-eight 8 mm long implants with a diameter of 3.5 mm were placed according to the following protocol. In two of the monkeys, six implants were placed and left to heal submerged for 3 months (group A). In seven monkeys, 21 implants were placed in one side of the mandible and loaded after 3 months of submerged healing (group B). The group B implants were loaded with temporary resin bridges at the same time as another 21 implants that were loaded immediately (group C) after placement in the contralateral side of the mandibles of the same monkeys. The occlusion of group B and C implants was checked for optimal relationship of the resin bridges that were replaced 1 month later with metal bridges and loaded for an additional 2 months. The group A animals were sacrificed after 3 months of submerged healing without loading; group B and C animals were sacrificed after 3 months of implant loading. Specimens were examined histologically and histomorphometrically. RESULTS: All implants osseointegrated without presenting any gap in the metal-bone interface. Compact cortical bone was found in contact with the implant surfaces. Group A implants demonstrated in the interface cancellous bone with loose connective tissue. Group B and C implants showed a thick cortical plate with extensive bone trabeculae formation. There was a significant difference in bone-to-implant contact (BIC) between the various loading conditions. No significant difference (P < 0.05) was found between groups B and C. There was an increased area of bone (BA) within the threads as well as around the apices of group B and C implants. CONCLUSIONS: Implant loading might have stimulated increased bone formation and thus may be a key factor in influencing positive osseointegration. In addition, immediately loaded implants may osseointegrate in a similar manner as delayed loaded implants.

Animals↗

PubMed2003

Treatment of advanced periodontal destruction with immediately loaded implants and simultaneous bone augmentation: a case report.

BACKGROUND: Advanced periodontal destruction is often associated with extraction of the teeth. Oral rehabilitation in these cases may include the traditional prosthetic restoration or an implant-supported reconstruction. Immediately loaded implants present an alternative treatment modality using a bar in the anterior mandible, along with the placement of higher numbers of implants, which are connected with a fixed prosthetic reconstruction. METHODS: This clinical case report presents the surgical and prosthetic rehabilitation in a patient who had lost all teeth due to advanced periodontal bone destruction. Six implants were placed in the upper and lower jaw each. Some implants required guided bone regeneration in conjunction with autologous bone grafting. All of the implants were connected with their abutments, and a temporary fixed restoration was placed immediately after surgery. The final metalloceramic-fixed reconstruction was cemented after 6 weeks of loading. RESULTS: All of the implants were osseointegrated and showed no clinical signs of mobility or infection. Mobility values were evaluated during healing and were found to be reduced. Radiological findings showed a stable peri-implant bone level during the total 18-month loading observation period. CONCLUSIONS: This case report presents an alternative treatment concept for the oral rehabilitation in a patient with advanced periodontal destruction. The concept of immediate loading of implants might provide a better opportunity to meet patient needs than more traditional treatment modalities.

Alveolar Bone Loss↗

PubMedDate not supplied

Histologic and histomorphometric evaluation of peri-implant bone subjected to immediate loading: an experimental study with Macaca fascicularis.

PURPOSE: Immediately loaded splinted implants can become osseointegrated when they are placed in the anterior part of the mandible. The concept of immediate loading has not been well examined in the posterior mandible. The aim of this study was to evaluate the hard tissue reactions around immediately loaded implants placed in the posterior mandible in the monkey model. MATERIALS AND METHODS: Six adult M. fascicularis monkeys were used in this study. Thirty-six Ankylos implants (Degussa Dental, Hanau-Wolfgang, Germany) were placed after extraction of the second premolar, first, and second molar teeth and complete healing of the sockets. Control (C) group implants were placed and, after osseointegration, were loaded for 1 month using temporary acrylic resin prostheses and later for 2 months using splinted metal crowns. In the contralateral region of the mandible, test (T) group implants were placed and loaded immediately with the same sequence as carried out for the C implants. After sacrifice of the animals, specimens were examined histologically and evaluated histomorphometrically. RESULTS: All implants were osseointegrated. Compact, cortical bone in contact with the implant surface without any gaps or connective tissue formation was demonstrated. DISCUSSION: Histomorphometric findings of the bone-implant-contacts showed no significant differences between the T and C group implants. Peri-implant mineralized bone areas presented statistically significant differences and showed a higher density of bone between the threads of immediately loaded implants (P < .05). CONCLUSIONS: Immediately loaded splinted implants in the posterior mandible can become osseointegrated with a hard tissue peri-implant response similar to that of delayed loaded implants. Moreover, immediate loading seems to increase the ossification of the alveolar bone around endosseous implants.

Alveolar Process↗

PubMedDate not supplied

Immediate loading with complete implant-supported restorations in an edentulous heavy smoker: histologic and histomorphometric analyses.

The clinical case presented is that of an edentulous female patient, a heavy smoker, who received implant-supported complete restorations in the maxilla and mandible using the immediate loading concept according to the Ankylos implant system. The patient received 12 commercially pure titanium (grade 2) Ankylos implants, 6 in the maxilla and 6 in the mandible. The implants were loaded immediately after surgery with temporary acrylic resin prostheses fabricated chairside using a prefabricated customized splint. The definitive ceramometal restorations were seated 4 months after surgery. Clinical and radiologic evaluation at 7 months after implant placement indicated functional bone anchorage of all implants, despite the patient being a smoker and having poor bone quality. The patient died 7 months after implant placement because of lung cancer; however, there was no known disease at the time of implant placement. After her death, the implants with the surrounding tissues were removed en bloc and examined histologically and histomorphometrically using undecalcified cut and ground sections. All implants were osseointegrated to some extent and surrounded by lamellar bone. However, around the upper, nonthreaded parts of the implants, much of the bone had been resorbed. In this region, fibrous connective tissue was in close contact with the titanium surface. Epithelial proliferation with pocket formation could not be observed in any of the implants. The histomorphometric evaluation of bone-implant contact in threads demonstrated a mean of approximately 51% of the available surface and a mean bone volume of approximately 52%, with a tendency toward greater contact and volume around the implants in the maxilla. If the nonthreaded cylindric portions of the implants were included, mean bone-implant contact was 46% and mean bone volume was 47%.

Acrylic Resins↗