Soft tissue conditions and marginal bone levels of implants with a laser-microtextured collar: a 5-year, retrospective, controlled study.

AIM: To compare clinical and radiographic outcomes of implants with a Laser-Lok®-microtextured collar to implants with a resorbable blast textured (RBT) collar after a 5-year follow-up period. MATERIALS AND METHODS: Thirty-four implants with a Laser-Lok®-microtextured collar (test group [TG]) and 31 implants with an RBT collar (control group [CG]) were placed in 45 non-smoking, periodontally healthy patients. The full-mouth plaque score, full-mouth bleeding score, number of sites with plaque, and the number of sites with bleeding on probing (BOP) were recorded at baseline, and at 1-, 2-, 3-, 4-, and 5-year follow-up. Probing depth (PD) and mucosal recession were assessed at baseline and after the 5-year follow-up period. The radiographic marginal bone loss (MBL) was calculated by subtracting the bone level at the time of crown insertion from the bone level at the 5-year follow-up. RESULTS: An implant survival rate of 94% and of 90% was reported for the TG and the CG, respectively. No statistical differences were found between the study groups for presence of plaque (10.1% vs. 25%) or for number of sites with BOP (10.3% vs. 23%). The differences between both study groups were statistically significant for mean MBL (0.81 ± 0.24 vs. 2.02 ± 0.32 mm), mean PD (2.32 ± 0.44 vs. 4.25 ± 0.87 mm), and mean mucosal recession (0.16 ± 0.3 vs. 0.22 ± 0.3 mm). CONCLUSIONS: Within the limitations of this study, results suggest that the laser-microtextured implant collar surface may provide more favorable conditions for the attachment of hard and soft tissues, and reduce the level of MBL.

Dimensional ridge alterations following immediate implant placement in molar extraction sites: a six-month prospective cohort study with surgical re-entry.

AIM: To assess dimensional ridge alterations following immediate implant placement in molar extraction sites. MATERIAL AND METHODS: Twelve subjects received 12 immediate transmucosal implants in molar extraction sites. Peri-implant defects were treated according to the principles of Guided Bone Regeneration by means of a deproteinized bone substitute and a bioresorbable collagen membrane. Changes in vertical (IS-BD, CREST-BD) and horizontal distances (EC-I, IC-I) of alveolar bony walls to the bottom of the defects (BD) and to the implant surfaces (I) were compared between implant placement and surgical re-entry at 6 months. RESULTS: The implant survival rate at 6 months was 100%. Statistically significant differences (P<0.01) were observed in the mean changes in vertical distances IS-BD and CREST-BD between baseline and re-entry. At re-entry, all peri-implant marginal defects assessed from the internal socket wall to the implant surface (IC-I) were healed. The residual combined thickness of the buccal wall with the newly formed peri-implant bone at sites with an initial thickness of 1 mm was statistically significantly smaller (P<0.05) compared with that of sites with an initial buccal thickness of 2 mm (2.50 +/- 0.76 vs. 4+/-0 mm). CONCLUSIONS: The marginal defects around immediate implants placed in molar extraction sites were completely filled after 6 months of healing through de novo bone formation. Bone resorption was observed from the external aspects of the buccal and oral socket walls. Dimensional changes of the external socket walls were mostly pronounced at the buccal aspects.

Soft tissues healing at immediate transmucosal implants placed into molar extraction sites with buccal self-contained dehiscences. A 12-month controlled clinical trial.

AIM: To assess soft tissues healing at immediate transmucosal implants placed into molar extraction sites with buccal self-contained dehiscences. MATERIAL AND METHODS: For this 12-month controlled clinical trial, 15 subjects received immediate transmucosal tapered-effect (TE) implants placed in molar extraction sockets displaying a buccal bone dehiscence (test sites) with a height and a width of > or =3 mm, respectively. Peri-implant marginal defects were treated according to the principles of Guided Bone Regeneration (GBR) by means of deproteinized bovine bone mineral particles in conjunction with a bioresorbable collagen membrane. Fifteen subjects received implants in healed molar sites (control sites) with intact buccal alveolar walls following tooth extraction. In total, 30 TE implants with an endosseous diameter of 4.8 mm and a shoulder diameter of 6.5 mm were used. Flaps were repositioned and sutured, allowing non-submerged, transmucosal soft tissues healing. At the 12-month follow-up, pocket probing depths (PPD) and clinical attachment levels (CAL) were compared between implants placed in the test and the control sites, respectively. RESULTS: All subjects completed the 12-month follow-up period. All implants healed uneventfully, yielding a survival rate of 100%. After 12 months, statistically significantly higher (P<0.05) PPD and CAL values were recorded around implants placed in the test sites compared with those placed in the control sites. CONCLUSIONS: The findings of this controlled clinical trial showed that healing following immediate transmucosal implant installation in molar extraction sites with wide and shallow buccal dehiscences yielded less favorable outcomes compared with those of implants placed in healed sites, and resulted in lack of 'complete' osseointegration.

Nucleation-controlled aggregation of deoxyhemoglobin S. Effect of organic phosphates on the kinetics of aggregation of deoxyhemoglobin S in concentrated phosphate buffer.

The kinetics of the aggregatin of deoxyhemoglobin S in concentrated phosphate buffer were studied turbidimetrically in the presence of organic phosphates. The addition of inositol hexsphosphate shortened the delay time by 35-80%, the range depending on the hemoglobin concentration. The logarithmic plot of delay time versus hemoglobin concentration in 1.85 M potassium phosphate buffer, pH 7.34, showed a linear relationship with a slope (n value) of 2.5 +/- 0.14 in the absence of inositol hexaphosphate, while the slope was decreased to 2.1 in the presence of inositol hexaphosphate. The turbidity (A700) of aggregates per g deoxy Hb S was found to be lower in the presence of inositol hexaphosphate than in the absence of inositol hexaphosphate. The solubility of deoxy Hb S was decreased by inositol hexaphosphate. 2,3-Diphosphoglyceric acid also showed an effect similar to that of inositol hexaphosphate. However, if the pentacyclohexylammonium salt of diphosphoglyceric acid were used, the delay time was increased significantly. The opposite effect of the pentacyclohexylammonium salt of diphosphoglyceric acid on the delay time was found to be attributed to the anti-gelation effect of the pentacyclohexoxylammonium ion. The difference in the effect of inositol hexaphosphate and diphosphoglyceric acid on the delay time appears to be related to their effect on the solubility of deoxy Hb S.

Histological evaluation of the peri-implant bone around plasma-sprayed non-submerged titanium implants retrieved from man: a report of two cases.

Two cases of non-submerged implants are reported: one was removed, unloaded, after 1 year, for psychiatric reasons, and the other, after a loading period of 4 years, for a fracture of the implant. The implants and surrounding tissues were processed to obtain thin ground sections. In the first case compact lamellar bone was observed in close contact with the titanium all around the implant perimeter. No connective tissue or empty spaces were found at the bone-implant interface. Histochemical staining with von Kossa demonstrated that all the bone around the implant was highly mineralized. No areas of osteoid tissue were found at the bone-implant interface. In the implant retrieved due to fracture it was possible to observe a very high percentage of bone-implant contact.

Evaluation of guided bone regeneration in rabbit tibia using bioresorbable and non-resorbable membranes.

The aim of this study was an evaluation of the possibility of bone regeneration in connection with implant placement, using a new bioresorbable membrane (Guidor Matrix Barrier) used previously in periodontal tissues regeneration. The study compared the bone regeneration obtained around Bonefit-ITI implants inserted in rabbit tibia using Guidor membranes, Gore-Tex membranes and in control sites. Microscopic analysis was performed after 6, 9 and 12 weeks. It was possible to see that the amount of bone around implants covered by Guidor and Gore-Tex membranes was roughly equivalent in all experimental sites at the 6-, 9- and 12-week time intervals. Also, all control sites healed completely. It could be concluded from this study that: (1) rabbit tibia cannot be recommended in research connected with guided bone regeneration, as all control sites healed in the same way as the test sites; (2) in no case did the presence or the degradation of the resorbable membrane prevent the formation of new bone; (3) no inflammatory reaction was present around the bioresorbable and the non-resorbable membranes; (4) bone formed in all cases on the outer surface of the non-resorbable membranes; (5) large Guidor membrane fragments were present in the 6-week specimens, while in the 12-week specimens only small fragments were recognizable; (6) Guidor membranes can be used in guided bone regeneration.

Early tissue reactions to polylactic acid resorbable membranes: a histological and histochemical study in rabbit.

The aim of this study, in rabbit tibia, was an evaluation of the early reactions of the tissues to the insertion of polylactic membranes, used in connection with titanium implants. The specimens were retrieved after 1-4 weeks, and a histological analysis was performed. It was possible to see that, in the early implantation phases, no degradation of the macrostructure of the membrane was present. On the outer portion of the membrane many multinucleated giant cells (MGC) were present and membrane fragments were present inside the cytoplasm of these cells. These cells could explain the inflammatory processes reported, in some reports, with the use of materials made by polylactic and polyglycolic acid. We did not observe detrimental effects in the bone tissue around the membrane, and the membrane appeared to have a mechanical stability for the time necessary for bone regeneration.

A microscopical evaluation of 24 retrieved failed hollow implants.

Twenty-four hollow ITI implants (four screws, and 20 cylinders) were retrieved because of failure, and evaluated in our laboratory, in a eight-year period (1989-1996), to see if a common cause could be observed in this implant design. No selection of these implants was carried out, and they represented the total number of implants of this type received in the above-mentioned time frame. The implants had been inserted by several different clinicians and were received from four universities and a private practice. The implants had been removed for mobility, pain, and presence of a vertical bone loss. About two-thirds of the implants were unstable in the jaw at the time of retrieval. Twenty implants had been used as single implants restoration and four in bridge reconstructions. Most of our specimens showed that the inflammatory process had reached the hollow portion of the implants. The following microscopical features were present in almost all our specimens: calculus and plaque on the coronal portion of the implant surface, presence of proliferating epithelium and of bone sequestra, and presence of bone apically to the inflammatory process. Perhaps, when the inflammatory process reaches the implant hollow portion, the infection runs a more rapid course due to the scarce vascularity of the bone inside this part.

Treatment of pediculosis pubis. Clinical comparison of efficacy and tolerance of 1% lindane shampoo vs 1% permethrin creme rinse.

Pediculosis pubis (PP) is a common sexually transmitted disease. Current therapy with 1% lindane or various synergized pyrethrins as a single dose has been accepted as adequate by the medical community. We treated 53 men with the diagnosis of PP with either 1% lindane (Kwell) shampoo for four minutes or 1% permethrin (Nix) creme rinse for ten minutes, according to random assignment. All patients combed with fine-toothed combs immediately after therapy. They were examined for tolerance and efficacy at 24 to 48 hours and again at ten days (eight- to 12-day range). In the lindane group, ten (40%) of 25 subjects were infested at the final assessment. In the permethrin group, 12 (43%) of 28 subjects were infested at the final assessment. The difference was not statistically significant. Both treatments were well tolerated, with one mild adverse reaction in each group. We concluded that both agents were equivalent in the treatment of PP. On the basis of the high failure rate, we propose that the therapy of PP with any agent should include a second treatment at ten days.

Liposuction of the chest and back.

Subcutaneous fat deposition on the chest and back is notoriously diet and exercise resistant. The "top heavy" appearance is a source of frustration for patients as well as surgeons. Fortunately, with advent of tumescent liposuction surgery the disparity between the upper and lower torso can now be reconciled.

A regional approach to patient selection and evaluation for liposuction.

Any area of the body where the deformity is due to regional excess fat and where there is overlying good skin tone is presumably amenable to body contouring by liposuction. It is an understandable temptation to attempt to remove large quantities of fat without major surgery and without noticeable scars. With experience, the surgeon will be able to estimate preoperatively the amount of fat that should be removed. However, liposuction is a procedure that requires conservatism because overzealous fat removal can generally leave unsightly permanent sequelae. Careful patient selection and proper identification of the correct indications of the technique are of paramount importance in achieving good aesthetic results and in avoiding complications. The ideal candidate is young, with good skin tone, moderate localized fatty deposits, and realistic expectations. There is certainly a wide range of patients who will benefit from the use of liposuction, and the average patient with less-than-ideal indications is more commonly encountered. The poor candidate is obese or has a significant deformity, poor skin tone, and, ironically, the most unrealistic expectations. Old age is not an absolute contraindication, although with increased age there is a concomitant decrease in elastic fibers, resulting in decreased capability to adapt a new contour. However, many patients "past their prime" will also have an acceptable cosmetic result and are particularly pleased with their changed, clothed silhouette. Appropriate patient selection, appreciation of the underlying anatomy, and judicious surgical technique are all essential for optimal results and patient satisfaction. Liposuction as described, either alone or as an adjunct to other procedures, allows for optimal aesthetic correction of figure faults due to adipose tissue.

Chemical face peels.

Application of caustic chemicals to improve cosmesis and reverse actinic damage has been used for centuries. Although still not an exact science, it was not until the latter part of this century that peeling became more systematized. The indications, patient selection, armamentarium, histology, comprehension of the mechanisms of action, and safety parameters of peels have only recently become more extensively defined. Phenol, when used in the Baker's formula, provides the most dramatic results but also holds the most potential for systemic complications. Ideally suited for fair-skinned women, a phenol peel can provide substantial improvement in rhytidosis and actinic damage. Although the results of medium-depth peels approach those of Baker's peels, they are not quite as profound. Use of TCA and the medium-depth peels has filled an important gap between deep and superficial peels, however. Also ideal for light complexions, this category of peels lightens pigmentary problems and improves rhytides with minimal potential for systemic toxicity; however, local complications, including scarring and pigmentary anomalies, should not be underestimated. [table: see text] Superficial peels do not effectively eradicate the ravages of time and sun, but when done repetitively, they do improve pigmentary irregularities and may improve some minor surface changes and thus impart a fresher appearance to facial skin. Although pigmentary changes can occur, superficial peels are relatively safe, and maximal results can be achieved with serial applications. Peels have been categorized by patient indications and the corresponding depth of peeling required for improvement (Table 4). The depth is determined in turn by a host of factors (Table 5). Neither the classification scheme nor the peel process should be viewed dogmatically. Patients will often benefit from the concurrent use of different skin preparations and wounding agents. Localized gradations can be achieved not only with occlusion but also by employing different solutions as well as different concentrations of the same solution and skin preparation. Selection of the appropriate technique relies on critical analysis of the skin defect one wishes to treat balanced against the risks of treatment. The final protocol should be individualized for the needs of each patient. Despite heightened public awareness of the harmful effects of ultraviolet radiation, actinically damaged skin is no longer a problem restricted to an older-patient population. Fueled by the lay press and practitioners, there is a growing patient demand for chemical peels. Chemical peels alone or combined with ancillary aesthetic procedures can provide a dramatic improvement in facial appearance. The potential for improved cosmesis is not without inherent risk, however.(ABSTRACT TRUNCATED AT 400 WORDS)

Chemical peels. Trichloroacetic acid and phenol.

Chemical peeling is the most widely used modality for treating photoaged skin. The classification, indications, techniques, complications, and histology of two of the most widely used peeling agents, trichloroacetic acid and phenol, are presented.

Cutaneous resurfacing.

Cutaneous resurfacing can be accomplished with application of acids, abrasive modalities, or the new generation of carbon dioxide lasers. Ultimately, the universal goal is removal and replacement of the epidermis and dermal collagen remodeling. The indications range from therapeutic and reconstruction to the treatment of the stigmata associated with senescence. The indications are not technique-specific, and the art of cutaneous resurfacing is identifying the cutaneous defect and selecting the appropriate tool or tools to realize the optimal clinical results.

Cellular colonization and bone formation into expanded polytetrafluoroethylene membranes: a light microscopical and histochemical time course study in the rabbit.

We report on a time course study of cellular colonization of expanded polytetrafluoroethylene (ePTFE) membranes in rabbits. Bone defects (8 mm) were prepared with low speed burs in rabbit tibial metaphyses and covered with ePTFE membranes. The membranes were retrieved after 3, 6, 9, and 12 weeks. At 3 weeks, all membranes were filled by cells and osteoid tissue: no mineralized tissue was found. Osteoblasts positive for alkaline phosphatase (ALP) were observed on the outer surface and inside the material interstices of the membrane. At 6 weeks, it was possible to observe an increase of the quantity of the osteoid material inside the membranes. At 9 weeks, bone tissue was present and it usually originated from the most external part of the membrane, and spread to the central part of the membrane. Only the central portion of this bone appeared to be completely mineralized. A sharp decrease in the number of ALP-positive osteoblasts was observed. At 12 weeks, the quantity of bone present appeared to be substantially increased. Only a small percentage of the bone inside the membrane appeared to be completely mineralized. No cells positive to acid phosphatase were observed. These histological results confirm the high biocompatibility of ePTFE membranes and the bone formation inside the ePTFE interconnected nodes could, probably, help in achieving a good biomaterial-tissue integration with predictable results in bone regeneration.

Hollow implants retrieved for fracture: a light and scanning electron microscope analysis of 4 cases.

One of the possible complications of implant treatment is the occurrence of an implant fracture. Metal fatigue and biomechanical overload seem to be the most common causes of fractured implants. This study evaluated 4 implants (3 hollow cylinders and 1 hollow screw) which fractured after a mean loading period of 2.8 years. All implants had a 4 mm diameter and had been inserted in a posterior location. In 3 cases parafunctional habits were present. In all cases a vertical resorption of the peri-implant bone was present. The endosseous portion of the implant presented always a very high bone-implant contact percentage. Scanning electron microscopic examination showed that at least one of the implant holes was involved in the fracture line; no porosities or material defects were observed on the fractured surface of the implant. In hollow implants the holes could represent a site of less resistance.

Juvenile hyaline fibromatosis of gingiva: a case report.

Juvenile hyaline fibromatosis is an extremely rare inherited condition, probably resulting from an inborn error of metabolism. It is characterized by cutaneous nodules, gingival hypertrophy and joint contractions. It affects children but usually it is not present at birth, and is microscopically characterized by a conspicuous hyalinization of the connective tissue.

Treatment guidelines for botulinum toxin type A for the periocular region and a report on partial upper lip ptosis following injections to the lateral canthal rhytids.

Inactivation of the orbicularis oculi muscle by chemodenervation with botulinum toxin type A (Botox, Allergan, Inc., Irvine, Calif.) as a sole procedure or in conjunction with blepharoplasty has proved to be a reliable method to improve the appearance of the periocular area. Botox has the unique and ideal characteristic in that, with repeated use, there is potential for a prolonged clinical effect with smaller dosages. In addition, if a complication does arise--while not aesthetically acceptable and potentially untoward--it is time-limited, and the anatomical area will eventually return to its pretreatment baseline status. In this study, in three cases [in more than 1000 crow's feet treatment sessions (2000 sides)] over the course of 1 year, partial lip ptosis resulting from weakening of the zygomaticus major muscle after the injection of Botox into the periocular region are reported. This article reviews suggested treatment guidelines and anatomic considerations for the periocular region to maintain injection standardization and improve the safety profile of Botox as the aesthetic indications for its use expand and the number of individuals who inject it increases.

Botulinum A exotoxin for the management of platysma bands.

Injections of botulinum A exotoxin are successfully used to treat neuromuscular disorders and to improve hyperkinetic muscles and dynamic rhytids of the upper face. Using these principles, we extended its use to the treatment of the aging neck (hypertrophic platysma muscle bands). A classification system (I to IV) based on horizontal neck rhytids, platysma bands, and skin laxity was devised to categorize the degree of deformity and serve as a guideline for suggested dosages of botulinum. The results correlated with the degree of age-related neck degeneration. Type II (mild horizontal neck rhytids; thin, mild platysma muscle flaccidity; and mild skin laxity) and III (moderate horizontal neck rhytids; thick, moderate platysma muscle flaccidity; and moderate skin laxity) patients were the most satisfied, followed closely by types I and IV. A total of 1500 patients were treated by three independent practices. The majority of them achieved good-to-excellent results, as evaluated by both the physician and patient. The degree of muscle flaccidity and hypertrophy were the factors that most influenced success rates, not the anatomic variations in muscle configuration.

Deep chemical peeling.

Facial skin wrinkling and sagging are concerns that often compel patients to seek counsel on rejuvenative procedures. Facial plasty procedures will alleviate many of these concerns. However, deep chemical peels, in conjunction with surgery or alone, can often significantly improve both the ravages of excess sun exposure and the stigmata of aging.