Fernando Salimon Ribeiro

Biologic width changes around loaded implants inserted in different levels in relation to crestal bone: histometric evaluation in canine mandible

OBJECTIVES The aim of the present study was to evaluate histometric changes around dental implants inserted at different levels in relation to the crestal bone, under different loading conditions. MATERIAL AND METHODS Thirty-six implants were inserted in the edentulous mandible of six mongrel dogs. Each implant was assigned to an experimental group according to the distance from the top of the implant to the crestal bone: Bone Level (at the crestal bone level), Minus 1 (1 mm below the crestal bone) or Minus 2 group (2 mm below the crestal bone). Each hemimandible was submitted to a loading protocol: conventional or immediate restoration. After 90 days, the animals were killed. Specimens were processed, and measurements were performed concerning the length of soft and hard peri-implant tissues. Data were analyzed using ANOVA and Students t test (alpha=5%). RESULTS Among conventionally restored sites, the distance from the most coronal position of soft tissue margin (PSTM) and first bone-implant contact (fBIC) was greater for Minus 2 than for Bone Level and Minus 1 sites (P=0.03), but significant differences were not observed among immediately restored sites. Differences among groups were not observed concerning the PSTM, and the distance from the implant-abutment junction to fBIC. Greater amounts of lateral bone loss were observed for conventionally than for immediately restored sites (P=0.006). CONCLUSIONS These findings suggest that the apical positioning of the top of the implant may not jeopardize the position of soft peri-implant tissues, and that immediate restoration can be beneficial to minimize lateral bone loss. Further studies are suggested to evaluate the clinical significance of these results in longer healing periods.

Success rate of immediate nonfunctional loaded single-tooth implants: immediate versus delayed implantation.

Purpose:The aim of this study was to evaluate the success rate of maxillary immediate nonfunctional single-tooth loaded implants used into fresh extraction sites (immediate placement condition) or healed ridge (delayed placement condition). Materials and Methods:Eighty-two dental implants were placed in the maxilla of 64 consecutive patients from private practice office and from a specialization course in Implantology. Forty-six implants were inserted under immediate placement condition, and 36 were inserted under delayed placement condition. The criteria used to evaluate success rate were those previously described by Albrektsson and Zarb (Int J Prosthodont. 1993;6:95–105), and follow-up period ranged from 18.0 to 39.7 months. Results:Seventy-nine implants fulfilled the success rate criteria (96.3%). Moreover, differences concerning implantation condition were not significant (P = 0.33, Qui-square test): three of the failed implants were from immediate placement group (success rate of 93.5%), and none was from delayed placement group (success rate of 100.0%). Conclusion:In the present sample, no statistically significant differences were detected for immediate nonfunctional single-tooth loaded implants under immediate placement condition in comparison with those inserted under delayed placement condition; both protocols had high success rate in maxillary incisors, canines, and premolars areas.

Treatment of Oroantral Communication Using the Lateral Palatal Sliding Flap Technique

Herein, we present a case of oroantral communication that was to be treated with clinical examination, tomography, and prototyping. A patient presented with oroantral communication with purulent exudation for 4 months, since the displacement of the dental implant and O-ring component to the maxillary sinus. Tomographic examination and prototyping revealed a 5 mm bone gap. The patient underwent local washes and antibiotic therapy. After local palpation, a bone defect detected by prototyping was suspected to be greater than that observed. For the surgery, a communication tunnel was made, and the bone defect was found to be 12 mm in diameter. A pedicle flap was raised on the palate, followed by sliding and suturing. No complications were observed during the postoperative period, and the suture was removed after a week. Four months later, communication did not resume, and the patient did not complain of pain, foul smelling, or purulent discharge and was satisfied with the outcome. The findings of this case suggest that the lateral sliding flap can be used as an efficient technique for closing oroantral communications. An accurate clinical examination is a critical tool that can be used instead of tomography and prototyping, which can be misleading.

Bone-implant contact around crestal and subcrestal dental implants submitted to immediate and conventional loading.

The present study aims to evaluate the influence of apicocoronal position and immediate and conventional loading in the percentage of bone-implant contact (BIC). Thus, 36 implants were inserted in the edentulous mandible from six dogs. Three implants were installed in each hemimandible, in different positions in relation to the ridge: Bone Level (at crestal bone level), Minus 1 (one millimeter apical to crestal bone), and Minus 2 (two millimeters apical to crestal bone). In addition, each hemimandible was submitted to a loading protocol: immediate (prosthesis installed 24 hours after implantation) or conventional (prosthesis installed 120 days after implantation). Ninety days after, animals were killed, and implant and adjacent tissues were prepared for histometric analysis. BIC values from immediate loaded implants were 58.7%, 57.7%, and 51.1%, respectively, while conventional loaded implants were 61.8%, 53.8%, and 68.4%. Differences statistically significant were not observed among groups (P = 0.10, ANOVA test). These findings suggest that different apicocoronal positioning and loading protocols evaluated did not interfere in the percentage of bone-implant contact, suggesting that these procedures did not jeopardize osseointegration.

Periodontal treatment in a patient with generalized idiopathic dystonia.

Dystonia is a neurological disorder that can cause constant muscle contractions and motor limitations. This work reports a clinical case of periodontal treatment in a patient with generalized idiopathic dystonia. The intraoral clinical examination was focused on the presence of caries and periodontal diseases. The plaque index (PI), probing depth (PD), and bleeding on probing (BOP) were measured. Initially, oral hygiene instruction was provided using a soft conventional toothbrush and dental floss, but the clinical results achieved using these methods were inadequate. Alternative methods of plaque removal were offered, such as the use of a power toothbrush and a dental floss fork, which resulted in improvement in the PI, PD, and BOP and allowed the patient to undergo periodontal surgery for the restoration of subgingival caries. Our results suggested that generalized idiopathic dystonia leads to motor limitations that may cause difficulty with regard to plaque control, but adaptations of the methods used for oral hygiene may improve the oral health conditions in these patients.

Torque Analysis of a Triple Acid-Etched Titanium Implant Surface

The present study aimed to evaluate the removal torque of titanium implants treated with triple acid etching. Twenty-one rats were used in this study. For all animals, the tibia was prepared with a 2 mm drill, and a titanium implant (2 × 4 mm) was inserted after treatment using the subtraction method of triple acid etching. The flaps were sutured. Seven animals were killed 14, 28, and 63 days after implant installation, and the load necessary for removing the implant from the bone was evaluated by using a torque meter. The torque values were as follows: 3.3 ± 1.7 Ncm (14 days), 2.2 ± 1.3 Ncm (28 days), and 6.7 ± 1.4 Ncm (63 days). The torque value at the final healing period (63 days) was statistically significantly different from that at other time points tested (ANOVA, p = 0.0002). This preliminary study revealed that treatment with triple acid etching can create a promising and efficient surface for the process of osseointegration.

Connective tissue graft as a biological barrier for guided tissue regeneration in intrabony defects: a histological study in dogs

BackgroundThe use of the autogenous periosteal graft as biological barrier has been proposed for periodontal regeneration. The aim of this study was to evaluate the histometric findings of the subepithelial connective tissue graft as barrier in intrabony defects compared to a bioabsorbable membrane.MethodsThree-walled intrabony defects were created surgically in the mesial aspect of the right and left maxillary canines in five healthy mongrel dogs. The defects were chronified, and two types of barriers were randomly carried out for guided tissue regeneration in a split-mouth design: the test group with a subepithelial connective tissue graft and the control group with a bioabsorbable membrane. The specimens were processed for histometric analyses of the epithelium (E), connective tissue (CT), newly formed cementum (NC), new bone (NB), and total newly formed tissues (NFT).ResultsThe test side showed smaller mean of NC (3.6 ± 1.2), NB (2.1 ± 0.7), and NFT (7.7 ± 0.8) than the control group (NC 7.3 ± 0.5; NB 5.3 ± 1.3; NFT 10.1 ± 2.2; P < 0.05). No statistically significant differences were verified for E (test 3.1 ± 2.0; control 2.8 ± 2.1; P > 0.05) and CT (test 2.5 ± 1.1; control 2.0 ± 0.5; P > 0.05) between groups.ConclusionThe bioabsorbable membrane was more effective in maintaining the space for periodontal regeneration than periosteal connective graft when used as barrier.Clinical relevanceThe bioabsorbable membrane showed more favorable regenerative results in intrabony defects in dogs than the subepithelial connective tissue graft as biological barrier.

Oral Myiasis Caused by Cochliomyia hominivorax in a Disabled Person

Myiasis is a parasitic disease caused by developing maggots of fly species, which can infect humans. Patients with special needs, especially those with severe neuropsychomotor limitations, may have oral manifestations of this disease. Here, we present a clinical case in which a disabled person was affected by oral myiasis caused by Cochliomyia hominivorax. Maggots were found in two ulcerated lesions, a 2 cm diameter lesion in the maxilla and a 6 cm diameter lesion in the mandible. Forty-five maggots were removed during inspection, whereas 75 maggots were surgically removed under general anesthesia with nasotracheal intubation. Dipyrone, ivermectin, and clindamycin were prescribed, and the patient remained hospitalized for 3 days. Seven days after surgical intervention, no maggots were observed. Our study emphasizes that dentists must recognize the symptoms and behaviors of parasitic diseases that affect the oral cavity.

Multiple Marginal Tissue Recession Treated with a Simplified Lateral Sliding Flap Technique

Marginal tissue recession is a common esthetic problem that is usually accompanied by dentin sensitivity, and patients frequently report a fear of dental loss. Lateral sliding flaps have been used for localized recession, but they are rarely used for multiple recessions. The aim of this paper was to report a case of coverage of multiple marginal tissue recessions by means of a lateral sliding flap associated with a connective tissue graft. This was a modification of Nelsons technique, which was originally described as the combination of the double papilla technique, lateral sliding flap, and connective tissue graft. In the present case, double papilla was not performed, rendering the maneuver less complicated. After surgery on teeth #23 to #25, total root coverage, decreased dentin sensitivity, and increased keratinized tissue band and gingival thickness were achieved. In the present case, modified Nelson technique proved to be a more simple procedure for the treatment of multiple recessions in one session, resulting in adequate healing, predictable root coverage, and, more importantly, esthetic and functional success.