Retraction: Bacterial adhesion and colonization differences between zirconia and titanium implant abutments: an in vivo human study

This article has been retracted at the request of the Editor-in-Chief, because the authors plagiarized a previously published paper that had appeared in: Int J Oral Maxillofac Implants, 26 (2011) 101–107. This article presented the same table and figures as the original study, and changed 2 of the tables to figures. This article reflects severe abuse of the scientific publishing system, and has therefore been retracted.

Chemosis as complication in transconjunctival approach for orbital trauma

The aim of this report was to discuss a complication resulting from a transconjunctival approach to treating an orbital fracture. A 30-year-old male patient presented with a fracture to the zygomatic orbital complex. He was treated with transconjunctival conventional surgical treatment. Two days after surgical treatment, the patient presented with secondary chemosis which was initially slight and then subsequently worsened. The clinical situation was managed with topical and systemic corticosteroids and resolved within one postoperative month. Two-year follow-up showed ptosis of the upper eyelid and limited infraversion in the affected eye. This unusual complication associated with an orbital trauma was resolved with minor functional alterations, although the consequences observed after 2 years were not completely satisfactory.

Clinical and biological analysis in graftless maxillary sinus lift

Maxillary sinus lift for dental implant installation is a well-known and versatile technique; new techniques are presented based on the physiology of intrasinus bone repair. The aim of this review was to determine the status of graftless maxillary sinus lift and analyze its foundations and results. A search was conducted of the literature between 1995 and 2015 in the Medline, ScienceDirect, and SciELO databases using the keywords “maxillary sinus lift,”“blood clot,”“graftless maxillary sinus augmentation,” and “dental implant placement.” Ten articles were selected for our analysis of this technique and its results. Despite the limited information, cases that were followed for at least six months and up to four years had a 90% success rate. Published techniques included a lateral window, elevation of the sinus membrane, drilling and dental implant installation, descent of the membrane with variations in the installation of the lateral wall access and suturing. The physiology behind this new bone formation response and the results of the present research were also discussed. We concluded that this is a promising and viable technique under certain inclusion criteria.

Mechanical evaluation of the use of conventional and locking miniplate/screw systems used in sagittal split ramus osteotomy

OBJECTIVES: The aim of this study was to compare the mechanical resistance of four different osteosyntheses modeled in two different sagittal split ramus osteotomy (SSRO) designs and to determine the linear loading in a universal testing machine. MATERIALS AND METHODS: An in vitro experiment was conducted with 40 polyurethane hemimandibles. The samples were divided into two groups based on osteotomy design; Group I, right angles between osteotomies and Group II, no right angles between osteotomies. In each group, the hemimandibles were distributed into four subgroups according to the osteosynthesis method, using one 4-hole 2.0 mm conventional or locking plate, with or without one bicortical screw with a length of 12.0 mm (hybrid technique). Each subgroup contained five samples and was subjected to a linear loading test in a universal testing machine. RESULTS: The peak load and peak displacement were compared for statistical significance using PASW Statistics 18.0 (IBM Co., USA). In general, there was no difference between the peak load and peak displacement related to osteotomy design. However, when the subgroups were compared, the osteotomy without right angles offered higher mechanical resistance when one conventional or locking 2.0 mm plate was used. One locking plate with one bicortical screw showed higher mechanical resistance (162.72±42.55 N), and these results were statistically significantly compared to one conventional plate with monocortical screws (P=0.016) and one locking plate with monocortical screws (P=0.012). The difference in peak displacement was not statistically significant based on osteotomy design or internal fixation system configuration. CONCLUSION: The placement of one bicortical screw in the distal region promoted better stabilization of SSRO. The osteotomy design did not influence the mechanical behavior of SSRO when the hybrid technique was applied.

Stability of the prosthetic screws of three types of craniofacial prostheses retention systems

OBJECTIVES: This study aimed to evaluate the stability of prosthetic screws from three types of craniofacial prostheses retention systems (bar-clip, ball/O-ring, and magnet) when submitted to mechanical cycling. MATERIALS AND METHODS: Twelve models of acrylic resin were used with implants placed 20 mm from each other and separated into three groups: (1) bar-clip (Sistema INP, São Paulo, Brazil), (2) ball/O-ring (Sistema INP), and (3) magnet (Metalmag, São Paulo, Brazil), with four samples in each group. Each sample underwent a mechanical cycling removal and insertion test (f=0.5 Hz) to determine the torque and the detorque values of the retention screws. A servo-hydraulic MTS machine (810-Flextest 40; MTS Systems, Eden Prairie, MN, USA) was used to perform the cycling with 2.5 mm and a displacement of 10 mm/s. The screws of the retention systems received an initial torque of 30 Ncm and the torque values required for loosening the screw values were obtained in three cycles (1,080, 2,160, and 3,240). The screws were retorqued to 30 Ncm before each new cycle. RESULTS: The sample was composed of 24 screws grouped as follows: bar-clip (n=8), ball/O-ring (n=8), and magnet (n=8). There were significant differences between the groups, with greater detorque values observed in the ball/O-ring group when compared to the bar-clip and magnet groups for the first cycle. However, the detorque value was greater in the bar-clip group for the second cycle. CONCLUSION: The results of this study indicate that all prosthetic screws will loosen slightly after an initial tightening torque, also the bar-clip retention system demonstrated greater loosening of the screws when compared with ball/O-ring and magnet retention systems.

An in vitro comparison between two different designs of sagittal split ramus osteotomy

OBJECTIVES: To evaluate the influence of the type of osteotomy in the inferior aspect of the mandible on the mechanical performance. MATERIALS AND METHODS: The study was performed on 20 polyurethane hemimandibles. A sagittal split ramus osteotomy (SSRO) was designed in 10 hemimandibles (group 1) with a vertical osteotomy in the buccal side (second molar level) and final osteotomy was performed horizontally on the lingual aspect, while the mandible body osteotomy was finalized as a straight osteotomy in the basilar area, perpendicular to the body. For group 2, the same osteotomy technique was used, but an oblique osteotomy was done in the basilar aspect of the mandibular body, forming continuity with the sagittal cut in the basilar area. Using a surgical guide, osteosynthesis was performed with bicortical screws using an inverted L scheme. In both groups vertical compression tests were performed with a linear load of 1 mm/min on the central fossa of the first molar and tests were done with models made from photoelastic resin. Data were analyzed using Student's t-test, establishing a statistical significance when P <0.05. RESULTS: A statistical difference was not observed in the maximum displacements obtained in the two osteotomies (P <0.05). In the extensiometric analysis, statistically significant differences were identified only in the middle screw of the fixation. The photoelastic resin models showed force dissipation towards the inferior aspect of the mandible in both SSRO models. CONCLUSION: We found that osteotomy of the inferior aspect did not influence the mechanical performance for osteosynthesis with an inverted L system.

Segmental osteotomy for mobilization of dental implant

PURPOSE: The aim of this work is to evaluate a surgical technique for mobilization of mal posed dental implant in anterior area. METHODS: A 38-year-old patient consulted our unit for esthetic dissatisfaction with the implant treatment of a central incisor. An implant was observed in 11 and 21, where 11 was 3 mm above the ideal limit, with excessive vestibular angulation. The choice was made to perform a segmental osteotomy and mobilize the bone block and the implant down and forward; a bone block extracted from the mandibular ramus was installed between the implant block and the bed to stabilize the segment. RESULTS: After 4 months, a conventional fixed prosthesis was created and the esthetic result achieved was close to what the patient wanted, with no need for further surgery. The surgical condition was stabilized and maintained for the long-time and no complications how necrosis, infection or bone defects was present. CONCLUSIONS: It was concluded that the procedure is efficient, and the biological arguments in favor of the procedure are discussed.

Bacterial adhesion and colonization differences between zirconia and titanium implant abutments: an in vivo human study

PURPOSE: Several parameters have been described for determining the success or failure of dental implants. The surface properties of transgingival implant components have had a great impact on the long-term success of dental implants. The purpose of this study was to compare the tendency of two periodontal pathogens to adhere to and colonize zirconia abutments and titanium alloys both in hard surfaces and soft tissues. METHODS: Twelve patients participated in this study. Three months after implant placement, the abutments were connected. Five weeks following the abutment connections, the abutments were removed, probing depth measurements were recorded, and gingival biopsies were performed. The abutments and gingival biopsies taken from the buccal gingiva were analyzed using real-time polymerase chain reaction to compare the DNA copy numbers of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and total bacteria. The surface free energy of the abutments was calculated using the sessile water drop method before replacement. Data analyses used the Mann Whitney U-test, and P-values below 0.05 find statistical significance. RESULTS: The present study showed no statistically significant differences between the DNA copy numbers of A. actinomycetemcomitans, P. gingivalis, and total bacteria for both the titanium and zirconia abutments and the biopsies taken from their buccal gingiva. The differences between the free surface energy of the abutments had no influence on the microbiological findings. CONCLUSIONS: Zirconia surfaces have comparable properties to titanium alloy surfaces and may be suitable and safe materials for the long-term success of dental implants.

Consideraciones actuales en hiperplasia fibrosa inflamatoria / Current considerations in inflammatory fibrous hyperplasia

El objetivo de esta investigación es evaluar los aspectos clínicos, histológicos y las posibilidades de tratamiento de la hiperplasia fibrosa inflamatoria (HFI). Esta lesión se origina frecuentemente a partir de prótesis totales o parcial mal adaptadas, las cuales generan un traumatismo crónico de baja intensidad. Se han descrito lesiones en mandíbula y maxila, no existiendo predilección por ninguna de las arcadas dentales. Lesiones pequeñas pueden ser tratadas de manera conservadora, con remoción del agente causal o mediante atrofia por presión con nuevas prótesis, mientras que lesiones extensas y de larga evolución necesitarán de escisión quirúrgica. Si el tratamiento quirúrgico es considerado, éste debe incluir la remoción total de la lesión, usando diversas técnicas como bisturí “frío” (lámina), láser o electrocirugía.La remoción quirúrgica es necesaria, pues restaura el contorno normal del tejido y la adaptación protética. Algunos autores han reportado alteraciones displásicas en la HFI, pero la posibilidad de que ésta sufra una transformación maligna aún es muy discutida.

The objective of this research is an evaluate of clinical and histologic aspects of fibrous inflammatory hyperplasia and the possibilities of its treatment. This lesion is frequently originated for using total or partial prosthesis which are inadequate adapted generating a chronic traumatism of low intensity. Clinical cases in jaw and maxila have been reported, not existing predilection for any dental arches. Small lesions can be treated by the conservative way that means removing the causal agent or atrophying by putting pressure with a new prosthesis, whereas extensive lesions of large evolution need surgical excision. If the surgical treatment is considered, this should include the total removal of the lesion, using varieties of techniques such as “cold” scalpel, laser or electrosurgical techniques. The surgical removal is necessary because recover the normal contour of tissue and the prosthetic adaptation. reports exist about dysplasic alterations related to fibrous inflammatory hyperplasia, but the possibility of a malignant transformation is actually controversial.