Assessment of Changes in the Outcome of Autogenous Tooth Grafts Over Time: A Clinical Study Evaluating Periodontal Healing in Bone Defects After Lower Third Molar Removal.

BACKGROUND: The removal of impacted lower third molars (ILTMs) is associated with bone defects in the distal area of second molars. Different methods have been described to minimize these defects. PURPOSE: The primary objective was to assess changes in probing depth (PD) over time (up to 36 months) between test (grafted) and control (ungrafted) groups; the graft was obtained from the extracted ILTM. STUDY DESIGN, SETTING, SAMPLE: This split-mouth randomized clinical trial was conducted at the Postgraduate Course in Oral Surgery of the Faculty of Dentistry of the Complutense University of Madrid. Adult patients requiring bilateral ILTM extraction with adjacent second molars were recruited, excluding pregnant/lactating women, patients in treatment with nonsteroidal anti-inflammatory drugs and patients with periodontal diseases. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The predictor variable was the graft technique. The bone defect after ILTM removal was treated with autogenous tooth graft (ATG) in the test group, leaving the control group ungrafted. MAIN OUTCOME VARIABLE: PD on the distobuccal, distomedial, and distolingual surfaces was recorded in both groups and averaged at baseline (T0), 3 (T1), 6 (T2), and 36 months (T3) postoperatively. COVARIATES: Sex, age, surgical time, ILTM situation and position between groups were assessed. ANALYSES: ANOVA repeated measures for comparisons between groups and the Friedman test for comparisons within the groups over time were applied. Statistical significance was established with a confidence interval of 95% (P < .05). RESULTS: The sample comprised 22 patients (6 males, 16 females) with a mean age of 21.68 ± 2.19 years; 44 ILTM extractions were performed. Statistically significant differences in PD average were found between groups (P < .001, 95% confidence interval) at 3 (1.63 ± 0.29), 6 (1.76 ± 0.3), and 36 months (1.74 ± 0.36). Reductions from T0 to T3 of 2.74 ± 0.28 (P < .001) and 0.54 ± 0.3 (P = .43) were observed in test and control groups, respectively. CONCLUSION AND RELEVANCE: ATG placed on the distal surface of lower second molars and almost completely filling the extraction socket improved PD 3, 6 and 36 months after ILTM. Furthermore, no significant changes in PD were observed over time; no major complications occurred. ATG appears to be a viable alternative graft material for this procedure.

The Influence of Anxiety on Postoperative Quality of Life Regarding Implant Treatments: An Epidemiological Study.

Dental treatment anxiety is highly prevalent worldwide. This is particularly important in the field of implantology since, in daily clinical practice, it translates into an increase in the difficulty of treatments, extending surgical times and having repercussions in the postoperative period. The aim of this multicentre, cross-sectional, epidemiological study was to determine the influence of anxiety levels in the postoperative period of an implant treatment on patients treated at two dental departments in Extremadura (Spain). To analyse anxiety levels, the modified Corah's Dental Anxiety Scale questionnaire was administered before surgical treatment. To analyse the postoperative period, another questionnaire was provided 7 days after surgery. The study was conducted on a total of 102 patients (55 men and 47 women), with a mean age of 47.99 years. The results indicated that patients with a high and severe degree of anxiety had a poorer quality of life in general. Patients with a higher degree of anxiety perceived greater swelling at 24, 48, 72 h and one week after surgery.

Autogenous particulated dentin for alveolar ridge preservation. A systematic review.

PURPOSE: This review aimed to investigate the clinical outcomes of autogenous particulated dentin (APD) used for alveolar ridge preservation (ARP), evaluating volume gain, histologic/histomorphometric data, and associated complications. MATERIAL AND METHODS: The review followed PRISMA guidelines and was registered in the International Prospective Register of Systematic Reviews (PROSPERO). An automated search was made in four databases (Medline/Pubmed, Scopus, Web of Science, and Cochrane Library) supplemented by a manual search for relevant clinical articles published before March 10th, 2022. The review included human studies of at least four patients in which extraction and subsequent ARP were performed in a single surgery. Both comparative studies and studies that assessed ARP with APD exclusively were admitted. The quality of evidence was assessed with the Cochrane bias assessment tool, the Newcastle-Ottawa Quality Assessment Scale, and the Joanna Briggs Institute Critical Appraisal tool. RESULTS: Eleven studies fulfilled the inclusion criteria and were included for descriptive analysis, with a total of 215 patients, and 337 alveoli preserved by APD, spontaneous healing (blood clot), or other bone substitutes, obtaining comparatively less vertical and horizontal resorption when APD was used. CONCLUSIONS: After dental extraction, autogenous dentin was effective in terms of volume maintenance, showing promising results in histologic/histomorphometric analysis, and a low complication rate. Nevertheless, few comparative studies with comparable parameters have been published and so more research providing long-term data is needed to confirm these findings.

Dental Transmigration: An Observational Retrospective Study OF52 Mandibular Canines.

The aim of this study was to analyze the prevalence of transmigrated canines in a Spanish population by evaluating their clinical and radiological characteristics. The descriptive observational study obtained 6840 orthopantomographs from all patients seeking dental care in the years 2017-21 via the Patient Reception Service and Dentistry Service at the Faculty of Dentistry at the Complutense University of Madrid and the Central Hospital of the Red Cross of Madrid (Spain). In total, 52 patients presented transmigrated canines, establishing a prevalence of 0.76%. This sample comprised 28 women and 24 men. Whenever a transmigrated canine was identified, a CBCT scan was obtained and used to evaluate the clinical and radiological variables associated with canine transmigration. The predominant side of the transmigration was the left (57.69%) compared to the right side (42.30%). The position of the canine, in order of frequency, according to the Mupparapu classification, corresponded to type IV (42.30%), type II (36.53%), type I (15.38%), and type V (5.76%), with no type III transmigrations found. Clinical manifestations were only recorded in 17.30% of cases, and 11.53% of the radiological findings showed the presence of tooth cysts that were confirmed by histopathological studies. Other impactions, in addition to the transmigrated canine, were found in five patients (9.61%), with the majority being the presence of third molars.

Anatomical variations and accessory structures in the maxilla in relation to implantological procedures: an observational retrospective study of 212 cases using cone-bean computed tomography.

PURPOSE: This study used cone-beam computed tomography (CBCT) to analyze the prevalence of several maxillary anatomical/accessory structures, as well as variations within each type, assessing how accurate diagnosis can minimize the risk of intraoperative complications during implantological procedures in the oral cavity. METHODS: 212 CBCT scans of the maxilla were analyzed, captured over a period of 18 months for surgical planning purposes. The prevalence of posterior superior alveolar arteries (PSAA), maxillary sinus septa (MSS), and branches of the canalis sinuosus (CS) were evaluated, as were the diameter and location of each anatomical structure in horizontal and vertical planes. P < 0.05 was considered statistically significant. RESULTS: PSAAs were observed in 99.1% of cases, the intrasinus type being the most frequent; MSS were noted in 15.6% of the sample, mainly in the posterior region with sagittal orientation; CS branches were observed in 50% of patients, mainly in relation to the incisors and significantly more prevalent among males. CONCLUSIONS: The use of CBCT significantly increases the possibility of clearly identifying these anatomical structures. The differences found between patients highlight the importance of carrying out an exhaustive radiological study of the individual to prevent complications, such as Schneiderian membrane perforation, neurovascular damage or bleeding during surgery.

Analysis of the Radiological Changes of the Sinus Membrane Using Cone Beam Computed Tomography and Its Relationship with Dental Treatments. A Retrospective Study.

The aim of this study was to identify the most relevant dental factors and iatrogenic causes in the development of pathological changes to the sinus membrane and to analyse their possible influence on the development of odontogenic sinusitis. A descriptive, observational study was designed, with 276 patients who had been evaluated via cone beam computed tomography, analysing possible sinus thickening factors, such as apical infections, endodontic treatments, periodontitis, radicular cysts and impacted teeth, as well as iatrogenic factors caused by implant treatments or the development of oroantral communications produced during tooth extraction manoeuvres. Among the dental factors, periodontitis (47.1%), apical pathology (23.5%) and endodontic treatments (23.1%) were the predominant causes of sinus membrane thickening that most frequently produced an occupancy between 2 and 10 mm. Regarding the implant treatments, the placement of implants through the floor of the maxillary sinus was the main cause (9.8%), followed by sinus elevation techniques (6.2%). Dental extraction was the first cause of oroantral communication (5.0%), being the procedure that caused the greatest thickening of the sinus membrane. This study highlights the importance of dental treatments and iatrogenic factors in sinus pathology, and the need for diagnostic interrelations between the different specialists who address this pathology.

Clinical Evaluation of Dental Implants with a Double Acid-Etched Surface Treatment: A Cohort Observational Study with Up to 10-Year Follow-Up.

BACKGROUND AND OBJECTIVES: The main purpose of this study was to evaluate the survival and success rates of dental implants with a double acid-etched surface treatment with evaluation times up to 10 years post-loading. Materials and Methods: This study was conducted at a hospital oral surgery and implantology unit. It included 111 dental implants with a double acid-etched surface. Three groups were created: Group 1 (1-3 years loading), Group 2 (3-5 years loading), and Group 3 (over 5 years loading). Probing depth, resonance frequency analysis (ISQ value), and marginal bone loss were evaluated. Results: The data obtained underwent statistical analysis. Overall, 78 patients were included in the study, who received, in total, 111 dental implants, all replacing single teeth. Mean probing depth was 3.03 mm and mean ISQ was 65.54. Regarding marginal bone loss, in Group 1, 67.6% of implants did not undergo any thread loss, in Group 2, 48.3%, and in Group 3, 59.6%; 59.10% of all implants did not present thread loss with a mean bone loss of 0.552 mm. The implant survival rate was 99.1%, and the success rate was 96.37%. Conclusions: Implants with a double acid-etched surface showed excellent success rates in terms of marginal bone loss, ISQ, and probing depth after up to 10 years of loading, making them a clinically predictable treatment option. Future studies are needed to compare this implant surface with other types in different restorative situations.

Surgical approach combining implantoplasty and reconstructive therapy with locally delivered antibiotic in the treatment of peri-implantitis: A prospective clinical case series.

BACKGROUND: Nonsurgical treatment, resective surgery, reconstructive surgery, or combined approaches have been proposed for the treatment of peri-implantitis, with variable results. PURPOSE: To evaluate the 1-year clinical and radiographic outcomes following combined resective and reconstructive surgical treatment with topical piperacillin/tazobactam antibiotic in the management of peri-implantitis. MATERIAL AND METHODS: Forty-three patients diagnosed with peri-implantitis were included. Surgical treatment consisted of implantoplasty of the supra-crestal component of the defect, the application of a topical antibiotic solution over the implant surface, and subsequent reconstruction of the intra-osseous component of the peri-implant defect. The primary outcome was disease resolution, defined as the absence of bleeding on probing (BoP) and/or suppuration on probing (SoP), a peri-implant pocket probing depth (PPD) ≤5 mm, and no bone loss >0.5 mm 1 year after surgery. Secondary outcomes included changes in BoP, PPD, SoP, and peri-implant marginal bone levels. One implant per patient was included in the analysis. RESULTS: The treatment success rate of the 43 dental implants included in the study was 86% at 1 year after surgery. Mean PPD and BoP decreased from 6.41 ± 2.11 mm and 100% at baseline to 3.19 ± 0.99 mm (p < 0.001) and 14% (p < 0.001) at 1 year, respectively. SoP was significantly reduced from 48.8% at baseline to 0% 1 year after surgery (p < 0.001). Radiographically, a mean defect fill of 2.64 ± 1.59 mm was recorded (p < 0.001). CONCLUSIONS: The combination of a resective and reconstructive surgical approach together with locally delivered antibiotic achieved a high disease resolution rate after 1 year of follow-up and constitutes a viable option for the management of peri-implantitis.

Use of Phentolamine Mesylate in Implant Surgery: Analysis of Adverse Effects and Haemodynamic Changes.

The clinical application of phentolamine mesylate (PM) as an anaesthetic reversal agent has been documented in the paediatric population and in conservative dentistry, but no studies have been conducted regarding dental implant surgery. A prospective randomised study was conducted on 60 patients eligible for mandibular implant treatment, randomly divided between a control group (CG) and an experimental group (EG), to whom PM was administered. Haemodynamic changes, adverse effects and patient satisfaction were assessed. No statistically significant differences in haemodynamic changes and postoperative pain were found between CG and EG (p < 0.05), except for systolic blood pressure (SBP), which increased slightly in EG, without posing a risk to patients. There were no differences in the occurrence of adverse effects between the two groups, except for greater difficulty in chewing and biting (p < 0.05) in CG and greater pain in the injection area (p = 0.043) in EG. Among EG patients, 83.3% reported that they would request PM again for future dental treatment. The use of PM offers an alternative to implant surgery, thereby increasing patients' quality of life without increasing the risks.

Management of Schneiderian membrane perforations during maxillary sinus floor augmentation with lateral approach in relation to subsequent implant survival rates: a systematic review and meta-analysis.

BACKGROUND: This systematic review aimed to propose a treatment protocol for repairing intraoperative perforation of the Schneiderian membrane during maxillary sinus floor augmentation (MSFA) procedures with lateral window technique. In turn, to assess subsequent implant survival rates placed below repaired membranes compared with intact membranes and therefore determine whether membrane perforation constitutes a risk factor for implant survival. MATERIAL AND METHODS: This review was conducted according to PRISMA guidelines. Two independent reviewers conducted an electronic search for articles published between 2008 and April 30, 2020, in four databases: (1) The National Library of Medicine (MEDLINE/PubMed) via Ovid; (2) Web of Science (WOS); (3) SCOPUS; and (4) Cochrane Central Register of Controlled Trials (CENTRAL); also, a complementary handsearch was carried out. The Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of evidence in the studies reviewed. RESULTS: Seven articles fulfilled the inclusion criteria and were analyzed. A total of 1598 sinus lift surgeries were included, allowing the placement of 3604 implants. A total of 1115 implants were placed under previously perforated and repaired membranes, obtaining a survival rate of 97.68%, while 2495 implants were placed below sinus membranes that were not damaged during surgery, obtaining a survival rate of 98.88%. The rate of Schneiderian membrane perforation shown in the systematic review was 30.6%. In the articles reviewed, the most widely used technique for repairing perforated membranes was collagen membrane repair. CONCLUSIONS: Schneiderian membrane perforation during MFSA procedures with lateral approach is not a risk factor for dental implant survival (p=0.229; RR 0.977; 95% CI 0.941-1.015). The knowledge of the exact size of the membrane perforation is essential for deciding on the right treatment plan.

Clinical performance of alveolar ridge augmentation with xenogeneic bone block grafts versus autogenous bone block grafts. A systematic review.

INTRODUCTION: This systematic literature review aimed to evaluate the feasibility of xenogeneic bone blocks for ridge augmentation compared with autogenous blocks by analyzing block survival rates, block resorption, subsequent implant survival rate, post-surgical complications, and histomorphometric findings. MATERIALS AND METHODS: Electronic searches were conducted in the Medline (PubMed), Web of Science and Cochrane databases, complimented by a manual search in specialist journals, for relevant articles published up to March 2020. Inclusion criteria were human studies in which the outcomes of xenogeneic bone block grafts were evaluated by means of their survival rates and subsequent implant survival rates. RESULTS: Sixteen articles fulfilled the inclusion criteria and were analyzed. 333 patients were recruited with a total of 337 xenogeneic bone blocks and 82 autogenous bone blocks, showing block failure rates of 6.82% and 6.1%, respectively. Bone gain, in both height and width, was similar among xenogeneic and autogenous bone blocks, but autogenous bone blocks suffered greater resorption. Implant survival rates were slightly lower for xenogeneic bone blocks. Histological and histomorphometric analysis observed more bone formation and less residual bone substitute with autogenous bone blocks than xenogeneic bone blocks. CONCLUSIONS: Atrophic alveolar crest reconstruction with xenogeneic bone block grafts would appear to offer a viable alternative to autogenous bone block grafts, obtaining similar block graft failure rate, fewer sensitive postoperative complications but a slightly lower implant survival rate. Further investigations generating long term data are needed to confirm the feasibility of xenogeneic bone blocks in different clinical scenarios.

Placing Dental Implants through Impacted Teeth to Support a Fixed Partial Denture in a Geriatric Patient as an Alternative to Invasive Extraction Surgeries.

Multiple dental impactions not associated with craniofacial syndromes are a rare condition and present the dentist with a therapeutic challenge when it comes to performing surgical/restorative treatments in adult patients. This case report describes a geriatric patient with multiple impacted teeth restored by means of two different protocols. In the second quadrant, an impacted tooth was extracted followed by regeneration and placement of an implant. In the third quadrant, implants were placed though impacted teeth for restoration with a fixed partial prosthesis. Placing dental implants through impacted teeth may offer a possible therapeutic option for implant-supported restorations in middle-aged or elderly patients, for whom surgery and orthodontic traction are not possible, and/or patients who refuse to undergo more invasive extraction surgery.

Autogenous Dentin Graft in Bone Defects after Lower Third Molar Extraction: A Split-Mouth Clinical Trial.

Various biomaterials are currently used for bone regeneration, with autogenous bone being considered the gold standard material because of its osteogenic, osteoconductive, and osteoinductive properties. In recent years, the use of autogenous dentin as a graft material has been described. This split-mouth clinical trial assesses the efficacy of autogenous dentin for the regeneration of periodontal defects caused by bone loss associated with impacted lower third molar extraction. Fifteen patients underwent bilateral extraction surgery (30 third molars) using dentin as a graft material on the test side, and leaving the control side to heal spontaneously, comparing the evolution of the defects by evaluating probing depth at three and six months post-operatively. Bone density and alveolar bone crest maintenance were also evaluated six months after surgery, and pain, inflammation, mouth opening capacity on the second and seventh days after surgery. Probing depth, radiographic bone density, and alveolar bone crest maintenance showed significant differences between the test and control sides. Autogenous dentin was found to be an effective biomaterial for bone regeneration after impacted lower third molar extraction.

Epidemiological Features and Clinical Repercussions of Supernumerary Teeth in a Multicenter Study: A Review of 518 Patients with Hyperdontia in Spanish Population.

OBJECTIVES: The aim of this study was to establish the prevalence of supernumerary teeth (ST) in a sector of the population of Madrid, as well as possible complications associated with the presence of these teeth. MATERIALS AND METHODS: The study investigated patients (n = 28,114) who sought dental care at the Oral Surgery Service of three different centers between May 2005 and April 2018. Cases that did not present this numeric dental developmental variation were discarded, registering only those presenting ST. STATISTICAL ANALYSIS: Statistical analysis consisted of univariate analysis (mean, standard deviation, median, etc.), bivariate analysis applying the chi-squared test, whereby statistical significance was established with a confidence interval (CI) of 95% (p < 0.05), and multivariate analysis by means of classification and decision trees. RESULTS: The study found ST in 518 patients, representing a prevalence of 1.84%. The 518 patients presented a total of 726 ST. Distomolars were the most common, representing 37.7% of the sample, followed by premolars (20.1%). About 70.5% of the sample were located in the maxilla and 78% of ST were impacted. Radiographs revealed that 39.7% of STs were associated with disorders. Supplementary morphology appeared in 52.1% of the sample. CONCLUSIONS: Although mesiodens is considered the most common ST, the present study found distomolars and supernumerary premolars to be the most frequently occurring. Pathology was associated with 39.7% of the ST sample. Early diagnosis allows optimal patient management and treatment planning, with intervention at an appropriate time to prevent complications in development and so reduce later treatment need.

Comparison of peri-implant soft tissues in submerged versus transmucosal healing: A split mouth prospective immunohistochemical study.

OBJECTIVE: The present split-mouth prospective study involves an immunohistochemical evaluation of peri-implant soft tissue healing after the osseointegration period, comparing submerged and transmucosal approaches using two-piece implant systems. The null hypothesis was that both surgical procedures elicit a similar immune response of the peri-implant soft tissues. DESIGN: Thirty-one healthy patients were included in this study, in which two implants were placed in the right and left maxillary pre-molar regions. A total of 62 dental implants were analyzed, establishing a control side with 31 submerged implants, and a study side with 31 exposed implants bearing healing abutments. After a three-month healing period, a soft tissue biopsy was collected and prepared for immunohistochemical analysis of the proportions of different lymphocyte subpopulations. RESULTS: The comparative analysis between the submerged and transmucosal approaches failed to identify statistically significant differences in CD19+ B cells, CD4+ T cells, CD8+ T cells, CD25+ T cells or γd T cells. However, significant differences in NK lymphocytes (p = 0.012) were recorded with the submerged surgical procedure. CONCLUSIONS: Peri-implant soft tissue immune response with submerged or transmucosal healing protocols demonstrated comparable outcomes after the osseointegration period. There is sufficient evidence that the null hypothesis of no difference cannot be rejected. To the best of our knowledge, this is the first study of its kind. Further research is therefore needed to further clarify the role of these lymphocyte subpopulations in peri-implant soft tissues.

Clinical and radiographic evaluation of implants placed by means of inferior alveolar nerve lateralization: a 5-year follow-up study.

OBJECTIVE: To evaluate clinical and radiological responses of implants placed in combination with inferior alveolar nerve lateralization, analyzing survival and success rates over 5 years functional loading. MATERIALS AND METHODS: This prospective, longitudinal, single-center study recruited 40 patients with mandibular atrophy in the posterior sectors, who underwent lateralization of the inferior alveolar nerve. Three months after surgery and implant placement, the implants were loaded by means of screw-retained implant-supported partial prostheses or fixed complete prostheses. Clinical and radiographic examinations were performed immediately after implant placement and at 12, 24, 36, 48 and 60-month follow-up visits. RESULTS: The 40 patients received a total of 129 implants (Phibo TSA™ , Phibo Dental Solutions, Sentmenat, Barcelona, Spain). Two implants were lost in the first month after surgery, generating an implant cumulative survival rate (CSR) of 98.44%. The success rate after 5 years of loading was 98.44%. No intra-operative or postoperative soft tissue or prosthetic complications occurred during the 5-year follow-up. CONCLUSIONS: Inferior alveolar nerve lateralization performed to allow placement of (Phibo TSA™ ) implants in patients with mandibular atrophy obtained predictable clinical and radiological results over five years of functional loading.

Dental considerations in diagnosis of maxillary sinus carcinoma: A patient series of 24 cases.

BACKGROUND: Maxillary sinus carcinoma is a rare entity with an incidence of 0.2% and a low patient survival rate due to the frequency of late diagnosis. METHODS: In this multicenter, transversal, retrospective, observational study, the authors analyzed patients who had received a diagnosis of maxillary sinus carcinoma, registering their oral symptoms, histologic type, treatment efficacy, and survival rate. RESULTS: Maxillary sinus carcinoma was diagnosed in 24 patients (15 men and 9 women), of which 75% were squamous cell carcinomas. All patients had dental mobility, and some had swelling, orosinus fistula, or some dental loss. Mean patient survival rate was 38.83 months. CONCLUSIONS: A history of pain or swelling of unknown origin, an unexplained widening of periodontal ligament space, or mobility of the teeth should be considered warning signs of maxillary sinus carcinoma. PRACTICAL IMPLICATIONS: Recognition of oral symptoms by the dentist would help in making an early diagnosis of maxillary sinus carcinoma, improving the patient's chances of survival and quality of life.

Does the postoperative administration of antibiotics reduce the symptoms of lower third molar removal? A randomized double blind clinical study.

BACKGROUND: To date there is little scientific evidence that clarifies the therapeutic effect of antibiotics for managing the postoperative symptoms of impacted third molar surgery. The aim of this study was to evaluate the efficacy of antibiotic treatment for reducing non-infectious clinical symptoms. MATERIAL AND METHODS: Patient data was collected from the patients´ medical records and the results were statistically evaluated with SPSS versión 21.0; SPSS, IBM; Chicago, IL, USA). This longitudinal prospective study consisted of a randomized simple-blind clinical assay of 293 patients attending the Department of Oral Medicine and Surgery, Faculty of Dentistry at the Complutense University of Madrid (Spain). The predictive variable evaluated was the effect of antibiotic treatment on non-infectious symptoms after third molar extraction. The variables evaluated were pain, swelling, and oral aperture. RESULTS: The 293 patients were divided into 2 groups: a control group of 147 patients treated with analgesics and anti-inflammatories after surgery and a study group of 146 patients, who were also administered antibiotics. Better outcomes were observed in the study group treated with antibiotics. Pain, swelling and oral aperture variables presented better results in the antibiotic group with statistically significant difference. CONCLUSIONS: The results suggest that antibiotic administration decreases the post-operative non-infectious clinical symptoms of impacted third molar surgery. However, the prolonged administration of antibiotics had no real medical indications to justify their use and can cause serious health problems in the long term. Key words:Antibiotic, post-operative, impacted lower third molar.

Palatal positioning of implants in severely atrophic edentulous maxillae: five-year cross-sectional retrospective follow-up study.

PURPOSE: To evaluate the 5-year outcome of a previously reported case series of patients with severely atrophic maxillae treated with palatally positioned implants and fixed full-arch rehabilitations. MATERIALS AND METHODS: A retrospective cross-sectional clinical study of patients treated between January 2000 and January 2004 with palatally positioned implants was carried out. The parameters evaluated at the 5-year follow-up visit were: implant success rate, peri-implant soft-tissue conditions, biological and prosthetic post-loading complications, radiographic peri-implant marginal bone loss, and patient satisfaction. RESULTS: A total of 33 patients with 151 palatally positioned implants were included in the study; 15 patients had received cemented prostheses and 18 had received screwed full-arch prostheses. The success rate for palatally positioned implants after 5 years was 98.7%. Average peri-implant mucosa retraction was 0.39 ± 0.94 mm and the average probing depth was 2.89 ± 0.77 mm. Plaque Index was 0 in 63.1% of the implants, 1 in 18.8%, 2 in 8.7%, and 3 in 9.4%. The modified Bleeding Index was 0 in 71.1%, 1 in 14.1%, and 2 in 14.8%. Mucositis was found in 5.2% of the implants and none had peri-implantitis. Prosthetic complications occurred in 12.1% of the cases. Average peri-implant marginal bone loss was 1.03 ± 1.28 mm. General patient satisfaction averaged 8.2 ± 1.8 according to a 10-point visual analog scale, and good quality of life was reported by most patients. CONCLUSIONS: Palatally positioned implants were found to be an adequate treatment for patients with severely atrophic maxillae. A high implant success rate, good peri-implant soft tissue stability, low marginal bone loss, high patient satisfaction and few complications were registered.

Biological response to porcine xenograft implants: an experimental study in rabbits.

PURPOSE: The aim of this study was to evaluate the effect of a new porcine biomaterial and collagen paste in 20 New Zealand rabbits. MATERIALS AND METHODS: Forty implants using a porcine xenograft made up of 80% corticocancellous collagenated bone particles of ≤300 µm in size were placed in the proximal metaphyseal area of both tibiae. Four periods of time were formed: 1h, 5, 8, and 15 months. After implantation, an anteroposterior and lateral radiological study was carried out. Samples were sectioned at 5 µm and stained using hematoxylin-eosin, Masson's trichromic, and Gordon-Switt reticulin stains. RESULTS: These results confirmed the biocompatibility of this porcine biomaterial-collagen paste; only a few, occasional macrophages and scattered lymphocytes were observed. No fibrosis was observed between the implants and the bone. Moreover, the material was osteoconductive acting as a "scaffold" for bone cells, and there was a progressive increase in bone growth in and around the implants. CONCLUSION: This new porcine biomaterial-collagen paste seemed to be biocompatible, bioresorbable, and osteoconductive.