Antibiotic-Prescribing Habits in Dentistry: A Questionnaire-Based Study.

The problem of antibiotic resistance is becoming increasingly serious worldwide due to uncontrolled prescription. Dentists are among the groups that prescribe the most antibiotics, often to delay urgent treatment. The purpose of the present study is to investigate the prescribing protocols adopted by dentists for prophylaxis and antibiotic therapy in major clinical surgical indications. METHODS: A ten-question survey was administered to a group of Italian dentists. The participants were asked about their preferences for antibiotic administration for the prevention of infective endocarditis, the administration of antibiotics to patients allergic to penicillin, the insertion of implants, and the extraction of third molars. The retrieved data were screened and analyzed. RESULTS: A total of 298 surveys were filled out. The most-prescribed antibiotic was amoxicillin or amoxicillin with clavulanic acid or macrolides for allergic patients. The administration of two grams of amoxicillin one hour before surgery was the most widely used prescriptive protocol for prophylaxis. International guidelines on antibiotic prophylaxis for infective endocarditis were only partially followed. The most heterogeneous results emerged for prophylaxis associated with dental implants or provided prior to surgical third-molar extraction. CONCLUSIONS: The present study shows widespread antibiotic prescriptive heterogeneity among the sample of dentists analyzed, especially in conditions where international guidelines are lacking. An evidence-based consensus on prescriptive modalities in dentistry would be desirable in the near future.

Efficacy of different mouthwashes against COVID-19: A systematic review and network meta-analysis.

To evaluate the effectiveness of antiseptic mouthwashes in reducing SARS-CoV-2 load clinically and in vitro. A systematic electronic search (MEDLINE/Scopus/Cochrane) was conducted to identify prospective clinical and in vitro studies published between 2019 included and 16 June 2023 assessing the effectiveness of mouthwashes in reducing SARS-CoV-2 load in saliva or surrogates. Data were summarized in tables and a network meta-analysis was performed for clinical trials. Thirty-five studies (14 RCTs, 21 in vitro) fulfilled the inclusion criteria. The risk of bias was judged to be high for 2 clinical and 7 in vitro studies. The most commonly test product was chlorhexidine alone or in combination with other active ingredients, followed by povidone-iodine, hydrogen peroxide and cetylpyridinium chloride. Overall, the descriptive analysis revealed the effectiveness of the mouthwashes in decreasing the salivary viral load both clinically and in vitro. Network meta-analysis demonstrated a high degree of heterogeneity. Among these studies, only chlorhexidine 0.20% was associated to a significant Ct increase in the saliva 5 min after rinsing compared to non-active control (p = 0.027). Data from clinical and in vitro studies suggested the antiviral efficacy of commonly used mouthwashes. Large well-balanced trials are needed to identify the best rinsing protocols.

Bleeding Disorders and Dental Implants: Review and Clinical Indications.

BACKGROUND: Bleeding disorders can be divided into three categories: congenital coagulation disorders (CCDs), antiplatelet-induced bleeding disorders (APBDs) and anticoagulant-induced bleeding disorders (ACBDs). Implant placement can be challenging in these kinds of patients. The aim of this study is to provide evidence on implant surgery in patients with bleeding disorders and to generate some practical recommendations for clinicians. MATERIAL AND METHODS: Pubmed/MEDLINE, Scopus, Web of Science and Cochrane Library databases were screened. The latest search was performed in July 2022. Case reports, case series, cohort studies, cross-sectional studies, case control studies, reviews, consensus reports, surveys and animal studies were included in the analysis. RESULTS: Seventeen articles on CCDs were found, fourteen on APBDs and twenty-six on ACBDs. Most of these articles were case reports or case series. Patients with CCDs can be treated after the infusion of the missing coagulation factor. Patients with APBDs can be treated without withdrawing the therapy. Patients with ACBDs should be treated depending on the anticoagulative medication. CONCLUSION: Despite the low level of evidence, dental implants can be safely placed in patients with bleeding disorders. However, careful preoperative evaluation and the adoption of local and post-operative bleeding control measures are mandatory.

"Diagnostic ability in oral pathology among different population clusters".

OBJECTIVES: To assess the diagnostic ability in detecting oral lesions among dentists, dental hygienists, dentistry students, oral hygiene students, and non-healthcare subjects. MATERIALS AND METHODS: Participants were invited to classify 30 images of oral lesions in "benign" or "suspected malignant" only based on the visual appearance of the lesion. Diagnostic accuracy was assessed by calculating sensitivity and specificity with 95% confidence intervals and stratified by population group and image features (color, shape, and size of the lesions). RESULTS: A total of 16,590 examinations by 553 subjects were analyzed. Overall sensitivity and specificity were 57% (95% confidence interval 56%-58%) and 64% (95% confidence interval 63%-65%). Diagnostic accuracy varied among population groups, with experienced dentists showing the lowest sensitivity (52%) and the highest specificity (71%). Red lesions, flat lesions, and large lesions had the lowest sensitivity (42%, 36%, 57%) but the highest specificity (70%, 75%, 76%). CONCLUSIONS: We found worrying low ability to detect suspected malignant oral lesions by both healthcare workers and non-healthcare subjects. Lesion-specific characteristics may lead to differences in recognition. Specific courses and more adequate teaching methods should be proposed to increase identification of oral lesions.

Influence of soft tissue thickness on marginal bone level around dental implants: A systematic review with meta-analysis and trial-sequential analysis.

OBJECTIVES: The aim of the present review and meta-analysis was to evaluate the influence of soft tissue thickness on initial bone remodeling after implant installation. MATERIALS AND METHODS: A literature search was conducted by two independent reviewers on electronic databases up to May 2022. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) performed on human subjects were included. The risk of bias was evaluated using Cochrane Collaboration's tool. Meta-analysis and Trial Sequential Analysis (TSA) were performed on the selected articles. The primary outcome was marginal bone loss. RESULTS: After screening, 6 studies were included in the final analysis, with a total of 354 implants, and a follow-up from 10 to 14 months. 194 implants were placed in a ≥ 2 mm soft tissue thickness, while 160 had <2 mm soft tissue thickness before implant placement. The included studies had a high level of heterogeneity (I2  > 50%). The meta-analysis indicated a statistically significant difference between the two groups (0.54; p = .027) and the TSA analysis confirmed the results, despite the limited number of dental implants. Additional analysis showed that age and follow-up parameters were not statistically significant factors influencing the bone loss (p = .22 and p = .16, respectively). CONCLUSIONS: Based on the available RCTS and CCTs, initial soft tissue thickness seems to influence marginal bone loss after a short follow-up period. Based on TSA analysis, further studies are needed to assess the influence of the soft tissue thickness on marginal bone loss. PROSPERO registration number: CRD42021235324.

The Follow-Up Necessity in Human Papilloma Virus-Positive vs. Human Papilloma Virus-Negative Oral Mucosal Lesions: A Retrospective Study.

Human papilloma virus (HPV) is known as the main cause of cervical cancer. Data also indicate its role in head-neck cancer, especially oropharyngeal cancer. The correlation between high-risk HPV and oral cancer is still controversial. HPV-related lesions of the oral cavity are frequent and, in most cases, benign. The primary aim of this study was to establish if there is a different follow-up necessity between HPV-positive compared to HPV-negative oral lesions. The secondary aim was to evaluate the recurrence of HPV-related lesions. All patients who underwent a surgical procedure of oral biopsy between 2018 and 2022, with ulterior histopathological examination and HPV typing, were examined. A total of 230 patients were included: 75 received traumatic fibroma as diagnosis, 131 HPV-related lesions, 9 proliferative verrucous leukoplakia, and 15 leukoplakia. The frequency and period of follow-up varied in relation to HPV positivity and diagnosis. This study confirms what has already been reported by other authors regarding the absence of recommendations of follow-up necessity in patients with oral mucosal lesions. However, the data demonstrate that there was a statistically significant difference in the sample analyzed regarding the follow-up of HPV-positive vs. HPV-negative patients. It also confirms the low recurrence frequency of HPV-related oral lesions.

Mandibular Molar Uprighting Using Skeletal Anchorage: A Novel Approach.

BACKGROUND: The management of eruption anomalies affecting second molars, although quite uncommon, may represent a real challenge for the clinician. The aim of this study is to present a novel technique that combines the surgical and orthodontic approach in order to obtain the retrieval of impacted second molars through a complex distalizing movement and skeletal anchorage. METHODS: Nineteen consecutive patients with impacted second molars were treated according to this technique, which involved extraction of the third molar followed by the placement of a distally positioned screw, and the subsequent use of a coil spring to connect the screw to an eyelet directly bonded on the second molar. In selected cases, it proved to be necessary to reposition the second molar through traditional orthodontics. All of the parameters were recorded: the time required for completing the treatment, the initial angle between the second molar and the adjacent tooth, and treatment related-complications. RESULTS: Twenty impacted second molars were correctly repositioned. The mean initial angle of the second molar was 55.7° (SD 22.6°, min 13.3°, max 104.8°). The mean treatment time was 10 months. There were no major complications. CONCLUSIONS: Given that periodontal tissues were minimally affected, the temporary anchorage device was fully controlled, and there was no unwanted movement of adjacent teeth, the presented technique not only proved effective but also minimally invasive.

Oral Hygiene in Adolescence: A Questionnaire-Based Study.

Oral health is fundamental to our well-being, especially in adolescence. The aim of this study is to investigate oral hygiene knowledge through a questionnaire in a sample of adolescents, paying particular attention to those wearing orthodontic braces. The study was designed as a descriptive report of a local survey. An anonymous questionnaire was distributed to individuals born between 2000 and 2005, both on paper and online. Among 213 adolescents answering the questionnaire, 206 went to the dentist at least once (most of them between 5 and 9 years old), and 144 experienced at least one session of professional oral hygiene. Approximately 83% of the sample brushed their teeth at least twice a day, while only 7% used dental floss daily. Only 54% of respondents wearing orthodontic braces were advised to undergo professional oral hygiene during their orthodontic treatment. Education on oral hygiene at home came only from their parents for 61% of the whole sample. Most respondents had their first visit to the dentist apparently too late. Flossing was rare, whether the adolescents wore orthodontic braces or not. In many cases, professional oral hygiene was not common during orthodontic treatment. Adolescents did not learn about oral hygiene from a dental specialist.

Guided implant surgery and sinus lift in severely resorbed maxillae: A retrospective clinical study with up to 10 years of follow-up.

OBJECTIVES: In the posterior maxilla, due to the presence of maxillary sinus, residual bone height lower than 3mm is a critical factor that can affect implant stability and survival. The use of guided surgery may facilitate the surgical procedures and the implant insertion in case of severely resorbed maxillae. Moreover, it may have beneficial effects on the long-term survival and success of implant-supported restorations. This study aimed to evaluate implant supported restorations on severely resorbed maxilla (<3 mm) after sinus lift with collagenated xenograft and guided surgery. METHODS: Forty-three patients with need for implant rehabilitation and residual bone height between 1 and 3 mm were recruited. Surgical and prosthetical aspects were planned following digital approach with the use of Realguide 5.0 (3diemme, Varese, Italy). Lateral window sinus lift was performed and implants were placed simultaneously to the augmentation procedure with a tooth-supported pilot drill surgical template. A pre-hydrated collagenated porcine bone matrix was adopted as regenerative material. Computer-aided-design/computer-aided-manufacturing (CAD/CAM) restorations were delivered after six months of healing. Milled titanium chamfer abutments with CAD/CAM crowns were used. Bone height at implant site level was measured using an image software analysis applied to the pre- and post-surgical radiographs and at the follow-up. Biological and technical complications were recorded during all the follow-up periods. RESULTS: Fifty-four sinus were treated. After a mean follow-up time of 5.11 years (SD: 2.47), no implants were lost nor showed signs of disease. The mean pristine bone height was 2.07 mm (SD: 075). At the final evaluation the augmented sinus height was 12.83 mm (SD: 1.23). Two cases experienced minor perforation of the membrane, while five patients developed minimal post-operative complications, completely resolved with pharmacologic therapy. No mid-term biological complications were experienced by the patients. No cases experienced peri-implant mucositis and peri-implantitis during the whole follow-up period. Four patients (7.4%) faced an unscrewing of the prosthesis. CONCLUSIONS: The present study showed the efficacy in the mid-term of the digital planning and the guided surgery in restoring severely resorbed posterior maxilla with dental implants. CLINICAL SIGNIFICANCE: This paper underlines the high potential of the digital approach in the mid-term to implant rehabilitation of severely resorbed maxilla simultaneously with sinus lift.

Marginal Bone Maintenance and Different Prosthetic Emergence Angles: A 3-Year Retrospective Study.

The aim of the present retrospective study was to assess marginal bone changes around implants restored with different prosthetic emergence profile angles. Patients were treated with implants supporting fixed dentures and were followed for 3 years. Marginal bone levels (MBL) measured at the prosthesis installation (t0) and at the 3-year follow-up visit (t1) were considered. The MBL change from t0 to t1 was investigated. Two groups were considered: Group 1 for restorations with an angle between implant axis and prosthetic emergence profile >30°, and Group 2 for those with an angle ≤30°, respectively. Moreover, peri-implant soft tissue parameters, such as the modified bleeding index (MBI) and plaque index (PI) were assessed. Seventy-four patients were included in the analysis and a total of 312 implants were examined. The mean EA in groups 1 and 2 was 45 ± 4 and 22 ± 7 degrees, respectively. The mean marginal bone level change (MBL change) of 0.06 ± 0.09 mm and 0.06 ± 0.10 mm were, respectively, in groups 1 and 2. The difference in the MBL change between the two groups was not statistically significant (p = 0.969). The MBL change does not seem to be influenced by the emergence angle for implants with a stable internal conical connection and platform-switching of the abutment diameter.

Systemic Diseases and Biological Dental Implant Complications: A Narrative Review.

The relationship between periodontitis and such systemic disorders as diabetes, cardiovascular disease and obesity has been extensively investigated. There is less scientific evidence available, however, regarding the influence of systemic diseases on the risk of late failure of dental implant rehabilitation due to peri-implantitis. The aim of the present study was to review the literature on the role of several common systemic disorders (diabetes, obesity, cardiovascular disease, hypertension and osteoporosis) in the onset of peri-implantitis. A database search initially yielded 2787 studies of potential interest published up to 1 March 2022 (993 in PubMed; 908 in Web of Science; and 886 in Scopus). After removing 1190 duplicate articles and checking the titles, abstracts and full texts for relevance, 70 articles were selected for the present analysis. Only cohort, case-control studies and clinical case series were considered. Most of the literature concludes for no association between diabetes, cardiovascular disease, hypertension or osteoporosis and the risk of peri-implantitis. On the other hand, almost all the studies that investigated obesity as a risk factor for implant rehabilitation found a positive association between the two. Further longitudinal studies are needed to better understand the effects of systemic diseases on rehabilitation with dental implants.

Third Molar Extraction: Irrigation and Cooling with Water or Sterile Physiological Solution: A Double-Blind Randomized Study.

BACKGROUND: The present study aimed to ascertain whether any significant reduction in patients' postoperative pain and inflammation could be achieved by using sterile physiological solution instead of normal water to irrigate the surgical field and cool the dental bur during third molar extractions. METHODS: The study concerned 22 patients (11 females and 11 males) in good general health, who were referred to the Dental Clinic at Padova University hospital for lower third molar extractions. They were randomly assigned to two groups. Only the fluid used to irrigate the surgical field and cool the dental bur differed between the two study groups, being sterile physiological solution for group A, and mains water for group B. Postoperative pain, swelling, trismus and inflammation with high sensitivity CRP where measured and statistically evaluated. The numerosity of our sample was calculated on the grounds of an endpoint based on data in the literature. RESULTS: Eighteen patients needed bilateral extractions, and 4 required only one extraction, so a total of 40 third molars were extracted. A sterile physiological solution was used to irrigate the surgical field in 20 extractions, while water was used in the other 20 cases. Data analysis with Wilcoxon test show no differences between the two groups (p < 0.05). CONCLUSIONS: no differences between groups for any of the parameters considered, after third molar extraction procedures undertaken using either sterile physiological solution or water for irrigation and cooling purposes.

Incidental findings detected with panoramic radiography: prevalence calculated on a sample of 2017 cases treated at a major Italian trauma and cancer centre.

OBJECTIVES: This study aimed to assess the prevalence of incidental findings, not strictly related to dentistry, viewed with panoramic radiography. METHODS: Panoramic radiographs performed between December 2013 and June 2016 were retrospectively collected. These images were analyzed, searching for incidental findings. All the information collected was statistically analysed RESULTS: A total of 2307 Panoramic Radiograph were analyzed and 2017 of them were included in the study. 529 incidental findings were seen: 255 (48.2%) were ESP (Elongation of Styloid Process), 167 were CAC (Carotid Artery Calcification) (31.57%), 36 were maxillary sinus pathologies (6.8%) and 71 were other incidental findings (13.42%). The total prevalence of IF was 26, 23%., CAC was 8.28% in the total population, and it was higher in women (9.82%) than men (6.54%). 48.5% of CAC were bilateral. When unilateral, the right side showed a higher right side prevalence. The prevalence of ESP was 12.64% in total population (men: 13.82%; women: 11.60%). 84.71% of ESP were bilateral and, when present unilaterally, no side difference was seen. 13.33% of the ESP appeared segmented. The prevalence of maxillary sinus pathologies was 1.78% (men: 2.32%; women: 1.31%). Only 8.33% of these pathologies were bilateral, and, when unilateral, they were mostly present on the right side. Between the 71 other IF (prevalence: 3.52%), sialoliths and tonsilloliths were assessed most frequently. CONCLUSION: Due to the high prevalence of incidental findings detected with panoramic radiography, dental practitioners should be aware of the various pathologic conditions seen on the panoramic radiographs.

The Use of Antibiotics in Implant Therapy: A Systematic Review and Meta-Analysis with Trial Sequential Analysis on Early Implant Failure.

PURPOSE: The aim of this systematic review was to estimate if an antibiotic prophylaxis regimen reduces implant failure and postoperative infection in healthy patients who are going to receive dental implants. MATERIALS AND METHODS: An electronic database search (MEDLINE/PubMed, Scopus, Web of Science, Cochrane Library) until June 30, 2019, for randomized controlled trials (RCTs) was performed. The Cochrane Handbook for Systematic Reviews of Interventions to assess the risk of bias in individual studies was used. Patient- and implant-level data were extracted for the analyzed outcomes. The risk ratio (RR) and the 95% confidence interval were calculated as meta-analytic effects. A fixed- or a random-effect model was employed on the basis of the presence/absence of heterogeneity (I2 > 50%). Differences between groups were analyzed using the inverse of variance test. The Higgins Index and chi-square test were used to assess the studies' heterogeneity. Additionally, in order to evaluate the power of evidence and to adjust the meta-analytic findings for type 1 and 2 errors, a trial sequential analysis (TSA) was performed. RESULTS: Nine studies including 1,984 patients and 3,588 implants were selected. Eight hundred eighty-five patients (1,617 implants) received no antibiotics or a placebo therapy before the implant surgery; 1,971 implants (1,099 patients) were treated with an antibiotic therapy. The meta-analysis at the patient level showed a statistically significant reduction in the rate of early implant failure associated with the use of antibiotics (I2 = 0%) (RR = 0.32 [0.20, 0.51], P > .001). Similar results were obtained after pooling the implant-level data with the fixed-effect model (RR = 0.33 [0.22, 0.51], P > .001). Such results were also confirmed by the TSA after adjusting for type 1 and 2 errors. CONCLUSION: The results of this systematic review with meta-analysis indicate that an antibiotic prophylaxis prevents early implant failures in the case of healthy patients. No information can be provided on peri-implant infections.

Selection of Collagen Membranes for Bone Regeneration: A Literature Review.

Several treatment modalities have been proposed to regenerate bone, including guided bone regeneration (GBR) where barrier membranes play an important role by isolating soft tissue and allowing bone to grow. Not all membranes biologically behave the same way, as they differ from their origin and structure, with reflections on their mechanical properties and on their clinical performance. Collagen membranes have been widely used in medicine and dentistry, because of their high biocompatibility and capability of promoting wound healing. Recently, collagen membranes have been applied in guided bone regeneration with comparable outcomes to non-resorbable membranes. Aim of this work is to provide a review on the main features, application, outcomes, and clinical employment of the different types of collagen membranes. Comparisons with non-resorbable membranes are clarified, characteristics of cross-linked collagen versus native collagen, use of different grafting materials and need for membrane fixation are explored in order to gain awareness of the indications and limits and to be able to choose the right membrane required by the clinical condition.

Metal Nanoparticles Released from Dental Implant Surfaces: Potential Contribution to Chronic Inflammation and Peri-Implant Bone Loss.

Peri-implantitis is an inflammatory disease affecting tissues surrounding dental implants. Although it represents a common complication of dental implant treatments, the underlying mechanisms have not yet been fully described. The aim of this study is to identify the role of titanium nanoparticles released form the implants on the chronic inflammation and bone lysis in the surrounding tissue. We analyzed the in vitro effect of titanium (Ti) particle exposure on mesenchymal stem cells (MSCs) and fibroblasts (FU), evaluating cell proliferation by MTT test and the generation of reactive oxygen species (ROS). Subsequently, in vivo analysis of peri-implant Ti particle distribution, histological, and molecular analyses were performed. Ti particles led to a time-dependent decrease in cell viability and increase in ROS production in both MSCs and FU. Tissue analyses revealed presence of oxidative stress, high extracellular and intracellular Ti levels and imbalanced bone turnover. High expression of ZFP467 and the presence of adipose-like tissue suggested dysregulation of the MSC population; alterations in vessel morphology were identified. The results suggest that Ti particles may induce the production of high ROS levels, recruiting abnormal quantity of neutrophils able to produce high level of metalloproteinase. This induces the degradation of collagen fibers. These events may influence MSC commitment, with an imbalance of bone regeneration.

Subcrestal placement of dental implants with an internal conical connection of 0.5 mm versus 1.5 mm: Three-year after loading results of a multicentre within-person randomised controlled trial.

PURPOSE: To evaluate whether there are some clinical benefits by placing single dental implants either 0.5 mm or 1.5 mm subcrestally in healed bone crests. MATERIALS AND METHODS: Sixty partially edentulous patients requiring two single implant-supported crowns had both sites randomly allocated either to 0.5-mm or 1.5-mm subcrestal implant placement according to a split-mouth design at six centres and submerged in aesthetic areas or non-submerged in non-aesthetic areas for 3 months. Provisional acrylic crowns were delivered and were replaced after 2 months by definitive metal-ceramic crowns. Patients were followed to 3 years after loading. Outcome measures were: crown and implant failures, complications, aesthetics assessed using the pink aesthetic score (PES), peri-implant marginal bone level changes and patient preference, recorded by blinded assessors. RESULTS: One patient dropped out. One patient lost both implants for infection at impression taking. Seven complications affected seven patients of the 0.5-mm group and four complications affected four patients of the 1.5-mm subcrestal group. Three patients had complications at both implants. There were no statistically significant differences for complications between group (OR = 4; 95% CI: 0.45 to 35.79; P (McNemar test) = 0.375). At delivery of definitive crowns, 2 months after loading, the mean PES was 11.22 ± 1.91 and 11.12 ± 1.59 for the 0.5- and 1.5-mm groups, respectively. At 1 year after loading, the mean PES was 12.09 ± 1.66 and 12.10 ± 1.52 for the 0.5- and 1.5-mm groups, respectively. At 3 years after loading, the mean PES was 11.99 ± 1.94 and 12.19 ± 1.78 for the 0.5- and 1.5-mm groups, respectively. There were no statistically significant differences between the two groups at 2 months (P = 0.626), at 1 year (P = 0.920) or at 3 years (P = 0.296). One year after loading, patients of the 0.5-mm group lost on average 0.21 ± 0.51 mm and those of the 1.5-mm group 0.11 ± 0.36 mm, the difference being not statistically significant (difference = 0.10 mm; 95% CI: -0.01 to 0.20; P = 0.078). Three years after loading, patients of the 0.5-mm group lost on average 0.34 ± 0.87 mm and those of the 1.5-mm group 0.19 ± 0.54 mm, the difference being statistically significant (difference = 0.15 mm; 95% CI: 0.00 to 0.30; P = 0.046). Patients did not prefer any depth of the implant placement over the other. There were no differences in outcomes between centres. CONCLUSIONS: No appreciable clinical differences were noticed when placing implants 0.5 mm or 1.5 mm subcrestally; therefore clinicians can do as they prefer.

On the role of keratinised mucosa at dental implants: a 5-year prospective single-cohort study.

PURPOSE: The purpose of this study was to evaluate the role of keratinised mucosa on the long-term success of dental implants. MATERIALS AND METHODS: Thirty-two edentulous patients had one of their dental arches rehabilitated with a provisional screw-retained resin reinforced cross-arch fixed prosthesis supported by four immediately loaded implants. The two central straight implants were randomly allocated in two equal groups, according to a parallel-group design, to receive or not intermediate abutments (Multi-Unit Abutment, MUA). However, for the purpose of the present publication, the study was considered as a prospective single cohort study. To be immediately loaded, implants had to be inserted with a minimum torque of 30 Ncm, which was achieved by all implants. Provisional prostheses were delivered within 24 hours and were replaced, after 4 months, by definitive screw-retained metal-ceramic prostheses. Patients were followed up to 5 years after loading. Prostheses were removed every 8 months to facilitate professionally delivered maintenance. Outcome measures were prosthesis and implant failures, complications, peri-implant marginal bone level (MBL) changes, bleeding on probing (BoP) and keratinised mucosa height (KMH). The absence of vestibular or lingual keratinised mucosa was put in relation with peri-implant bone loss and BoP. RESULTS: Five-years after loading two patients dropped out and no implant or prosthetic failure occurred. Four patients were affected by prosthetic complications. At delivery of definitive prostheses, 32 (25%) implants had at least one vestibular or lingual site with no KMH and 96 (75%) implants had both sites with some KMH. Multi-level models did not show any statistically significant association between KMH at the time of delivery of the definitive prosthesis and changes in MBL and BoP at 5 years (estimate = 0.02; 95% CI: -0.02 to 0.05; P = 0.3393; and 1.02; 95% CI: 0.79 to 1.33; P = 0.8695, respectively). When KMH was analysed as dichotomous variable, implants with presence of KMH at delivery of definitive prosthesis at both vestibular and lingual aspects showed a trend of less BoP (estimate = -0.8; 95% CI: -1.69 to 0.08; P = 0.0741) but a statistically significant greater MBL loss compared to implants where KMH was only present at one site (estimate = 0.18; 95% CI: -0.1 to 0.3; P = 0.0041). CONCLUSIONS: The 5-year after loading outcome of immediately loaded screw-retained cross-arch prostheses supported by four implants is excellent in both the maxilla and mandible. Although the height of the keratinised mucosa did not seem to alter the clinical outcomes, its presence both at vestibular and lingual sites was associated with an increased marginal bone loss when compared to implants having at least one side without keratinised mucosa.

Five-year prospective study on conometric retention for complete fixed prostheses.

PURPOSE: To evaluate the reliability of a conometric system for fixed retention of complete prostheses (CPs) on four implants after 5 years of function. MATERIALS AND METHODS: Twenty-five patients with a completely edentulous mandible received four implants supporting a CP. A total of 100 implants were immediately loaded with CPs on conometric abutments. A follow-up of 5 years was observed for each patient. Outcome measures were prosthesis and implant success, complications, probing pocket depth changes, marginal bleeding and plaque changes, and patient satisfaction. RESULTS: One patient dropped-out. In total, 96 implants supporting the 24 CPs completed the follow-up examination at 5 years. No implant failed. Two framework fractures occurred after 4 and 5 years of function. No loss of retention was recorded for the CPs. Mucositis was recorded for two implants after 1 year of prostheses function for two patients, for one implant after 3 years and for two implants after 4 years in different patients and successfully treated with interceptive supportive therapy. No significant differences were found between Plaque Index (PI) at baseline and after 2 years (P = 1.0); similar findings were calculated between PI at baseline and after 5 years (P = 0.6) of function. At baseline, after 2 and after 5 years, respectively, 69%, 64% and 56% of implants showed a PI of 0; 31%, 36% and 44% of implants showed a PI between 1 and 3. Modify Bleeding Index (MBI) was not significantly different both between baseline and after 2 years of function (P = 1.0) and between baseline and 5 years of function (P = 0.5). At baseline, after 2 and after 5 years, respectively, 69%, 65% and 61% of implants showed a MBI of 0; 27%, 28% and 29% of implants showed a MBI of 1; and 4%, 7% and 10% of implants showed a MBI of 2. The mean probing pocket depth was 1.2 ± 0.4 mm at baseline, 1.2 ± 0.4 mm after 2 years and 1.4 ± 0.5 mm after 5 years of function. The differences were not statistically significant between baseline and 2 years (P = 1.0) and between baseline and 5 years (P = 0.1). From the patient satisfaction questionnaire, 85% percent of patients were satisfied from both aesthetic and functional points of view after 5 years of conometric prostheses function. CONCLUSIONS: The present implant-supported conometric retention system can be used to give fixed retention to a CP supported by four implants. An adequate metal framework should be provided to the definitive restoration in order to avoid fractures in the long term.

Cone-beam volumetric imaging in craniofacial medicine.

With the development of X-ray computed tomography (CT) in the 1960s and its first use for clinical studies in 1972 by Sir Godfrey Hounsfield, radiological tomography attained widespread use and today is one of the essential imaging techniques in medical radiology. It is a technically mature and clinically widely accepted method and complements classical X-ray panoramic radiography in many areas. The technology is frequently used in craniofacial radiology, because of its characteristic low radiation dose, high spatial resolution and lower cost compared with CT. The aim of this work was to describe the principles of cone beam computed tomography, to make a brief description of the existing devices, to present briefly the use of 3D diagnosis in craniofacial medicine.