Point-of-care testing for hepatitis C virus infection at an Italian dental clinic: portrait of the pilot study population.

The dental clinic is an appropriate place to promote the prevention of hepatitis C virus (HCV) infection and fast access for care of HCV-positive subjects with new-generation anti-HCV drugs. This study aimed to determine the socio-demographic profile of subjects screened for HCV virus in a dental clinic to acquire useful information for future campaigns of prevention. An easy, free-of-charge, screen salivary test was offered to patients referred to the dental clinic of San Raffaele Scientific Research Hospital in Milan, Italy for dental procedures. These patients were also asked to complete an anonymous questionnaire on demographics and risk behaviours. A total of 1388 of 2097 (66.19%) questionnaires were evaluable. The demographics of the population responding to this initiative was primarily Italians citizen (96.47%), homogeneous gender distribution (55.55%), age over 50 (609 subjects; 43.88%), with high-level education and stable professional positions. 905 subjects (65.20%) were never tested for HCV before. The test showed positive reactivity in 22 cases (1.05%); of these, 21 subjects were known to be HCV-positive, and the test confirmed their status. One subject was newly diagnosed as HCV-positive. The percentage of subjects who were never tested for HCV infection appears too high (905 subjects, i.e., 65.20%), especially among subjects with high level of education and professions, and among adults over 40 or young people (18-25). The easy screening test in dental clinic can help raise awareness, promote early diagnosis and prevention, and provide a fast link to care for HCV infection.

The distraction osteogenesis in midfacial hypoplasia.

Distraction osteogenesis (DO) can generate new bone in a gap between 2 vascularized bone surfaces in response to application of graduated tensile stress across the bone gap. The authors present the clinical result in a cleft patient with severe maxillary deficiency treated by a rigid external distraction (RED) device. A boy complained of both masticatory and psychological problems because of cleft with severe midfacial retrusion. The treatment aimed to create a well-balanced facial profile, increase maxillary incisal display, create proper overjet and overbite, and align his dentition. By the RED system, the traction is applied to the maxilla through the dentition by an intraoral splint. A complete Le Fort I osteotomy was performed, including pterygomaxillary and septal disjunction, with mobilization. Once osteotomy was completed, the halo portion of the RED device was adjusted for the width of the neurocranium and was rigidly fixed around the head with 2 scalp screws on each side. A well-balanced facial profile and a good alignment of the dentition were obtained. The patients had considerable improvement in his self-esteem. Clinical reports have suggested that maxillary advancements achieved by distraction are more stable than those achieved with orthognathic surgery with a minimal influence on velopharyngeal competence.

IL-37 evaluation in chronic periodontitis after periodontal treatment with and without low level laser therapy.

BACKGROUND: Periodontal disease poses a significant global health challenge. Traditional treatments focus on reducing inflammation and bacterial load, yet novel approaches are continually being investigated. Recent research suggests that IL-37, a potent anti-inflammatory cytokine, may play a crucial role in modulating the inflammatory processes associated with periodontal disease. In conjunction with IL-37, low-level laser therapy (LLLT) has gained attention for its potential in promoting tissue repair, reducing inflammation, and enhancing cellular processes. This study aims to investigate the effects of LLLT on IL-37 in periodontal disease management. METHODS: Thirty patients were enrolled: the G1 group patients were treated with only scaling and root planning-SRP, the G2 group was treated with SRP and LLLT. Before treatment (T0) all periodontal probing pocket depth and bleeding on probing were obtained. Before (T0) and 10 (T1), 30 (T2) and 60 (T3) days after treatment, was achieved plaque sample and specimens of gingival crevicular fluid. Diode laser wavelength range was used between 600-1000 nm and 0.04-60 J/cm2 energy density for 3-s spotlights. RESULTS: In all patients PPD, BOP and IL-37 have shown healing improved parameters. CONCLUSIONS: Although LLLT is widely recommended for its biostimulatory and anti-inflammatory roles, it only showed additional short-term merits in reducing the pocket depth after conventional SRP. Its long-term adjunctive benefits remain unclear. Future RCTs with better study designs, adequate sample power and longer durations of follow-up are required to assess the effectiveness of LLLT as an adjunctive treatment strategy in patients with periodontal disease.

Prevalence of peri-implantitis in a sample of HIV-positive patients.

OBJECTIVES: This study aimed to assess the prevalence of peri-implantitis in human immunodeficiency virus (HIV)-positive patients and the presence of a possible correlation between the immunological profile and serological values, of peri-implantitis, and of possible differences between all-on-4 and single crown/bridge prostheses. SUBJECTS AND METHODS: This retrospective study included 58 adult HIV-positive patients (222 implants) with either all-in-4 prostheses or single crowns/bridges on at least one dental implant loaded for more than a year who were followed for 3 year (mean follow-up). Data pertaining to the probing pocket depth (PPD), bleeding on probing, and immunological and systemic profile were collected. RESULTS: Patients with single crown/bridge implant rehabilitation showed higher prevalence of peri-implantitis (34%) than patients with all-on-4 rehabilitation (0%) (p = 0.012). Patients with all-on-4 rehabilitation were significantly older than those with single crowns/bridges (p = 0.004). Patients with peri-implantitis had implants for a significantly longer duration than those without (p = 0.001), implying that the probability of peri-implantitis increases as the age of implant increases. CONCLUSIONS: The prevalence of peri-implantitis was 26% in the HIV-positive patients population. No correlation was found between patients' immunological and serological factors and peri-implantitis. The most important risk factor for peri-implantitis and mucositis was implant age.

A randomized prospective multicenter trial evaluating the platform-switching technique for the prevention of postrestorative crestal bone loss.

PURPOSE: The purpose of this study was to evaluate the effectiveness of the platform-switching technique to prevent crestal bone loss following the restoration of dental implants. MATERIALS AND METHODS: This randomized prospective multicenter trial analyzed 60 partially edentulous adults recruited at 12 professional dental centers. Subjects were randomly selected to receive either platform-enlarged or control cylindric implants in three different surgical procedures: conventional nonsubmerged, submerged, and submerged with a reduced abutment. The primary outcome measure was the change in crestal bone level assessed radiographically 12 and 24 months following placement. Nonparametric analysis of variance for repeated measures (the Friedman test) was used to assess the overall significance over time of the differences among implants in changes in crestal bone levels. Comparisons among and between groups of implants were performed by the nonparametric Friedman and Wilcoxon tests, respectively. In all the analyses an alpha = .05 was considered significant. RESULTS: A total of 360 implants were placed (60 for each group). Three control implants failed during the 2nd year following placement. All submerged and 92% of nonsubmerged platform-enlarged implants exhibited no bone loss. Control implants with an abutment as large as the implant platform exhibited more bone loss than their platform-enlarged counterparts (P < .001) or control implants with a reduced abutment (P < .001). Submerged implants with an enlarged platform showed better crestal bone preservation than submerged control implants with a reduced abutment (P = .06). CONCLUSIONS: The findings of the current trial indicated that the use of implants with an enlarged platform can result in better preservation of crestal bone as compared with conventional cylindric implants when a reduced abutment is mounted.

Thermal Changes During Guided Flapless Implant Site Preparation: A Comparative Study.

PURPOSE: To compare intrabony thermal changes induced by two different protocols for guided implant surgery during the whole drilling procedure. MATERIALS AND METHODS: Two protocols for guided implant placement were evaluated in vitro using artificial bone cylinders. The control protocol provided traditional metal sleeves and a standard drilling sequence composed of four cylindrical triflute drills (cutting surface length = 16 mm). The test protocol provided a three-slot polyurethane sleeve and two cylindrical drills (second drill cutting surface length = 4 mm). Forty automated intermittent and graduated osteotomies (depth = 14 mm) were performed under external irrigation. Temperatures were measured in real time by three sensors at different depths (2, 8, and 13 mm). The temperature changes generated by the final drill of each protocol during the shearing and withdrawing processes were recorded as experimental results and subjected to the Student t test. RESULTS: Maximum temperature increases were recorded during the process of withdrawing in both protocols. In the control group, the mean thermal changes were 10.18°C, 8.61°C, and 5.78°C at depths of 2, 8, and 13 mm, respectively. In the test group, the mean thermal changes were 1.44°C, 4.46°C, and 3.58°C at depths of 2, 8, and 13 mm, respectively. The control group revealed statistically significantly (P < .0001) higher thermal changes than the test group, both in the superficial and deeper bone areas. CONCLUSION: An appropriate irrigation system could be crucial for thermal lowering during a guided implant osteotomy mainly in the coronal and middle third of the implant site. Copious irrigation should be provided during the withdrawing process since greater thermal increases could be expected. Lower temperature increases could be achieved, reducing drill-to-bone contact, ie, cutting surface length, due to short frictional force exposure.

Buccal-Lingual Bone Remodeling in Immediately Loaded Fresh Socket Implants: A Cone Beam Computed Tomography Study.

The aim of this study was to evaluate buccal-lingual bone remodeling after fresh socket implant placement and immediate loading at 3 years of follow-up by cone beam computed tomography (CBCT). A total of 96 implants were placed in fresh sockets in anterior maxillary regions and immediately loaded. The sockets were divided into two groups related to buccal bone thickness: group A, with a buccal bone thickness > 1 mm, and group B, with a thickness ≤ 1 mm. The CBCT scans were performed before tooth extractions and 3 years after implant placement, and measurements were assessed. At 3 years, all fresh sockets in both groups presented considerable buccal-palatal crestal reduction. In both groups, statistically significant (P < .05) bone loss was found between time points. There was no statistically significant difference in bone reduction between groups at 3 years of follow-up. Nevertheless, sockets with vertical axis presented more bone volume reduction than those with axis parallel to buccal bone after implant placement.

Digital versus Traditional Workflow for Posterior Maxillary Rehabilitations Supported by One Straight and One Tilted Implant: A 3-Year Prospective Comparative Study.

OBJECTIVES: The aim of the study was to evaluate and compare digital and traditional prosthetic workflow for posterior maxillary restorations supported by an upright and a distally tilted implant at 3-year follow-up. MATERIALS AND METHODS: Twenty-four patients were treated in the posterior maxilla with 24 immediately loaded axial and 24 distally tilted implants supporting 3-unit or 4-unit screw-retained prostheses. Three months after initial loading patients were randomly stratified into two groups: definitive traditional impressions were carried out in the control group, while digital impressions were performed in the test group. The framework-implant connection accuracy was evaluated by means intraoral digital radiographs at 3, 6, 12, and 36 months of follow-up examinations. Outcome considerations comprised implant and prosthetic survival and success rates, marginal bone level changes, and required clinical time to take impressions. RESULTS: A total of 24 patients received immediately loaded screw-retained prostheses supported by an upright and a distally tilted implant (total 48 implants). No implant dropouts occurred, showing an overall survival rate of 100% for both groups. None of the 24 fixed prostheses were lost during the observation period (prosthetic survival rate of 100%). No statistically significant differences in marginal bone loss were found between control and test groups. The digital impression procedure required on average less clinical time than the conventional procedure. CONCLUSIONS: Clinical and radiologic results suggest that digital impression is a predictable procedure for posterior maxillary restorations supported by an upright and a distally tilted implant.

Prefabricated Bar System for Immediate Loading in Edentulous Patients: A 5-Year Follow-Up Prospective Longitudinal Study.

OBJECTIVES: The aim of this clinical study was to evaluate a new type of prefabricated bar system, supported by axial and tilted implants at 5-year follow-up. MATERIALS AND METHODS: Twenty-nine consecutive participants (19 females, 10 males) (mean age 61.4 years), edentulous in one or both jaws, with severe atrophy of the posterior regions, were treated according to the All-on-four® protocol with immediately loaded axial (64) and tilted (64) implants supporting complete-arch screw-retained prostheses (12 maxillary, 20 mandibular) featuring a prefabricated bar as framework. Follow-up visits were performed at 3, 6, 12, 24, 48, and 60 months after implant insertion. Radiographic assessments were made using panoramic radiographs obtained immediately after surgery and at each follow-up visit. Bone level measurements around the axial and tilted implants were compared by means of the Student's t-test. RESULTS: One axial implant failed in the lower jaw and did not compromise prosthetic function. The 60-month overall implant survival rate was 100% for axially positioned implants and 98.44% for tilted implants. The implant survival rates were 100% in the maxilla and 98.75% in the mandible. None of the 32 fixed prostheses were lost during the observation period, representing a prosthetic survival rate of 100%. No statistically significant differences (P > 0.05) in marginal bone loss between tilted and axial implants were detected in either jaw over time. CONCLUSIONS: The use of the evaluated prefabricated bar for immediately loaded implants placed according to the All-on-four concept may significantly reduce implant failures; however, more long-term prospective clinical trials are needed to affirm the effectiveness of the surgical-prosthetic protocol.

Delayed Implants Outcome in Maxillary Molar Region.

BACKGROUND: The aim of the present study was to assess bone volume changes in maxillary molar regions after delayed implants placement. MATERIALS AND METHODS: Patients presented large bone defects after tooth extractions. Reactive soft tissue was left into the defects. No grafts were used. Cone beam computed tomography (CBCT) scans were performed before tooth extractions, at implant placement (at 3 months from extraction) and 3 years after implant placement, bone volume measurements were assessed. RESULTS: Bucco-lingual width showed a statistically significant decrease (p = .013) at implant placement, 3 months after extraction. Moreover, a statistically significant increase (p < .01) was measured 3 years after implant placement. No statistically significant differences (p > .05) were found between baseline values (before extraction) and at 3 years from implant placement. Vertical dimension showed no statistically significant differences (p > .05) at implant placement, 3 months after extraction. Statistically significant differences (p < .0001) were found between baseline values (before extraction) and at 3 months from implant placement as well as between implant placement values and 3 years later. CONCLUSION: CT scans presented successful outcome of delayed implants placed in large bone defects at 3-year follow-up.

Implant Prosthetic Rehabilitation in Controlled HIV-Positive Patients: A Prospective Longitudinal Study with 1-Year Follow-Up.

PURPOSE: The clinical trial aimed to evaluate the survival of implant-prosthetic rehabilitation in controlled HIV-positive patients. MATERIALS AND METHODS: This mono-centric study included HIV patients with a stable disease, requiring implant rehabilitation, with good oral hygiene. Each patient received at least one dental implant. After 90 days in the upper jaw and 60 days in the lower jaw, the appropriate prosthesis was delivered.Primary outcome measures were prosthetic failures, implant failures, peri-implant marginal bone level changes (MBLCs), and biological complications (peri-implantitis, pus, pain, paresthesia). Data were recorded before the intervention (T0), and 6 (T1) and 12 months (T2) after. RESULTS: Implants were positioned in 68 patients (22 females and 46 males; 194 implants). Two dropouts occurred for exacerbation of the disease before the sixth month of follow-up, and 66 patients (with 190 implants) completed the study. Forty-eight patients (70.6%) received total removable dentures; 11 patients (16.2%) received partial prosthesis, and nine patients (13.2%) received single elements.Implant failure occurred in nine patients (15 fixtures out of 190). These were early implant failures due to primary infection (five fixtures out of 190: 2.6%) and to peri-implantitis (10 fixtures out of 190: 5.2%). Prosthetic failure was registered in two patients (3% of patients) due to the loss of all the fixtures. Pus and pain were observed in 4/7 and 3/7 patients with peri-implantitis, respectively. No fractures of fixtures or paresthesia were registered. At T2, the mean peri-implant MBLC was -1.19 ± 0.87 mm. CONCLUSIONS: Within its limitations, the study showed that in a well-controlled population of HIV patients implant rehabilitation can be a suitable options with results slightly worse to those obtained in normal population. A higher incidence of peri implant infections in the first six months was present pointing to the need of a proper protocol for infection control.

A Prospective Longitudinal Study on Implant Prosthetic Rehabilitation in Controlled HIV-Positive Patients with 1-Year Follow-Up: The Role of CD4+ Level, Smoking Habits, and Oral Hygiene.

BACKGROUND: A recent study showed that implant-prosthetic rehabilitation in well-controlled HIV patients gave slightly worse results than in an healthy population, and failures were all linked to infection. PURPOSE: The aim of this study was to examine the associations between the success of implant-prosthetic treatment and systemic CD4+ level, smoking habits, and oral hygiene. MATERIALS AND METHODS: This mono-centric study included HIV patients with a stable disease and good oral hygiene requiring implant rehabilitation. Each patient received at least one dental implant. Prosthesis were delivered after 90 days in the upper jaw and 60 days in the lower jaw. Primary outcome measures were prosthetic failures, implant failures, peri-implant marginal bone level changes, and biological complications (peri-implantitis, pus, pain, paresthesia). The possible association with CD4 count, smoking habits, and oral hygiene was analyzed. RESULTS: Sixty-eight patients received 194 implants, and 66 patients (190 implants) were followed for 1 year. No significant associations were found between CD4+ count, oral hygiene-associated variables, and any of the outcome measures. If compared with nonsmoking/light smoking patients, patients who smoked >10 cigarettes/day suffered a statistically significant greater number of implant failures (p ≤ .005), presented a comparatively higher number of peri-implantitis (p < .001), as well as a higher frequency of pus (p ≤ .007), and reported pain (p ≤ .009). CONCLUSION: Within the limitation of the present study, placement of dental implants in HIV-positive patients with stable disease seems a reasonable treatment option, regardless of CD4+ cell count, provided that they are in a normal range. Oral hygiene variables were not influent in this group of patient following recall appointments, while HIV-positive heavy smokers (>10 cigarettes/day) demonstrated an increased risk of early implant failure, peri-implantitis, episodes of pus, and self-reported pain.

Reactive Soft Tissue Preservation in Maxillary Large Bone Defects.

PURPOSE: Granulation tissue containing reactive soft tissue with potential multipotent stem cells can help socket healing following extraction. The aim of this study was to assess bone healing of maxillary large bone defects while maintaining reactive soft tissue. MATERIALS AND METHODS: A total of 32 patients presenting large bone defects were selected for this prospective study. Eight patients (Group A) presented with large bone defects but an intact buccal cortical plate, while 24 patients (Group B) presented with large bone defects lacking a buccal cortical plate. Teeth were extracted, and reactive soft tissue was left in the defects. Bone volume was assessed through cone beam computed tomography (CBCT) both before tooth extraction and at 4 months. A histomorphometric evaluation was performed. RESULTS: CBCT and cylinder bone cores were obtained for histology and histomorphometry analysis. At 4 months after tooth extraction, CBCT showed bone volume preservation and bone formation and no statistically significant difference in bone volume before and after tooth extraction in group A. However, in group B, over the same time period, a statistically significant increase (P < .01) of vertical bone volume was reported. Biopsy specimens showed the presence of vital bone in the defects 4 months later. CONCLUSION: Reactive soft tissue left in large bone defects after tooth extraction may support a significant bone volume gain and vital bone formation.

Transmucosal Implant Placement with Submarginal Connective Tissue Graft in Area of Shallow Buccal Bone Dehiscence: A Three-Year Follow-Up Case Series.

The aim of the present case series study was to evaluate the short- and long-term (3 years) soft tissue stability of a surgical technique combining transmucosal implant placement with submarginal connective tissue graft (CTG) in an area of shallow buccal bone dehiscence. A sample of 20 patients were treated by positioning a transmucosal implant in an intercalated edentulous area. A CTG sutured to the inner aspect of the buccal flap was used to cover the shallow buccal bone dehiscence. Clinical evaluations were made at 6 months (T1) and 1 (T2) and 3 (T3) years after the surgery. Statistically significant increases in buccal soft tissue thickness and improvement of vertical soft tissue level were achieved at the T1, T2, and T3 follow-ups. A significant increase in keratinized tissue height was also found at T3. No significant marginal bone loss was recorded. The submarginal CTG technique was able to provide simultaneous vertical and horizontal soft tissue increases around single implants with shallow buccal bone dehiscence and no buccal mucosal recession or clinical signs of mucositis or peri-implantitis at 1 and 3 years.

Vascular endothelial growth factor behavior in different stages of tooth germ development.

BACKGROUND: Scientific studies show a possible influence of intercellular and intracellular proteins (VEGF) on the development of physiological and pathological tissue. VEGF, a key regulator of angiogenesis, it would seem essential to take action during the embryonic development of the dental germ. The purpose of the study is to investigate the importance of the enzymatic activity of VEGF through protein quantification at different stages of tooth germ development. METHODS: The quantification of VEGF protein was performed by 3 different laboratory tests: Western-blot analysis, semi-quantitative reverse transcriptase-polymerase chain reaction analysis (RT-PCR) and finally immunohistochemical analysis. Cell cultures of tooth tissue examined are: endothelial cells, stellate reticulum cells, odontoblasts and ameoblast. RESULTS: The VEGF peptide seems to induce an intense cell proliferation, not concomitant with differentiation towards the endothelial line. The expression of VEGF in the inner enamel epithelium (ameloblasts) would seem to depend on the stage of differentiation, leading us to deduce that VEGF and its respective receptor are expressed in dental germ and that induce alterations not only on the vascularization, but also on the inner epithelium activation and then on dental enamel development, respectively on cap and bell stages of embryogenesis. CONCLUSIONS: In our survey, the positive expression of VEGF in all the samples examined, might suggest a fundamental role of angiogenic gene proteins during all stages of embryonic tooth development. It is also characteristic the behavior of stellate reticulum cells, with a significant reduction in VEGF action between early and late stage, which could suggest a possible role of stellate reticulum cells, which would be able to promote and maintain an adequate energy supply to the tissues during early and late stages of differentiation and proliferation.

Influence of the implant drill design and sequence on temperature changes during site preparation.

PURPOSE: The purpose of this study was to compare bone temperature changes during implant drilling with two drill designs employed in three different drilling sequences. MATERIALS AND METHODS: Two implant drill designs and three drilling sequences were evaluated in vitro using artificial bone cylinders. The evaluated drills were different only in the cutting-surface length (control, 16 mm; test, 4 mm). Three drilling sequences (control A, test B1, and test B2) were evaluated with and without irrigation. Temperatures were measured with thermocouple technology. The temperature changes generated by the final drill of each sequence were recorded as the experimental results and were subjected to the Student t test. RESULTS: There were statistically significant differences in temperature changes when comparing the control group A with the test groups B1 (P = .001) and B2 (P = .01) during drilling without coolant. The mean temperature changes were 12.4°C, 6.5°C, and 13.7°C for groups A, B1, and B2, respectively. The Student t test showed statistically significant differences between temperature changes of the control group A and the test groups B1 (P < .01) and B2 (P < .05) during drilling with coolant. The mean temperature changes were 0.9°C, 0.7°C, and 1.9°C for groups A, B1, and B2, respectively. CONCLUSION: Reduction in length of the cutting surface of the drill may limit frictional heat. Drills with the same length of cutting surface may induce lower bone temperature changes, when considering a preliminary drilling step with a pilot drill.

Immediate Loaded Implants in Split-Crest Procedure.

BACKGROUND: The aim of this study was to assess survival rate of immediate loading implants placed after split-crest technique. METHODS: Thirty-six patients were enrolled in the study. They underwent placement of 93 dental implants in edentulous region after split-crest ridge expansion procedure. Implants followed an immediate loading procedure. Crestal bone levels were measured at baseline, at temporary prosthesis placement, at 1 year, and at 2 years from implant placement. RESULTS: For dental implants, a survival rate of 98.92% was reported at 2-year follow-up, with a mean value bone loss of -1.02 ± 0.48. CONCLUSION: This study assessed immediate loading implant placement after split-crest procedure at 2-year follow-up.

Four-year follow-up of larger-diameter implants placed in fresh extraction sockets using a resorbable membrane or a resorbable alloplastic material.

PURPOSE: The aim of this randomized study was to evaluate and compare the long-term success rates of cylindric, screw-type titanium implants with a larger diameter (5.9 mm) that were placed in fresh extraction sockets in association with resorbable bone substitutes or a resorbable membrane. MATERIALS AND METHODS: Eighty-three partially edentulous adult patients, selected from among those treated in 1997 and 1998 at the San Raffaele Institute in whom 1 or more implants had been placed into fresh posterior mandibular or maxillary sockets, were included in the study. A total of 111 implants were placed, 36 in mandibles and 75 in maxillae. Fifty-six implants were placed in combination with resorbable hydroxyapatite (HA group) and 55 with a resorbable membrane (MR group). Intraoral radiographs and follow-up examinations, including verification of implant stability via the Periotest, were carried out at second-stage surgery 3, 6, 9, and 12 months later; and then annually up to 4 years after placement of the definitive restoration. The radiographic examination was conducted by means of a standardized procedure to verify osseointegration. RESULTS: There was 100% attendance at the follow-up examination after 4 years. At second-stage surgery, which was performed after 4 to 6 months' healing time, none of the implants showed any signs of mobility, peri-implantitis, or bone loss. Two implants failed in the MR group, one at 3 months and one at 9 months after placement; 1 implant failed in the HA group at 4 months after placement. After 4 years, the implant success rate was 97.3% (108 of 111 implants were considered successful). The success rate did not differ significantly between the HA group (98.2%) and the MR group (96.4%). DISCUSSION: The use of larger-diameter implants served to minimize the anatomic discrepancies that would have evolved when substituting a molar with a standard-diameter implant. According to the accepted criteria for success, the 5-year success rate should be at least 85%; therefore both methods may be considered satisfactory. CONCLUSION: Implants placed in combination with a resorbable allogeneic material or with a resorbable membrane provided predictable long-term results when restored with a fixed partial denture.

Bone recontouring in fresh sockets with buccal bone loss: a cone beam computed tomography study.

PURPOSE: The aim of this study was to assess buccal bone plate recontouring in maxillary fresh extraction sockets with buccal bone loss using cone beam computed tomography (CBCT). MATERIALS AND METHODS: Healthy patients who required the extraction of one tooth with buccal bone loss in the maxilla were included in this study. CBCT examinations were made before extractions and after 3 months. The alveolar bone levels were assessed from the most coronal, buccal, and palatal bone in which the crest was identified. Buccolingual width at the apical and coronal level was also measured. RESULTS: Fifty healthy patients underwent 50 extractions. Mean bone levels for both single-rooted and multiple-rooted teeth, from a buccopalatal perspective, showed no statistically significant difference between preextraction status and 3 months later. However, in both groups, mean bone levels of the buccal bone plate showed statistically significant differences between extraction and 3 months later. In single-rooted teeth, a mean bone gain of 5.36 ± 2.65 mm was seen after 3 months, and for multiple-rooted teeth, a mean bone gain of 5.89 ± 2.88 mm was seen. Growth in buccolingual width was seen; nevertheless, volume dimensional changes were reported after tooth extraction. CONCLUSIONS: In the first months after extraction, it is possible to observe the formation of buccal bone in sockets with previous buccal bone loss.

Enamel structural changes induced by hydrochloric and phosphoric acid treatment.

PURPOSE: The aim of this study was to evaluate enamel acid-induced structural changes after 2 different treatments, by means of Raman and infrared (IR) spectroscopy analyses, and to correlate these findings with permeability measured as fluid discharge from outer enamel. METHODS: Two different treatments were investigated: 10 enamel slices were etched with 15% hydrochloric acid (HCl) for 120 seconds and 10 slices with 37% phosphoric acid gel (H3PO4) for 30 seconds, rinsed for 30 seconds and then air-dried for 20 seconds. Powders of enamel treated as previously described were produced. Replicas of enamel subjected to the same treatments were obtained to evaluate the presence of fluid droplets on enamel surface. RESULTS AND CONCLUSIONS: Raman and IR spectroscopy showed that the treatment with both hydrochloric and phosphoric acids induced a decrease in the carbonate content of the enamel apatite. At the same time, both acids induced the formation of HPO42- ions. After H3PO4 treatment, the bands due to the organic component of enamel decreased in intensity, while they increased after HCl treatment. Replicas of H3PO4 treated enamel showed a strongly reduced permeability. Replicas of HCl 15% treated samples showed a maintained permeability. A decrease of the enamel organic component, as resulted after H3PO4 treatment, involves a decrease in enamel permeability, while the increase of the organic matter (achieved by HCl treatment) still maintains enamel permeability.The results suggested a correlation between organic matter and enamel permeability. Permeability was affected by etching technique and could be involved in marginal seal, gap and discoloration at the enamel interface, still causes of restoration failure.