Hemorrhagic Complications in Implant Surgery: A Scoping Review on Etiology, Prevention, and Management.

This article seeks to provide the most relevant aspects of the etiology, prevention, and management of bleeding in routine implant surgery. A comprehensive and systematic electronic search was conducted in MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews databases until June 2021. Further references of interest were retrieved from bibliographic lists of the selected articles and the "Related Articles" feature of PubMed. Eligibility criteria were papers about bleeding, hemorrhage, or hematoma associated with routine implant surgery on human subjects. Twenty reviews and 41 case reports fulfilled eligibility criteria and were included in the scoping review. Involved implants were mandibular in 37 and maxillary in 4 cases. The major number of bleeding complications was in the mandibular canine region. The most injured vessels were sublingual and submental arteries, due mainly to perforation of the lingual cortical plate. Time to bleeding occurred intraoperatively, at suturing, or postoperatively. The most reported clinical manifestations were swelling and elevation of the mouth floor and the tongue with partial or complete airway obstructions. First aid to manage airway obstruction was intubation and tracheostomy. For active bleeding control, gauze tamponade, manual or digital compression, hemostatic agents, and cauterization were applied. When conservative procedures failed, hemorrhage was controlled by intra- or extraoral surgical approaches to ligate injured vessels or by angiographic embolization. The present scoping review provides knowledge and evidence on the most relevant aspects of the etiology, prevention, and management of implant surgery bleeding complications.

Effects of an amino acid buffered hypochlorite solution as an adjunctive to air-powder abrasion in open-flap surface decontamination of implants failed for peri-implantitis: an ex vivo randomized clinical trial.

OBJECTIVES: To evaluate ex vivo the efficacy of an amino acid buffered hypochlorite solution supplemented to surface debridement with air-powder abrasion in removing bacterial biofilm following open-flap decontamination of implants failed due to peri-implantitis. MATERIALS AND METHODS: This study was an ex vivo, single-blind, randomized, intra-subject investigation. Study population consisted of 20 subjects with at least three implants failed for peri-implantitis (in function for > 12 months and progressive bone loss exceeding 50%) to be explanted. For each patient, implants were randomly assigned to surface decontamination with sodium bicarbonate air-powder abrasion (test-group 1) or sodium bicarbonate air-powder abrasion supplemented by amino acid buffered hypochlorite solution (test-group 2) or untreated control group. Following open-flap surgery, untreated implants (control group) were explanted. Afterwards, test implants were decontaminated according to allocation and explanted. Microbiological analysis was expressed in colony-forming units (CFU/ml). RESULTS: A statistically significant difference in the concentrations of CFU/ml was found between implants of test-group 1 (63,018.18 ± 228,599.36) (p = 0.007) and implants of test-group 2 (260.00 ± 375.80) (p < 0.001) compared to untreated implants (control group) (86,846.15 ± 266,689.44). The concentration of CFU/ml on implant surfaces was lower in test-group 2 than in test-group 1, with a statistically significant difference (p < 0.001). CONCLUSION: The additional application of amino acid buffered hypochlorite solution seemed to improve the effectiveness of implant surface decontamination with air-powder abrasion following open-flap surgery. CLINICAL RELEVANCE: Lacking evidence on the most effective method for biofilm removal from contaminated implant surfaces, the present experimental study provides further information for clinicians and researchers.

Immediate flapless full-arch rehabilitation of edentulous jaws on 4 or 6 implants according to the prosthetic-driven planning and guided implant surgery: A retrospective study on clinical and radiographic outcomes up to 10 years of follow-up.

OBJECTIVES: to retrospectively evaluate clinical and radiographic outcomes of immediate, flapless full-arch prostheses, supported by 4/6 implants according to prosthetic-driven planning and guided surgery. MATERIALS AND METHODS: The study involved 28 edentulous patients (20 female/8 males; average age 67.75 ± 8.627 years), 32 prostheses (17 all-on-4/15 all-on-6) and 164 implants. The Implants survival, prostheses success/survival, peri-implant marginal bone loss, incidence of biological and prosthetic complications were evaluated. Multiple linear regression analysis was performed to analyze the influence of implant and patient characteristics on marginal bone loss. RESULTS: Cumulative implant survival rate was 89.7% for all-on-four (seven failures) and 99.0% for all-on-six (one failure) after a mean follow-up of 6.46 ± 2.236 years (range 1-10 years). Cumulative prosthesis success rate was 51.5% (58.8% for all-on-four/ 43.8% for all-on-six). Prosthesis survival rate was 88.2% for all-on-four. No failure was registered in all-on-six. Mean value of marginal bone loss was 1.38 ± 0.1.28 mm at 5-year and 2.09 ± 0.56 mm at 10-year follow-up. No difference was found in the mean value of marginal bone resorption between all-on-four (1.56 ± 1.61 mm) and all-on-six (1.20 ± 0.85 mm) (p = 0.104) and between tilted (1.22 ± 1.29 mm) and axial implants (1.44 ± 1.27 mm) (p = 0.385) after 5-year follow-up. The incidence of biological complications was 1.0% in all-on-six (one mucositis) and 10.3% in all-on-four (two peri-implantitis). Prosthetic complications affected teeth of final rehabilitations with 3 detachments, 10 chippings or fractures, and 3 severe occlusal wears. CONCLUSIONS: Based on the results and within the limitations of the present study, the implant-supported hybrid prosthesis according to prosthetic-driven planning and guided surgery showed to be an efficient, safe, and effective approach to rehabilitate edentulous jaws.

Effects of ibuprofen administration timing on oral surgery pain: A randomized clinical trial.

OBJECTIVE: This study aimed to compare the analgesic effect of ibuprofen 400 mg given 30 min before or immediately after third molars surgery under local anaesthesia. MATERIALS AND METHODS: The single-centre, randomized, split-mouth, triple-blind, clinical trial involved 38 outpatients, for a total of 76 bilateral symmetrical fully bone impacted mandibular third molars. Each patient was undergone to separate surgical sessions for the right and left side, and ibuprofen was randomly administered 30 min before or immediately after the intervention. Study participants recorded pain intensity using Numerical Rating Scale-11, the timing of rescue therapy intake and overall tablets consumption over 3 days. RESULTS: The overall pain intensity score was lower in the group receiving ibuprofen immediately after (3.13 ± 2.46) than before (3.58 ± 2.40) surgery, with statistically significant differences only on the second and third days. The mean time to the first using rescue therapy was longer in the postoperative (598.33 ± 422.62 min) than in the preoperative (406.25 ± 149.79 min) analgesic treatment group (p = .123). The number of supplemented ibuprofen tablets did not differ (p = .530) between both groups. CONCLUSIONS: Within the limits of the present study, ibuprofen administration immediately after surgery seemed to be more effective than preoperative administration.

COMPARATIVE ANALGESIC EFFECTS OF SINGLE-DOSE PREOPERATIVE ADMINISTRATION OF PARACETAMOL (ACETAMINOPHEN) 500 mg PLUS CODEINE 30 mg AND IBUPROFEN 400 mg ON PAIN AFTER THIRD MOLAR SURGERY.

BACKGROUND: Efficacy and rapid onset of postsurgical oral pain relief are critical to improve clinical outcomes and reduce the risk of excessive dosing with analgesic drugs. PURPOSE: To compare analgesic effects of preoperative administration of paracetamol 500 mg plus codeine 30 mg in single-tablet and effervescent formulation to ibuprofen 400 mg, and placebo in the management of moderate to severe postoperative pain after mandibular third molar surgery. MATERIALS AND METHODS: One hundred twenty healthy outpatients aged 15-29 years undergoing surgical removal of 1 bony impacted mandibular third molar were enrolled in this, single-center, prospective, randomized, triple-blind parallel-group, placebo-controlled, clinical trial. Study participants were randomly assigned to three treatment arms. According to the concealed allocation, each patient 30 minutes before surgery received paracetamol 500 mg plus codeine 30 mg (group APAP/COD), ibuprofen 400 mg (group IBU) or placebo (group PLA). Rescue therapy allowed in the postoperative period was paracetamol 500 mg plus codeine 30 mg in groups APAP/COD and PLA and ibuprofen 400 mg in group IBU. Patients recorded on Numerical Rating Scale-11 (NRS-11) the pain intensity, total number of postoperative-supplement medications and time of the first intake, until 12-hours after surgery and over extra 2 days, RESULTS: Over postoperative 3 days, patients in the APAP/COD group (2.33 ± 1.99) displayed significantly (P< .001) less pain intensity than IBU (3.43 ± 2.47) and placebo (3.57 ± 2.62) groups. The first-day postoperative pain was significantly (P < .001) higher in group PLA than in groups APAP/COD and IBU, but not between the latter 2 groups. However, at 2 hours postdose, the IBU group displayed average pain intensity lower than APAP/COD group (P> .05). On the next 2 days, pain intensity was significantly (P< .001) lower in group APAP/COD than in groups IBU and PLA but failed to reach statistical significance between groups IBU and PLA. Although the time to the first using rescue therapy was longer (445.88 ± 159.96 minute) in group IBU, compared to groups APAP/COD (392.67 ± 138.90 minutes) and PLA (323.00 ± 143.95 minutes), the number of supplemented tablets was significantly higher in group IBU (2.89 ± 2.13) than in groups APAP/COD (1.24 ± 1.79) (P= .001) and PLA (1.53 ± 1.67) (P = .008). No adverse events were registered for all groups. CONCLUSIONS: Within the limits of the present study, over postoperative 3 days, a statistically significant intensity pain reduction and decreased rescue therapy consumption were recorded in the paracetamol-codeine group than to ibuprofen group. Nevertheless, lower pain intensity at 2 hours postdose and longer time using rescue therapy was found in the ibuprofen group without statistical significance. No adverse events occurred over the studied period.

Subcutaneous Facial Emphysema Following Open-Flap Air-Powder Abrasive Debridement for Peri-Implantitis: A Case Report and an Overview.

Subcutaneous facial emphysema related to dental treatments is a well-known clinical complication due to incidental or iatrogenic air or gas penetration into the subcutaneous tissues and fascial planes, leading to distension of the overlying skin. To the best of our knowledge, from 1960 to the current date, only six cases have been reported arising from peri-implant cleaning or non-surgical peri-implantitis treatment. Therefore, the present case of subcutaneous facial emphysema following open-flap air-powder abrasive debridement was the first report during surgical peri-implantitis therapy. Swelling on the left cheek and periorbital space suddenly arose in a 65-year-old woman during open-flap debridement with sodium bicarbonate air-powder abrasion (PROPHYflex™ 3 with periotip, KaVo, Biberach, Germany) of the infected implant surface. The etiology, clinical manifestations, diagnosis, potential complications, and management of subcutaneous emphysema are also briefly reviewed. The present case report draws the attention of dental practitioners, periodontists, oral surgeons, and dental hygienists to the potential iatrogenic risk of subcutaneous emphysema in using air-powder devices in implant surface debridement.

Survival and complication rates of tooth-implant versus freestanding implant supporting fixed partial prosthesis: a systematic review and meta-analysis.

PURPOSE: This systematic review was performed to compare tooth, implant and prosthesis failures and biological and technical complications in toothimplant vs freestanding implant supported fixed partial prostheses, in order to evaluate the effectiveness and predictability in combining teeth and implants in the same fixed partial prosthesis. STUDY SELECTION: A comprehensive and systematic literature research was conducted, according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement, to identify human trials, with a minimum sample size of 10 patients, comparing tooth-implant to freestanding implant supported fixed partial prostheses. Four groups of meta-analyses were performed based on the patients treated with toothimplant vs freestanding implant-supported fixed partial prostheses: abutment failures, biological and mechanical complications, prosthesis failures, and prosthetic (technical) complications. RESULTS: The search yielded 749 records, after removal of duplicates. Based on the title assessment, the abstracts reading and the full-texts evaluation, 8 articles, published between 1999 and 2013, fulfilled the inclusion criteria and were included in the meta-analysis. The studies included were: 4 controlled clinical trials, 2 prospective and 2 retrospective cohort studies. The meta-analysis revealed no significant difference between tooth-implant and implant-implant supported fixed in the number of abutment (implant or tooth) failures, biological complications, prosthesis lost, and prosthetic complications. CONCLUSIONS: Within the limitations of the present systematic review, although the freestanding implant supported fixed partial prosthesis remains the first choice, joining teeth and implants to support fixed prosthesis in partially edentulous patients becomes a valid alternative with an acceptable success rate.

Comparison of the effects of air-powder abrasion, chemical decontamination, or their combination in open-flap surface decontamination of implants failed for peri-implantitis: an ex vivo study.

OBJECTIVES: To compare, using an ex vivo model, the biofilm removal of three surface decontamination methods following surgical exposure of implants failed for severe peri-implantitis. MATERIALS AND METHODS: The study design was a single-blind, randomized, controlled, ex vivo investigation with intra-subject control. Study participants were 20 consecutive patients with at least 4 hopeless implants, in function for >12 months and with progressive bone loss exceeding 50%, which had to be explanted. Implants of each patient were randomly assigned to the untreated control group or one of the three decontamination procedures: mechanical debridement with air-powder abrasion, chemical decontamination with hydrogen peroxide and chlorhexidine gluconate, or combined mechanical-chemical decontamination. Following surgical exposure, implants selected as control were retrieved, and afterwards, test implants were decontaminated according to allocation and carefully explanted with a removal kit. Microbiological analysis was expressed in colony-forming-units (CFU/ml). RESULTS: A statistically significant difference (p < 0.001) in the concentrations of CFU/ml was found between implants treated with mechanical debridement (531.58 ± 372.07) or combined mechanical-chemical decontamination (954.05 ± 2219.31) and implants untreated (37,800.00 ± 46,837.05) or treated with chemical decontamination alone (29,650.00 ± 42,596.20). No statistically significant difference (p = 1.000) was found between mechanical debridement used alone or supplemented with chemical decontamination. Microbiological analyses identified 21 microbial species, without significant differences between control and treatment groups. CONCLUSIONS: Bacterial biofilm removal from infected implant surfaces was significantly superior for mechanical debridement than chemical decontamination. CLINICAL RELEVANCE: The present is the only ex vivo study based on decontamination methods for removing actual and mature biofilm from infected implant surfaces in patients with peri-implantitis.

Vertical Guided Bone Regeneration with Mineralized Cancellous Bone Allograft in a Severe Anterior Maxillary Defect: A Clinical Report with 14-Year Follow-Up.

PURPOSE: To report the supracrestal bone regeneration of approximately 10 mm using solvent-dehydrated mineralized cancellous bone allograft and nonresorbable membrane in rehabilitation of unsuccessful implants in the anterior maxilla and stability of the regenerated bone at the 14th-year follow-up. CASE PRESENTATION: A 24-year-old female patient with a history of anterior dentoalveolar trauma resulting in the loss of upper left incisors and canine underwent rehabilitation several years ago with three implant-supported fixed prostheses. The prosthesis was both functionally and aesthetically inadequate, and the patient complained of gingival swelling, bleeding, and food impaction at the site of the implants. A staged approach for retreatment was planned, wherein the first surgical stage aimed at removing the existing implants and preparing the bone ridge and soft tissues for the augmentation procedure. The second stage was vertical ridge augmentation and simultaneous prosthetic-driven placement of two new implants at the sites of the left central incisor and canine. After nine months of uneventful healing, complete regeneration of the bony defect was achieved, and the new prosthetic rehabilitation satisfied both functional and aesthetic requirements. CONCLUSION: The therapeutic approach followed in the present case proved effective in achieving satisfactory functional and aesthetic results and in maintaining the stability of the regenerated bone at 14 years of follow-up.

First and second permanent molars with failed or delayed eruption: Clinical and statistical analyses.

INTRODUCTION: The aim of this work was to analyze data of patients with failed or delayed eruption of first and second permanent molars, to assess the effectiveness of the treatment methods used. METHODS: Epidemiologic and clinical data of 125 patients (mean age 14.08 ± 4.04 years) with 197 affected molars (30 first and 167 second molars) were retrospectively analyzed. The treatment outcome was known in 161 molars after patient drop-out (20 patients with 36 molars). The cases were categorized into 8 groups according to the choice of treatment: orthodontic uprighting, surgical-orthodontic uprighting, surgical uprighting, surgical repositioning, surgical exposure, first or second molar extraction, third molar extraction, or removal of pathologic conditions. RESULTS: The overall treatment outcome was positive in 141 molars (87.6%). It was positive in all cases treated with orthodontic uprighting (7 molars), surgical exposure (10 molars), surgical uprighting (38 molars), and surgical repositioning (8 molars), but it was significantly lower for surgical-orthodontic uprighting (34/48 molars, 70.8%). The positive outcome was significantly lower for inclusion (52/68 molars, 76.5%) than for early-diagnosed condition (11/11 molars, 100%) and retention (78/82 molars, 95.1%), and for total bone crown coverage (21/28 molars, 75.0%) than for osteomucosal or mucosal crown coverage (120/133 molars, 90.2%). CONCLUSIONS: This study demonstrates that an early diagnosis results in a better outcome regardless of the treatment used, with the number of cases with a positive outcome being higher in younger patients.

Sequelae in permanent teeth after traumatic injuries to primary dentition.

Traumatic injuries to the primary dentition are critical events in dentistry not only due to the need for urgent care, but also since they have potential sequelae in the permanent dentition, with a prevalence ranging from 12% to 74%. The aim of this article was to provide an overview of the prevalence, etiology, and clinical and radiographic characteristics as well as the management of permanent teeth sequelae resulting from traumatic injuries to their deciduous predecessors. An extensive literature review was performed to reveal the current evidence on enamel discoloration with or without hypomineralization/hypoplasia, crown dilaceration, odontoma-like malformation, root anomalies, partial or complete arrest of root formation, sequestration of the permanent tooth germ, and eruption disturbances.

Clinical and radiographic outcomes of a surgical reconstructive approach in the treatment of peri-implantitis lesions: A 5-year prospective case series.

OBJECTIVES: The aim of this study was to evaluate the 5-year clinical and radiographic outcomes following reconstructive therapy of peri-implantitis lesions using mineralized dehydrated bone allograft and resorbable membrane in the nonsubmerged mode of wound healing. MATERIALS AND METHODS: Thirty-four patients with at least one implant diagnosed with peri-implantitis were treated by mechanical debridement; chemical decontamination using hydrogen peroxide (3%), chlorhexidine (0.2%), and a tetracycline hydrochloride solution; and bone defect filling with mineralized dehydrated bone allograft and resorbable membrane. Clinical and radiographic assessments were obtained during 5-year follow-up. The primary outcome was the absence of additional marginal peri-implant bone loss ≥1.0 mm after surgery, and the composite outcome included the additional marginal peri-implant bone loss, absence of probing depth (PD) ≥5 mm, and absence of bleeding on probing (BoP)/suppuration. RESULTS: According to the primary and composite outcomes, the success rate of 34 implants included in the study was 100% and 91% (N = 31), at 1 year after surgery, and decreased progressively to 77% (N = 26) and to 59% (N = 20) at 5-year follow-up, respectively. Five years following treatment, only the BoP reduction was statistically significant compared to baseline (p < 0.001), and no difference was found in PD (p = 0.318) and in marginal peri-implant bone level (p = 0.064). CONCLUSIONS: At 1-year follow-up, the surgical reconstructive therapy showed clinical improvement and radiographic defect filling. However, the results appeared to be unpredictable over time, due to a progressive decrease in the bone filling of the peri-implant defects and an increase in the mean PD.

Efficacy of Preoperative Administration of Paracetamol-Codeine on Pain following Impacted Mandibular Third Molar Surgery: A Randomized, Split-Mouth, Placebo-Controlled, Double-Blind Clinical Trial.

Objectives. The aim of this study was to determine the effectiveness of preoperative administration of single-dose of paracetamol-codeine, in the relieving of acute postoperative pain after the surgical removal of an impacted mandibular third molar. Materials and Methods. The study cohort consisted of 32 Caucasian outpatients, giving a total of 64 bilateral symmetrical impacted mandibles. Patients were randomized in two experimental groups to receive a preoperative oral dose of paracetamol-codeine (analgesic group) or a placebo (placebo group) at the first and second surgeries. Study participants were asked to record pain intensity scores during the operation and the next 2 days, the time of the first request for rescue analgesic, and the total number of postoperative-supplement paracetamol-codeine tablets. Results. The pain intensity score on the first day was significantly lower in the analgesic group than in the placebo group (p < 0.001). The time to using rescue therapy was significantly longer in the analgesic group than in the placebo group (p = 0.004). The number of paracetamol-codeine tablets used postoperatively did not differ between the analgesic and placebo groups (p = 0.104). Conclusions. Preoperative paracetamol-codeine is effective in providing immediate postoperative pain control after third molar surgery and in delaying the initial onset of pain. This trial is registered with ClinicalTrials.gov Identifier (Registration Number): NCT03049878.

Surgical approach to malformation of maxillary central incisor following trauma to its predecessor. Two case reports.

In the case reports, two different approaches have been described to treat the developmental disturbances in the maxillary central incisors due to trauma to its predecessor. The treatment plan was chosen according to the type and severity of the malformations, the exact location and the morphology of the involved teeth. In the first case, the disimpaction of the maxillary right central incisor was achieved with the combined of surgical and orthodontic therapy, that was planned in two consecutive stages. In the second case the severe root angulation and the failure of the previous orthodontic traction made impossible the repositioning of the upper right central incisor, which was surgical removed.

Prevention of neurological injuries during mandibular third molar surgery: technical notes.

Surgery to the mandibular third molar is common, and injuries to the inferior alveolar nerve and the lingual nerve are well-recognized complications of this procedure. The aim of these technical notes is to describe operative measures for reducing neurological complications during mandibular third molar surgery. The following procedure should be used to prevent damage to the inferior alveolar nerve: a well-designed mucoperiosteal flap, to obtain appropriate access to the surgical area; a conservative ostectomy on the distal and distal-lingual side; tooth sectioning, to facilitate its removal by decreasing the retention zones; tooth dislocation in the path of withdrawal imposed by the curvature of the root apex; and careful socket debridement, when the roots of the extracted tooth are in intimate contact with the mandibular canal. To prevent injury to the lingual nerve, it is important (I) to assess the integrity of the mandibular inner cortex and exclude the presence of fenestration, which could cause the dislocation of the tooth or its fragment into the sublingual or submandibular space; (II) to avoid inappropriate or excessive dislocation proceedings, in order to prevent lingual cortex fracture; (III) to perform horizontal mesial-distal crown sectioning of the lingually inclined tooth; (IV) to protect the lingual flap with a retractor showing the cortical ridge; and (V) to pass the suture not too apically and from the inner side in a buccal-lingual direction in the retromolar area.

Survival Analysis of Implant in Patients With Diabetes Mellitus: A Systematic Review.

AIM: To determine the survival trend of dental implants after functional loading for ≥1 year in diabetic patients. MATERIAL AND METHODS: An electronic search of the Cochrane Oral Health Group's Trials Register, Medline and Embase, plus a manual search up to December 2015 was performed. Studies assessing the survival rate of dental implants in patients with a diagnosis of diabetes mellitus were considered eligible. Screening of studies, quality assessment, and data extraction were conducted independently by 2 reviewers. Life-table analysis and Kaplan-Meier survival curves were used to evaluate implant survival and to plot the cumulative survival rate and cumulative hazard ratio. RESULTS: Seven studies, including 1142 implants were identified. The cumulative survival rate was 0.96 ± 0.10 before loading, 0.93 ± 0.10 and 0.91 ± 0.10 at 1 year, and at the end of the follow-up period, respectively. The hazard ratio was 4% during the period of osseointegration, 3% during the first year of loading, and remained constant over the 6-year follow-up. CONCLUSIONS: Patients with diabetes mellitus showed an increasing trend of implant failure during the period of osseointegration and the first year of loading.

Comparison of Conventional Methods and Laser-Assisted Rapid Prototyping for Manufacturing Fixed Dental Prostheses: An In Vitro Study.

This study assessed whether there are differences in marginal fit between laser-fusion and conventional techniques to produce fixed dental prostheses (FDPs). A master steel die with 2 abutments was produced to receive a posterior 4-unit FDPs and single copings. These experimental models were divided into three groups (n = 20/group) manufactured: group 1, Ni-Cr alloy, with a lost-wax casting technique; group 2, Co-Cr alloy, with selective laser melting (SLM); and group 3, yttria-tetragonal zirconia polycrystal (Y-TZP), with a milling system. All specimens were cut along the longitudinal axis and their adaptation was measured at the marginal and shoulder areas on the right and left sides of each abutment. Measurements were made using a stereomicroscope (×60 magnification) and a scanning electron microscope (×800 magnification). The data were analyzed using one-way analysis of variance and the Bonferroni post hoc test, with a significance cutoff of 5%. Significant differences (P < 0.05) were observed between group 3 and the other groups. The marginal opening was smallest with Co-Cr alloy substructures, while the shoulder opening was smallest with Ni-Cr alloy substructures. Within the limitations of this study, the marginal fit of an FDP is better with rapid prototyping (RP) via SLM than conventional manufacturing systems.

Histological and Histomorphometric Human Results of HA-Beta-TCP 30/70 Compared to Three Different Biomaterials in Maxillary Sinus Augmentation at 6 Months: A Preliminary Report.

OBJECTIVE: The aim of this investigation was to examine the bone regenerative potential of newly biphasic calcium phosphate ceramics (HA-ß-TCP 30/70), by assessing histological and histomorphometric results of human specimens retrieved from sinuses augmented with HA-ß-TCP 30/70, and comparing them to anorganic bovine bone (ABB), mineralized solvent-dehydrated bone allograft (MSDBA), and equine bone (EB), after a healing period of 6 months. MATERIALS AND METHODS: Four consecutive patients with edentulous atrophic posterior maxilla were included in this report. A two-stage procedure was carried out for sinus augmentation with HA-ß-TCP 30/70, ABB, MSDBA, and EB. After 6 months, specimens were retrieved at the time of implant placement and processed for histological and histomorphometric analyses. RESULTS: At histological examination, all biomaterials were in close contact with the newly formed bone and showed the same pattern of bone formation; the grafted granules were surrounded by a bridge-like network of newly formed bone. A limited number of ABB particles were partially covered by connective tissue. The histomorphometric analysis revealed 30.2% newly formed bone for Ha-ß-TCP 30/70, 20.1% for ABB, 16.4% for MSDBA, and 21.9% for EB. CONCLUSIONS: Within the limitations of the present investigation, these results support the successful use of HA-ß-TCP 30/70 for sinus augmentation.

Is erbium:yttrium-aluminum-garnet laser versus conventional rotary osteotomy better in the postoperative period for lower third molar surgery? Randomized split-mouth clinical study.

PURPOSE: Lasers have been extensively used in dentistry for several applications. We investigated and compared the use of an erbium:yttrium-aluminum-garnet laser and conventional rotary instruments for bone removal in third molar surgery. MATERIALS AND METHODS: We implemented a randomized, split-mouth clinical trial. Patients with bilateral and symmetrical third molar impaction referred to the Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, were enrolled in the study. Each patient was treated once with the erbium:yttrium-aluminum-garnet laser and once with conventional rotary instruments for bone removal during third molar surgery. Pain, swelling, and trismus were taken into account to match the 2 techniques.In addition, the times required to complete osteotomy and for the full operation were recorded. Descriptive and bivariate statistics were computed, and the P value was set at .05. RESULTS: The sample was composed of 15 patients (8 men and 7 women) ranging in age from 18 to 30 years. Pain perceived in the laser-treated group was significantly less than that in the conventional group(P = .0013). This also was true for trismus (P = .0002) and swelling. The operating time for osteotomy was longer in the laser group. CONCLUSIONS: The results of this study suggest that the laser could be an interesting alternative to conventional rotary instruments. Future studies with a larger number of patients are required to confirm the conclusions achieved from this work.