Enrico Gherlone

Osteotomy and membrane elevation during the maxillary sinus augmentation procedure. A comparative study: piezoelectric device vs. conventional rotative instruments.

OBJECTIVES The aim of the present study was to investigate in a randomized-controlled clinical trial the performance of rotary instruments compared with a piezoelectric device during maxillary sinus floor elevation. MATERIALS AND METHODS Thirteen patients who required a bilateral maxillary sinus augmentation for implant-prosthetic rehabilitation were included in this study. A within-patient control study was carried out. The osteotomy for sinus access was performed on one side of the maxilla using the piezosurgery (test sites) and on the other side using conventional rotary diamond burs (control sites). The parameters recorded were as follows: bony window length (L), bony window height (H), bone thickness (T) and osteotomy area (A)--calculated by multiplying L and H. In addition, the time necessary for the osteotomy and sinus membrane elevation as well as the number of surgical complications were calculated. RESULTS The mean length and height of the bone window were similar in both groups. The osteotomy area (A) obtained by multiplying L and H was wider in the control group (151.2 +/- 20.4 mm(2)) compared with the test group (137 +/- 24.2 mm(2)). The time necessary for the osteotomy and the sinus membrane elevation with conventional instruments was 10.2 +/- 2.4 min, while with the piezoelectric device it was 11.5 +/- 3.8 min. Moreover, membrane perforation occurred in 30% of the maxillary sinuses in the test group and in 23% of the control group. None of the differences observed between the two groups reached a level of significance. CONCLUSIONS Within the limits of the present study, it may be concluded that piezosurgery and conventional instruments did not show any differences in the clinical parameters investigated for the maxillary sinus floor elevation.

The relationship of bruxism with craniofacial pain and symptoms from the masticatory system in the adult population

The association of bruxism with craniofacial pain and symptoms of dysfunction of the masticatory system was assessed in a sample of 483 adult subjects, aged 18-75 years and selected from the general population living in the municipality of Segrate, a metropolitan area in northern Italy. Subjects were interviewed by a questionnaire about oral conditions, occurrence of symptoms of masticatory disturbances, craniofacial and neck pain. The overall prevalence of bruxism was 31;4% (95% confidence interval (CI): 27;3-35;5%). At univariate analysis bruxism was significantly associated with craniofacial pain, difficulty in closing the mouth, difficulty in opening the mouth wide or in locking the mouth, temporomandibular joint sounds, pain on movement, a feeling of stiffness or fatigue of the jaws, and neck pain. After adjustment for reciprocal influences and confounding variables, logistic regression analysis disclosed a strong independent association of bruxism with difficulty in closing the mouth (adjusted odds ratio, (OR): 2;84, 95% CI: 1;68-4;48), and a weaker relationship with craniofacial pain (adjusted OR: 1;84, 95% CI: 1;16-2;93) and temporomandibular joint sounds (adjusted OR: 1;64, 95% CI: 1;00-2;69). The findings show that in the general adult population there is a complex connection among bruxism, craniofacial pain and symptoms of masticatory disturbances. Furthermore, they suggest that the most direct relationship of bruxism may be with difficulties in mouth movements, but also an independent association may exist with craniofacial pain and other symptoms of temporomandibular disorder.

Fresh-socket implants in periapical infected sites in humans.

BACKGROUND The aim of the present study is to compare the outcome of the immediate placement of implants when used in the replacement of teeth with and without chronic periapical lesions. METHODS Thirty patients requiring a single-tooth extraction of a monoradicular or premolar tooth were selected. The control group (CG) included 15 patients without periapical lesions but with root caries and root fractures. The test group (TG) included 15 patients with periapical lesions, periapical radiolucencies, and no signs of pain, fistulas, or suppuration. Thirty teeth were extracted, and implants were immediately positioned in fresh sockets and loaded after 3 months in both groups. Clinical parameters (probing depth [PD], modified plaque index, modified bleeding index [mBI], marginal gingiva level [MGL], and keratinized mucosa [KM]) and marginal bone levels were evaluated at baseline and 12 and 24 months after implant placement. Comparisons between CG and TG values over time were performed by the Student two-tailed t test. RESULTS At the 24-month follow-up, a survival rate of 100% was reported for all implants. The mean bone loss was 0.82 +/- 0.52 mm for the CG and 0.86 +/- 0.54 for the TG. Plaque accumulation was 0.74 +/- 0.29 for the CG and 0.69 +/- 0.29 for the TG. The mBI was 0.77 +/- 0.33 for the CG and 0.72 +/- 0.36 for the TG. The soft tissue profile MGL and KM remained stable for up to 24 months for the CG and TG. The mean PD was 2.05 +/- 0.66 mm for the CG and 1.99 +/- 0.57 mm for the TG. Differences that were not statistically significant were reported between the CG and TG over time and between time points. CONCLUSION At the 24-month follow-up, endosseous implants placed immediately in extraction sites affected by periapical infection rendered an equally favorable soft and hard tissue integration of the implants, revealing a predictable outcome.

Prevalence of white-spot lesions before and during orthodontic treatment with fixed appliances

The aim of the study was to determine the prevalence of white-spot lesions (WSLs) in patients with fixed orthodontic appliances. The cross-sectional study sample consisted of three groups of patients: group I, 59 patients treated orthodontically for 6 months; group II, 64 patients treated for 12 months; group 0 (control), 68 patients examined immediately before appliance placement. All groups were treated with a 0.022-inch slot preadjusted appliance and they wore a functional fixed appliance. The presence of WSLs was evaluated by visual examination using the scoring system proposed by Gorelick. The groups were evaluated for differences in the prevalence of at least one WSL using Fishers exact test, followed by Bonferroni pairwise comparisons. The prevalence of WSLs by tooth type was evaluated with logistic regression (P < 0.05). Intraobserver agreement was assessed by means of the Cohen ĸ statistical method. There were no significant differences in the prevalence of WSLs between patients treated for 6 and 12 months (P = 0.855); however, there were significantly more WSLs in groups I and II than in group 0 (P = 0.000). No significant differences were found between girls and boys (P = 1.000). The mandibular first molars and maxillary lateral incisors were the most affected teeth, in both the treated and untreated groups. The study revealed significant decalcification at 6 months after orthodontic bonding. Considering how quickly these lesions can develop and become irreversible, early diagnosis is of critical importance.

Effect of Implant Angulation, Connection Length, and Impression Material on the Dimensional Accuracy of Implant Impressions: An In Vitro Comparative Study

BACKGROUND With regard to implant-supported prostheses, to date no technique has been proven to guarantee a completely passive fit of prosthetic frameworks. Several clinical variables may affect the precision of impressions, particularly in the presence of implants. PURPOSE To compare the accuracy of implant impressions made with different materials, lengths of impression coping connections, and not parallel position of the implants. MATERIALS AND METHODS A calibrated testing device allowing reproducible standardized positions was used. Two control groups of master models and eight experimental groups with predetermined undercuts were used to make addition silicon and polyether implant impressions by means of the open-tray pick-up technique. Four reference distances were evaluated on each study cast by using a profile projector and a standardized measurement protocol. The data were statistically analyzed by means of three-factor analysis of variance. RESULTS The impressions made in the presence of angulated implants were significantly less accurate than the ones made with parallel implants. The tested addition silicon resulted advantageous in presence of nonparallel implants whereas the polyether achieved the best results with parallel implants and standard impression copings. CONCLUSIONS The angulation of the implants may cause strains of impressions, probably because of the higher forces required for the impression removal. Moreover, undercuts negatively affected the impression accuracy. More accurate casts were obtained using the tested addition silicon in the presence of nonparallel implants and using a standard length connection of the copings in the presence of parallel implants, respectively.

Degree of conversion of three composite materials employed in the adhesive cementation of indirect restorations: A micro-Raman analysis

OBJECTIVES Adhesive luting of indirect restorations can be carried out employing dual- or light-curing materials. This in vitro study evaluated the degree of conversion (DC) of the materials employed in this procedure, seeking how the combination of time and power of curing applied during polymerisation, as well as the temperature of the light-curing composite, influenced the DC. MATERIALS AND METHODS One hundred and eighty onlays of different thicknesses (2 mm, 3 mm, 4 mm) were luted with three different composites: two dual-curing cements (Variolink II and Calibra) and a light-curing composite (Venus). The same halogen lamp was used with three different modalities selected to provide a constant quantity of energy. The time/power combinations tested were 400 mW/cm(2) for 120 s, 800 mW/cm(2) for 60s and 1200 mW/cm(2) for 40 s. The light-curing composite was employed at room temperature and after preheating at 54 degrees C. Each sample was examined in three positions using the Micro-Raman Dilor HR LabRam spectrometer to evaluate the polymer conversion degree. The data were analysed using analysis of variance and the Student-Newman-Keuls test (p=0.05). RESULTS The dual-curing materials showed average conversion percentages close to 64%, although onlays thickness clearly influence the degree of conversion, the light-curing composite showed satisfactory results only when onlays thickness was thin, however preheating significantly improved the performance of the light-curing composite under onlays of great thickness. CONCLUSIONS Optimal luting of indirect restorations is clearly dependent from light source power, irradiation time and dual-cure luting cement or light-curing composite chosen. It should be calibrated for each material to acquire high DCs. Preheating of light-curing only composites allows for the materials to reach optimal conversion degrees.

Immediate transmucosal implant placement in molar extraction sites: a 12‐month prospective multicenter cohort study

AIM To assess the clinical and radiographic outcomes of immediate transmucosal placement of implants into molar extraction sockets. STUDY DESIGN Twelve-month multicenter prospective cohort study. MATERIAL AND METHODS Following molar extraction, tapered implants with an endosseous diameter of 4.8 mm and a shoulder diameter of 6.5 mm were immediately placed into the sockets. Molars with evidence of acute periapical pathology were excluded. After implant placement and achievement of primary stability, flaps were repositioned and sutured allowing a non-submerged, transmucosal healing. Peri-implant marginal defects were treated according to the principles of guided bone regeneration (GBR) by means of deproteinized bovine bone mineral particles in conjunction with a bioresrobable collagen membrane. Standardized radiographs were obtained at baseline and 12 months thereafter. Changes in depth and width of the distance from the implant shoulder (IS) and from the alveolar crest (AC) to the bottom of the defect (BD) were assessed. RESULTS Eighty-two patients (42 males and 40 females) were enrolled and followed for 12 months. They contributed with 82 tapered implants. Extraction sites displayed sufficient residual bone volume to allow primary stability of all implants. Sixty-four percent of the implants were placed in the areas of 36 and 46. GBR was used in conjunction with the placement of all implants. No post-surgical complications were observed. All implants healed uneventfully yielding a survival rate of 100% and healthy soft tissue conditions after 12 months. Radiographically, statistically significant changes (P<0.0001) in mesial and distal crestal bone levels were observed from baseline to the 12-month follow-up. CONCLUSIONS The findings of this 12-month prospective cohort study showed that immediate transmucosal implant placement represented a predictable treatment option for the replacement of mandibular and maxillary molars lost due to reasons other than periodontitis including vertical root fractures, endodontic failures and caries.

A 4-Year Evaluation of the Peri-Implant Parameters of Immediately Loaded Implants Placed in Fresh Extraction Sockets

BACKGROUND The present study considers the correlation between the meaning of keratinized mucosa (KM) and the long-term maintenance of endosseous root-form dental implants placed in fresh sockets and immediately loaded. METHODS Twenty-nine patients requiring extractions of ≥2 teeth in the maxilla and mandible were selected. One-hundred thirty-two maxillary and 32 mandibular teeth, in the incisor, canine, and premolar regions, were extracted. Implants were positioned in fresh sockets and immediately loaded. Based on the amounts of KM, implants were categorized as follows: KM ≥2 mm (group A) and KM <2 mm (group B). Clinical parameters (probing depth, modified plaque index, modified bleeding index, and gingival index) and marginal bone levels were followed at 4 years after implant placement. Comparisons between group A and B values were performed by the Student two-tailed t test. RESULTS At 4-year follow-up, a survival rate of 100% was reported for all implants. The mean values of group B were significantly higher (P <0.05) than group A for the following parameters: gingival index (group A, 0.67 ± 0.09; group B, 1.01 ± 0.11); modified plaque index (group A, 1.18 ± 0.09; group B, 1.71 ± 0.12); and modified bleeding index (group A, 0.35 ± 0.05; group B, 0.78 ± 0.05). Gingival recession was significantly elevated in group B. In both group A and group B, up to 60% of gingival recession occurred within the first 6 months. For mean bone loss values, statistically non-significant differences were reported between groups. CONCLUSIONS At 4-year follow-up, the results suggested that the presence of mid-buccal KM is not a critical factor in the maintenance of interproximal bone level around fresh socket implants immediately loaded. Conversely, less width of KM is significantly associated with more gingival inflammation, more plaque accumulation, and more gingival recession.

Immediate Loading of Dental Implants Placed in Periodontally Infected and Non-Infected Sites: A 4-Year Follow-Up Clinical Study

BACKGROUND The aim of the present study is to compare the outcomes of immediate loading of implants in replacing teeth with and without chronic periodontal lesions at 4 years of follow-up. METHODS Thirty-seven patients were included in this study. A total of 275 implants were placed and immediately loaded in extraction sockets, 197 in periodontally infected sites (infected sites group [IG]), and 78 implants in non-infected sites (non-infected sites group [NG]). Marginal bone levels and clinical parameters (plaque accumulation and bleeding index) were evaluated at baseline and 12, 24, and 48 months after implant placement. Comparisons between IG and NG values over time were performed by the Student two-tailed t test. RESULTS At 48 months of follow-up, the IG presented a survival rate of 98.9% because two implants were lost 1 month after placement; the NG reported a survival rate of 100%. The marginal bone level was 0.79 +/- 0.38 mm for the IG and 0.78 +/- 0.38 mm for the NG, plaque accumulation was 0.72 +/- 0.41 for the IG and 0.71 +/- 0.38 for the NG, and the bleeding index was 0.78 +/- 0.23 for the IG and 0.75 +/- 0.39 for the NG. No statistically significant differences were reported between the IG and NG over time and between time points. CONCLUSION At 48 months of follow-up, dental implants that were placed and immediately loaded in periodontally infected sockets showed no significant differences compared to implants placed in uninfected sites.

Magnesium-Enriched Hydroxyapatite Versus Autologous Bone in Maxillary Sinus Grafting: Combining Histomorphometry With Osteoblast Gene Expression Profiles Ex Vivo

BACKGROUND Many biomaterials are proposed for sinus floor lifting and grafting in the posterior maxilla for insufficient bone volume (BV). The aim of this study was to compare the use of magnesium-enriched hydroxyapatite (mHA) versus autogenous bone graft (AB) for maxillary sinus lift procedures by histomorphometric and ex vivo gene expression profiling. METHODS Fifteen patients requiring bilateral maxillary sinus augmentation received autologous bone particles (group A) and mHA (group B) (split-mouth design). Five months later, implants were placed, and biopsies were obtained. Bone specimens were analyzed by histomorphometry, BV and vital bone (VB) percentages were calculated, and ex vivo osteoblast expansion followed by highly sensitive osteoblast specific gene expression profiling for cbfa1, osteocalcin, osteopontin, collagen type I, receptor activator of nuclear factor-kappa B ligand (RANKL), and osteoprotegerin (OPG) by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) were performed. Comparisons were made using the Student t test. RESULTS After healing with no complications, BV was comparable in the two groups (80.79% +/- 14.27% for autologous versus 76.72% +/- 11.47% for mHA; P = not statistically significant), but VB was lower in the mHA group (29.65% +/- 9.81% versus 78.40% +/- 16.72%; P <0.05). Real-time RT-PCR analyses showed significantly higher expression of the osteoblast differentiation factor Cbfa1 and the matrix formation marker osteocalcin in the mHA group compared to the AB group, whereas type I collagen was comparable, and osteopontin was decreased. Attesting to a lower osteoclastogenic potential, the RANKL/OPG ratio was diminished. CONCLUSIONS Autogenous bone samples provided higher vital over comparable total bone levels than mHA-grafted sites. Osteoblast gene expression profiles from mHA grafts revealed higher expression of certain specific markers of osteoblast differentiation and bone formation, associated with a lower osteoclastogenic potential.