Renzo Bassetti

The alveolar ridge splitting/expansion technique: a systematic review.

PURPOSE The aim of this systematic review was to evaluate clinical, radiological and histological outcomes of the alveolar ridge splitting/expansion technique (ARST) with or without GBR. MATERIALS AND METHODS A screening of two databases MEDLINE (PubMed) and EMBASE (OVID) and hand search of articles were performed. Human and animal studies reporting on dental implants placed with simultaneous ARST up to May 31st 2014 were considered. Quality assessment of selected full-text articles was performed according to the ARRIVE guidelines and the Cochrane collaborations tool to assess risk of bias. RESULTS Overall, 18 human and six animal studies (risk of bias: high/unclear) were included in this review. No randomized controlled trials were found. Due to the heterogeneity of study designs, definitions of success criteria, outcome variables, observation times and surgical procedures, no meta-analysis was performed. Reported survival (18 studies) and success (nine studies) rates ranged from 91.7 to 100% and 88.2 to 100%, respectively, with a mean follow-up of 1-10 years. Crestal bone level changes (∆CBL) in some studies indicate slightly higher bone loss before and after loading. Histologic and histomorphometric data from six animal studies confirm the crestal bone loss, particularly at buccal sites. CONCLUSIONS Within the limitations of this review, ARST seems to be a well-functioning one-stage alternative to extended two-stage horizontal grafting procedures. Data indicate that during healing and first year of loading, increased ∆CBL particularly at buccal sites must be anticipated. Additional horizontal GBR can help to preserve buccal bone height and width.

Piezoelectric Alveolar Ridge-Splitting Technique with Simultaneous Implant Placement: A Cohort Study with 2-Year Radiographic Results

PURPOSE Extended grafting procedures in atrophic ridges are invasive and time-consuming and increase cost and patient morbidity. Therefore, ridge-splitting techniques have been suggested to enlarge alveolar crests. The aim of this cohort study was to report techniques and radiographic outcomes of implants placed simultaneously with a piezoelectric alveolar ridge-splitting technique (RST). Peri-implant bone-level changes (ΔIBL) of implants placed with (study group, SG) or without RST (control group, CG) were compared. MATERIALS AND METHODS Two cohorts (seven patients in each) were matched regarding implant type, position, and number; superstructure type; age; and gender and received 17 implants each. Crestal implant bone level (IBL) was measured at surgery (T0), loading (T1), and 1 year (T2) and 2 years after loading (T3). For all implants, ΔIBL values were determined from radiographs. Differences in ΔIBL between SG and CG were analyzed statistically (Mann-Whitney U test). Bone width was assessed intraoperatively, and vertical bone mapping was performed at T0, T1, and T3. RESULTS After a mean observation period of 27.4 months after surgery, the implant survival rate was 100%. Mean ΔIBL was -1.68 ± 0.90 mm for SG and -1.04 ± 0.78 mm for CG (P = .022). Increased ΔIBL in SG versus CG occurred mainly until T2. Between T2 and T3, ΔIBL was limited (-0.11 ± 1.20 mm for SG and -0.05 ± 0.16 mm for CG; P = .546). Median bone width increased intraoperatively by 4.7 mm. CONCLUSIONS Within the limitations of this study, it can be suggested that RST is a well-functioning one-stage alternative to extended grafting procedures if the ridge shows adequate height. ΔIBL values indicated that implants with RST may fulfill accepted implant success criteria. However, during healing and the first year of loading, increased IBL alterations must be anticipated.

A cross-sectional analysis of the prevalence of dental anxiety and its relation to the oral health-related quality of life in patients with dental treatment needs at a university clinic in Switzerland

OBJECTIVES The aim of this observational, cross-sectional study was to analyse the relationship between dental anxiety (DA) and health-related quality of life aspects associated with oral conditions of a population with dental treatment needs in Switzerland. METHODS The measurements of DA were collected by means of two questionnaires, the Dental Anxiety Scale (DAS) and a Visual Analogue Scale (VAS). Oral health-related quality of life (OHRQoL) was assessed with the Oral Health Impact Profile (OHIP). The sample included 223 patients enrolled at a university clinic which specialises in oral prosthetic rehabilitation and temporomandibular disorders. Of them, 78.9% were at or above the age of 50. RESULTS No gender or age dependencies were observed. A comparison of answers regarding OHRQoL and DA revealed a significant interdependence (p = 0.0118); highly anxious patients were 3.55 times more likely to suffer from poor quality of life compared with less anxious ones. CONCLUSION This cross-sectional study of mostly elderly patients seeking dental treatment in Switzerland found that increased DA was associated with an impaired OHRQoL. The average DA was slightly higher than the results of other industrialised countries and the average OHRQoL was reduced.

Soft tissue grafting to improve the attached mucosa at dental implants: A review of the literature and proposal of a decision tree.

BACKGROUND Scientific data and clinical observations appear to indicate that an adequate width of attached mucosa may facilitate oral hygiene procedures thus preventing peri-implant inflammation and tissue breakdown (eg, biologic complications). Consequently, in order to avoid biologic complications and improve long-term prognosis, soft tissue conditions should be carefully evaluated when implant therapy is planned. At present the necessity and time-point for soft tissue grafting (eg, prior to or during implant placement or after healing) is still controversially discussed while clinical recommendations are vague. OBJECTIVES To provide a review of the literature on the role of attached mucosa to maintain periimplant health, and to propose a decision tree which may help the clinician to select the appropriate surgical technique for increasing the width of attached mucosa. RESULTS The available data indicate that ideally, soft tissue conditions should be optimized by various grafting procedures either before or during implant placement or as part of stage-two surgery. In cases, where, despite insufficient peri-implant soft tissue condition (ie, lack of attached mucosa or movements caused by buccal frena), implants have been uncovered and/or loaded, or in cases where biologic complications are already present (eg, mucositis, peri-implantitis), the treatment appears to be more difficult and less predictable. CONCLUSION Soft tissue grafting may be important to prevent peri-implant tissue breakdown and should be considered when dental implants are placed. The presented decision tree may help the clinician to select the appropriate grafting technique.

Is a grooved collar implant design superior to a machined design regarding bone level alteration? An observational pilot study

OBJECTIVE This retrospective observational pilot study examined differences in peri-implant bone level changes (ΔIBL) between two similar implant types differing only in the surface texture of the neck. The hypothesis tested was that ΔIBL would be greater with machined-neck implants than with groovedneck implants. METHOD AND MATERIALS 40 patients were enrolled; n = 20 implants with machined (group 1) and n = 20 implants with a rough, grooved neck (group 2), all placed in the posterior mandible. Radiographs were obtained after loading (at 3 to 9 months) and at 12 to 18 months after implant insertion. Case number calculation with respect to ΔIBL was conducted. Groups were compared using a Brunner-Langer model, the Mann-Whitney test, the Wilcoxon signed rank test, and linear model analysis. RESULTS After the 12- to 18-month observation period, mean ΔIBL was -1.11 ± 0.92 mm in group 1 and -1.25 ± 1.23 mm in group 2. ΔIBL depended significantly on time (P < .001), but not on group. In both groups, mean marginal ΔIBL was significantly less than -1.5 mm. Only insertion depth had a significant influence on the amount of periimplant bone loss (P = .013). Case number estimate testing for a difference between group 1 and 2 with a power of 90% revealed a sample size per group of 1,032 subjects. CONCLUSION ΔIBL values indicated that both implant designs fulfilled implant success criteria, and the modification of implant neck texture had no significant influence on ΔIBL.

The patent nasopalatine duct: a potential cause of unclear pain in the anterior maxilla.

OBJECTIVE The aim of this report is to describe symptoms that can suggest the presence of a patent nasopalatine duct and to illustrate three cases. SUMMARY Patent nasopalatine ducts connecting the oral cavity with the nasal cavity are extremely rare. This malformation can be considered a developmental abnormality. Clinically, patent nasopalatine ducts appear as single or double spherical or oval apertures lateral or posterior to the incisive papilla. This type of anatomical malformation can be associated with an unclear pain sensation in the anterior maxillary region, which may be misinterpreted for example as toothache of endodontic origin. However, persisting nasopalatine ducts can also exist as an asymptomatic abnormality with no clinical sign of discomfort. Accordingly, understanding the differential diagnosis of a possible patent nasopalatine duct can prevent a general practitioner from performing unnecessary interventions, such as endodontic treatments, apical surgeries, or tooth extractions.

Immediate implant placement in mandible and prosthetic rehabilitation by means of all-zirconium oxide restorations: case report of a woman with a history of periodontitis.

Owing to its single surgical intervention, immediate implant placement has the advantage of shortening treatment time, and thus positively affects patient morbidity. According to the bone resorption pattern after tooth extraction, bone loss should be anticipated if immediate implant placement is considered. The present case report aims to present a possible treatment option and to demonstrate that a partially edentulous arch may be rehabilitated esthetically by immediate implant placement and by corresponding anticipatory measures.

Implant-Assisted Removable Partial Denture Prostheses: A Critical Review of Selected Literature

PURPOSE A critical review of selected relevant publications assessed clinical efficacy and effectiveness of implant-assisted removable partial dentures (IARPDs) with implant survival and failure rates, biologic and technical complications, and maintenance and patient satisfaction after rehabilitation as outcomes. MATERIALS AND METHODS Screening of three databases (Medline [PubMed], Embase [OVID], and the Cochrane Library [CENTRAL]) and a manual search of related articles were performed. Reports on outcomes from human studies conducted between 1 January 1980 and 31 May 2016 were considered. A quality assessment of the identified full-text articles was performed to assess risk of bias and to evaluate heterogeneity. RESULTS Only nine studies were included, and all nine demonstrated high risk of bias. The mean observation period ranged from 1 to 10 years, and only four studies included at least one control group. The studies reported implant survival rates of 91.7% to 100%, abutment tooth survival rates of 79.2% to 100%, and prosthesis survival rates of 90% to 100%. Approximal peri-implant crestal bone level changes (ΔCBL) ranged from -0.17 to -2.2 mm. IARPDs were associated with a higher frequency of technical complications and maintenance interventions than biologic complications. Only two question-based studies assessed patient satisfaction before and after treatment, and both reported marked improvement. A meta-analysis was not possible because of substantial heterogeneity in study design. CONCLUSION Limited availability of robust publications related to the selected review topic precluded significant conclusions. Nonetheless, the preliminary assessment suggests that IARPDs are a simple and cost-effective approach to providing symmetric prosthesis support and stability, plus improved patient satisfaction.

Are there differences in the changes in oral-health-related quality of life (OHRQoL) depending on the type (rigidity) of prosthetic treatment?

OBJECTIVE This prospective pilot study investigated differences in changes in oral-health-related quality of life (OHRQoL) depending on the prosthetic treatment type (rigidity). METHOD AND MATERIALS Sixty participants seeking prosthetic treatment were included. The following data were collected before (T1) and 4 weeks after completion of prosthetic treatment (T2): OHRQoL (OHIP-G14) and dental status, categorized in terms of rigidity of the denture as fixed dental prosthesis (FDP, maximal rigidity), removable partial denture prosthesis (RPD, medium rigidity), or complete dentures (CDs, minimal rigidity). After prosthetic treatment, there were three groups of 20 participants: group 1, change in dental status to less rigid; group 2, equally rigid; group 3, more rigid restorations. Data were evaluated using nonparametric statistical test methods and power analysis. The minimally important difference (MID) of two OHIP-G14 units was determined to be clinically relevant. RESULTS At T1, 20 participants had FDP, 18 RPD, and 22 CD; at T2, 10 had FDP, 37 RPD, and 13 CD. Overall, average OHIP-G14 values improved clinically relevantly and statistically significantly (P < .001) with treatment. OHRQoL improved more in group 3, with a median of 8 (IQR 14.75; P = .002), than in group 2, with 2.5 (IQR 9.5; P = .033), or group 1, with 4.5 (IQR 16.5; P = .116). Applying MID, all groups improved clinically significantly. Compared to groups 1 and 2, group 3 improved clinically more significantly. CONCLUSION OHRQoL improved with prosthetic treatment. A patient-customized treatment regime seems as important as prosthesis type (rigidity).

Factors Associated with Bone Level Alterations at Implants with Inner-Cone Connection and Platform Switching

Purpose. This retrospective cohort study evaluated factors for peri-implant bone level changes (ΔIBL) associated with an implant type with inner-cone implant-abutment connection, rough neck surface, and platform switching (AT). Materials and Methods. All AT placed at the Department of Prosthodontics of the University of Bern between January 2004 and December 2005 were included in this study. All implants were examined by single radiographs using the parallel technique taken at surgery (T0) and obtained at least 6 months after surgery (T1). Possible influencing factors were analysed first using t-test (normal distribution) or the nonparametric Wilcoxon test (not normal distribution), and then a mixed model q variance analysis was performed. Results. 43 patients were treated with 109 implants. Five implants in 2 patients failed (survival rate: 95.4%). Mean ΔIBL in group 1 (T1: 6–12 months after surgery) was  mm and  mm in group 2 (T1: >12 months after surgery) (). Greater implant insertion depth in diameter 3.5 mm implants might be associated with increased ΔIBL (). In the anterior region, the bone alteration was more pronounced (). Conclusions. ΔIBL values indicated that the implant system used in this study fulfilled implant success criteria.