The ‘double-barrel’ approach to the removal of dental implants from the maxillary sinus

The purpose of this article is to present a new surgical technique – the double-barrel approach – employed for the extraction of dental implants from the maxillary sinus, and to compare it with the classic canine fossa puncture (CFP). The surgical steps in the performance of the double-barrel approach (DBA) are systematically described. In order to compare the two techniques (CFP versus DBA), a prospective, randomized study was carried out between 2004 and 2011, comparing the length of duration of the procedure and the incidence of adverse effects. The average duration was 6.3 ± 5.2 min for the DBA group and 14.8 ± 8.4 min for the CFP group (P = 0.0001, Mann–Whitney test). Nevertheless, the incidence of adverse effects within the first postoperative week did not differ between the two groups. We have demonstrated that the double-barrel approach is faster, has the same incidence of adverse effects, provides excellent visualization, and permits a more accurate withdrawal of implants in comparison with the classic CFP. It is minimally invasive, requires no sutures, and minimizes the risks to local vascular and neural structures.     

Endoscopic sinus surgery for dental implant displacement into the maxillary sinus—a retrospective clinical study

The aims of this retrospective clinical study were to present our management protocol for the retrieval of impacted dental implants that have become displaced into the maxillary sinus cavity and to define the role of endoscopic sinus surgery in this setting. All 24 patients (25 implants) who underwent surgical retrieval of dental implants displaced into the maxillary sinus between 2012 and 2019 were included. Data on surgical interventions and complications were collected retrospectively. Eleven patients (46%) had chronic sinusitis associated with the migrated implant. All implants were successfully retrieved via transnasal endoscopic approach alone: 80% via a middle meatal antrostomy and 20% via a combined middle and inferior meatal antrostomy. Five patients required a concomitant transoral approach for oro-antral fistula repair. None required a transoral approach for displaced implant retrieval. All patients healed uneventfully without complications. Transnasal endoscopic sinus surgery via a middle meatal antrostomy or a combined middle and inferior antrostomy is recommended as the primary choice for dental implant retrieval from the maxillary sinus. A transoral approach should be performed simultaneously only for oro-antral fistula repair. This surgical protocol proved to be safe and efficient, and it obviated the need for osteotomies of the anterolateral maxillary wall.     

Adenoid cystic carcinoma of the maxillary sinus: a clinical–pathological report of 10 years of experience from a single institution

Adenoid cystic carcinoma (ACC) is the most common malignant salivary gland tumour of the maxillary sinus. The present study describes 24 cases seen over a period of 10 years at the Brazilian National Cancer Institute. Socio-demographic, clinical, pathological, and follow-up data were retrieved from the medical files for the period 1997–2006. The mean age of the patients was 51.1 years. Twenty-one (87.5%) presented advanced tumours. The main signs and symptoms found were a tumour mass (87.5%), pain (50%), nasal obstruction (25%), and epistaxis (20.8%). Most cases (62.5%) were treated with surgery and radiation therapy. Follow-up data showed two patients (8.3%) with residual disease, local recurrences in four (16.7%) patients, and distant metastasis in five (20.8%). The overall 5- and 10-year survival rates were 72.61% and 62.11%, respectively. Maxillary sinus ACC has an aggressive but indolent behaviour, typically presenting at an advanced T stage that reflects a poor prognosis for patients.     

Can degradation products released from dental implants affect peri‐implant tissues?

This study aimed to assess the literature available on the effects, on peri‐implant tissues, of degradation products released from dental implants as a consequence of therapeutic treatment for peri‐implantitis and/or of wear‐corrosion of titanium. A literature review of the PubMed medline database was performed up to December 31, 2016. The following search terms were used: “titanium wear and dental implant”; “titanium corrosion and dental implant”; “bio‐tribocorrosion”; “peri‐implantitis”; “treatment of peri‐implantitis”; “titanium particles release and dental implant”; and “titanium ion release and dental implant”. The keywords were applied to the database in different combinations without limits of time period or type of work. In addition, the reference lists of relevant articles were searched for further studies. Seventy‐nine relevant scientific articles on the topic were retrieved. The results showed that pro‐inflammatory cytokines, infiltration of inflammatory response cells and activation of the osteoclasts activity are stimulated in peri‐implant tissues in the presence of metal particles and ions. Moreover, degenerative changes were reported in macrophages and neutrophils that phagocytosed titanium microparticles, and mutations occurred in human cells cultured in medium containing titanium‐based nanoparticles. Debris released from the degradation of dental implants has cytotoxic and genotoxic potential for peri‐implant tissues. Thus, the amount and physicochemical properties of the degradation products determine the magnitude of the detrimental effect on peri‐implant tissues.     

Patient satisfaction 8–14 years after dental implant therapy – a questionnaire study

Objective: The aim of this questionnaire study was to investigate patient satisfaction 8–14 years after dental implant therapy and complications influencing the degree of satisfaction.

Materials and methods: A questionnaire was sent by post to 587 patients at a specialist clinic of periodontology. The questionnaire consisted of 19 statements or questions such as the degree of satisfaction with the implants and knowledge of complications. In nine of the questions, respondents were asked to grade the extent of their agreement with a statement by selecting from fixed answers. Three of the questions were designed to be answered using a visual analog scale.

Results: In total, 400 individuals (81%) responded to the questionnaire. The mean time elapsed since implant installation was 10 years. A great majority (81%) experienced a high chewing comfort and was satisfied or sufficiently satisfied (94%) with the aesthetic aspects of their implant restorations, while 32% of the individuals had experienced problems with their implant reconstructions. The disadvantage that patients remarked on was the cost of the treatment. Those who had experienced problems with their implant reconstructions were also less satisfied with the treatment.

Conclusion: A great majority of the patients expressed a high degree of satisfaction with their dental implants 8–14 years after the treatment. Patients were less satisfied if they had experience of problems with their implant reconstructions and in cases when the clinicians were unable to resolve their complications.     

Influence of crown–implant ratio on implant success rate of ultra-short dental implants: results of a 8- to 10-year retrospective study

Clinical Oral Investigations - The use of short implants has been suggested in recent years as an option for facilitating prosthetic restoration in resorbed jawbones. The aim of the present study...     

Aesthetic aspects of adjacent maxillary single-crown implants—influence of zirconia and titanium as implant materials

The purpose of this retrospective survey was to assess the esthetic aspects of adjacent zirconia and titanium implants in the anterior maxillary area. A total of 40 patients and 109 adjacent implants (17 patients with 47 titanium implants and 23 patients with 62 zirconia implants) was included. The primary aim of this survey was to assess the papillary fill (Jemt score). Additionally, further esthetic aspects were assessed. Papillae were fully present (Jemt score 3) around 39.1% of adjacent zirconia implants and 17.4% of adjacent titanium implants (p < 0.01). The papilla deficit was significantly higher 1.64 mm (SD 1.35) around titanium compared to zirconia implants 0.92 mm (SD 0.94, p < 0.01). The evaluation of the soft tissue recessions revealed no differences between implant materials, whereas titanium implants presented more visible implant shadows (p < 0.01). Zirconia implants had more implants with papillae that filled the entire proximal space compared to titanium implants. Furthermore, titanium implants had a greater frequency of visible implant shadowing than the zirconia implants. Esthetic rules such as the interdental contact area and golden percentage rules did not differ significantly between the titanium and zirconia implants.     

Are mucous retention cysts and pseudocysts in the maxillary sinus a risk factor for dental implants? A systematic review

Background Mucous retention cysts and pseudocysts of the maxillary sinus are benign lesions present in up to 13% of adult patients. Different surgical approaches for sinus lift and dental implant placement in the presence of these lesions have been proposed. Material and Methods A systematic review was performed following the PRISMA statement recommendations to answer the PICO question: Does the aspiration or removal of mucous retention cysts/pseudocysts before or during sinus lifting and dental implant placing, affect the survival of the implants? The study was pre-registered in PROSPERO (CRD42020185528). Included articles quality was assessed using the “NIH quality assessment tool” and “The Newcastle-Ottawa scale”. Results Previous literature in this field is scarce and with a low level of evidence. There are no randomized prospective studies. Only 19 studies were identified, being composed of 2 cohort studies and 17 case series/reports. These studies involved 182 patients with a previous history of mucous retention cyst or pseudocyst in 195 maxillary sinuses where 233 implants were placed. The mean age of the patients was 45.5 (range: 12-80 years); 122 (67%) were male patients and 60 (33%) were female patients. The mean follow-up of the patients was 17.6 (range: 4-90 months). Only two fail was reported. No differences were identified in relation to the surgical approach or in relation to the removal/aspiration of the sinus lesion (prior to or simultaneous to sinus grafting) or not. Conclusions The level of evidence was grade 4 according to the CEBM and further studies are needed to confirm this observations, but with the available data, dental implants placement after sinus lift procedure in patients with mucous retention cysts and pseudocysts seems to be safe and present high survival regardless on the removal of the lesion or not. Key words:Dental implants, maxillary sinus, sinus lift, mucous retention cyst, pseudocyst.     

Chair-side generated posterior lithium disilicate crowns after 4 years

Objectives

The objective of this prospective clinical study was to evaluate the performance of chair-side generated crowns after 48 months.

Materials and methods

Forty-one posterior full contour crowns made of a machinable lithium disilicate ceramic (e.max CAD LT) were inserted in 34 patients applying a chair-side CAD/CAM technique. One crown per patient was randomly selected for evaluation at baseline, after 6, 12, 24, 36, and 48 months according to modified US Public Health Service criteria.

Results

After a mean observation time of 51 months (min, 48 months; max, 56 months; SD?±?2.3 months), 29 crowns were available for re-examination. Within the observation period, one failure occurred due to a crown fracture after 2.8 years. Four abutment teeth revealed signs of biological complications: Two abutment changed sensibility perception from positive to negative within the first 13 month. Two abutment teeth showed secondary caries below the crown margin, one after the 24, and another after the 48 month recall. Both abutments received cervical adhesive composite fillings. The failure-free rate was 96.3 % after 4 years according to Kaplan–Meier (CI: upper bound, 4.4 years; lower bound, 4.7 years).

Conclusions

Due to the fact that the secondary caries was not caused as a result of an inaccuracy of the crown margins and the endodontic complications were in a normal range, the clinical performance of the crowns was completely satisfying.

Clinical relevance

The chair-side application of lithium disilicate crowns can be recommended.     

In vitro fit of CAD-CAM complete arch screw-retained titanium and zirconia implant prostheses fabricated on 4 implants

Statement of problem

Computer-aided designed and computer-aided manufactured (CAD-CAM) titanium and zirconia implant-supported fixed implant prostheses on 4 implants have become popular. The precision and accuracy of their interface fit has not been widely researched.

Immediate function dental implants inserted with less than 30 N·cm of torque in full-arch maxillary rehabilitations using the All-on-4 concept: retrospective study

The aim of this retrospective clinical study was to evaluate the short-term implant success rate and marginal bone loss in full-arch fixed prosthetic maxillary rehabilitations supported by implants in immediate function with the All-on-4 treatment concept placed with insertion torque of <30 N·cm or ≥30 N·cm. This study included 83 patients (69 female, 14 male) with 332 implants placed (120 inserted with <30 N·cm and 212 inserted with ≥30 N·cm) who were treated between January 2010 and March 2013. Outcome measures were implant success and marginal bone loss at 1 year of follow-up. Ten patients (12.0%; 13 implants inserted with <30 N·cm and 27 implants with ≥30 N·cm) were lost to follow-up. The cumulative implant success rate was 97.5% at the patient level, and 98.3% for implants inserted with <30 N·cm and 97.5% for implants inserted with ≥30 N·cm. The mean ± standard deviation marginal bone loss at 1 year was 1.14 ± 0.38 mm for implants inserted with <30 N·cm and 1.39 ± 0.49 mm for implants inserted with ≥30 N·cm (significant difference; P < 0.001, Wilcoxon signed rank test). These results indicate that implants with insertion torques of <30 N·cm may render comparable success rates and marginal bone loss at 1 year compared to implants inserted with insertion torques of ≥30 N·cm.     

Systematic review of short- (5–10 years) and long-term (10 years or more) survival and success of full-arch fixed dental hybrid prostheses and supporting implants

Objectives

The aim of this systematic review was to investigate the short-term (5–10 year mean follow-up) and long-term (10 year or more) survival and success of fixed full arch dental hybrid prosthesis and supporting dental implants.

Methods

Studies reporting interventions with full-arch fixed dental hybrid prostheses were identified by searching PubMed/Medline (NCBI), Web of Science (Thomson Reuters), the Cochrane Register of Controlled Clinical Trials (EBSCO), and Dentistry and Oral Sciences Source (DOSS; EBSCO) from the earliest available dates through July 17, 2013. Through a series of review process by two examiners, potentially qualifying studies were identified and assessed with respect to the inclusion criteria.

Results

A total of 18 studies were included for the quality assessment and the systematic review. Within the limitation of available studies, high short-term survival rates of full arch fixed dental hybrid prostheses (93.3–100%) and supporting implants (87.89–100%) were found. However, the availability of studies investigating long-term outcomes seemed scarce. Furthermore, the included studies were subjected to potential sources of bias (i.e. publication, reporting, attrition bias).

Conclusions

Despite seemingly high short-term survival, long-term survival of implant supported full arch fixed dental hybrid prosthesis could not be determined due to limited availability of true long-term studies. Although it may be a valuable option for a patient with a completely edentulous ridge(s), the strategic removal of teeth with satisfactory prognosis for the sake of delivering an implant supported full-arch dental hybrid prosthesis should be avoided.     

Tooth wear in maxillary anterior teeth from 14 to 23 years of age

Using a planimetric method, the size of horizontal wear facets on maxillary anterior teeth was studied longitudinally in the permanent dentition of 35 subjects at ages 14, 18, and 23?years. The study subjects had not previously undergone any orthodontic treatment and had Class I occlusion. We studied the association between the amount of wear and reported parafunctions and maximal bite force. Total wear areas in age groups 14, 18, and 23?years were 29.5?mm² (SD 11.4), 39.1?mm² (SD 12.7), and 45.0?mm² (SD 13.0), respectively. The total wear area increased significantly both from 14 to 18?years of age and from 18 to 23?years of age (p<0.0001). Between 18 and 23?years of age, the maxillary canines showed strongest wear, although the central incisors had largest wear facets. It can be concluded that wear of permanent anterior teeth is a continuous phenomenon in adolescence and young adulthood.     

Short implants (≤8 mm) compared to standard length implants (>8 mm) in conjunction with maxillary sinus floor augmentation: a systematic review and meta-analysis

The objective was to test the hypothesis of no difference in the treatment outcome after the installation of short implants (≤8 mm) in the posterior part of the maxilla compared to standard length implants (>8 mm) in conjunction with maxillary sinus floor augmentation (MSFA) using the lateral window technique, after an observation period of ≥3 years. A search of the MEDLINE, Embase, and Cochrane Library databases, in combination with a hand-search of relevant journals, was conducted. The search yielded 1102 titles. Finally, three studies that fulfilled the inclusion criteria were included. All were considered to have a low risk of bias. Meta-analyses revealed no significant differences in implant survival or peri-implant marginal bone loss between the two treatment modalities. However, the use of standard length implants in conjunction with MSFA was characterized by a tendency towards more peri-implant marginal bone loss. There was no statistically significant difference between the two treatment modalities with regard to overall patient satisfaction. Short implants seem to be a suitable alternative to standard length implants in conjunction with MSFA. However, further randomized controlled trials with larger patient samples and an observation period of more than 3 years are needed before one treatment modality might be considered superior to the other.     

The antibacterial effect of gas ozone after 2 months of in vitro evaluation

The aim of this study was to evaluate the effect of HealOzone on two microorganisms, 4 and 8 weeks after treatment, using a tooth cavity model. Four groups of caries-free third molars (n = 12) were used (A, B, C and D). Three cavities were prepared into each tooth. After sterilization, groups A and B were inoculated with Streptococcus mutans, and groups C and D, with Lactobacillus casei for 48 h. One cavity of each tooth was used to evaluate the infection. After inoculation, groups B and D were treated with ozone (60 s), and groups A and C were used as controls. Then, the two cavities of each tooth were filled with composite, and the teeth were stored in sucrose medium. The restorations were removed after 4 and 8 weeks, respectively; dentin chips were collected, and the amount of microorganisms was determined. Ozone treatment reduced significantly the amount of S. mutans compared to the control group (p ≤ 0.05). This antibacterial effect was able to be seen after 4 (p = 0.0005) and 8 (p = 0.0002) weeks. No significant difference was found between the control and treated group as far as L. casei is concerned (p > 0.05). HealOzone (60 s) can provide some antibacterial treatment against S. mutans even after 8 weeks. However, an elimination of the microorganisms through HealOzone seems not to be possible. L. casei was more resistant to ozone. Although ozone exerts a significant antibacterial effect against S. mutans, it is probably not enough as the only antibacterial method, during the fillings therapy.