Effect of denture adhesives on masticatory performance: Multicenter randomized controlled trial.

PURPOSE: The purpose of this study is to investigate the effects of denture adhesives on masticatory performance via a 10-center, parallel, randomized, controlled trial of complete denture wearers in Japan. METHODS: The trial was conducted between September 2013 and October 2016. The inclusion criteria were complete edentulism, willingness to undergo new complete denture treatment, and willingness to return for recall treatment. The exclusion criteria were age 90 years or older, presence of severe systemic illness, inability to understand the questionnaires, wearing metal base complete dentures, denture adhesive user, wearing prosthetics for maxillofacial defects, wearing complete dentures with tissue conditioners, and severe xerostomia. Randomization of the powder-type denture adhesive (powder), cream-type denture adhesive (cream), and control (saline) groups was performed using a sealed envelope system. Masticatory performance was measured using color-changeable chewing gum. Intervention blinding was not feasible. RESULTS: Sixty-seven control, 69 powder, and 64 cream participants are analyzed using the intention-to-treat principle. The participants in all groups show significantly improved masticatory performance at post-intervention (paired t-test with Bonferroni correction P < 0.0001). However, no significant difference in masticatory performance is detected among the three groups (one-way analysis of variance). A significant negative correlation between pre- and post-changes in masticatory performance and intraoral condition scores is observed (Pearson's correlation coefficient, P < 0.0001). CONCLUSIONS: Although denture adhesives improved the masticatory performance of complete denture wearers, their clinical effects are comparable to those of saline solution. The use of denture adhesives is more effective in complete denture wearers with unsatisfactory intraoral conditions.

Effects of denture adhesives on denture retention and occlusal forces in complete denture wearers: A multicenter, randomized controlled trial.

PURPOSE: This study aimed to determine the effects of denture adhesives on denture retention and occlusal force in complete denture wearers in a multicenter, randomized, parallel-group controlled trial. METHODS: Two hundred edentulous patients wearing complete dentures were allocated to three groups: powder-type denture adhesive, cream-type denture adhesive, and control (saline solution). Denture adhesives and saline solution were applied to the dentures for 4 days. The retentive force of the dentures and occlusal force were measured using a force transducer occlusal force meter at baseline and after 4 days of intervention. In addition to between-group comparisons, subgroup analyses of denture retention and occlusal force were performed based on the level of difficulty of the edentulism treatment. The levels were ranked as I (easy), II, III, and IV (difficult). RESULTS: Cream-type denture adhesives significantly improved the retentive force of the dentures (P<0.01) and occlusal force (P<0.05), with no significant differences between baseline and post-intervention forces in the powder-type denture adhesive and control groups. In within-group comparisons, cream-type denture adhesives improved both the retentive and occlusal forces at Level II (P<0.05), and powder-type denture adhesives improved the occlusal force at Level II (P<0.01). CONCLUSIONS: Application of cream-type denture adhesives effectively improves the denture retention and occlusal force in complete denture wearers with a moderate degree of difficulty during edentulism treatment.

Multivariate analysis reveals oral health-related quality of life of complete denture wearers with denture adhesives: a multicenter randomized controlled trial.

Purpose To investigate the difference in improvement of oral health-related quality of life (OHR-QoL) depending on the oral and denture conditions of a complete denture wearer when using a cream or powder type denture adhesive in a 10-center parallel randomized clinical trial.Methods Two hundred edentulous subjects who wore complete dentures were allocated to each of the three groups according to denture adhesive type: cream, powder, and control (saline solution). The materials were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention were collected. OHR-QoL was assessed using the Japanese version of the modified Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) scale for outcome. Multivariate analysis was used to investigate improvements in OHR-QoL according to participant characteristics among complete denture wearers using these materials.Results OHIP-EDENT-J scores were significantly decreased in all groups after the intervention (p < 0.05); however, there were no statistically significant differences among the groups. Multiple logistic regression analysis revealed a significant association between the vertical height of the maxillary and mandibular alveolar ridge and OHIP-EDENT-J scores in the cream-type denture adhesive group. In contrast, there were no significant association between participant characteristics and OHIP-EDENT-J scores in the powder-type adhesive and control groups.Conclusions The use of denture adhesives could improve OHR-QoL for complete denture wearers. The cream-type denture adhesives may be expected to improve OHR-QoL in patients with poor residual ridge conditions compared with patients with good residual ridge conditions.

Effect of denture adhesives on oral moisture: A multicenter randomized controlled trial.

PURPOSE: The purpose of this study was to investigate the effect of denture adhesives on oral moisture in a 10-center parallel randomized clinical trial. METHODS: Two hundred edentulous subjects wearing complete dentures were allocated into three groups: cream-type adhesive, powder-type adhesive and control groups. The adhesives (and saline solution in the control group) were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention for eight meals over 4 days were obtained. For the main outcome, oral moisture was measured with a moisture checking device. Secondary outcomes were denture satisfaction, masticatory performance, denture retention, and occlusal force. In addition to between-group and within-group comparisons of oral moisture, investigations for secondary outcomes were undertaken in subgroups classified according to the degree of oral moisture at baseline (normal subgroup and dry mouth subgroup). Intention-to-treat analysis was also performed. RESULTS: Between-group and within-group comparisons of oral moisture showed no significant differences. The cream-type and powder-type denture adhesives were significantly effective in the dry mouth group for denture satisfaction ratings of ability to masticate, stability, retention, and comfort of mandibular dentures (p<0.05). The masticatory performance and retentive force of the dry mouth denture adhesive using groups were significantly improved after intervention (p<0.05). CONCLUSIONS: The oral moisture of complete denture wearers was not influenced by the use of denture adhesives. Our findings showed that denture adhesives improved subjective denture satisfaction, masticatory performance, and retention for complete denture patients with oral dryness.

Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures: the Denture Adhesive Guideline trial: study protocol for a randomized controlled trial.

BACKGROUND: Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application. METHODS: This ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. DISCUSSION: This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries. TRIAL REGISTRATION: ClinicalTrials.gov NCT01712802 . Registered on 17 October 2012.

Influence of Occlusal Force on Electroencephalograms in Edentulous Patients.

PURPOSE: This study explored the effect of improved occlusal force resulting from complete denture treatment on electroencephalogram (EEG) findings to determine if such an outcome is a factor contributing to activation of synaptic/neuronal dysfunction in the brain. MATERIALS AND METHODS: Twenty-three individuals with complete upper and lower dentures who visited the Department of Removable Prosthodontics at Tsurumi University Dental Hospital were included in this study. The Dental Prescale Occluzer FPD-705 system was used to perform an objective measurement of occlusal force before and after denture treatment. EEGs were recorded for 3 minutes in patients receiving complete dentures before and after denture treatment. Then, Dα values were calculated using a diagnosis method of neuronal dysfunction analysis to evaluate changes in synaptic/neuronal dysfunction of the brain. To investigate whether occlusal force affects Dα, Spearman's rank correlation coefficient (α = 0.05) was used to test the association between occlusal force (N) and Dα based on the rates of change in occlusal force and Dα calculated by dividing the measurement values after denture treatment by the measurement values before denture treatment. RESULTS: Medial occlusal force increased from 184.9 N before treatment to 277.2 N after treatment. A statistically significant increase in occlusal force (p < 0.05) was observed, with a total of 22 participants exhibiting increased occlusal force after denture treatment. The medial Dα value increased from 0.943 before treatment to 0.957 after treatment. A statistically significant increase in Dα (p < 0.05) was observed, and a total of 19 participants exhibited increased Dα values after denture treatment. The regression line was calculated as Y = 14.049X - 12.450. As occlusal force increased, Dα values increased as well. A significant positive correlation was observed between occlusal force and Dα (r = 0.498, p < 0.05). CONCLUSIONS: A positive correlation was observed between improved occlusal force attained via complete denture treatment and the activation of Dα. This finding reveals occlusal force as a denture treatment outcome that contributes to the activation of synaptic/neuronal dysfunction in the brain.

Investigation of trends and characteristics in patients with obstructive sleep apnea.

BACKGROUND: Oral appliance (OA) therapy for obstructive sleep apnea (OSA) has only been part of Japan's National Health care coverage plan since 2004. Subsequently, not enough time has passed to establish the medical trends and characteristics of OSA patients in Japanese Dental Hospitals. AIM: The aim of this study was to investigate the medical trends and the characteristics in patients with OSA who visited our clinic, and to compare our findings with previous studies. SETTING AND DESIGN: Epidemiological survey (retrospective study). MATERIALS AND METHODS: Two hundred and one patients were recruited at the Internal Medicine Division in the Tsurumi University Dental Hospital from February 2006 to December 2008, consecutively. Patients received a medical interview, and a detailed sleep analysis that included a polysomnography (PSG) to verify the exact nature of their condition. The efficacy of OA was assessed in 49 patients who wore an OA and underwent PSG. RESULTS: Of all subjects, 141 patients visited the Prosthodontic Division to receive OA therapy, 38 patients were treated or received a follow up examination in the Internal Medicine Division. The dropout rate was 10.4% in the all subjects, 17.0% in patients who visited the Prosthodontic Division. The male-to-female ratio was 3.3:1, 3.0:1 in patients who visited the Prosthodontic Division. In addition, females had a lower rate of OAS severity than males. In our patients, the major complication was hypertension and cardiac disease. The success rate of OA was 75.5%. CONCLUSION: This approach allowed us to reveal some of the trends and characteristics in our patients.

Survey on use of titanium dentures in Tsurumi University Dental Hospital for 11 years.

PURPOSE: The purpose of this study was to survey the production of titanium dentures in Tsurumi University Dental Hospital and to study the actual use of titanium dentures in our university. METHODS: The survey was based on the metal base dentures produced at Tsurumi University Dental Hospital during an 11-year period between April 1995 and March 2006, with relation to the types of metals used in the dentures, types of dentures, dental condition, and the number of artificial teeth. RESULTS: 1871 metal base dentures were produced in the study period. The dentures consisted of 1290 cobalt-chromium alloy dentures (68.9%), 350 titanium dentures (18.7%) and 231 platinum-added gold alloy dentures (12.3%). Within the titanium denture groups, 132 were complete dentures (37.7%), 55 were complete overdentures (15.7%) and 163 were removable partial dentures (46.6%). JIS type 3 pure titanium was used in the titanium base of 252 dentures (72.0%). The average number of artificial teeth was 10.9, which was the highest among the three types of metal bases, exhibiting significant differences (P<0.01). CONCLUSION: Approximately 32 titanium dentures per year on average were delivered at our university and they were applied to almost edentulous arch compared with the other metal base dentures.

Implant overdenture using Konus telescope on one-piece implant: a case report.

An implant-retained Konus (tapered double crown) telescopic complete overdenture was fabricated for a mandibular edentulous patient. The Konus telescopic overdenture coping crowns and framework assembly were cast with commercially pure (CP) titanium, joined using laser welding and placed on four one-piece implants. Sufficient retention and stability were obtained using this method.

A new retainer using magnetic attachment.

PATIENT: A 58-year-old man with a complaint of masticatory disturbance presented. His mandibular left premolars and molars were missing, and the mandibular left canine, which was neighboring to the missing part, showed marked labial tipping. A cobalt-chromium removable partial denture was fabricated using a new magnetic attachment retainer because it seemed difficult to apply a conventional clasp for this case. This retainer is constructed from the buccal hook arm sliding bucco-lingually and the magnetic attachment which works to lock the movable part when it was closed. Six years after the delivery of this denture, both the abutment tooth and the periodontal tissue are healthy, and the denture is functioning well. DISCUSSION: As this retainer does not use the elasticity of clasp arms, block out area can be minimized, and the maximum area of the contacting surface of the hook arm brings about very positive retention and bracing. The function of attractive force is to resist the splitting force and not to become directly involved in the retention of the denture. Therefore, the attractive force for this system does not need to be very strong. This system also provides the advantages of a sectional denture, allowing protection of the abutment tooth and the use of the abutment tooth in its original form. CONCLUSION: The retainer described in this report has many advantages including, no hazardous lateral force, adequate retentive force, and application to natural teeth or tipped teeth.

Effect of implant support on distal-extension removable partial dentures: in vivo assessment.

PURPOSE: The use of a limited number of implants for support of a removable partial denture (RPD) changes a Kennedy Class I or II situation to that of a Class III. This in vivo pilot study evaluated implant-supported distal-extension removable partial dentures (RPD) in 5 partially edentulous patients. MATERIALS AND METHODS: Two implants (Brånemark TU MK III, Nobel Biocare) were placed in a mandibular Kennedy Class I arch. To fabricate an implant-supported RPD (ISRPD), a conventional RPD base was fitted to the healing abutment with autopolymerizing acrylic resin (Uni-fast II, GC) to support the posterior aspect of the RPD. By changing the healing abutment to a healing cap, there was no connection between the denture base and implant, and the ISRPD became a conventional RPD (CRPD). Using a crossover study design, the masticatory movements (mandibular movements during mastication) of both dentures were measured using a commercially available tracking device (BioPACK, Bioresearch, Japan). The occlusal force and contact area were also measured using pressure-sensitive sheets and an image scanner (T-scan system). Using a visual analog scale (VAS), the 4 criteria of comfort, chewing, retention, and stability were evaluated. All the data obtained were analyzed using Wilcoxen signed rank tests (alpha = .05). RESULTS: There were no significant differences (P > .05) in masticatory movements between the ISRPD and the CRPD (5 patients: 4 women, 1 man). However, the ISRPD had significantly greater force and greater area than the CRPD (P = .043). The center of occlusal force of the ISRPD tended to move more distally compared to the CRPD. All the patients preferred the ISRPD for comfort, chewing, retention, and stability. CONCLUSIONS: One implant per edentulous area and a simple attachment technique yielded a stable distal extension RPD.

Comparison of occlusal condition and prevalence of bone change in the condyle of patients with and without temporomandibular disorders.

OBJECTIVE: The purpose of this study was to compare the differences in dental and occlusal conditions, and prevalence of bone change in the condyle, between a group of patients with temporomandibular disorders (TMD) and a group of dental patients without such complaints. STUDY DESIGN: A group of 504 patients with temporomandibular disorders (TMD patients) and a group of 970 patients without such complaints (dental patients), all 25 years of age or older, were compared using the criteria of age, sex, dental and occlusal condition, and prevalence of bone change in the condyle based on panoramic radiographs and imaging request forms. RESULTS: In both groups, the rate of complete dental arch was high for both jaws. According to Eichner's index, the rate for group A among the dental patients was 59.6%, whereas it was 84.7% in the TMD patients (P < .01). The prevalence of bone change in the condyle was 17.7% for the TMD patients and 11.6% for the dental patients (P < .01). Eichner's group C was somewhat high for the dental patients, and group A was high for the TMD patients. However, there were no significant differences in the occlusal conditions based on the prevalence of bone change. Deformity was the most common abnormality of bone change for both the dental and the TMD patients. In the TMD patients, the rate of osteophytes was the second most common abnormal finding. Osteophytes were the highest among the average age for all abnormal bone changes in the condyle. With the TMD patients, all the changes were more commonly found in Eichner's group A. CONCLUSIONS: It was demonstrated that the symptoms of TMD correlated with age, sex, and dental and occlusal conditions. However, the prevalence of bone change in the condyle correlated poorly with age, sex, and dental and occlusal condition with and without TMD.

Effect of surface reaction layer on grindability of cast titanium alloys.

OBJECTIVE: The purpose of this study was to investigate the effect of the cast surface reaction layer on the grindability of titanium alloys, including free-machining titanium alloy (DT2F), and to compare the results with the grindability of two dental casting alloys (gold and Co-Cr). METHODS: All titanium specimens (pure Ti, Ti-6Al-4V and DT2F) were cast using a centrifugal casting machine in magnesia-based investment molds. Two specimen sizes were used to cast the titanium metals so that the larger castings would be the same size as the smaller gold and Co-Cr alloy specimens after removal of the surface reaction layer (alpha-case). Grindability was measured as volume loss ground from a specimen for 1 min using a handpiece engine with a SiC abrasive wheel at 0.1 kgf and four circumferential wheel speeds. RESULTS: For the titanium and gold alloys, grindability increased as the rotational speed increased. There was no statistical difference (p>0.05) in grindability for all titanium specimens either with or without the alpha-case. Of the titanium metals tested, Ti-6 Al-4V had the greatest grindability at higher speeds, followed by DT2F and CP Ti. The grindability of the gold alloy was similar to that of Ti-6 Al-4V, whereas the Co-Cr alloy had the lowest grindability. SIGNIFICANCE: The results of this study indicated that the alpha-case did not significantly affect the grindability of the titanium alloys. The free-machining titanium alloy had improved grindability compared to CP Ti.

In vitro wear resistance of three types of composite resin denture teeth.

STATEMENT OF PROBLEM: The wear resistance of artificial teeth is important to the life of the removable prosthesis for the edentulous patient. The ability of artificial teeth to maintain a stable occlusal relationship over time may be influenced by this property. PURPOSE: The purpose of this in vitro study was to evaluate the wear resistance of artificial teeth based on composite resin filler content when opposed by a denture tooth antagonist. MATERIAL AND METHODS: The right first molars (both maxillary and mandibular) of 3 composite resin denture teeth (Endura, 47% organic filler; Duradent, 42% organic and inorganic filler; and Duracross, 68% organic filler) were secured in an in vitro 2-body wear-testing apparatus that simulated masticatory function (60 strokes/min, grinding distance of 2 mm, under 37 degrees C flowing water). Wear resistance was assessed as volume loss (mm3) and height loss (mm) at 5 kgf (grinding force) after 50,000 strokes (6 pairs for each type). The Vickers microhardness (VHN) of the occlusal surfaces was measured with a load of 50 g and a loading time of 30 seconds. After testing, the worn surfaces were observed with a scanning electron microscope (SEM). Mean values were analyzed using a 1-way analysis of variance followed by the Fisher test (alpha=.05). RESULTS: The volume loss of Duradent teeth (0.87 +/- 0.03 mm3) was significantly higher than of the 2 other types of teeth tested (P<.001). The Duracross teeth (0.22 +/- 0.08 mm3 and 0.11 +/- 0.04 mm) exhibited the best wear resistance of the denture teeth tested. The wear resistance of the materials tested was consistent with their hardness (Endura 27.54 +/- 0.67 VHN, Duradent 24.00 +/- 0.60 VHN, Duracross 39.64 +/- 3.11 VHN). SEM observation showed that many filler particles were missing from the matrix of Duradent. CONCLUSION: The wear resistance among the 3 types of teeth was significantly different; Duracross and Endura were more wear resistant than Duradent. Although the densities as reported by the manufacturer were similar, hardness and microstructure were the primary factors affecting the wear resistance of artificial teeth. Hardness appears to correlate with wear resistance since the wear resistance of Duradent with a lower VHN of 24 was greater than the other 2 types of teeth with greater hardness.

[A clinical study on the feeling of oral dryness in denture wearers. Part 1. Results of a questionnaire survey].

PURPOSE: We surveyed youths and denture wearers to evaluate the feeling of oral dryness. In the denture wearers group, we evaluated the association between dentures and feeling of oral dryness. MATERIALS AND METHODS: The survey was performed in 100 denture wearers (mean age, 66.2+/-8.6 years) who visited our department from June to October 2003. A similar survey was performed in 50 youths (mean age, 25.6+/-2.4 years, 20-29 year-old group). The survey consisted of a questionnaire and oral and denture examination. The questionnaire asked about oral dryness symptoms, general condition and current medications. The oral and denture examination examined the condition of the remaining teeth, the kinds of prosthesis, materials of dentures and form of the denture base. RESULTS: A feeling of oral dryness was observed in 11 of the 20-29 year-old group (22%) and 48 denture wearers (48%), hence the incidence was significantly higher in the denture wearers group (p<0.01). No association was observed between the oral dryness symptoms and age, sex, general condition, current medications, or number of residual teeth. The kinds of prosthesis (no denture, partial denture, complete denture) and form of the denture base have no relationship with the feeling of oral dryness. CONCLUSIONS: 48% of the denture wearers had the feeling of oral dryness, and the incidence was higher than in the 20-29 year-old group. However, no association was observed between the oral dryness symptoms and dentures. Further studies are necessary to evaluate factors associated with the development of the feeling of oral dryness.

[A clinical study on the feeling of oral dryness in denture wearers. Part 2. Measurement of the height of the salivary moisture area].

PURPOSE: We surveyed youths and denture wearers to evaluate the feeling of oral dryness. MATERIALS AND METHODS: The survey was performed in 100 denture wearers (mean age, 66.2+/-8.6 years) who visited our department from June to October 2003. A similar survey was performed in 50 20-29 year-old persons (mean age, 25.6+/-2.4 years). Measurement of the height of the salivary moisture area, and detection of Candida were performed. We used Saliva Wet Tester for measuring the height of the salivary moisture area. RESULTS: The mean height of the salivary moisture area was significantly lower in the denture wearers group than in the 20-29 year-old group (p<0.05). No association was observed between the height of the salivary moisture area and general condition, current medications, number of residual teeth, or the denture base. In the denture wearers group, the height of the salivary moisture area was high in patients with bounded saddle dentures or unilateral distal extension dentures in either or both jaws but low in those with dentures covering the entire palatal and lingual mucosa in both the upper and lower jaws. However, the feeling of oral dryness was not always consistent with the height of the salivary moisture area. In the denture wearers group, the height of the salivary moisture area matched the low tendency of detection of Candida of 100 CFU or more in patients. CONCLUSIONS: The mean height of the salivary moisture area was significantly lower in the denture wearers group than in the 20-29 year-old group. However, the feeling of oral dryness was not always consistent with the height of the salivary moisture area. Further study, including a mental factor, is necessary.

Retentive force of O-ring attachment to use Immediate Provisional Implant (IPI)-retained overdenture.

This study evaluated the retentive force of the O-ring attachment to an Immediate Provisional Implant (IPI)-retained overdenture. Two sizes of O-rings (#1, #2) were placed on the IPI abutment head. As the controls, soft relining material, silicone lining material, and the PMMA resin were used to connect the IPI abutment head. The retentive forces (n=5, N) obtained at a crosshead speed of 40 mm/min were analyzed by ANOVA/Tukey's HSD test (alpha=0.05). O-ring #1 showed the significantly greatest force among all materials tested (p0.05). Appropriate retention was obtained using the smaller O-ring#1 for the IPI-retained overdenture.

Titanium removable partial denture clasp repair using laser welding: a clinical report.

This clinical report describes repair of a fractured removable partial denture clasp using laser welding rather than a conventional torch soldering technique.

A technique for making a diagnostic and surgical template.

Implant-supported restorations can restore function and esthetics provided that the implants are placed in the predetermined location and properly angulated. This article describes the fabrication of a diagnostic template incorporating a silicone radiopaque marker as a guide for achieving 3-dimensional evaluation of bone without artifacts using computed tomography. The diagnostic template may be easily transformed into a surgical template by removing the silicone marker.

O-ring attachments for transitional implant-retained overdentures.

The lack of proper stability and retention is frequently found in mandibular complete dentures. The stability and retention of existing complete dentures may be improved by using transitional implants (TIs) incorporating the O-ring retention system. This article describes the procedures used to convert an existing conventional complete denture to a TI-retained complete overdenture with O-ring.