Changing Locator Attachments (Locator Males) on an Implant-retained Overdenture

This patient presented with a chief complaint of a very loose overdenture that would fall even during regular conversations.  So, it was a good educational opportunity for me.  Here is a little background on implant-supported overdentures. 

• Locator attachments, such as those marketed by Zestanchors,  allow us to provide retention to overdentures by using them as attachments with single implants, implant supported bars, or even with roots of natural teeth.
• One advantage that they offer is their design, which allows them to compensate for paths of insertions of up to 40 degrees divergence.
• In any case, the Locator Males, pictured below, need to be changed periodically because they wear out over time or if the patient is not happy with the level of retention.
• There are different color-coded Locator Males with different retention capability that can be used to accommodate the needs of patients.  One of the companies that offers them is Zestanchors.
•  The following are some of the more common Locator Males with their specified retention forces.

 

 

•  To change the above Locator males, you need the 3-in-1 Locator Core tool, which can be used to replace Locator Males from the Locator Denture Cap.

 

• To use the Core Tool, unscrew the top of it by twisting it to the left.  Push it onto the old Locator Male, and twist the top back to the right to core out the old Locator Male.  Keep screwing it to the right until the Locator Male pops off from the Denture Cap as shown below.

• So, this patient had a 4 implant supported overdenture.

• As you can see, I removed only one of the Locator Males in the picture below.  I believe the locator Males were green, which corresponds to 4 lbs, but they were worn away.

• To put in the new Locator Males in the Denture Cap, unscrew the tip of the Core tool and place your new Male on it.  Then simply push it onto the Denture Cap until it snaps in.

Here we replaced a green Male with a Pink Male, which is by the way lower in retention force.  Here we determined that the patient's C.C originated from the worn out Locator Males.

 

Complete Denture Fabrication

A fairly young patient came in with retained roots for his entire dentition.  A diagnostic record base and wax rims were prepared to evaluate the patient's VDO along with other clinical factors.  Patient was referred to Oral Surgery for the removal of all the retained roots and alveoloplasty, using a surgical stent prepared using diagnostic models.  Roughly four weeks after extractions another alveoloplasty of mandible and maxilla was performed to remove undercuts and sharp bony areas that resulted after the extractions.  Six weeks of healing was allowed after the last alveoloplasty.

Below are the step-by-step procedure for the Fabrication of Complete Maxillary and Mandibular Dentures:

Step 1: Take Dx Alginate impressions with stock trays and pour them with either yellow stone or snap stone if you are short on time.  Block undercuts with either red sticky wax or baseplate wax.

Step 2: Draw lines 2-3 mm short of the vestibule and fabricate custom trays to those lines.  There is NO need to use any spacers.  Build the Custom trays on the intaglio surface of both arches. During the light curing of the custom trays, make sure you remove the custom trays several times to make sure they do not get locked onto the models.

Step 3: Trim your custom trays with low speed and acrylic burs to make sure you have smooth edges.  Try the custom trays on the pt, and make sure they seat well short of the vestibule.  It is important to make sure they do NOT impenge on freni or any other muscle attachments. 

Step 4: Prepare for Border Molding.  There are several ways to border mold, one of which uses green stick compound.  In the following steps, we used two different methods to do the border molding for the maxillary and the mandibular arches.

Step 4A: For the Maxillary arch, Puddy was used for border molding.  First, put adhesive on the edges of the custom tray.  Simply use the same ratio of buddy base and catalyst, mix them together with hands, and apply on the custom tray. 

Step 5: Insert the Tray into the patient's mouth and do your border molding movements.  Remove and trim any excess Puddy as shown below.

Blurry image of border molded maxillary custom tray.

Step 6: For Mandibular border molding, heavy body PVS impression material was used using the same steps as in Maxillary border molding.

Step 7: Maxillary and Mandibular Final Denture impressions were taken using light body PVS impression material.

Notice the yellow spot: It was a slight void that was corrected with Bees wax!  Got to love wax.

Step 8: Bead and Box the impressions and pour them with Yellow lab stone.  Make sure you keep your land area intact as shown below.

Final impressions and their corresponding Models.

 Step 9: Block undercuts on Maxillary and Mandibular models.

 Step 10: Create "Record Bases" for both Maxillary and Mandibular Arches.  Here, I used Triad pink Denture base per manufacturer instructions.  You should extend the Record bases to the depth of the Vestibules.

 Step 11: Draw your landmarks on the Final casts using the following diagrams.  These will guide you in the fabrication of your Occlusal Rims and teeth placement.

 Step 12: Mandibular occlusal rims made using Baseplate wax.  The height of the occlusal rim should be between 1/2 to 2/3 the Retromolar pad height.

 Step 13: Fabricate Occlusal rims for Maxilla using the same steps.  Make sure there is 1-2 mm horizontal overjet between mandible and maxilla to avoid cheek biting after teeth set up.

Step 14:  First, the maxillary record base was tried in and adjustments were made to make sure that the anterior wax rims extended 1-2 mm below the lips and that the pt's lower lip followed the contour of the wax rims.  The posterior segments of the maxillary wax rims were made to extend superiorly distally (using fox plane as a reference).  Furthermore, reduction in the width of the maxillary wax rims were made to allow for buccal corridors.
Then, the mandibular record base along with wax rim was tried in and first adjustment in wax rim was made to make it level with the superior edge of the lower lip.  Posteriorly, adjustments were made to allow for the rims to be at the level of 1/2 to 2/3 up the retromolar pads.  The wax rims were aligned on the mandibular ridge.

MMR taken via the following procedure:
The metal plate with holes used.  Two V notches made in maxillary wax rims.  Regisil used on metal plate to record the maxillary bite outside of the mouth.  The the maxillary record base inserted into the pt's mouth.  Next metal plate with regisil inserted into mouth.  Next, MMR instruments used to take the bite.  Plate removed, and MMR set aside. 

VDO determined by allowing the pt to go into rest position after swallowing and then resting.  2-3 mm allowed for freeway space.  Fricative sounds like 50 or 66 also used to determine VDO. 

2 V notches made in mandibular record base, and some wax removed posterior to the notches to allow for Alu wax, which was heated and placed on mandibular wax rims.  Maxillary record base inserted into the mouth followed by mandibular record base.  Pt instructed to bite by moving tongue to the posterior roof of the mouth.  Bite taken.

Shade guide shown to the pt and pt's mom.  They choose B1 shade after adequate information was given to them.  Tooth mold guide also shown to the pt and pt's mom, and they chose mold 22E which corresponds to H for lower teeth and 630 for posterior teeth.  0 degrees Teeth were ordered and acquired.

Models were mounted on a Articulator using the MMR and Facebow Transfer.

Anterior tooth Try-in. Upper anterior teeth were set in the wax rims and adjustments were made to follow the lower lip contour and symmetry of the face.  Once the proper adjustments were set and the desired look achieved, as approved my the pt, next appointment for posterior try-in was made.

 Step 15: Full maxillary and Mandibular tooth try-in.  Further adjustments were made to achieve the desired look.  Note that some of the teeth were adjusted after this picture was taken.

 Step 16: After the patient was satisfied with the tooth set up, they were sent in for processing.

Processed Denture with name tag in each.

 Step

Internal Bleaching - A step-by-step guide

A Couple of weeks ago, I got the chance to do Internal Bleaching on a patient who was very self concious of her smile and is really motivated to regain her smile back .  Tooth #8 has had a Hx of trauma.  It was avulsed as a result of a sport injury, and was subsequently fixated with a wire.  The tooth underwent Root Canal Therapy (RCT) and internal bleaching roughly four years after the day of trauma.  The tooth has discolored since then.
The following are the steps followed in Internal Bleaching:
Step 1: Get your basic Armamentarium ready, as you would for a RCT case.

Step 2:  A photo of the tooth with the appropriate shade guide is taken for future reference.  In this case the shade for the discolored tooth was A35 while the surrounding dentition has a shade of A1. 

Step 3:  Anesthetize the gingiva surrounding the tooth and place a rubber dam with a clamp.  Then, access the tooth from the lingual using a round bur with a high speed drill.  In this case a lingual composite had been placed on top of a cotton ball which had been left in the pulp chamber.  Note that it is not recommended to leave a cotton in the chamber.  The cotton appeared discolored upon removal.

Step 3: Anesthetize the gingiva surrounding the tooth and place a rubber dam with a clamp.  Then, access the tooth from the lingual using a round bur with a high speed drill.  In this case a lingual composite had been placed on top of a cotton ball which had been left in the pulp chamber.  Note that it is not recommended to leave a cotton in the chamber.  The cotton appeared discolored upon removal.

Step 4: After removing the entire composite restoration, irrigate the tooth chamber and the canal using Chlorohexidine.  This is an important step because it removes any contaminants from the pulp chamber.  DO NOT use Sodium Hypochlorite for irrigation as it will interfere with the subsequent bonding step.

Step 5: Follow the following diagram to place composite seal at the cervical end of the canal to prevent the bleaching material from entering the dental structure below the CEJ.

Step 6: Very accurate measurements are necessary in order to put the composite plug.  First measure the the distance from the incisal edge to the CEJ at the outer surface of the tooth, then remove enough Gutta Percha from the coronal end of the canal to get the measured distance + 3 mm. 

Step 7:  One you have removed 3 mm  of Gutta Percha below CEJ, acid etch the canal walls for 10-15 seconds and rinse with water for 20 seconds.  Dry the canal using a cotton swab.  DO NOT over dry! 

Step 8: The use of a flowable composite with its compatible bonding system is the easiest way to place the composite plug.  So, use the bonding system, followed by 3 mm of flowable composite. 

 

Step 9:  Use a condenser instrument to condense the composite to the CEJ level. Note that the placement of composite in increments is necessary.

Step 10: Light Cure according to the manufacturer's instructions.  Usually forty seconds to get full curing.

Step 11: Mix Sodium Perborate with 18% Hydrogen peroxide on a glass slab.

Step 12: Make sure you mix enough Sodium perborate powder with 18% H2O2 liquid to get a mushy consistency

Step 13: Condense the mixture into the tooth chamber, and allow ~3 mm space from the orafice.

Step 14: Here a fugi temporary material, readily used at the endodontics clinic, was used to seal the tooth.  Pt was given post op instructions and asked to immediately call back if the temporary material fell out.  Pt placed on one week recall.

Visit 2: At the second visit, there was a considerable improvement in the shade of the tooth.  The shade went from a shade of A35 to Shade A1.  However, improving the shade even further is recommended since the tooth might revert to a darker shade after the bleaching material is removed and replaced with a restorative material. 

Step 1: Pt did not want any anesthesia, so only topical benzocaine used to anesthetize the gingiva surrounding the tooth for the purpose of RD and clamp placement. Temporary restoration and Na Perborate/ 18% H2O2 mixture removed.  The chamber rinsed with water.

Step 2: Sodium perborate granules mixed with water to get a mushy consistency.  Condensed the mixture in the chamber, leaving 3 mm space for temporary material.

Step 3: Fugi temporary restoraton placed to seal the tooth.  Pt placed on one week recall.

Third visit: Ideal shade acquired. Pt very satisfied.  Topical 20% benzocaine on surrounding gingiva, RD placed as shown below.  Temporary restoration and Na Perborate removed. 

Step 1: The chamber was acid etched with 37% phosphoric acid for 10 seconds, rinsed with water for 25 seconds, dried using a cotton swab.  Optibond bonding agent used and light cured for 25 seconds.  Condensed A1 composite in VERY, VERY SMALL increments and light cured.  The entire chamber filled with composite.  The middle tooth in the image below shows the restoration. 

Tooth #8 Final results after bleaching!  Very successful, and a very satisfied Pt.

Supervising Faculty: Dr. KOSUKE
Student Dentist: SEYAR BAQI
Blue Hen Dental
Dentist in Smyrna, DE 19977
BlueHenDental.com
231 S. DuPont BLVD
Smyrna, DE 19977
302-314-3077