Exhibit 99.1

INSTRUCTIONS AS TO USE OF

BIOLASE, INC.

SUBSCRIPTION RIGHTS CERTIFICATES

Please consult Georgeson LLC the information agent for the Rights Offering,

or your bank or broker as to any questions

The following instructions relate to a rights offering (the “Rights Offering”) by BIOLASE, Inc., a Delaware corporation (the “Company”), to the holders of record of shares of its common stock, par value $0.001 per share (the “Common Stock”) and the holders of warrants issued in a private placement transaction that was consummated on June 10, 2020 (the “June 2020 Warrants”), as described in the Company’s Prospectus, dated [July 1], 2020 (the “Prospectus’“). Holders of record of shares of Common Stock and the June 2020 Warrants as of 5:00 p.m.. New York City time, on July 1, 2020 (the “Record Date”) will receive, at no charge, non-transferable subscription rights (the “Rights”) to subscribe for and purchase Units at a subscription price of $1,000 per Unit (the “Subscription Price”). Each holder will receive one Right for each share of Common Stock (or in the case of the holder of June 2020 Warrants, for each share of Common Stock the holder had the right to acquire pursuant to the exercise of the June 2020 Warrants) owned of record on the Record Date (each, a “Basic Subscription Right”). Holders who fully exercise their Basic Subscription Rights will be entitled to exercise an over-subscription privilege to subscribe for and purchase, for the Subscription Price, additional Units that remain unsubscribed as a result of unexercised Basic Subscription Rights (the “Oversubscription Privilege”), subject to proration and stock ownership limitations.

Computershare Trust Company, N.A. is acting as subscription agent for the Rights Offering (the “Subscription Agent”).

The Rights will expire at 5:00 p.m., New York City time, on July 15, 2020, unless such time is extended by the Company as described in the Prospectus (such date and time, as the same may be extended, the “Expiration Date”).

The Company will not issue fractional shares in the Rights Offering. The Company will only distribute Subscription Rights to acquire whole Units, rounded down to the nearest whole number of underlying common shares giving rise to such Subscription Rights. Any excess subscription payments received by the Subscription Agent will be returned within 10 business days after expiration of the Rights Offering, without interest or deduction. The Rights will be evidenced by non-transferable subscription Rights certificates {“Rights Certificates”). The number of Rights to which you are entitled is printed on the face of your Rights Certificate. You should indicate your wishes with regard to the exercise of your Rights, including the exercise of your Basic Subscription Right and Over-Subscription Privilege, if any, by completing the appropriate section on the back of your Rights Certificate and returning the Rights Certificate with your payment to the Subscription Agent in the envelope provided, or, if you hold your shares of Common Stock or June 2020 Warrants in the name of a broker, dealer, bank or other nominee, by instructing your broker, custodian bank or other nominee to do so on your behalf.

If you hold your shares of Common Stock or June 2020 Warrants in the name of a broker, dealer, bank or other nominee and you wish to exercise your Rights, you should instruct your nominee to exercise your Rights on your behalf by delivering all documents and payment on your behalf prior to 5:00 p.m., New York City time, on the Expiration Date. This means that you should give such instructions to your nominee sufficiently in advance of the Expiration Date to enable nominee to exercise your Rights on your behalf before the Expiration Date. The Company will ask your nominee to notify you of the Rights Offering. You should complete and return to your nominee the appropriate subscription documentation you receive from such nominee. Your Rights will not be considered exercised unless the Subscription Agent receives from your nominee all of the required documents and your full subscription payment prior to 5:00 p.m., New York City time, on the Expiration Date. Nominee holders of Rights will be required to certify to the Subscription Agent, before any Right may be exercised with respect to any particular beneficial owner, as to the aggregate number of Units subscribed for pursuant to the Right by such beneficial owner.

Nominees who hold shares of Common Stock and/or the June 2020 Warrants for the account of others should notify the respective beneficial owners as soon as possible to ascertain the beneficial owners’ intentions and to obtain instructions with respect to the Rights. If the beneficial owner so instructs, the nominee should exercise the Rights on behalf of the beneficial owner and deliver all documents and payment prior to 5:00 p.m., New York City time, on the Expiration Date. Whether you are a record holder or hold through a nominee, the Company will not be obligated to honor your exercise of Rights if the Subscription Agent receives the documents, including payment, relating to your exercise from you or from your nominee, as applicable, after the Expiration Date, regardless of when you transmitted the documents.

The Company and the Subscription Agent will accept only properly completed and duly executed Rights Certificates actually received at the applicable address listed below, prior to 5:00 p.m., New York City time, on the Expiration Date.

The Rights Certificate and payment must be delivered to the Subscription Agent by one or more of the following methods:

DELIVERY TO AN ADDRESS OTHER THAN THAT PROVIDED ABOVE DOES NOT CONSTITUTE VALID DELIVERY AND. ACCORDINGLY. MAY BE REJECTED BY THE COMPANY. PLEASE DO NOT SEND RIGHTS CERTIFICATES OR PAYMENTS TO THE COMPANY.

6. Execution.

(a) Execution by Registered Holder. The signature on the Rights Certificate must correspond with the name of the registered holder exactly as it appears on the face of the Rights Certificate without any alteration or change whatsoever. Persons who sign the Rights Certificate in a representative or other fiduciary capacity must indicate their capacity when signing on behalf of the registered holder and, unless waived by the Subscription Agent in its sole and absolute discretion, must present to the Subscription Agent satisfactory evidence of their authority to so act.

(b) Execution by Person Other than Registered Holder. If the Rights Certificate is executed by a person other than the holder named on the face of the Rights Certificate, proper evidence of authority of the person executing the Rights Certificate must accompany the same unless, for good cause, the Subscription Agent dispenses with proof of authority.

(c) Signature Guarantees. Your signature must be guaranteed by an Eligible Institution if you specify special delivery instructions.

7. Method of Delivery.

The method of delivery of Rights Certificates and payment of the subscription payments to the Subscription Agent will be at the election and risk of the participating Rights holder, but, if sent by mail, it is recommended that such certificates and payments be sent by overnight courier or by registered mail, properly insured, with return receipt requested, and that a sufficient number of days be allowed to ensure delivery to the Subscription Agent and clearance of payment prior to 5:00 p.m., New York City time, on the Expiration Date. If you are a beneficial owner, you must act promptly to ensure that your nominee acts for you and that all required certificates and payments are actually received by the Subscription Agent prior to the Expiration Date of the Rights Offering. The Company is not responsible if your nominee fails to ensure that all required certificates and payments are actually received by the Subscription Agent prior to the Expiration Date of the Rights Offering.

8. No Revocation.

All exercises of Rights are irrevocable.

9. Special Provisions Relating to the Delivery of Rights Through DTC.

In the case of Rights that are held of record through the Depository Trust Company (“DTC”), exercises of Rights may be effected by instructing DTC to transfer the Rights from the DTC account of such holder to the DTC account of the Subscription Agent, and by delivering to the Subscription Agent, by no later than 5:00 p.m., New York City time, on the Expiration Date, the required certification as to the number of Units to be subscribed for under the Basic Subscription Rights and the Over-Subscription Privilege, if applicable, by each beneficial owner of Rights on whose behalf such nominee is acting, together with payment in full of the aggregate Subscription Price for amount invested under the Basic Subscription Right and the Over-Subscription Privilege on behalf of all such beneficial owners.